Journal of Functional Biomaterials

16 pages, 9194 KiB

Open AccessArticle

Evaluation of the In Vivo Biocompatibility of Amorphous Calcium Phosphate-Containing Metals

by Pio Moerbeck-Filho, Suelen C. Sartoretto, Marcelo J. Uzeda, Maurício Barreto, Alena Medrado, Adriana Alves and Mônica D. Calasans-Maia

J. Funct. Biomater. 2020, 11(2), 45; https://doi.org/10.3390/jfb11020045 - 23 Jun 2020

Cited by 8 | Viewed by 4328

Abstract

Among the biomaterials based on calcium phosphate, hydroxyapatite has been widely used due to its biocompatibility and osteoconduction. The substitution of the phosphate group by the carbonate group associated with the absence of heat treatment and low synthesis temperature leads to the formation [...] Read more.

Among the biomaterials based on calcium phosphate, hydroxyapatite has been widely used due to its biocompatibility and osteoconduction. The substitution of the phosphate group by the carbonate group associated with the absence of heat treatment and low synthesis temperature leads to the formation of carbonated hydroxyapatite (CHA). The association of CHA with other metals (strontium, zinc, magnesium, iron, and manganese) produces amorphous calcium phosphate-containing metals (ACPMetals), which can optimize their properties and mimic biological apatite. This study aimed to evaluate the biocompatibility and biodegradation of ACPMetals in mice subcutaneous tissue. The materials were physicochemically characterized with Fourier Transform InfraRed (FTIR), X-Ray Diffraction (XRD), and Atomic Absorption Spectrometry (AAS). Balb-C mice (n = 45) were randomly divided into three groups: carbonated hydroxyapatite, CHA (n = 15), ACPMetals (n = 15), and without implantation of material (SHAM, n = 15). The groups were subdivided into three experimental periods (1, 3, and 9 weeks). The samples were processed histologically for descriptive and semiquantitative evaluation of the biological effect of biomaterials according to ISO 10993-6:2016. The ACPMetals group was partially biodegradable; however, it presented a severe irritating reaction after 1 and 3 weeks and moderately irritating after nine weeks. Future studies with other concentrations and other metals should be carried out to mimic biological apatite. Full article

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X-ray diffraction (XRD). Diffractogram of the carbonated hydroxyapatite (CHA) and of the amorphous calcium phosphate-containing metals (ACPMetals) groups. Full article ">Figure 2
Infrared vibrational spectroscopy with Fourier transform (FTIR). The spectrum of the CHA and of the ACPMetals groups. Full article ">Figure 3
Photomicrographs representative of the region of implantation of the SHAM group (without implantation of material) (A,B), CHA (C,D) and ACPMetals (E,F) group 1 week after implantation. (A,C,E) Circle: epidermis and papillary dermis with hair follicle (HF), recovering connective tissue (CT) with focal intense and inflammatory cells (*); muscle fibers (MF) and adipocyte tissue (AT) are noted. Biomaterial zone (BM), specifically in C,E. (B) Detail in highest objective, disorganized muscular fibers (MF) permeated by connective tissue (CT) and inflammatory infiltrate (*). (D,F) Detail in highest objective, particulate biomaterial (black arrow) intermediated by connective tissue (CT) with inflammatory mononuclear cells predominantly (*). A,C,E, 40× magnification, scale bar: 500 μm; B,D,F, 400× magnification, scale bar: 50 μm. Hematoxylin and eosin staining. Full article ">Figure 4
Photomicrographs representative of the region of implantation of the SHAM (A,B), CHA (C,D) and ACPMetals (E,F) group 3 weeks after implantation. (A,C,E) Circle: epidermis and papillary dermis with hair follicle (HF), recovering connective tissue (CT) with inflammatory cells (*); muscle fibers (MF) and adipocyte tissue (AT). Note C,E granulation reaction in the biomaterial zone (BM). (B) Detail in highest objective, collagen and muscle fibers in organization process with moderate inflammatory cells. (D,F) Detail in highest objective, particulate biomaterial (BM) intermediated by connective tissue (CT) with granulations reaction (*); multinucleated giant cells were observed (black arrow). A,C,E, 40× magnification, scale bar: 500 μm; B,D,F, 400× magnification, scale bar: 50 μm. Hematoxylin and eosin staining. Full article ">Figure 5
Photomicrographs representative of the region of implantation of the SHAM (A,B), CHA (C,D) and ACPMetals (E,F) group 9 weeks after implantation. (A,C,E) Circle: epidermis and papillary dermis with hair follicle (HF), recovering connective tissue (CT) with inflammatory cells (*); muscle fibers (MF) and adipocyte tissue (AT). Note in C,E the granulation reaction in the biomaterial zone (BM). (B) Detail in highest objective, mature collagen and muscle fibers. (D,F) Detail in highest objective, particulate biomaterial (BM) intermediated by fibrous connective tissue (CT) inflammatory cells (*) and multinucleated giant cells was observed (black arrow). A,C,E, 40× magnification, scale bar: 500 μm; B,D,F, 400× magnification, scale bar: 50 μm. Hematoxylin and eosin staining. Full article ">Figure 6
Inflammatory cells response (A–F) and overall tissue reaction (G–I). Note that CHA groups responded extremely favorably with only mild increases in inflammation when compared to the negative Sham control. The ACPMetals group presented more intense inflammatory reaction when compared to the other groups at lymphocytes, plasma cells, macrophages, giant cells and neovascularization scorings (data +/− standard deviation; p < 0.05); (°) represents significantly greater when compared to the Sham group; (*) represents significantly greater when compared to the CP group. Full article ">Figure 7
Score of inflammatory reaction according ISO 10993-6:2016. The differences between the scores of the CHA and ACPMetals groups subtracted from the control (SHAM). The groups were ranked according criteria of ISO 10993-6:2016: Nonirritating (0.0 to 2.9); slightly irritating (3.0 to 8.9); moderately irritating (9.0 to 15.0); seriously irritating (>15); the columns represent the mean values. Full article ">

11 pages, 3497 KiB

Open AccessEditor’s ChoiceArticle

Time-Transient Effects of Silver and Copper in the Porous Titanium Dioxide Layer on Antibacterial Properties

by Masaya Shimabukuro, Akari Hiji, Tomoyo Manaka, Kosuke Nozaki, Peng Chen, Maki Ashida, Yusuke Tsutsumi, Akiko Nagai and Takao Hanawa

J. Funct. Biomater. 2020, 11(2), 44; https://doi.org/10.3390/jfb11020044 - 22 Jun 2020

Cited by 23 | Viewed by 4338

Abstract

Recently, silver (Ag) and copper (Cu) have been incorporated into a titanium (Ti) surface to realize their antibacterial property. This study investigated both the durability of the antibacterial effect and the surface change of the Ag- and Cu-incorporated porous titanium dioxide (TiO₂ [...] Read more.

Recently, silver (Ag) and copper (Cu) have been incorporated into a titanium (Ti) surface to realize their antibacterial property. This study investigated both the durability of the antibacterial effect and the surface change of the Ag- and Cu-incorporated porous titanium dioxide (TiO₂) layer. Ag- and Cu-incorporated TiO₂ layers were formed by micro-arc oxidation (MAO) treatment using the electrolyte with Ag and Cu ions. Ag- and Cu-incorporated specimens were incubated in saline during a period of 0–28 days. The changes in both the concentrations and chemical states of the Ag and Cu were characterized using X-ray photoelectron spectroscopy (XPS). The durability of the antibacterial effects against Escherichia coli (E. coli) were evaluated by the international organization for standardization (ISO) method. As a result, the Ag- and Cu-incorporated porous TiO₂ layers were formed on a Ti surface by MAO. The chemical state of Ag changed from Ag₂O to metallic Ag, whilst that of Cu did not change by incubation in saline for up to 28 days. Cu existed as a stable Cu₂O compound in the TiO₂ layer during the 28 days of incubation in saline. The concentrations of Ag and Cu were dramatically decreased by incubation for up to 7 days, and remained a slight amount until 28 days. The antibacterial effect of Ag-incorporated specimens diminished, and that of Cu was maintained even after incubation in saline. Our study suggests the importance of the time-transient effects of Ag and Cu on develop their antibacterial effects. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Scanning electron microscopy (SEM) images of (A) the Ag- and (B) the Cu-incorporated TiO2 layers before and after incubation in saline during 28 days and the cross-sectional views of the specimens before incubation. Full article ">Figure 2
X-ray diffraction (XRD) spectra obtained from the (A) Ag- and (B) the Cu-incorporated specimens before and after incubation in saline during 28 days. The spectra presented at the bottom in each figure was obtained from the control. Full article ">Figure 3
X-ray photoelectron spectroscopy (XPS) survey scan spectra obtained from the (A) Ag- and (B) the Cu-incorporated specimens before and after incubation in saline during 28 days. Full article ">Figure 4
Wagner plot of (A) the Ag and (B) the Cu in the oxide layer incubated in saline for 28 days based on the photoelectron peaks and the Auger peaks. Each parameter of the Ag and the Cu compounds is plotted according to the previous studies [<a href="#B46-jfb-11-00044" class="html-bibr">46</a>,<a href="#B47-jfb-11-00044" class="html-bibr">47</a>,<a href="#B48-jfb-11-00044" class="html-bibr">48</a>]. Full article ">Figure 5
Changes in the atomic concentrations in (A) the Ag- and (B) the Cu-incorporated TiO2 layers with the incubation time. Full article ">Figure 6
Comparison of the antibacterial effects of the untreated Ti control specimen (micro-arc oxidation (MAO)-treated Ti without antibacterial elements), the Ag- and the Cu-incorporated specimens. Data are shown as the mean ± standard deviation. * Significant difference between specimens (p < 0.05). Full article ">Figure 7
Changes of the antibacterial effects of (A) the Ag- and (B) the Cu-incorporated specimens before and after incubation in saline. Data are shown as the mean ± SD. * Significant difference between the specimens before and after incubation (p < 0.05). Full article ">

4 pages, 606 KiB

Open AccessEditorial

“Monoclonal-Type” Plastic Antibodies for COVID-19 Treatment: What Is the Idea?

by Francesco Puoci

J. Funct. Biomater. 2020, 11(2), 43; https://doi.org/10.3390/jfb11020043 - 17 Jun 2020

Cited by 12 | Viewed by 5804

Abstract

In late December 2019, an outbreak due to a novel coronavirus, initially called 2019-nCoV, was reported in Wuhan, China [...] Full article

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9 pages, 1966 KiB

Open AccessEditor’s ChoiceArticle

Novel Coatings to Minimize Bacterial Adhesion and Promote Osteoblast Activity for Titanium Implants

by Samira E. A. Camargo, Tanaya Roy, Patrick H. Carey IV, Chaker Fares, Fan Ren, Arthur E. Clark and Josephine F. Esquivel-Upshaw

J. Funct. Biomater. 2020, 11(2), 42; https://doi.org/10.3390/jfb11020042 - 16 Jun 2020

Cited by 22 | Viewed by 4690

Abstract

Titanium nitride (TiN) and silicon carbide (SiC) adhesion properties to biofilm and the proliferation of human osteoblasts were studied. Quaternized titanium nitride (QTiN) was produced by converting the surface nitrogen on TiN to a positive charge through a quaternization process to further improve [...] Read more.

Titanium nitride (TiN) and silicon carbide (SiC) adhesion properties to biofilm and the proliferation of human osteoblasts were studied. Quaternized titanium nitride (QTiN) was produced by converting the surface nitrogen on TiN to a positive charge through a quaternization process to further improve the antibacterial efficiency. The SiC required a nitridation within the plasma chamber of the surface layer before quaternization could be carried out to produce quaternized SiC (QSiC). The antimicrobial activity was evaluated on the reference strains of Porphyromonas gingivalis for 4 h by fluorescence microscopy using a live/dead viability kit. All the coatings exhibited a lower biofilm coverage compared to the uncoated samples (Ti—85.2%; TiN—24.22%; QTiN—11.4%; SiC—9.1%; QSiC—9.74%). Scanning Electron Microscope (SEM) images confirmed the reduction in P. gingivalis bacteria on the SiC and TiN-coated groups. After 24 h of osteoblast cultivation on the samples, the cell adhesion was observed on all the coated and uncoated groups. Fluorescence images demonstrated that the osteoblast cells adhered and proliferated on the surfaces. TiN and SiC coatings can inhibit the attachment of Porphyromonas gingivalis and promote osteoblast adhesion on the titanium used for implants. These coatings may possess the ability to prevent the development of peri-implantitis and stimulate osteointegration. Full article

(This article belongs to the Special Issue Advanced Functional Biomaterials for Dental Implants)

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Live fluorescence images of P. gingivalis cultured for 4 h on the uncoated and coated titanium disks. The cultures were stained with SYTO® 9 to dye the living bacteria green. (A) Uncoated; (B) TiN-coated; (C) QTiN-coated; (D) SiC-coated; (E) QSiC-coated. The P. gingivalis coverage was calculated from at least 6 fields/disk at 10× g magnification using ImageJ software (F). Scale bar = 50 µm. Full article ">Figure 2
SEM adhesion of P. gingivalis after 24 h of cultivation on the uncoated and coated titanium disks. (A,B) Uncoated; (C,D) TiN-coated; (E,F) QTiN-coated; (G,H) SiC-coated; (I,J) QSiC-coated. Full article ">Figure 3
Cell proliferation after 24 h of culture on the uncoated and coated (TiN, QTiN, SiC, QSiC) titanium disks. The cells were quantified from at least 6 fields/disc at 10× g magnification using ImageJ software. Full article ">Figure 4
Adhesion of human osteoblasts (Nhost) on uncoated and coated surfaces after 24 h by fluorescence evaluation. (A,B) Uncoated; (C,D) TiN-coated; (E,F) QTiN-coated; (G,H) SiC-coated; (I,J) QSiC-coated. Scale bar = 40 µm and 20 µm. Full article ">

19 pages, 5990 KiB

Open AccessArticle

CaSiO₃-HAp Structural Bioceramic by Sol-Gel and SPS-RS Techniques: Bacteria Test Assessment

by Evgeniy Papynov, Oleg Shichalin, Igor Buravlev, Anton Belov, Arseniy Portnyagin, Vitaliy Mayorov, Evgeniy Merkulov, Taisiya Kaidalova, Yulia Skurikhina, Vyacheslav Turkutyukov, Alexander Fedorets and Vladimir Apanasevich

J. Funct. Biomater. 2020, 11(2), 41; https://doi.org/10.3390/jfb11020041 - 12 Jun 2020

Cited by 9 | Viewed by 3909

Abstract

The article presents an original way of getting porous and mechanically strong CaSiO₃-HAp ceramics, which is highly desirable for bone-ceramic implants in bone restoration surgery. The method combines wet and solid-phase approaches of inorganic synthesis: sol-gel (template) technology to produce the [...] Read more.

The article presents an original way of getting porous and mechanically strong CaSiO₃-HAp ceramics, which is highly desirable for bone-ceramic implants in bone restoration surgery. The method combines wet and solid-phase approaches of inorganic synthesis: sol-gel (template) technology to produce the amorphous xonotlite (Ca₆Si₆O₁₇·2OH) as the raw material, followed by its spark plasma sintering–reactive synthesis (SPS-RS) into ceramics. Formation of both crystalline wollastonite (CaSiO₃) and hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂) occurs “in situ” under SPS conditions, which is the main novelty of the method, due to combining the solid-phase transitions of the amorphous xonotlite with the chemical reaction within the powder mixture between CaO and CaHPO₄. Formation of pristine HAp and its composite derivative with wollastonite was studied by means of TGA and XRD with the temperatures of the “in situ” interactions also determined. A facile route to tailor a macroporous structure is suggested, with polymer (siloxane-acrylate latex) and carbon (fibers and powder) fillers being used as the pore-forming templates. Microbial tests were carried out to reveal the morphological features of the bacterial film Pseudomonas aeruginosa that formed on the surface of the ceramics, depending on the content of HAp (0, 20, and 50 wt%). Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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41 pages, 5366 KiB

Open AccessReview

On the Interaction between 1D Materials and Living Cells

by Giuseppe Arrabito, Yana Aleeva, Vittorio Ferrara, Giuseppe Prestopino, Clara Chiappara and Bruno Pignataro

J. Funct. Biomater. 2020, 11(2), 40; https://doi.org/10.3390/jfb11020040 - 10 Jun 2020

Cited by 7 | Viewed by 4866

Abstract

One-dimensional (1D) materials allow for cutting-edge applications in biology, such as single-cell bioelectronics investigations, stimulation of the cellular membrane or the cytosol, cellular capture, tissue regeneration, antibacterial action, traction force investigation, and cellular lysis among others. The extraordinary development of this research field [...] Read more.

One-dimensional (1D) materials allow for cutting-edge applications in biology, such as single-cell bioelectronics investigations, stimulation of the cellular membrane or the cytosol, cellular capture, tissue regeneration, antibacterial action, traction force investigation, and cellular lysis among others. The extraordinary development of this research field in the last ten years has been promoted by the possibility to engineer new classes of biointerfaces that integrate 1D materials as tools to trigger reconfigurable stimuli/probes at the sub-cellular resolution, mimicking the in vivo protein fibres organization of the extracellular matrix. After a brief overview of the theoretical models relevant for a quantitative description of the 1D material/cell interface, this work offers an unprecedented review of 1D nano- and microscale materials (inorganic, organic, biomolecular) explored so far in this vibrant research field, highlighting their emerging biological applications. The correlation between each 1D material chemistry and the resulting biological response is investigated, allowing to emphasize the advantages and the issues that each class presents. Finally, current challenges and future perspectives are discussed. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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16 pages, 1935 KiB

Open AccessArticle

A 2,5-Dihydroxybenzoic Acid–Gelatin Conjugate Inhibits the Basal and Hsp90-Stimulated Migration and Invasion of Tumor Cells

by Anastasiya V. Snigireva, Oleg S. Morenkov, Yuri Y. Skarga, Alexander V. Lisov, Zoya A. Lisova, Alexey A. Leontievsky, Mariya A. Zhmurina, Viktoria S. Petrenko and Veronika V. Vrublevskaya

J. Funct. Biomater. 2020, 11(2), 39; https://doi.org/10.3390/jfb11020039 - 3 Jun 2020

Cited by 2 | Viewed by 3604

Abstract

The extracellular cell surface-associated and soluble heat shock protein 90 (Hsp90) is known to participate in the migration and invasion of tumor cells. Earlier, we demonstrated that plasma membrane-associated heparan sulfate proteoglycans (HSPGs) bind the extracellular Hsp90 and thereby promote the Hsp90-mediated motility [...] Read more.

The extracellular cell surface-associated and soluble heat shock protein 90 (Hsp90) is known to participate in the migration and invasion of tumor cells. Earlier, we demonstrated that plasma membrane-associated heparan sulfate proteoglycans (HSPGs) bind the extracellular Hsp90 and thereby promote the Hsp90-mediated motility of tumor cells. Here, we showed that a conjugate of 2,5-dihydroxybenzoic acid with gelatin (2,5-DHBA–gelatin), a synthetic polymer with heparin-like properties, suppressed the basal (unstimulated) migration and invasion of human glioblastoma A-172 and fibrosarcoma HT1080 cells, which was accompanied by the detachment of a fraction of Hsp90 from cell surface HSPGs. The polymeric conjugate also inhibited the migration/invasion of cells stimulated by exogenous soluble native Hsp90, which correlated with the inhibition of the attachment of soluble Hsp90 to cell surface HSPGs. The action of the 2,5-DHBA–gelatin conjugate on the motility of A-172 and HT1080 cells was similar to that of heparin. The results demonstrate a potential of the 2,5-DHBA–gelatin polymer for the development of antimetastatic drugs targeting cell motility and a possible role of extracellular Hsp90 in the suppression of the migration and invasion of tumor cells mediated by the 2,5-DHBA–gelatin conjugate and heparin. Full article

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The 2,5-dihydroxybenzoic acid (2,5-DHBA)–gelatin conjugate inhibited the adsorption of pseudorabies virus (PRV) to cells. The degree of inhibition was determined by the plaque assay. The mean values of four to six repeats ± SD are presented. The statistical difference from control cells: * p < 0.05; ** p < 0.01. Full article ">Figure 2
The 2,5-DHBA–gelatin conjugate inhibited the basal unstimulated cell migration and invasion. (A,B) The migration/invasion of cells was determined in the presence of 2,5-DHBA–gelatin at concentrations of 10–50 μg/mL and of heparin, dermatan sulfate (DS), chondroitin sulfate A (ChS), and polyclonal anti-heat shock protein 90 (Hsp90) antibodies (concentration of 50 μg/mL for all reagents). The migration/invasion of untreated cells (control) was assumed to be 100%. The mean values of three to five repeats ± SD are presented. Asterisks indicate the statistical difference from control cells: * p < 0.05, ** p < 0.01. Full article ">Figure 3
The 2,5-DHBA–gelatin conjugate dissociated Hsp90α and Hsp90β from the cell plasma membrane. Cells were treated with 2,5-DHBA–gelatin at concentrations of 10–100 μg/mL and with heparin, dermatan sulfate (DS), or chondroitin sulfate A (ChS) (a concentration of 50 μg/mL for all substances). Incubation in all experiments was performed for 1 h at 37 °C, except one experiment in which cells were incubated at 4 °C (indicated in the graph). After the treatment, the expression of Hsp90 isoforms on the plasma membrane was determined by flow cytometry using Hsp90α- and Hsp90β-specific antibodies. (A,C) Representative flow cytometry histograms for A-172 and HT1080 cells. Control (untreated) cells (black lines), 2,5-DHBA–gelatin-treated cells (red lines), and cells treated with heparin (blue lines) were probed with antibodies directed to Hsp90α and Hsp90β; control cells were also probed with the isotype control antibody (green lines). (B,D) Quantification of membrane-associated Hsp90α and Hsp90β levels after different treatments. The Hsp90 isoform-specific mean fluorescence intensity (MFI) are presented; the MFIs of control cells were assumed to be 100%. The mean values of three to five repeats ± SD are presented. The representative results from two to four experiments are presented. Full article ">Figure 4
Treatment of cells with 2,5-DHBA–gelatin decreased the Hsp90-mediated stimulation of migration and invasion of cells. (A) Soluble native bovine Hsp90 stimulated cell motility. Cell migration/invasion was expressed in percent; the migration/invasion of control cells without Hsp90 was taken as 100%. (B) Hsp90-induced stimulation of cell migration. (C) Hsp90-induced stimulation of cell invasion. The degree of stimulation of cell migration/invasion by soluble Hsp90 was determined in the presence of the conjugate in the medium at concentrations of 10–50 μg/mL or in the presence of heparin, dermatan sulfate (DS), and chondroitin sulfate A (ChS) in the medium (50 μg/mL for all substances). The stimulation of migration/invasion induced by soluble Hsp90 was expressed in percent relative to control cells. (A–C) The mean values of three to five repeats ± SD are presented. Statistical difference from control cells: * p < 0.05, ** p < 0.01. Full article ">Figure 5
The 2,5-DHBA–gelatin polymeric conjugate impaired the binding of FITC-labelled native Hsp90 to cells. Cells were incubated with Hsp90–FITC for 1 h at 4 °C in the presence of the 2,5-DHBA–gelatin conjugate at concentrations in the range of 10–50 μg/mL and heparin (50 μg/mL). The binding of Hsp90–FITC was analyzed by flow cytometry. (A) Representative flow cytometry histograms. Cells incubated with Hsp90–FITC were treated with 2,5-DHBA–gelatin (green lines) and heparin (red lines); untreated (control) cells are represented as black lines, whereas blue lines represent cells incubated without Hsp90–FITC (autofluorescence). (B) Quantification of the binding of Hsp90–FITC to cells. The MFI of 2,5-DHBA–gelatin-treated and untreated control cells is presented; the MFIs of control untreated cells were taken as 100%. The mean values of three to five repeats ± SD are presented. Asterisks indicate the statistical difference from control cells: * p < 0.05, ** p < 0.01. Full article ">Figure 6
A hypothetical model of the action of the 2,5-DHBA–gelatin conjugate, heparin, and heparin-like substances on the Hsp90-mediated migration and invasion of tumor cells. Heparan sulfate (HS) glycosaminoglycan chains of cell surface heparan sulfate proteoglycans (HSPGs) bind with extracellular Hsp90s and facilitate Hsp90-mediated signaling via cell receptors LRP1 and Her2 associated with cell migration and invasion. The 2,5-DHBA–gelatin conjugate and heparin compete with HS for the binding with extracellular Hsp90, which results in the detachment of HSPG-associated Hsp90 from the cell surface HSPGs and the inhibition of binding of soluble Hsp90 to cell surface HSPGs. Both processes lead to the impairment of Hsp90-mediated motility-related signaling, which results in an inhibition of the migration and invasion of tumor cells. Full article ">

11 pages, 4239 KiB

Open AccessArticle

In Vitro Study on the Effect of a New Bioactive Desensitizer on Dentin Tubule Sealing and Bonding

by Minh N. Luong, Laurie Huang, Daniel C. N. Chan and Alireza Sadr

J. Funct. Biomater. 2020, 11(2), 38; https://doi.org/10.3390/jfb11020038 - 2 Jun 2020

Cited by 8 | Viewed by 5242

Abstract

Bioactive mineral-based dentin desensitizers that can quickly and effectively seal dentinal tubules and promote dentin mineralization are desired. This in vitro study evaluated a novel nanohydroxyapatite-based desensitizer, Predicta (PBD, Parkell), and its effect on bond strength of dental adhesives. Human dentin discs (2-mm [...] Read more.

Bioactive mineral-based dentin desensitizers that can quickly and effectively seal dentinal tubules and promote dentin mineralization are desired. This in vitro study evaluated a novel nanohydroxyapatite-based desensitizer, Predicta (PBD, Parkell), and its effect on bond strength of dental adhesives. Human dentin discs (2-mm thick) were subjected to 0.5 M EDTA to remove the smear layer and expose tubules, treated with PBD, and processed for surface and cross-sectional SEM examination before and after immersion in simulated body fluid (SBF) for four weeks (ISO 23317-2014). The effects of two dental desensitizers on the microshear bond strength of a universal adhesive and a two-step self-etch system were compared. SEM showed coverage and penetration of nanoparticles in wide tubules on the PBD-treated dentin at the baseline. After four weeks in SBF, untreated dentin showed amorphous mineral deposits while PBD-treated dentin disclosed a highly mineralized structure integrated with dentin. Desensitizers significantly reduced microshear bond strength test (MSBS) of adhesives by 15–20% on average, depending on the bonding protocol. In conclusion, PBD demonstrated effective immediate tubules sealing capability and promoted mineral crystal growth over dentin and into the tubules during SBF-storage. For bonding to desensitizer-treated dentin, a two-step self-etching adhesive or universal bond with phosphoric acid pretreatment are recommended. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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Methodology: Dentin discs were produced from human molar for morphological observation (A) and microshear bond strength test (B). For (A): Ten dentin discs were pretreated with EDTA (pH 7.4) to remove the smear layer and open dentinal tubules before rinsing. Half of the disc surfaces were subjected to Predicta Bioactive Desensitizer (PBD) and the other half served as control (no PBD). Five discs were immediately processed for SEM examination while the other five were stored for four weeks in simulated body fluid (SBF) for bioactivity test (specified by the ISO 23317:2014). For (B): Thirty dentin discs were allocated into three groups (n = 10): Teethmate Desensitizer (TMD) treatment, PBD treatment and no desensitizer as control. The universal adhesive (PUB) in self-etch (SE) or with phosphoric acid etching (PA)) and two-step self-etch adhesive Clearfil SE Bond 2 (CSE) were used. Small cylinders of the hybrid composite were bonded on the dentin surface and the wire loop bond test was performed at a crosshead speed of 1 mm/min. Full article ">Figure 2
Cross-sectional SEM images immediately after application of PBD. The patency of dentinal tubules and open lateral branch orifice (arrow) have been well sealed on the treated side. Full article ">Figure 3
SEM images four weeks after application of PBD and immersion in SBF. PBD-treated dentin demonstrates a solid layer of mineral formation while no coverage is distinguished in the untreated dentin away from the PBD-treated dentin. Full article ">Figure 4
Bond strength of the experiment group in MPa. Bars indicate no significant difference (p < 0.05). Two-way ANOVA indicated that both the use of desensitizers and application mode were significant factors in MSBS and their interaction was significant (p < 0.05). Predicta (PBD) and Teethmate (TMD) significantly reduced bond strength to dentin by 15%–20% on average; however, the effect depended on the adhesives. For Universal Adhesive (PUB), the groups using phosphoric acid etching (PUB-PA) consistently showed higher bond strength compared to the ones using self-etch (PUB). Bonding to PBD and TMD with either PUB-PA and Clearfil SE 2 (CSE) were comparable (p > 0.05). Full article ">

10 pages, 2998 KiB

Open AccessCommunication

Towards the Development of a Novel Ex Ovo Model of Infection to Pre-Screen Biomaterials Intended for Treating Chronic Wounds

by Elena García-Gareta, Justyna Binkowska, Nupur Kohli and Vaibhav Sharma

J. Funct. Biomater. 2020, 11(2), 37; https://doi.org/10.3390/jfb11020037 - 2 Jun 2020

Cited by 10 | Viewed by 4328

Abstract

This communication reports preliminary data towards the development of a live ex vivo model of persistent infection that is based on the chick embryo chorioallantoic membrane (CAM), which can be used for pre-screening biomaterials with antimicrobial properties for their antimicrobial and angiogenic potential. [...] Read more.

This communication reports preliminary data towards the development of a live ex vivo model of persistent infection that is based on the chick embryo chorioallantoic membrane (CAM), which can be used for pre-screening biomaterials with antimicrobial properties for their antimicrobial and angiogenic potential. Our results showed that it was possible to infect chicken embryos with Staphylococcus aureus, one of the main types of bacteria found in the persistent infection associated with chronic wounds, and maintain the embryos’ survival for up to 48 h. Survival of the embryos varied with the dose of bacteria inoculum and with the use and time of streptomycin application after infection. In infected yet viable embryos, the blood vessels network of the CAM was maintained with minimal disruption. Microbiological tests could confirm embryo infection, but quantification was difficult. By publishing these preliminary results, we hope that not only our group but others within the scientific community further this research towards the establishment of biomimetic and reproducible ex vivo models of persistent infection. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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Photos taken during the experimental procedure of this study showing (A) application of Staphylococcus aureus bacterial inoculum on the chorioallantoic membrane (CAM) of a viable embryo contained in a glass–cling film set-up and inoculation spots marked on the cover Petri dish lids, and (B) application of streptomycin-infused 6 mm diameter filter paper discs on the CAM using sterile tweezers. Full article ">Figure 2
Results from the streptomycin sensitivity assay. Graphs show average ± standard deviation (n = 3 per streptomycin concentration). Full article ">Figure 3
(A) Percentage of embryo survival after CAM infection (infected CAM) with 105 cfu/mL inoculum compared to non-infected CAMs (control CAM). Results show average (n = 3 for control and n = 6 for infected CAM at the beginning of the experiment). (B) S. aureus load in allantoic fluid samples of infected CAMs. X means that there were too many colonies and a count could not be performed. (C) Representative images of Luria-Bertani (LB) plates showing S. aureus colony formation after plating samples of the allantoic fluid from control and infected CAMs. Full article ">Figure 4
(A) Percentage of embryo survival after CAM infection (infected CAM) with 105 cfu/mL inoculum compared to non-infected CAMs (control CAM). Streptomycin was applied either at the time of inoculation (0 h) or 24 h after inoculation (24 h). Results show average (n = 2 per group). (B) Representative images of LB plates showing S. aureus colony formation after plating allantoic fluid samples (105 dilution). No colonies were observed in the control group plates. As can be observed, there were too many colonies to perform a count and subsequent quantification, which could only be done using a higher dilution. Full article ">Figure 5
Macroscopic images of the CAM with and without bacterial infection, where black arrows point at vessel damage due to the bacterial invasion. (A) Non-infected CAM incubated for 48 h. (B) CAM infected with 105 bacterial inoculum and incubated for 48 h. (C) CAM infected with 105 bacterial inoculum with antibiotic applied at the time of infection (0 h) and incubated for 24 h. (D) Same embryo as C after 48 h incubation. (E) CAM infected with 105 bacterial inoculum with antibiotic applied 24 h post-infection and incubated for 24 h. (F) Same embryo as (E) after 48 h incubation (embryo is dead and network of blood vessels is completely destroyed). (G) Stereomicroscopy image of non-infected CAM at 24 h showing a mostly clear background and well-defined blood vessels. (H) Stereomicroscopy image of infected CAM at 24 h post-infection showing a cloudy background (white arrows point at yellowish cloudy spots) and in some areas blood vessels appear less well-defined and fainter than in non-infected CAM. Please note that with the purpose of protecting the live ex vivo cultures, photos were taken with the Petri dish lid on, but the lid might have been taken off if the embryos were already dead or sacrificed. Additionally, the lid might have been moved (without opening) to capture the morphological changes in the CAM/embryo. Full article ">

17 pages, 3556 KiB

Open AccessArticle

Substituted Nano-Hydroxyapatite Toothpastes Reduce Biofilm Formation on Enamel and Resin-Based Composite Surfaces

by Andrei C. Ionescu, Gloria Cazzaniga, Marco Ottobelli, Franklin Garcia-Godoy and Eugenio Brambilla

J. Funct. Biomater. 2020, 11(2), 36; https://doi.org/10.3390/jfb11020036 - 1 Jun 2020

Cited by 32 | Viewed by 5730

Abstract

Background: Toothpastes containing nano-hydroxyapatite (n-HAp) substituted with metal ions provide calcium and phosphate ions to dental hard tissues, reducing demineralization, and promoting remineralization. Few data are available about the effect of these bioactive compounds on oral microbiota. Methods: This in vitro [...] Read more.

Background: Toothpastes containing nano-hydroxyapatite (n-HAp) substituted with metal ions provide calcium and phosphate ions to dental hard tissues, reducing demineralization, and promoting remineralization. Few data are available about the effect of these bioactive compounds on oral microbiota. Methods: This in vitro study evaluated the influence of two commercially-available substituted n-HAp-based toothpastes (α: Zn-carbonate substituted n-HAp; β: F, Mg, Sr-carbonate substituted n-HAp) on early colonization (EC, 12 h) and biofilm formation (BF, 24 h) by oral microbiota. Controls were brushed with distilled water. Artificial oral microcosm and Streptococcus mutans biofilms were developed using human enamel and a resin-based composite (RBC) as adherence surfaces. Two test setups, a shaking multiwell plate and a modified drip-flow reactor (MDFR), were used to simulate clinical conditions during the night (low salivary flow and clearance) and daytime, respectively. Energy-dispersive X-ray spectrometry (EDS) was used to evaluate specimens’ surfaces after toothpaste treatment. Fluoride release from β toothpaste was evaluated. Viable adherent biomass was quantified by MTT assay, and biofilms’ morphology was highlighted using confocal microscopy. Results: EDS showed the presence of remnants from the tested toothpastes on both adherence surfaces. β toothpaste showed significantly lower EC and BF compared to control using the artificial oral microcosm model, while α toothpaste showed lower EC and BF compared to control, but higher EC and BF compared to β toothpaste. The effect shown by β toothpaste was, to a minimal extent, due to fluoride release. Interestingly, this result was seen on both adherence surfaces, meaning that the tested toothpastes significantly influenced EC and BF even on RBC surfaces. Furthermore, the effect of toothpaste treatments was higher after 12 h than 24 h, suggesting that toothbrushing twice a day is more effective than brushing once. Conclusions: The efficacy of these treatments in reducing microbial colonization of RBC surfaces may represent a promising possibility in the prevention of secondary caries. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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Figure 1

Figure 1
Diagram of specimens processing for the present study. After brushing with the tested toothpastes or with distilled water, enamel and RBC specimens were rinsed, sterilized, then subjected to microbiological analysis and surface imaging (SEM, CLSM) and analysis (EDS). The microbiological analysis included two test setups, two microbiological models, and two incubation times. Full article ">Figure 2
The panel, to be read horizontally, depicts the SEM backscattered electrons micrographs (500× and 5000×, respectively) and EDS elemental maps (5000×) of the specimen surfaces. The EDS maps are additionally presented as single-channel maps to better identify the topographical presence of each element. The first two rows of the panel display the surfaces of the vacuum-dried toothpastes tested in this study: α toothpaste (containing Zn-carbonate substituted n-HAp) and β toothpaste (containing F, Mg, Sr-carbonate substituted n-HAp). Their aspect is very similar, showing silica microparticles (identified by Si signal) and clusters of n-HAp (identified by Ca and P signals). Zn and Sr signals were below the detection limits in mapping mode and were not displayed. The last two rows of the panel represent the surfaces of the tested restorative material after treatment with the toothpastes: RBC + α toothpaste and RBC + β toothpaste. The RBC composition included silica particles (identified by Si signal), and alumina and barium glass micro and nanoparticles (identified by Al and Ba signals). Ca signal was displayed as a marker of toothpaste remnants. It is noteworthy that toothpaste remnants could be associated with alumina and barium glass fillers rather than silica particles. Full article ">Figure 3
EDS spectra acquired from vacuum-dried tested toothpastes surfaces (α toothpaste containing Zn-carbonate substituted n-HAp, and β toothpaste containing F, Mg, Sr-carbonate substituted n-HAp). Strong Ca and P signals are identified belonging to the n-HAp, as well as the signals corresponding to the corresponding doping elements (Zn in α toothpaste and F, Mg, Sr, in β toothpaste). High counts of Si were also detected in both toothpastes, together with relatively low counts of Al and other elements. The relative amounts of n-HAp doping elements and other elements such as Al and S are below the conventionally considered detection limit of EDS (about 1 wt%). However, the presence of such elements is shown by peaks that were clearly identifiable on all acquired spectra. In this sense, the acquisition of several spectra over the surfaces of many specimens, and the use of statistical analysis on acquired data demonstrating low variability in signals among the different acquisitions (cf. <a href="#jfb-11-00036-t002" class="html-table">Table 2</a>) allows overcoming, to some extent, this detection limit, improving the performances of EDS analysis. Full article ">Figure 4
Biofilm formation on the surface of the tested specimens using the shaking multiwell plate test setup, according to the microbiological model (S. mutans monospecific biofilm or artificial oral microcosm, aerobically grown) and to the incubation time (12 h or 24 h). Sucrose-enriched sterile modified artificial saliva medium was used in all experiments. Low shear stress on specimens’ surfaces was obtained by an orbital incubator, to simulate oral conditions during the night. Moreover, the closed system setup allows a progressive increase in microorganism catabolites and antimicrobial agents released from the surfaces. Results of viable biomass assay are expressed as mean OD ± SE. Different superscript letters indicate significant differences between groups (student’s test, p < 0.05). α toothpaste contains Zn-carbonate substituted n-HAp; β toothpaste contains F, Mg, Sr-carbonate substituted n-HAp while Ctrl group was brushed with distilled water. β toothpaste significantly reduced the early colonization of the artificial oral microcosm on enamel surfaces when compared to the control. Full article ">Figure 5
Biofilm formation on the surface of the tested specimens using the MDFR bioreactor test setup, according to the microbiological model (S. mutans monospecific biofilm or artificial oral microcosm, aerobically grown) and to the incubation time (12 h or 24 h). Sucrose-enriched sterile modified artificial saliva medium was used in all experiments, being pumped through the flow-cells of the bioreactor. High hydrodynamic stress conditions that occur during the daytime can thus be simulated. An elution of microorganism catabolites and antimicrobial agents released from the surfaces can also occur. Results of viable biomass assay are expressed as mean OD ± SE. Different superscript letters indicate significant differences between groups (student’s test, p < 0.05). α toothpaste contains Zn-carbonate substituted n-HAp; β toothpaste contains F, Mg, Sr-carbonate substituted n-HAp while Ctrl group was brushed with distilled water. β toothpaste significantly reduced early colonization (enamel and RBC) and biofilm formation (RBC) of the artificial oral microcosm when compared to the control. Interestingly, the adherence surface showed a more considerable influence than toothpaste treatment on early colonization and biofilm formation, independent of the microbiological model or test setup applied. The effect of the toothpaste on RBC surfaces was not expected and opens the possibility to control microbial colonization on RBCs, and, ultimately, secondary caries prevention, by such treatments. Full article ">Figure 6
CLSM results of the adherence surfaces treated with the control and the tested toothpastes using the MDFR test setup and the artificial oral microcosm model for 12 h. Scans were analyzed 3D reconstructions obtained using Drishti software. Enamel surfaces provided a much higher early colonization than RBC surfaces. In the background of the enamel control specimen, a central microcolony shows a long tail detached from the surface and oriented horizontally downstream (to the right). This feature is typical of biofilms that develop on surfaces in the presence of relatively high shear stress and is also a means to colonize downstream surfaces rapidly. This feature demonstrates the good morphological resemblance of bioreactor-grown biofilms with in vivo ones. Enamel specimens treated with β toothpaste showed a higher amount of dead cells compared to the other groups. RBC specimens treated with β toothpaste showed the lowest early colonization overall, consistently with viable biomass results. Full article ">Figure 7
Immediate fluoride release (ppb/mm2 ± SE) after disks’ brushing and fluoride presence (ppm ± SE) in the biofilms grown over the disks’ surfaces after 12 and 24 h. Different superscript letters indicate significant differences between groups (Student’s test, p < 0.05). β toothpaste contains F, Mg, Sr-carbonate substituted n-HAp while Ctrl group was brushed with distilled water. β toothpaste did not increase the baseline fluoride presence in biofilms grown over enamel surfaces despite showing a low but significant immediate fluoride release. The reduction in fluoride presence seen in enamel specimens after 12 h of incubation when compared to the control may be due to an uptake of fluoride by the tested toothpaste. Full article ">

13 pages, 3637 KiB

Open AccessArticle

Sol-Gel Derived Tertiary Bioactive Glass–Ceramic Nanorods Prepared via Hydrothermal Process and Their Composites with Poly(Vinylpyrrolidone-Co-Vinylsilane)

by Dibakar Mondal, Andrei Zaharia, Kibret Mequanint and Amin S. Rizkalla

J. Funct. Biomater. 2020, 11(2), 35; https://doi.org/10.3390/jfb11020035 - 1 Jun 2020

Cited by 4 | Viewed by 4162

Abstract

Bioactive glass (BG) nanoparticles have wide applications in bone repair due to their bone-bonding and biodegradable nature. In this work, nanometric rod-shaped ternary SiO₂-CaO-P₂O₅ bioactive glass particles were prepared through sol-gel chemistry followed by a base-induced hydrothermal process [...] Read more.

Bioactive glass (BG) nanoparticles have wide applications in bone repair due to their bone-bonding and biodegradable nature. In this work, nanometric rod-shaped ternary SiO₂-CaO-P₂O₅ bioactive glass particles were prepared through sol-gel chemistry followed by a base-induced hydrothermal process at 130 °C and 170 °C for various times up to 36 h. This facile, low-temperature and surfactant-free hydrothermal process has shown to be capable of producing uniform nanorods and nanowires. One-dimensional growth of nanorods and the characteristics of siloxane bridging networks were dependent on the hydrothermal temperature and time. Hardened bioactive composites were prepared from BG nanorods and cryo-milled poly(vinylpyrrolidone-co-triethoxyvinylsilane) in the presence of ammonium phosphate as potential bone graft biomaterials. Covalent crosslinking has been observed between the organic and inorganic components within these composites. The ultimate compressive strength and modulus values increased with increasing co-polymer content, reaching 27 MPa and 500 MPa respectively with 30% co-polymer incorporation. The materials degraded in a controlled non-linear manner when incubated in phosphate-buffered saline from 6 h to 14 days. Fibroblast cell attachment and spreading on the composite were not as good as the positive control surfaces and suggested that they may require protein coating in order to promote favorable cell interactions. Full article

(This article belongs to the Special Issue Bioceramics and Bioactive Glass-Based Materials)

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Figure 1
Hydrothermal processing of sol-gel derived tertiary bioactive glass. (A) Schematic drawing of a hydrothermal processing unit; (B) digital photograph of the hydrothermal units; (C,D) scanning electron microscopy (SEM) images of as-prepared bioactive glasses by the sol-gel process before hydrothermal processing; (E–H) representative SEM images of bioactive glasses after 36 h hydrothermal processing at 130 °C (E,F), and at 170 °C (G,H). Full article ">Figure 2
The effect of hydrothermal processing time on the morphological evolution of bioactive glass (BG). (A) 170 °C for 3 h and (B) 170 °C for 24 h. (C) EDX spectra of nanorods prepared at 170 °C for 24 h. The region shown by the green square in the inset in Figure C was used to generate the EDX spectra. (D) XRD patterns of as-prepared and hydrothermally-processed BG; (•) indicates hydroxyapatite and (◊) SiO2. (E) Ca/P ratio of nanorods prepared at 170 °C for 24 h. Full article ">Figure 3
(A) FTIR spectra and (B) solid-state Si-NMR of sol-gel-derived and hydrothermal processing of BG glasses at 130 °C and 170 °C for 3 hrs and 24 h. Q represents the structure of bridging networks of BG at post-processing. Q4 indicates the Si is bonded with 4 -O-Si-, whereas Q1 indicates the Si is bonded with one -O-Si and three -OH. Q1Ca is associated with the peak for Q1 structure, where at least one -OH is replaced by calcium. Full article ">Figure 4
SEM images of composites consisting of hydrothermally-treated (at 170 °C for 24 h) BG nanorods without a co-polymer (A,B) and composites made of hydrothermally-treated (at 170 °C for 24 h) BG nanorods with a co-polymer (C,D). Solid-state Si-NMR of hydrothermally treated bioactive glass composites (E) and XRD profiles of the bioactive composites showed HA formation (F). Full article ">Figure 5
Compressive mechanical behavior and degradation profiles of bioactive composite materials. (A) Cylindrical bioactive composite ultimate compressive strength, (B) and compressive moduli. Data are means ± standard deviation (SD) (n = 8). Two-way ANOVA and Tukey’s multiple comparison tests were used for statistical analysis. Different lower-case letters indicate significance at p < 0.05. (C–H) SEM images of bioactive composites degraded in phosphate-buffered saline (PBS) at different times. Composite made of hydrothermally-processed (at 170 °C for 24 h) bioactive glass nanorods and 30 wt % co-polymer. Surfaces of composite disks following PBS soaking for 3 days (C,D), 7 days (E,F), and 14 days (G,H). (I) Weight loss over the time courses. Data are means ± SD (n = 5). Two-way ANOVA and Tukey’s multiple comparison tests were used for statistical analysis. Full article ">Figure 6
MC3T3-E1 cell adhesion on glass coverslips, PMMA disks and poly(VP-co-TEVS)-BG ceramic composites. Scale bar = 40 μm. Blue is nuclei, and red is F-actin. Full article ">

12 pages, 2940 KiB

Open AccessArticle

Coating Medpor^® Implant with Tissue-Engineered Elastic Cartilage

by Dong Joon Lee, Jane Kwon, Yong-Il Kim, Yong Hoon Kwon, Samuel Min and Hae Won Shin

J. Funct. Biomater. 2020, 11(2), 34; https://doi.org/10.3390/jfb11020034 - 22 May 2020

Cited by 10 | Viewed by 5315

Abstract

Inert biomaterials used for auricular reconstruction, which is one of the most challenging and diverse tasks in craniofacial or head and neck surgery, often cause problems such as capsule formation, infection, and skin extrusion. To solve these problems, scaffold consisting of inert biomaterial, [...] Read more.

Inert biomaterials used for auricular reconstruction, which is one of the most challenging and diverse tasks in craniofacial or head and neck surgery, often cause problems such as capsule formation, infection, and skin extrusion. To solve these problems, scaffold consisting of inert biomaterial, high-density polyethylene (Medpor^®) encapsulated with neocartilage, biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) was created using a tissue engineering strategy. PLGA scaffold without Medpor^® was created to serve as the control. Scaffolds were vacuum-seeded with rabbit chondrocytes, freshly isolated from the ear by enzymatic digestion. Then, cell-seeded scaffolds were implanted subcutaneously in the dorsal pockets of nude mice. After 12 weeks, explants were analyzed by histological, biochemical, and mechanical evaluations. Although the PLGA group resulted in neocartilage formation, the PLGA–Medpor^® group demonstrated improved outcome with the formation of well-surrounded cartilage around the implants with higher mechanical strength than the PLGA group, indicating that Medpor^® has an influence on the structural strength of engineered cartilage. The presence of collagen and elastin fibers was evident in the histological section in both groups. These results demonstrated a novel method of coating implant material with engineered cartilage to overcome the limitations of using biodegradable scaffold in cartilage tissue regeneration. By utilizing the patient’s own chondrocytes, our proposed method may broaden the choice of implant materials while minimizing side effects and immune reaction for the future medical application. Full article

(This article belongs to the Special Issue Innovative Biomaterial Solutions for Translational Tissue Engineering and Regenerative Medicine)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Scheme of the study. PLGA: poly(DL-lactic-co-glycolic acid) and Scanning electron microscopy (SEM). Full article ">Figure 2
Cartilage tissues were isolated from rabbit ear, digested of matrices in collagenase type II solution, and expanded in chondrocytes monolayer culture (A). Rabbit ear cartilage, scale bar: 200 μm (B); chondrocytes, scale bar: 20 μm (C); immunostained chondrocytes at P4 with anti-collagen type II antibody conjugated with FITC (D); and band expression of type II collagen Ge4ne and protein by PCR and Western blot, respectively (E). Full article ">Figure 3
Scanning electron microscopy of the cross section of PLGA, shown as P (A); Medpor®, shown as M (B); PLGA–Medpor® (C); and neocartilage regenerated with rabbit chondrocytes and Medpor® (D). Scale bar: 750 µm. Full article ">Figure 4
Histological analysis of cross-sectioned neocartilage with PLGA and PLGA–Medpor®. Collagen was stained blue by trichrome staining (C,D), prominent elastin expression was detected by Verhoeff staining in both neocartilages (E,F), and overall distribution of neocartilage was shown by H&E staining (A,B). Scale bars: 500 µm (left images, 4×) and 2.5 mm (right images, 20×). Quantification of collagen and elastin by ImageJ analysis (G,H); n = 3, * p > 0.05. Full article ">Figure 5
Compressive strengths of neocartilage with PLGA and PLGA–Medpor® after 12 weeks of implantation (A,B); n = 5, * p < 0.05. Representative stress and strain curve patterns of neocartilages with PLGA (C) and PLGA–Medpor® (D). Full article ">Figure 6
Vacuum cell seeding on PLGA and PLGA–Medpor®. After 12 weeks of implantation in the dorsal pocket of nude mice, neocartilage were formed around both PLGA and PLGA–Medpor®, demonstrated a solid morphology with milky color (Scale: 400 µm). Full article ">

13 pages, 6437 KiB

Open AccessArticle

Anti-Bacterial Properties and Biocompatibility of Novel SiC Coating for Dental Ceramic

by Samira Esteves Afonso Camargo, Azeem S. Mohiuddeen, Chaker Fares, Jessica L. Partain, Patrick H. Carey IV, Fan Ren, Shu-Min Hsu, Arthur E. Clark and Josephine F. Esquivel-Upshaw

J. Funct. Biomater. 2020, 11(2), 33; https://doi.org/10.3390/jfb11020033 - 20 May 2020

Cited by 24 | Viewed by 5511

Abstract

A 200 nm plasma-enhanced chemical vapor-deposited SiC was used as a coating on dental ceramics to improve anti-bacterial properties for the applications of dental prosthesis. A thin SiO₂ (20 nm) in the same system was deposited first, prior to SiC deposition, to [...] Read more.

A 200 nm plasma-enhanced chemical vapor-deposited SiC was used as a coating on dental ceramics to improve anti-bacterial properties for the applications of dental prosthesis. A thin SiO₂ (20 nm) in the same system was deposited first, prior to SiC deposition, to improve the adhesion between SiC to dental ceramic. Silane and methane were the precursors for SiC deposition, and the SiO₂ deposition employed silane and nitrous oxide as the precursors. SiC antimicrobial activity was evaluated on the proliferation of biofilm, Streptococcus sanguinis, and Streptococcus mutans on SiC-coated and uncoated dental ceramics for 24 h. The ceramic coating with SiC exhibited a biofilm coverage of 16.9%, whereas uncoated samples demonstrated a significantly higher biofilm coverage of 91.8%, measured with fluorescence and scanning electron microscopic images. The cytotoxicity of the SiC coating was evaluated using human periodontal ligament fibroblasts (HPdLF) by CellTiter-BlueCell viability assay. After 24 h of HPdLF cultivation, no obvious cytotoxicity was observed on the SiC coating and control group; both sets of samples exhibited similar cell adhesion and proliferation. SiC coating on a ceramic demonstrated antimicrobial activity without inducing cytotoxic effects. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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Figure 1
Roughness means values and standard deviation in non-coated (reference) and coated (ref SiC) samples (A). Atomic force microscopy (AFM) images of surface topography of non-coated (B) and coated SiC (C), with amplifications of 10 µm. Full article ">Figure 2
SEM images of roughness of non-coated and coated samples. (A,D) Non-coated fluorapatite disk, (B,E) glazed fluorapatite disk, and (C,F) SiC-coated fluorapatite disk. Full article ">Figure 3
Live coverage of Streptococcus mutans and Streptococcus sanguinis after 24 h of culture on the non-coated (control) and coated surfaces. Full article ">Figure 4
Live fluorescence images of S. mutans and S. sanguinis cultured for 24 h on the non-coated (A,B) and coated (C,D) surfaces. The cultures were stained with SYTO 9 to dye the living bacteria green. Full article ">Figure 5
SEM adhesion of polymicrobial biofilm of S. mutans and S. sanguinis after 24 h of cultivation on non-coated (A,B) and coated (C,D) ceramic disks. Full article ">Figure 6
Mean (±SD) of colony-forming units (CFU)/mL of monomicrobial biofilms of S. mutans (A) and S. sanguinis (B) presented in the non-coated (control) and coated groups. Full article ">Figure 7
Cytotoxicity of the non-coated (control) and coated groups after 24 h of human periodontal ligament fibroblasts (HPdLF) culture assessed by CellTiter-Blue absorbance. Full article ">Figure 8
SEM images showing the adhesion of HPdLF on non-coated (A,B) and coated (C,D) surfaces after 24 h of incubation. Full article ">

16 pages, 4139 KiB

Open AccessArticle

Determination and Quantification of the Distribution of CN-NL Nanoparticles Encapsulating Glycyrrhetic Acid on Novel Textile Surfaces with Hyperspectral Imaging

by Kudirat A. Obisesan, Simona Neri, Elodie Bugnicourt, Inmaculada Campos and Laura Rodriguez-Turienzo

J. Funct. Biomater. 2020, 11(2), 32; https://doi.org/10.3390/jfb11020032 - 20 May 2020

Cited by 7 | Viewed by 4742

Abstract

Chitin Lignin nanoparticles (CN-NL), standalone and encapsulating glycyrrhetic acid (GA), were applied on novel substrates for textiles to obtain antibacterial, antioxidant properties. Their homogeneous application is an important parameter that can strongly influence the final performance of the investigated textiles for its cosmetic [...] Read more.

Chitin Lignin nanoparticles (CN-NL), standalone and encapsulating glycyrrhetic acid (GA), were applied on novel substrates for textiles to obtain antibacterial, antioxidant properties. Their homogeneous application is an important parameter that can strongly influence the final performance of the investigated textiles for its cosmetic and medical use. In this paper, hyperspectral imaging techniques combined with chemometric tools were investigated to study the distribution and quantification of CN-NL/GA on chitosan and CN-NL on pullulan substrates. To do so, samples of chitosan and pullulan impregnated with CN-NL/GA and CN-NL were analysed through Short Wave Infrared (SWIR) and Visible-Near Infrared (VisNIR) hyperspectral cameras. Two different chemometric tools for qualitative and quantitative analysis have been applied, principal component analysis (PCA) and partial least square regression (PLSR) models. Promising results were obtained in the VisNIR range, which made it possible for us to visualize the CN-NL/GA compound on chitosan and CN-NL on pullulan substrates. Additionally, the PLSR model results had determination coefficient (

R_{C}^{2})

for calibration and cross-validation (

R_{C V}^{2})

values of 0.983 and 0.857, respectively. Minimum values of root-mean-square error for calibration (RMSEC) and cross-validation (RMSECV) of CN-NL/GA were 0.333 and 0.993 g, respectively. The results demonstrate that hyperspectral imaging combined with chemometrics offers a powerful tool for studying the distribution on chitosan and pullulan substrates and to quantify the content of CN-NL/GA compounds on chitosan substrates. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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Figure 1

Figure 1
Comparison of hyperspectral imaging signal obtained from (a) SWIR range, a spectrum corresponding to pure chitosan substrate and two spectra of chitosan impregnated with CN-NL/GA in two different zones from the same sample (sample 2) and (b) VisNIR range, a spectrum corresponding to pure chitosan substrate and two spectra of chitosan impregnated with CN-NL/GA in two different zones from the same sample (sample 2). Full article ">Figure 2
Comparison of hyperspectral imaging signal obtained from (a) SWIR range, corresponding to the pullulan substrate (sample 13) and spectra from pullulan impregnated with CN-NL in two different zones from sample 12 (set 6), and (b) VisNIR range, corresponding to the pullulan substrate (sample 13) and spectra of pullulan impregnated with CN-NL in two different zones from sample 12 (set 6). Full article ">Figure 3
PCA score images for the first principal components: (a) Picture of the chitosan and chitosan impregnated with CN-NL/GA (set 1, top images: chitosan with 2.68 g CN-NL/GA and set 2, down images: chitosan with 6 g of CN-NL/GA); (b) PC1 scores image for SWIR camera; and (c) PC1 scores image for VisNIR camera. Full article ">Figure 4
PCA scores images for the first principal components: (a) Picture of chitosan and chitosan impregnated with different quantities of CN-NL/GA compound (chitosan: 0 g, samples 3: 5 g; sample 4: 5.4 g; sample 5: 7 g; from set 3); (b) PC1 scores for SWIR camera; and (c) PC1 scores for VisNIR camera. Full article ">Figure 5
The PC1 Loadings plot result for chitosan and chitosan impregnated with CN-LN/GA for VisNIR camera. Full article ">Figure 6
PCA scores images for the first principal components: (a) Picture of pullulan reference (sample 13) and pullulan impregnated with CN-NL complex (sample 12); (b) PC1 scores for SWIR camera; and (c) PC1 scores for VisNIR camera. Full article ">Figure 7
The PC1 for loadings plot result of pullulan and pullulan impregnated with CN-NL for the VisNIR camera. Full article ">Figure 8
(a) Mean spectral for each of the samples; (b) PLS regression results for CN-NL/GA quantification, showing the actual grams of CN-NL/GA vs. the predicted grams of CN-NL/GA complex. Full article ">

13 pages, 1299 KiB

Open AccessReview

Autologous Matrix of Platelet-Rich Fibrin in Wound Care Settings: A Systematic Review of Randomized Clinical Trials

by Chayane Karla Lucena de Carvalho, Beatriz Luci Fernandes and Mauren Abreu de Souza

J. Funct. Biomater. 2020, 11(2), 31; https://doi.org/10.3390/jfb11020031 - 14 May 2020

Cited by 16 | Viewed by 5612

Abstract

Platelet-rich fibrin (PRF) consists of a matrix that provides the necessary elements for wound healing, acting as a biodegradable scaffold for cell migration, proliferation, and differentiation, in addition to the delivery of growth factors and angiogenesis. This study aims to determine the effectiveness [...] Read more.

Platelet-rich fibrin (PRF) consists of a matrix that provides the necessary elements for wound healing, acting as a biodegradable scaffold for cell migration, proliferation, and differentiation, in addition to the delivery of growth factors and angiogenesis. This study aims to determine the effectiveness of the autologous PRF in the treatment of wounds of different etiologies. We carried out a systematic review of randomized clinical trials, guided by the recommendations of the Cochrane Collaboration using the following databases: Pubmed/MEDLINE, EMBASE, Web of Science, and CENTRAL. The search strategy resulted in the inclusion of ten studies that evaluated the use of PRF dressings for the healing of acute or chronic wounds of multiple etiologies. Among the 172 participants treated with PRF in wounds of varying etiologies and different segment times, 130 presented favorable events with the use of the intervention. Among the 10 studies included, only two of them did not demonstrate better results than the control group. The studies showed clinical heterogeneity, making it impossible to perform a meta-analysis. The findings do not provide enough evidence to support the routine use of PRF dressings as the first line of treatment for the healing of acute or chronic wounds of different etiologies. There was great variability in the application of the various protocols and the ways to prepare the PRF, resulting in clinical heterogeneity. Therefore, it makes it impossible to synthesize and to collect evidence from different types of studies in the meta-analysis, which affects the results and their proper discussion. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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16 pages, 3040 KiB

Open AccessArticle

Modification of PLA-Based Films by Grafting or Coating

by Aleksandra Miletić, Ivan Ristić, Maria-Beatrice Coltelli and Branka Pilić

J. Funct. Biomater. 2020, 11(2), 30; https://doi.org/10.3390/jfb11020030 - 7 May 2020

Cited by 19 | Viewed by 5491

Abstract

Recently, the demand for the use of natural polymers in the cosmetic, biomedical, and sanitary sectors has been increasing. In order to meet specific functional properties of the products, usually, the incorporation of the active component is required. One of the main problems [...] Read more.

Recently, the demand for the use of natural polymers in the cosmetic, biomedical, and sanitary sectors has been increasing. In order to meet specific functional properties of the products, usually, the incorporation of the active component is required. One of the main problems is enabling compatibility between hydrophobic and hydrophilic surfaces. Therefore, surface modification is necessary. Poly(lactide) (PLA) is a natural polymer that has attracted a lot ofattention in recent years. It is bio-based, can be produced from carbohydrate sources like corn, and it is biodegradable. The main goal of this work was the functionalization of PLA, inserting antiseptic and anti-inflammatory nanostructured systems based on chitin nanofibrils–nanolignin complexes ready to be used in the biomedical, cosmetics, and sanitary sectors. The specific challenge of this investigation was to increase the interaction between the hydrophobic PLA matrix with hydrophilic chitin–lignin nanoparticle complexes. First, chemical modification via the “grafting from” method using lactide oligomers was performed. Then, active coatings with modified and unmodified chitin–lignin nanoparticle complexes were prepared and applied on extruded PLA-based sheets. The chemical, thermal, and mechanical characterization of prepared samples was carried out and the obtained results were discussed. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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16 pages, 2018 KiB

Open AccessReview

Synthetic Bone Substitutes and Mechanical Devices for the Augmentation of Osteoporotic Proximal Humeral Fractures: A Systematic Review of Clinical Studies

by Giuseppe Marongiu, Marco Verona, Gaia Cardoni and Antonio Capone

J. Funct. Biomater. 2020, 11(2), 29; https://doi.org/10.3390/jfb11020029 - 5 May 2020

Cited by 22 | Viewed by 5579

Abstract

Background: Different augmentation techniques have been described in the literature in addition to the surgical treatment of proximal humeral fractures. The aim of this systematic review was to analyze the use of cements, bone substitutes, and other devices for the augmentation of proximal [...] Read more.

Background: Different augmentation techniques have been described in the literature in addition to the surgical treatment of proximal humeral fractures. The aim of this systematic review was to analyze the use of cements, bone substitutes, and other devices for the augmentation of proximal humeral fractures. Methods: A systematic review was conducted by using PubMed/MEDLINE, ISI Web of Knowledge, Cochrane Library, Scopus/EMBASE, and Google Scholar databases according the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines over the years 1966 to 2019. The search term “humeral fracture proximal” was combined with “augmentation”; “polymethylmethacrylate, PMMA”; “cement”; “bone substitutes”; “hydroxyapatite”; “calcium phosphates”; “calcium sulfate”; “cell therapies”, and “tissue engineering” to find the literature relevant to the topic under review. Results: A total of 10 clinical studies considered eligible for the review, with a total of 308 patients, were included. Mean age at the time of injury was 68.8 years (range of 58–92). The most commonly described techniques were reinforcing the screw–bone interface with bone PMMA cement (three studies), filling the metaphyseal void with synthetic bone substitutes (five studies), and enhancing structural support with metallic devices (two studies). Conclusion: PMMA cementation could improve screw-tip fixation. Calcium phosphate and calcium sulfate injectable composites provided good biocompatibility, osteoconductivity, and lower mechanical failure rate when compared to non-augmented fractures. Mechanical devices currently have a limited role. However, the available evidence is provided mainly by level III to IV studies, and none of the proposed techniques have been sufficiently studied. Full article

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13 pages, 4005 KiB

Open AccessArticle

Open-Cell Tizr-Based Bulk Metallic Glass Scaffolds with Excellent Biocompatibility and Suitable Mechanical Properties for Biomedical Application

by Van Tai Nguyen, Xavier Pei-Chun Wong, Sin-Mao Song, Pei-Hua Tsai, Jason Shian-Ching Jang, I-Yu Tsao, Che-Hsin Lin and Van Cuong Nguyen

J. Funct. Biomater. 2020, 11(2), 28; https://doi.org/10.3390/jfb11020028 - 1 May 2020

Cited by 4 | Viewed by 3944

Abstract

A series of biocompatible high-porosity (up to 72.4%) TiZr-based porous bulk metallic glass (BMG) scaffolds were successfully fabricated by hot pressing a mixture of toxic element-free TiZr-based BMG powder and an Al particle space holder. The morphology of the fabricated scaffolds was similar [...] Read more.

A series of biocompatible high-porosity (up to 72.4%) TiZr-based porous bulk metallic glass (BMG) scaffolds were successfully fabricated by hot pressing a mixture of toxic element-free TiZr-based BMG powder and an Al particle space holder. The morphology of the fabricated scaffolds was similar to that of human bones, with pore sizes ranging from 75 to 250 μm. X-ray diffraction patterns and transmission electron microscopy images indicated that the amorphous structure of the TiZr-based BMG scaffolds remained in the amorphous state after hot pressing. Noncytotoxicity and extracellular calcium deposition of the TiZr-based BMG scaffolds at porosities of 32.8%, 48.8%, and 64.0% were examined by using the direct contact method. The results showed that the BMG scaffolds possess high cell viability and extracellular calcium deposition with average cell survival and deposition rates of approximately 170.1% and 130.9%, respectively. In addition, the resulting TiZr-based BMG scaffolds exhibited a considerable reduction in Young’s moduli from 56.4 to 2.3 GPa, compressive strength from 979 to 19 MPa, and bending strength from 157 MPa to 49 MPa when the porosity was gradually increased from 2.0% to 72.4%. Based on the aforementioned specific characteristics, TiZr-based BMG scaffolds can be considered as potential candidates for biomedical applications in the human body. Full article

(This article belongs to the Special Issue Application of Biomechanical Model on Tissue Engineering)

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11 pages, 2273 KiB

Open AccessArticle

Effect of Modification with Helium Atmospheric-Pressure Plasma and Deep-Ultraviolet Light on Adhesive Shear Strength of Fiber-Reinforced Poly(ether-ether-ketone) Polymer

by Seigo Okawa, Norimasa Taka and Yujin Aoyagi

J. Funct. Biomater. 2020, 11(2), 27; https://doi.org/10.3390/jfb11020027 - 1 May 2020

Cited by 9 | Viewed by 4015

Abstract

We investigated the effect of helium atmospheric-pressure plasma (PL) and deep-ultraviolet (UV) light treatments on the adhesive properties of fiber-reinforced poly(ether-ether-ketone) polymer (PEEK). PEEK disks reinforced with carbon (CPEEK) or glass (GPEEK) fibers were polished, modified with PL and UV for 60 s, [...] Read more.

We investigated the effect of helium atmospheric-pressure plasma (PL) and deep-ultraviolet (UV) light treatments on the adhesive properties of fiber-reinforced poly(ether-ether-ketone) polymer (PEEK). PEEK disks reinforced with carbon (CPEEK) or glass (GPEEK) fibers were polished, modified with PL and UV for 60 s, and the surface energy was calculated by measuring the contact angles. The disk surfaces were analyzed by X-ray photoemission spectroscopy. Shear bond strength testing was performed using a universal testing machine, and the fracture surfaces were observed by electron probe microanalyzer. Data were analyzed with one and two-way ANOVA and Tukey’s post-hoc test (p < 0.05). The surface energies were increased by the modifications, which created OH functional groups on the surfaces. The bond strengths of CPEEK were increased by PL, and those of GPEEK were increased by PL and UV, owing to chemical bonding at the interface. Full article

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11 pages, 2596 KiB

Open AccessCommunication

Clinoenstatite/Tantalum Coating for Enhancement of Biocompatibility and Corrosion Protection of Mg Alloy

by Hamid Reza Bakhsheshi-Rad, Aliakbar Najafinezhad, Esah Hamzah, Ahmad Fauzi Ismail, Filippo Berto and Xiongbiao Chen

J. Funct. Biomater. 2020, 11(2), 26; https://doi.org/10.3390/jfb11020026 - 13 Apr 2020

Cited by 14 | Viewed by 4627

Abstract

Biodegradable Mg alloys have appeared as the most appealing metals for biomedical applications, particularly as temporary bone implants. However, issues regarding high corrosion rate and biocompatibility restrict their application. Hence, in the present work, nanostructured clinoenstatite (CLT, MgSiO₃)/tantalum nitride (TaN) was [...] Read more.

Biodegradable Mg alloys have appeared as the most appealing metals for biomedical applications, particularly as temporary bone implants. However, issues regarding high corrosion rate and biocompatibility restrict their application. Hence, in the present work, nanostructured clinoenstatite (CLT, MgSiO₃)/tantalum nitride (TaN) was deposited on the Mg-Ca-Zn alloy via electrophoretic deposition (EPD) along with physical vapor deposition (PVD) to improve the corrosion and biological characteristics of the Mg-Ca-Zn alloy. The TaN intermediate layer with bubble like morphology possessed a compact and homogenous structure with a thickness of about 950 nm while the thick CLT over-layer (~15 μm) displayed a less compact structure containing nano-porosities as well as nanoparticles with spherical morphology. The electrochemical tests demonstrated that the as prepared CLT/TaN film is able to substantially increase the anticorrosion property of Mg-Ca-Zn bare alloy. Cytocompatibility outcomes indicated that formation of CLT and TaN on the Mg bare alloy surface enhanced cell viability, proliferation and growth, implying excellent biocompatibility. Taken together, the CLT/TaN coating exhibits appropriate characteristic including anticorrosion property and biocompatibility in order to employ in biomedical files. Full article

(This article belongs to the Special Issue Advanced Bioceramics)

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(a) Schematic demonstration of TaN-CLT-coated Mg alloy using PVD followed by EDP methods, (b) TaN coating, (c) cross sectional FESEM image of TaN coating, (d) EDS map of Ta and XRD patterns of (e) TaN coating and (f) CLT powder and CLT coating. Full article ">Figure 1 Cont.
(a) Schematic demonstration of TaN-CLT-coated Mg alloy using PVD followed by EDP methods, (b) TaN coating, (c) cross sectional FESEM image of TaN coating, (d) EDS map of Ta and XRD patterns of (e) TaN coating and (f) CLT powder and CLT coating. Full article ">Figure 2
(a) SEM images, (b) TEM images of the CLT nanopowders, (c) CLT coated and (d) cross sectional FESEM image of CLT coated, and (e) EDS analysis of point A. Full article ">Figure 3
(a) Images of water contact angle of Mg bare alloy, TaN coated and CLT coated and (b) bond strengths of TaN coated and CLT coated Mg alloy. Full article ">Figure 4
SEM micrograph of (a) Mg bare alloy, (b) TaN coated, (c) CLT coated after immersion into Kokubo for 14 days and (d) EDS analysis of A, (e) Potentiodynamic polarization curves, (f) corrosion rate, (g) pH value for Mg bare alloy, TaN coated and CLT coated Mg alloy and (h) XRD patterns and (i) Schematic demonstration of the corrosion mechanism of CLT coated Mg alloy after immersion in SBF solution for 14 days. Full article ">Figure 5
DAPI staining of MG63 osteoblasts cells on (a) Mg bare alloy, (b) TaN coated, (c) CLT coated, and (d) Cell viability of MG63 osteoblast cells after incubation in uncoated and coated Mg alloy specimens for 3 and 7 days. Full article ">

18 pages, 1177 KiB

Open AccessReview

The Role of Poly(Methyl Methacrylate) in Management of Bone Loss and Infection in Revision Total Knee Arthroplasty: A Review

by Leyla Hasandoost, Omar Rodriguez, Adel Alhalawani, Paul Zalzal, Emil H. Schemitsch, Stephen D. Waldman, Marcello Papini and Mark R. Towler

J. Funct. Biomater. 2020, 11(2), 25; https://doi.org/10.3390/jfb11020025 - 10 Apr 2020

Cited by 21 | Viewed by 7314

Abstract

Poly(methyl methacrylate) (PMMA) is widely used in joint arthroplasty to secure an implant to the host bone. Complications including fracture, bone loss and infection might cause failure of total knee arthroplasty (TKA), resulting in the need for revision total knee arthroplasty (rTKA). The [...] Read more.

Poly(methyl methacrylate) (PMMA) is widely used in joint arthroplasty to secure an implant to the host bone. Complications including fracture, bone loss and infection might cause failure of total knee arthroplasty (TKA), resulting in the need for revision total knee arthroplasty (rTKA). The goals of this paper are: (1) to identify the most common complications, outside of sepsis, arising from the application of PMMA following rTKA, (2) to discuss the current applications and drawbacks of employing PMMA in managing bone loss, (3) to review the role of PMMA in addressing bone infection following complications in rTKA. Papers published between 1970 to 2018 have been considered through searching in Springer, Google Scholar, IEEE Xplore, Engineering village, PubMed and weblinks. This review considers the use of PMMA as both a bone void filler and as a spacer material in two-stage revision. To manage bone loss, PMMA is widely used to fill peripheral bone defects whose depth is less than 5 mm and covers less than 50% of the bone surface. Treatment of bone infections with PMMA is mainly for two-stage rTKA where antibiotic-loaded PMMA is inserted as a spacer. This review also shows that using antibiotic-loaded PMMA might cause complications such as toxicity to surrounding tissue, incomplete antibiotic agent release from the PMMA, roughness and bacterial colonization on the surface of PMMA. Although PMMA is the only commercial bone cement used in rTKA, there are concerns associated with using PMMA following rTKA. More research and clinical studies are needed to address these complications. Full article

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14 pages, 6084 KiB

Open AccessArticle

Antimicrobial Materials with Lime Oil and a Poly(3-hydroxyalkanoate) Produced via Valorisation of Sugar Cane Molasses

by Pooja Basnett, Elena Marcello, Barbara Lukasiewicz, Rinat Nigmatullin, Alexandra Paxinou, Muhammad Haseeb Ahmad, Bhavana Gurumayum and Ipsita Roy

J. Funct. Biomater. 2020, 11(2), 24; https://doi.org/10.3390/jfb11020024 - 10 Apr 2020

Cited by 27 | Viewed by 6056

Abstract

A medium chain-length polyhydroxyalkanoate (PHA) was produced by Pseudomonas mendocina CH50 using a cheap carbon substrate, sugarcane molasses. A PHA yield of 14.2% dry cell weight was achieved. Chemical analysis confirmed that the polymer produced was a medium chain-length PHA, a copolymer of [...] Read more.

A medium chain-length polyhydroxyalkanoate (PHA) was produced by Pseudomonas mendocina CH50 using a cheap carbon substrate, sugarcane molasses. A PHA yield of 14.2% dry cell weight was achieved. Chemical analysis confirmed that the polymer produced was a medium chain-length PHA, a copolymer of 3-hydroxyoctanoate and 3-hydroxydecanoate, P(3HO-co-3HD). Lime oil, an essential oil with known antimicrobial activity, was used as an additive to P(3HO-co-3HD) to confer antibacterial properties to this biodegradable polymer. The incorporation of lime oil induced a slight decrease in crystallinity of P(3HO-co-3HD) films. The antibacterial properties of lime oil were investigated using ISO 20776 against Staphylococcus aureus 6538P and Escherichia coli 8739, showing a higher activity against the Gram-positive bacteria. The higher activity of the oil against S. aureus 6538P defined the higher efficiency of loaded polymer films against this strain. The effect of storage on the antimicrobial properties of the loaded films was investigated. After one-year storage, the content of lime oil in the films decreased, causing a reduction of the antimicrobial activity of the materials produced. However, the films still possessed antibacterial activity against S. aureus 6538P. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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Temporal profile of P(3HO-co-3HD) production by P. mendocina CH50 using sugarcane molasses as the sole carbon source. The profiling illustrates the polyhydroxyalkanoate (PHA) yield (<img alt="Jfb 11 00024 i001" src="/jfb/jfb-11-00024/article_deploy/html/images/jfb-11-00024-i001.png"/>), optical density (<img alt="Jfb 11 00024 i002" src="/jfb/jfb-11-00024/article_deploy/html/images/jfb-11-00024-i002.png"/>), pH (<img alt="Jfb 11 00024 i003" src="/jfb/jfb-11-00024/article_deploy/html/images/jfb-11-00024-i003.png"/>), DOT% (<img alt="Jfb 11 00024 i004" src="/jfb/jfb-11-00024/article_deploy/html/images/jfb-11-00024-i004.png"/>), biomass (<img alt="Jfb 11 00024 i005" src="/jfb/jfb-11-00024/article_deploy/html/images/jfb-11-00024-i005.png"/>) and the nitrogen concentration in the form of the ammonium ions throughout 48 h of fermentation. Full article ">Figure 2
Gas chromatography–mass spectrometry (GC–MS) data of the PHA copolymer produced with sugarcane molasses as the carbon source: (A) Gas chromatogram, (B) Mass spectrum of a peak with Rt = 7.7 min identified using the National Institute of Standards and Technology (NIST) library as methyl ester of 3-hydroxyoctanoic acid, and (C) mass spectrum of a peak with Rt = 9.2 min identified using NIST library as methyl ester of 3-hydroxydecanoic acid. Methyl benzoate was used as an internal standard (STD). Full article ">Figure 3
13C nuclear magnetic resonance (NMR) (A), and 1H NMR (B) spectra of PHA copolymer produced with sugarcane molasses as carbon source. The structure of P(3HO-co-3HD) is shown as an insert within the spectra. Full article ">Figure 4
Thermal analysis of P(3HO-co-3HD) neat film and films with incorporated lime oil. (A) Differential scanning calorimetry (DSC) thermograms: neat film (black lines), fresh film with lime oil (red lines), and aged films with lime oil (blue lines). First heating—solid line, second heating—dashed line. Thermograms were shifted vertically for better visibility. (B) Thermogravimetric analysis (TGA) curves for determination of oil content after isothermal evaporation at 150 °C for 2 h. Full article ">Figure 5
Halo test showing the antibacterial activity of aged lime oil containing P(3HO-co-3HD) films (a–c) and fresh lime oil containing films (d–f) against S. aureus 6538P (control: antibiotic disc containing 1 µg of oxacillin, left hand side). Full article ">

20 pages, 14494 KiB

Open AccessEditor’s ChoiceArticle

Skin-Compatible Biobased Beauty Masks Prepared by Extrusion

by Maria-Beatrice Coltelli, Luca Panariello, Pierfrancesco Morganti, Serena Danti, Adone Baroni, Andrea Lazzeri, Alessandra Fusco and Giovanna Donnarumma

J. Funct. Biomater. 2020, 11(2), 23; https://doi.org/10.3390/jfb11020023 - 6 Apr 2020

Cited by 28 | Viewed by 6877

Abstract

In the cosmetic sector, natural and sustainable products with a high compatibility with skin, thus conjugating wellness with a green-oriented consumerism, are required by the market. Poly(hydroxyalkanoate) (PHA)/starch blends represent a promising alternative to prepare flexible films as support for innovative beauty masks, [...] Read more.

In the cosmetic sector, natural and sustainable products with a high compatibility with skin, thus conjugating wellness with a green-oriented consumerism, are required by the market. Poly(hydroxyalkanoate) (PHA)/starch blends represent a promising alternative to prepare flexible films as support for innovative beauty masks, wearable after wetting and releasing starch and other selected molecules. Nevertheless, preparing these films by extrusion is difficult due to the high viscosity of the polymer melt at the temperature suitable for processing starch. The preparation of blends including poly(butylene succinate-co-adipate) (PBSA) or poly(butylene adipate-co-terephthalate) (PBAT) was investigated as a strategy to better modulate melt viscosity in view of a possible industrial production of beauty mask films. The release properties of films in water, connected to their morphology, was also investigated by extraction trials, infrared spectroscopy and stereo and electron microscopy. Then, the biocompatibility with cells was assessed by considering both mesenchymal stromal cells and keratinocytes. All the results were discussed considering the morphology of the films. This study evidenced the possibility of modulating thanks to the selection of composition and the materials processing of the properties necessary for producing films with tailored properties and processability for beauty masks. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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17 pages, 2844 KiB

Open AccessArticle

Cytotoxic Effects of Plant Sap-Derived Extracellular Vesicles on Various Tumor Cell Types

by Kimin Kim, Hye Ju Yoo, Jik-Han Jung, Ruri Lee, Jae-Kyung Hyun, Ji-Ho Park, Dokyun Na and Ju Hun Yeon

J. Funct. Biomater. 2020, 11(2), 22; https://doi.org/10.3390/jfb11020022 - 2 Apr 2020

Cited by 62 | Viewed by 7454

Abstract

Edible plants have been widely used in traditional therapeutics because of the biological activities of their natural ingredients, including anticancer, antioxidant, and anti-inflammatory properties. Plant sap contains such medicinal substances and their secondary metabolites provide unique chemical structures that contribute to their therapeutic [...] Read more.

Edible plants have been widely used in traditional therapeutics because of the biological activities of their natural ingredients, including anticancer, antioxidant, and anti-inflammatory properties. Plant sap contains such medicinal substances and their secondary metabolites provide unique chemical structures that contribute to their therapeutic efficacy. Plant extracts are known to contain a variety of extracellular vesicles (EVs) but the effects of such EVs on various cancers have not been investigated. Here, we extracted EVs from four plants—Dendropanax morbifera, Pinus densiflora, Thuja occidentalis, and Chamaecyparis obtusa—that are known to have cytotoxic effects. We evaluated the cytotoxic effects of these EVs by assessing their ability to selectively reduce the viability of various tumor cell types compared with normal cells and low metastatic cells. EVs from D. morbifera and P. densiflora sap showed strong cytotoxic effects on tumor cells, whereas those from T. occidentalis and C. obtusa had no significant effect on any tumor cell types. We also identified synergistic effect of EVs from D. morbifera and P. densiflora saps on breast and skin tumor cells and established optimized treatment concentrations. Our findings suggest these EVs from plant sap as new candidates for cancer treatment. Full article

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Characterization of plant sap-derived extracellular vesicles (EVs). (a) dynamic light scattering (DLS) measurements of particle size frequency distribution for DM-EVs, PD-EVs, TO-EVs, and CO-EVs. Insets: Intensity size distribution curves. (b) Nanoparticle tracking analysis (NTA) measurements of concentration and size distribution for DM-EVs, PD-EVs, TO-EVs, and CO-EVs. (c) TEM images of DM-EVs, PD-EVs, TO-EVs, and CO-EVs. DM, Dendropanax morbifera; PD, Pinus densiflora; TO, Thuja occidentalis; CO, Chamaecyparis obtusa. Scale bar: 200 nm. (d) Plant sap-derived EVs measured by Z-average and polydispersity index (PDI). Full article ">Figure 2
Internalization of DM-EVs in human breast cells. (a) Representative fluorescence microscopic images of cellular uptake of fluorescently labeled 10 µg/mL of DM-EVs for 3 h via different internalization pathways, determined using the inhibitors of 10 µg/mL amiloride (micropinocytosis), 10 µg/mL chlorpromazine (clathrin), 10 µg/mL cytochalasin D (phagocytosis), and 5 µg/mL filipin (caveolae). (b) Summary data showing a comparison of intracellular fluorescence intensity per cell for cells treated with different endocytic inhibitors. Data are presented as means ± standard error of the mean (SEM) (* p < 0.05, ** p < 0.01, **** p < 0.0001). Full article ">Figure 3
Cytotoxic effects of DM-EVs, PD-EVs, TO-EVs, and CO-EVs on five different cell types. (a) Viability of MCF10A, MDA-MB-231, and MCF7 human breast cells following treatment with DM-EVs or PD-EVs. (b) Viability of HNF and A431 human skin cells following treatment with DM-EVs or PD-EVs. (c) Viability of MCF10A, MDA-MB-231, and MCF7 human breast cells following treatment with TO-EVs or CO-EVs. (d) Viability of HNF and A431 human skin cells following treatment with TO-EVs or CO-EVs. Data are presented as means ± SEM (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001 vs. no treat). Full article ">Figure 4
Concentration–response curves for cisplatin, DM-EVs, PD-EVs, and the combination of DM-EVs and PD-EVs against breast and skin tumor cells. (a–d) Cytotoxicity of cisplatin (a), DM-EVs (b), PD-EVs (c), and DM-EVs + PD-EVs (d) against human breast cells. (e–h) Cytotoxicity of cisplatin (e), DM-EVs (f), PD-EVs (g), and DM-EVs + PD-EVs (h) against human skin cells. (i) half-maximal inhibitory concentration (IC50) values of cisplatin, DM-EVs, PD-EVs, and the combination of DM-EVs and PD-EVs for breast and skin cells. Cisplatin was used as a positive control. Full article ">Figure 5
Selective index for combined treatment with DM-EVs and PD-EVs against breast and skin tumor cells. (a) Selective index for cisplatin, DM-EVs, PD-EVs, and the combination of DM-EVs and PD-EVs. (b) Isobologram curve at the 50% cell viability level for each cell type. (c–e) Selective toxicity toward malignant cells relative to normal cells, measured as fold-difference in cell survival using 3-dimensional response plots. (c) MDA-MB-231 versus MCF10A; (d) MCF7 versus MCF10A; (e) A431 versus HNF. Full article ">

23 pages, 2742 KiB

Open AccessEditor’s ChoiceArticle

Properties and Skin Compatibility of Films Based on Poly(Lactic Acid) (PLA) Bionanocomposites Incorporating Chitin Nanofibrils (CN)

by Maria-Beatrice Coltelli, Laura Aliotta, Alessandro Vannozzi, Pierfrancesco Morganti, Luca Panariello, Serena Danti, Simona Neri, Cristina Fernandez-Avila, Alessandra Fusco, Giovanna Donnarumma and Andrea Lazzeri

J. Funct. Biomater. 2020, 11(2), 21; https://doi.org/10.3390/jfb11020021 - 1 Apr 2020

Cited by 39 | Viewed by 6826

Abstract

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing [...] Read more.

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing poly(ethylene glycol). Thanks to the use of a melt strength enhancer (Plastistrength) and calcium carbonate, the processability and thermal properties of bionanocomposites films containing CNs could be tuned in a wide range. Moreover, the resultant films were flexible and highly resistant. The addition of CNs in the presence of starch proved not advantageous because of an extensive chain scission resulting in low values of melt viscosity. The films containing CNs or CNs and calcium carbonate resulted biocompatible and enabled the production of cells defensins, acting as indirect anti-microbial. Nevertheless, tests made with Staphylococcus aureus and Enterobacter spp. (Gram positive and negative respectively) by the qualitative agar diffusion test did not show any direct anti-microbial activity of the films. The results are explained considering the morphology of the film and the different mechanisms of direct and indirect anti-microbial action generated by the nanobiocomposite based films. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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J. Funct. Biomater., Volume 11, Issue 2 (June 2020) – 25 articles

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