In this study, the effect of simultaneous substitution of titanium (Ti) and lithium (Li) to sol-g... more In this study, the effect of simultaneous substitution of titanium (Ti) and lithium (Li) to sol-gel derived 58S silicate BGs ( 60 Si O 2 − ( 31 − X ) CaO − 4 P 2 O 5 − 5 Ti O 2 − XLi 2 O , X=0, 3, 5, 8, 10 mol%) was investigated. X-ray Diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) tests were used to examining synthesized BGs. Alkaline phosphate (ALP) activity, 3-(4, 5dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, and antibacterial studies were performed to study in vitro biological properties. Results revealed that the TL-BG contain fixed 5 mol% Ti O 2 and 5 mol% Li 2 O (TL-5) showed better in vitro bioactivity against other samples while increasing the Li2O up to 10 mol% led to a sharp decrease in hydroxyapatite growth rate and grains size. Altogether, the TL-5 was suggested as an optimal candidate for the further in vivo evaluations due to its better in vitro bioactivity, higher biocompatibil...
Regeneration and engineering of functional new tissues containing the neural network have great i... more Regeneration and engineering of functional new tissues containing the neural network have great importance. Progression of neural network into the dental tissue has a crucial role in dental tissue regeneration. In the present study polymer-ceramic blended scaffolds containing different weight percentages of carbon nanotube in poly caprolactone nanofiber matrix were fabricated. Morphological, mechanical and electrical properties of the prepared scaffolds have been characterized. Results showed that the sample containing 5 weight % of carbon nanotube had the smallest mean fiber diameter (50 - 300 nm) and the highest mechanical behavior. Also, its electrical conductivity was suitable to be used in nerve tissue scaffolds. The static culture of the Schwann cells on the prepared scaffolds indicated that increasing weight percentage of carbon nanotube into the polycaprolactone matrix up to the 5 wt. % enhanced cell viability.
In this study, a type of SiO2-CaO-P2O5-MgO-ZnO bioactive glass was synthesized via the sol-gel me... more In this study, a type of SiO2-CaO-P2O5-MgO-ZnO bioactive glass was synthesized via the sol-gel method and then bioactive glass-gelatin composite scaffolds for bone tissue engineering were fabricated. The obtained composite scaffolds were characterized and their microstructural, thermal, mechanical and biological properties were studied by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The XRD patterns of the prepared glass and the composites before incubation in SBF showed the amorphous structure of the samples and no sharp peak was observed but after incubation in SBF solution, the peaks related to the presence of crystalline hydroxyapatite were evident and with increasing incubation time in SBF, the formation and crystallinity of the apatite increased. The FTIR spectra of the synthesized glass and the composite scaffold showed the band attributed to the glass and the gelatin in the samples. After immersion in SBF, the bands related to calcium phosphate formation were observable in agreement with the results of the XRD. The Average Young’s modulus and yield strength of the samples were 30 ± 2 and 5 ± 0.4 Mpa. Cellular biocompatibility tests illustrated optimal cell proliferation on the fabricated scaffolds. This material is seen to be non-toxic and compatible to be used as a potential bone tissue scaffold.
In this study, the effect of addition of magnesium as a stabilizer of amorphous phase on the stru... more In this study, the effect of addition of magnesium as a stabilizer of amorphous phase on the structure and bioactivity of amorphous calcium phosphate for biomedical applications was investigated. Therefore, amorphous calcium phosphate was synthesized by a precipitation and freeze drying method with different molar ratios of magnesium to calcium (Mg/Ca). Then the samples were incubated in simulated body fluid (SBF) for 3, 7 and 14 days to evaluate their bioactivity and the investigation of their phase conversion. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy were employed to characterize the prepared samples. According to X-ray diffraction patterns, the most stable amorphous phase was obtained at a magnesium to calcium (Mg/Ca) ratio of 0.3 and the magnesium acted as a stabilizer of the amorphous phase. After incubation in SBF solution, the hydroxyapatite phase was detected in XRD patterns of the samples, but with the addition of the magnesium, the crystallinity and formation of the hydroxyapatite phase was decreased. Also the FTIR analysis showed that the intensity of the peaks related to phosphate and hydroxyl groups decreased with the addition of magnesium, which indicated a more stable amorphous calcium phosphate phase. Finally, in-vitro experiments like MTT assay and alkaline phosphatase activity with human osteosarcoma cell lines (G-292) on the prepared samples were evaluated and discussed. The results indicated that amorphous calcium phosphate with a calcium to magnesium ratio of 0.3 revealed optimal cell proliferation and ALP activity. Eventually, this material is non-toxic and compatible to be used as a bone substitute material.
Dentin tissue engineering is one of innovative and effective regenerative method for treatment of... more Dentin tissue engineering is one of innovative and effective regenerative method for treatment of dental pulp and dental tissue, and our research concentrated on preparing an effective scaffold substrate containing carbon Nano tube in polycaprolactone Nano fiber matrix. Our characterization showed benefits of this complex structure and its effect on odontoblast cell interaction. The results indicated that the prepared nanofiber polymer contains 4% CNT have a great potential as biocompatible materials for use in dental tissue engineering and odontoblast cell interaction.
In this study four types of calcium phosphate cement/bioactive glass composites has been synthesi... more In this study four types of calcium phosphate cement/bioactive glass composites has been synthesized via mixing and sol-gel method and the effect of hydroxyapatite/tricalcium phosphate ratio to its mechanical properties and setting time was investigated. The prepared samples were characterized using X-ray diffraction (XRD), foureir transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical testing and setting time measurement. XRD analysis showed amorphous structure of the prepared bioactive glass. But the patterns of the prepared composite had sharp peaks because of their crystalline structure. FTIR analysis indicated that the composites had carbonated calcium phosphate structure. SEM micrographs illustrated amorphous calcium phosphate particles with irregular shapes. With increasing the HA/TCP ratio,…
Incorporation of hydroxyapatite (HA) with organic polymer would be used in bone and dental tissue... more Incorporation of hydroxyapatite (HA) with organic polymer would be used in bone and dental tissue engineering. According to prior researches, because of its chemical similarity to natural bone and dental, this scaffold could improve bioactivity and bone bonding ability. In this research, nano-hydroxyapatite/ chitosan scaffolds were synthesized by two different methods to investigate the effect of different method on scaffold properties. Morphological properties of scaffold such as pore size and fibers diameter were investigated using SEM evaluation, and also bioactivity of scaffolds were measured in simulated body fluid (SBF). The results indicate that Chitosan/nano-Hydroxyapatite scaffold might be a suitable scaffold for tooth engineering while electrospinning techniques present more flexibility and controllable pore size than freeze-drying while with freeze-drying technique percentage of usage hydroxyapatite could be risen up to 40% and shown better macro-mechanical and physical p...
In this study, biomimetic scaffolds were designed to investigate calcium phosphate formation via ... more In this study, biomimetic scaffolds were designed to investigate calcium phosphate formation via a double diffusion mechanism within a gelatin/chitosan hydrogel in biological pH and temperature. Three types of samples with initial percentages of chitosan (20, 30 and 40 wt. %) were prepared. Diffusion of calcium and phosphate ions through the hydrogel formed a precipitation layer. Samples were freeze dried to form porous scaffolds and soaked in glutaraldehyde to increase their mechanical properties. X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy and scanning electron microscopy (SEM) were employed to investigate the microstructure and to characterize the prepared scaffolds. Analysis of precipitation indicated the presence of brushite and hydroxyapatite. The amorphous calcium phosphate phase converted into crystalline hydroxyapatite after immersion in simulated body fluid which mimics the formation of hydroxyapatite in the human body. FTIR results suggested the presence of structural hydroxyl and phosphate bonds in the structure of the prepared scaffolds which could be due to the formation of hydroxyapatite. With increasing amount of chitosan in the composite scaffold, the water up-take ability was increased from 380 to 660 %, yield strength and Young’s modulus slightly decreased and the crystalinity of the precipitated phase increased. Mechanical properties obtained from the samples were in the range of cancellous bone. MTT assay results and alkaline phosphatase activity showed prepared scaffolds had proper biocompatibility.
The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test exper... more The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test experimental study was to (1) create a 3wt%-nanostrontium hydroxyapatite-enhanced calcium phosphate cement (Sr-HA/CPC) for increasing bone formation and (2) creating a simvastatin-loaded poly(lactic-co-glycolic acid) (SIM-loaded PLGA) microspheres plus CPC composite (SIM-loaded PLGA+nanostrontium-CPC). The third goal was the extensive assessment of multiple in vitro and in vivo characteristics of the above experimental explorative products in vitro and in vivo (animal and surgical studies). Physical and chemical properties of the prepared Sr-HA/CPC were evaluated. MTT assay and alkaline phosphatase activities, and radiological and histological examinations of Sr-HA/CPC, CPC and negative control were compared. X-ray diffraction (XRD) indicated that crystallinity of the prepared cement increased by increasing the powder-to-liquid ratio. Incorporation of Sr-HA into CPC increased MTT assay (biocompatibility) and ALP activity (P<0.05). Histomorphometry showed greater bone formation after 4weeks, after implantation of Sr-HA/CPC in 10 rats compared to implantations of CPC or empty defects in the same rats (n=30, ANOVA P<0.05). METHODS AND RESULTS PERTAINING TO SIM-LOADED PLGA MICROSPHERES+NANOSTRONTIUM-CPC COMPOSITE: After SEM assessment, the produced composite of microspheres and enhanced CPC were implanted for 8weeks in 10 rabbits, along with positive and negative controls, enhanced CPC, and enhanced CPC plus SIM (n=50). In the control group, only a small amount of bone had been regenerated (localized at the boundary of the defect); whereas, other groups showed new bone formation within and around the materials. A significant difference was found in the osteogenesis induced by the groups sham control (16.96±1.01), bone materials (32.28±4.03), nanostrontium-CPC (24.84±2.6), nanostrontium-CPC-simvastatin (40.12±3.29), and SIM-loaded PLGA+nanostrontium-CPC (44.8±6.45) (ANOVA P<0.001). All the pairwise comparisons were significant (Tukey P<0.01), except that of nanostrontium-CPC-simvastatin and SIM-loaded PLGA+nanostrontium-CPC. This confirmed the efficacy of the SIM-loaded PLGA+nanostrontium-CPC composite, and its superiority over all materials except SIM-containing nanostrontium-CPC.
In this study we employed the sol-gel method to synthesize new CaO–P2O5–SiO2–ZnO–B2O3 bioactive g... more In this study we employed the sol-gel method to synthesize new CaO–P2O5–SiO2–ZnO–B2O3 bioactive glasses. Three samples with various B2O3 content (5, 10 and 15 mol %) was prepared and their bioactivity were evaluated by immersion in simulated body fluid (SBF) and the glasses were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The experimental results revealed that with increasing the amount of boron content, a more crystalline domain can be observed in their XRD patterns and consequently the formation of hydroxyapatite (HA) increased. FTIR spectra showed that the sample containing 10 mol% of boron had the sharpest peaks attributed to the formation of hydroxyapatite. Biocompatibility of the samples was examined by MTT assay and alkaline phosphatase activity. The result ascertained that the synthesized bioactive glass had good biocompatibility and can serve as a bone substitute in bone defects.
Journal of Materials Engineering and Performance, 2016
Bioactive glasses in the system SiO2-CaO-Na2O-P2O5-MgO with different amounts of zinc (Zn) and si... more Bioactive glasses in the system SiO2-CaO-Na2O-P2O5-MgO with different amounts of zinc (Zn) and silver (Ag) were synthesized by the sol-gel technique and characterized. The bioactivity was studied during in vitro assays: the ability of hydroxycarbonate apatite (HCA) layer to form on the glass surface was examined after contact with simulated body fluid (SBF). The x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and inductively coupled plasma atomic emission spectrometry (ICP) studies were performed after immersion in vitro assays. Also, the antibacterial and antifungal activities of glass samples against Pseudomonas aeruginosa (ATCC 27853), E. coli (ATCC 25922), and Candida albicans were measured by the halo zone test. Introduction of zinc and silver as the trace elements induces several modifications on the observed phenomena at the glass surface and in SBF solution after immersion of the samples. The chemical durability of the glasses, the formation of the silica-rich layer, and the crystallization of the HCA layer were affected. Samples with the higher content of zinc and silver exhibited an excellent antibacterial/antifungal activity.
In this article, high-quality ZnS:Mn nanoparticles were synthesized from quaternary W/O micro-emu... more In this article, high-quality ZnS:Mn nanoparticles were synthesized from quaternary W/O micro-emulsion system with different Mn% for detecting the best concentration. The addition of biotin and the subsequent specific binding events alter the dielectric environment of the nanoparticle, resulting in a spectral shift of the particle plasmon resonance. Cyclohexane was used as oil, Triten X-100 as surfactant, n-hexanol as a co-surfactant and mercaptoethanol and thioglycolic acid for the best linking of biological part to nanoparticle (as linking agents). Surfactant and co-surfactant produce a stable emulsion with connection to surface of nanoparticles and prevention from contacting together. For qualitative and quantitative analyses of this product Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), Inductive coupled plasma (ICP), zeta meter for measurement of ZP and spectroscopy techniques are used. The results showed ...
In this project, we prepared biomimetic nanocomposite scaffolds from gelatin and chitosan and hyd... more In this project, we prepared biomimetic nanocomposite scaffolds from gelatin and chitosan and hydroxyapatite and subsequently the scaffolds were evaluated by common used bulk technique. For this purpose, the nanocomposite hydrogel/apatite bone tissue engineering scaffolds were fabricated using applied biomimetic method accompanied with freeze drying technique. The apatite was precipitated using double diffusion mechanism within gelatin hydrogel in similar pH and temperature to the human body. Chitosan initial percentage (20, 30 and 40%) was set as variables. Nanocomposites were soaked in glutaraldehyde solution in order to enhance mechanical properties and make them insoluble in water. Diffusion of calcium and phosphate from lateral hydrogel into the middle hydrogel caused formation of parallel white layer-formed precipitate. Analysis of precipitates formed within middle hydrogel for the samples, showed that detected materials are composed of carbonated hydroxyapatite and dicalcium ...
In this study, magnetite (Fe3O4) nanoparticles were synthesized by chemical co-precipitation from... more In this study, magnetite (Fe3O4) nanoparticles were synthesized by chemical co-precipitation from the solution containing iron salts in alkaline medium under N2 gas and room temperature. Magnetite nanoparticles were characterized by Xـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ * : يكينورتكلا تسپ ،تابتاكم لوئسم : abbasashuri@aut.ac.ir D ow nl oa de d fr om ja m e. iu t.a c. ir at 1 5: 15 IR D T o n S un da y S ep te m be r 20 th 2 02 0
In this study, the effect of simultaneous substitution of titanium (Ti) and lithium (Li) to sol-g... more In this study, the effect of simultaneous substitution of titanium (Ti) and lithium (Li) to sol-gel derived 58S silicate BGs ( 60 Si O 2 − ( 31 − X ) CaO − 4 P 2 O 5 − 5 Ti O 2 − XLi 2 O , X=0, 3, 5, 8, 10 mol%) was investigated. X-ray Diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) tests were used to examining synthesized BGs. Alkaline phosphate (ALP) activity, 3-(4, 5dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, and antibacterial studies were performed to study in vitro biological properties. Results revealed that the TL-BG contain fixed 5 mol% Ti O 2 and 5 mol% Li 2 O (TL-5) showed better in vitro bioactivity against other samples while increasing the Li2O up to 10 mol% led to a sharp decrease in hydroxyapatite growth rate and grains size. Altogether, the TL-5 was suggested as an optimal candidate for the further in vivo evaluations due to its better in vitro bioactivity, higher biocompatibil...
Regeneration and engineering of functional new tissues containing the neural network have great i... more Regeneration and engineering of functional new tissues containing the neural network have great importance. Progression of neural network into the dental tissue has a crucial role in dental tissue regeneration. In the present study polymer-ceramic blended scaffolds containing different weight percentages of carbon nanotube in poly caprolactone nanofiber matrix were fabricated. Morphological, mechanical and electrical properties of the prepared scaffolds have been characterized. Results showed that the sample containing 5 weight % of carbon nanotube had the smallest mean fiber diameter (50 - 300 nm) and the highest mechanical behavior. Also, its electrical conductivity was suitable to be used in nerve tissue scaffolds. The static culture of the Schwann cells on the prepared scaffolds indicated that increasing weight percentage of carbon nanotube into the polycaprolactone matrix up to the 5 wt. % enhanced cell viability.
In this study, a type of SiO2-CaO-P2O5-MgO-ZnO bioactive glass was synthesized via the sol-gel me... more In this study, a type of SiO2-CaO-P2O5-MgO-ZnO bioactive glass was synthesized via the sol-gel method and then bioactive glass-gelatin composite scaffolds for bone tissue engineering were fabricated. The obtained composite scaffolds were characterized and their microstructural, thermal, mechanical and biological properties were studied by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The XRD patterns of the prepared glass and the composites before incubation in SBF showed the amorphous structure of the samples and no sharp peak was observed but after incubation in SBF solution, the peaks related to the presence of crystalline hydroxyapatite were evident and with increasing incubation time in SBF, the formation and crystallinity of the apatite increased. The FTIR spectra of the synthesized glass and the composite scaffold showed the band attributed to the glass and the gelatin in the samples. After immersion in SBF, the bands related to calcium phosphate formation were observable in agreement with the results of the XRD. The Average Young’s modulus and yield strength of the samples were 30 ± 2 and 5 ± 0.4 Mpa. Cellular biocompatibility tests illustrated optimal cell proliferation on the fabricated scaffolds. This material is seen to be non-toxic and compatible to be used as a potential bone tissue scaffold.
In this study, the effect of addition of magnesium as a stabilizer of amorphous phase on the stru... more In this study, the effect of addition of magnesium as a stabilizer of amorphous phase on the structure and bioactivity of amorphous calcium phosphate for biomedical applications was investigated. Therefore, amorphous calcium phosphate was synthesized by a precipitation and freeze drying method with different molar ratios of magnesium to calcium (Mg/Ca). Then the samples were incubated in simulated body fluid (SBF) for 3, 7 and 14 days to evaluate their bioactivity and the investigation of their phase conversion. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy were employed to characterize the prepared samples. According to X-ray diffraction patterns, the most stable amorphous phase was obtained at a magnesium to calcium (Mg/Ca) ratio of 0.3 and the magnesium acted as a stabilizer of the amorphous phase. After incubation in SBF solution, the hydroxyapatite phase was detected in XRD patterns of the samples, but with the addition of the magnesium, the crystallinity and formation of the hydroxyapatite phase was decreased. Also the FTIR analysis showed that the intensity of the peaks related to phosphate and hydroxyl groups decreased with the addition of magnesium, which indicated a more stable amorphous calcium phosphate phase. Finally, in-vitro experiments like MTT assay and alkaline phosphatase activity with human osteosarcoma cell lines (G-292) on the prepared samples were evaluated and discussed. The results indicated that amorphous calcium phosphate with a calcium to magnesium ratio of 0.3 revealed optimal cell proliferation and ALP activity. Eventually, this material is non-toxic and compatible to be used as a bone substitute material.
Dentin tissue engineering is one of innovative and effective regenerative method for treatment of... more Dentin tissue engineering is one of innovative and effective regenerative method for treatment of dental pulp and dental tissue, and our research concentrated on preparing an effective scaffold substrate containing carbon Nano tube in polycaprolactone Nano fiber matrix. Our characterization showed benefits of this complex structure and its effect on odontoblast cell interaction. The results indicated that the prepared nanofiber polymer contains 4% CNT have a great potential as biocompatible materials for use in dental tissue engineering and odontoblast cell interaction.
In this study four types of calcium phosphate cement/bioactive glass composites has been synthesi... more In this study four types of calcium phosphate cement/bioactive glass composites has been synthesized via mixing and sol-gel method and the effect of hydroxyapatite/tricalcium phosphate ratio to its mechanical properties and setting time was investigated. The prepared samples were characterized using X-ray diffraction (XRD), foureir transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical testing and setting time measurement. XRD analysis showed amorphous structure of the prepared bioactive glass. But the patterns of the prepared composite had sharp peaks because of their crystalline structure. FTIR analysis indicated that the composites had carbonated calcium phosphate structure. SEM micrographs illustrated amorphous calcium phosphate particles with irregular shapes. With increasing the HA/TCP ratio,…
Incorporation of hydroxyapatite (HA) with organic polymer would be used in bone and dental tissue... more Incorporation of hydroxyapatite (HA) with organic polymer would be used in bone and dental tissue engineering. According to prior researches, because of its chemical similarity to natural bone and dental, this scaffold could improve bioactivity and bone bonding ability. In this research, nano-hydroxyapatite/ chitosan scaffolds were synthesized by two different methods to investigate the effect of different method on scaffold properties. Morphological properties of scaffold such as pore size and fibers diameter were investigated using SEM evaluation, and also bioactivity of scaffolds were measured in simulated body fluid (SBF). The results indicate that Chitosan/nano-Hydroxyapatite scaffold might be a suitable scaffold for tooth engineering while electrospinning techniques present more flexibility and controllable pore size than freeze-drying while with freeze-drying technique percentage of usage hydroxyapatite could be risen up to 40% and shown better macro-mechanical and physical p...
In this study, biomimetic scaffolds were designed to investigate calcium phosphate formation via ... more In this study, biomimetic scaffolds were designed to investigate calcium phosphate formation via a double diffusion mechanism within a gelatin/chitosan hydrogel in biological pH and temperature. Three types of samples with initial percentages of chitosan (20, 30 and 40 wt. %) were prepared. Diffusion of calcium and phosphate ions through the hydrogel formed a precipitation layer. Samples were freeze dried to form porous scaffolds and soaked in glutaraldehyde to increase their mechanical properties. X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy and scanning electron microscopy (SEM) were employed to investigate the microstructure and to characterize the prepared scaffolds. Analysis of precipitation indicated the presence of brushite and hydroxyapatite. The amorphous calcium phosphate phase converted into crystalline hydroxyapatite after immersion in simulated body fluid which mimics the formation of hydroxyapatite in the human body. FTIR results suggested the presence of structural hydroxyl and phosphate bonds in the structure of the prepared scaffolds which could be due to the formation of hydroxyapatite. With increasing amount of chitosan in the composite scaffold, the water up-take ability was increased from 380 to 660 %, yield strength and Young’s modulus slightly decreased and the crystalinity of the precipitated phase increased. Mechanical properties obtained from the samples were in the range of cancellous bone. MTT assay results and alkaline phosphatase activity showed prepared scaffolds had proper biocompatibility.
The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test exper... more The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test experimental study was to (1) create a 3wt%-nanostrontium hydroxyapatite-enhanced calcium phosphate cement (Sr-HA/CPC) for increasing bone formation and (2) creating a simvastatin-loaded poly(lactic-co-glycolic acid) (SIM-loaded PLGA) microspheres plus CPC composite (SIM-loaded PLGA+nanostrontium-CPC). The third goal was the extensive assessment of multiple in vitro and in vivo characteristics of the above experimental explorative products in vitro and in vivo (animal and surgical studies). Physical and chemical properties of the prepared Sr-HA/CPC were evaluated. MTT assay and alkaline phosphatase activities, and radiological and histological examinations of Sr-HA/CPC, CPC and negative control were compared. X-ray diffraction (XRD) indicated that crystallinity of the prepared cement increased by increasing the powder-to-liquid ratio. Incorporation of Sr-HA into CPC increased MTT assay (biocompatibility) and ALP activity (P<0.05). Histomorphometry showed greater bone formation after 4weeks, after implantation of Sr-HA/CPC in 10 rats compared to implantations of CPC or empty defects in the same rats (n=30, ANOVA P<0.05). METHODS AND RESULTS PERTAINING TO SIM-LOADED PLGA MICROSPHERES+NANOSTRONTIUM-CPC COMPOSITE: After SEM assessment, the produced composite of microspheres and enhanced CPC were implanted for 8weeks in 10 rabbits, along with positive and negative controls, enhanced CPC, and enhanced CPC plus SIM (n=50). In the control group, only a small amount of bone had been regenerated (localized at the boundary of the defect); whereas, other groups showed new bone formation within and around the materials. A significant difference was found in the osteogenesis induced by the groups sham control (16.96±1.01), bone materials (32.28±4.03), nanostrontium-CPC (24.84±2.6), nanostrontium-CPC-simvastatin (40.12±3.29), and SIM-loaded PLGA+nanostrontium-CPC (44.8±6.45) (ANOVA P<0.001). All the pairwise comparisons were significant (Tukey P<0.01), except that of nanostrontium-CPC-simvastatin and SIM-loaded PLGA+nanostrontium-CPC. This confirmed the efficacy of the SIM-loaded PLGA+nanostrontium-CPC composite, and its superiority over all materials except SIM-containing nanostrontium-CPC.
In this study we employed the sol-gel method to synthesize new CaO–P2O5–SiO2–ZnO–B2O3 bioactive g... more In this study we employed the sol-gel method to synthesize new CaO–P2O5–SiO2–ZnO–B2O3 bioactive glasses. Three samples with various B2O3 content (5, 10 and 15 mol %) was prepared and their bioactivity were evaluated by immersion in simulated body fluid (SBF) and the glasses were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The experimental results revealed that with increasing the amount of boron content, a more crystalline domain can be observed in their XRD patterns and consequently the formation of hydroxyapatite (HA) increased. FTIR spectra showed that the sample containing 10 mol% of boron had the sharpest peaks attributed to the formation of hydroxyapatite. Biocompatibility of the samples was examined by MTT assay and alkaline phosphatase activity. The result ascertained that the synthesized bioactive glass had good biocompatibility and can serve as a bone substitute in bone defects.
Journal of Materials Engineering and Performance, 2016
Bioactive glasses in the system SiO2-CaO-Na2O-P2O5-MgO with different amounts of zinc (Zn) and si... more Bioactive glasses in the system SiO2-CaO-Na2O-P2O5-MgO with different amounts of zinc (Zn) and silver (Ag) were synthesized by the sol-gel technique and characterized. The bioactivity was studied during in vitro assays: the ability of hydroxycarbonate apatite (HCA) layer to form on the glass surface was examined after contact with simulated body fluid (SBF). The x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and inductively coupled plasma atomic emission spectrometry (ICP) studies were performed after immersion in vitro assays. Also, the antibacterial and antifungal activities of glass samples against Pseudomonas aeruginosa (ATCC 27853), E. coli (ATCC 25922), and Candida albicans were measured by the halo zone test. Introduction of zinc and silver as the trace elements induces several modifications on the observed phenomena at the glass surface and in SBF solution after immersion of the samples. The chemical durability of the glasses, the formation of the silica-rich layer, and the crystallization of the HCA layer were affected. Samples with the higher content of zinc and silver exhibited an excellent antibacterial/antifungal activity.
In this article, high-quality ZnS:Mn nanoparticles were synthesized from quaternary W/O micro-emu... more In this article, high-quality ZnS:Mn nanoparticles were synthesized from quaternary W/O micro-emulsion system with different Mn% for detecting the best concentration. The addition of biotin and the subsequent specific binding events alter the dielectric environment of the nanoparticle, resulting in a spectral shift of the particle plasmon resonance. Cyclohexane was used as oil, Triten X-100 as surfactant, n-hexanol as a co-surfactant and mercaptoethanol and thioglycolic acid for the best linking of biological part to nanoparticle (as linking agents). Surfactant and co-surfactant produce a stable emulsion with connection to surface of nanoparticles and prevention from contacting together. For qualitative and quantitative analyses of this product Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), Inductive coupled plasma (ICP), zeta meter for measurement of ZP and spectroscopy techniques are used. The results showed ...
In this project, we prepared biomimetic nanocomposite scaffolds from gelatin and chitosan and hyd... more In this project, we prepared biomimetic nanocomposite scaffolds from gelatin and chitosan and hydroxyapatite and subsequently the scaffolds were evaluated by common used bulk technique. For this purpose, the nanocomposite hydrogel/apatite bone tissue engineering scaffolds were fabricated using applied biomimetic method accompanied with freeze drying technique. The apatite was precipitated using double diffusion mechanism within gelatin hydrogel in similar pH and temperature to the human body. Chitosan initial percentage (20, 30 and 40%) was set as variables. Nanocomposites were soaked in glutaraldehyde solution in order to enhance mechanical properties and make them insoluble in water. Diffusion of calcium and phosphate from lateral hydrogel into the middle hydrogel caused formation of parallel white layer-formed precipitate. Analysis of precipitates formed within middle hydrogel for the samples, showed that detected materials are composed of carbonated hydroxyapatite and dicalcium ...
In this study, magnetite (Fe3O4) nanoparticles were synthesized by chemical co-precipitation from... more In this study, magnetite (Fe3O4) nanoparticles were synthesized by chemical co-precipitation from the solution containing iron salts in alkaline medium under N2 gas and room temperature. Magnetite nanoparticles were characterized by Xـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ * : يكينورتكلا تسپ ،تابتاكم لوئسم : abbasashuri@aut.ac.ir D ow nl oa de d fr om ja m e. iu t.a c. ir at 1 5: 15 IR D T o n S un da y S ep te m be r 20 th 2 02 0
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