Chitosan Nanoparticles

We report the synthesis, characterization, and biological properties of chitosan nanoaggregates from gladius of squid, Uroteuthis duvauceli. í µí»½-Chitin extracted from gladius was deacetylated to chitosan and further reduced to nanosize using ionic gelation process. The morphology and occurrence of chitosan nanoaggregates (CSNA) were observed using transmission electron microscopy (TEM). The degree of deacetylation (DD%) calculated from Fourier transform infrared (FTIR) spectrum showed high value (∼94 ± 1.25%) for chitosan. The CSNA depicts low molecular weight, stable positive zeta potential, and less ash and moisture content with high water and fat binding capacity. The antimicrobial activity was tested against pathogenic microorganisms, which depicted significant rate of inhibition against Staphylococcus aureus and Escherichia coli due to high cellular uptake. The antioxidant analysis for CSNA demonstrated high reducing power and scavenging activity towards superoxide radicals compared with the commercially available chitosan. Furthermore, nanoaggregates exhibited low cytotoxic behavior in biological in vitro tests performed using cervical cancer cell line. These results indicate that chitosan nanoaggregates synthesized from waste gladius will be highly efficient and safe candidate for biological applications as food packing film, drug carrier, and tissue engineering.

Chitosan was modified into nanoparticle chitosan in order to increase its absorptivity and solubility in water so that it can be applied in various fields. The objective of this research was to produce nanometer-sized chitosan, to characterizethe functional groups and the particle size of chitosan as well as to test its antimicrobial activity. Chitosan nanoparticles were synthesized through ionic gelation method by reacting chitosan with tripolyphosphate ions through ionic crosslinking reaction. The functional groups of chitosan were determined from its FTIR spectrum, the particle size was obtained from its X-ray diffractogram and particle size analysis (PSA). Chitosan nanoparticles with the smallest size based on XRD wereobtained at a concentration of 0.1% chitosan (CNPs 1) and chitosan 0.2% (CNPs 2) with the addition of 0.1 % tripolyphosphate ion. The sizes of chitosan nanoparticles,CNPs 1 and CNPs 2,obtained from the analysis of PSA were 224.68 and 204.32 nm, respectively. Polydi...

Fabrication of an ideal scaffold having proper composition, physical structure and able to have sustained release of growth factors still is challenging for bone tissue engineering. Current study aimed to design an appropriate three-dimensional (3-D) scaffold with suitable physical characteristics, including proper compressive strength, degradation rate, porosity, and able to sustained release of bone morphogenetic protein-2 (BMP2), for bone tissue engineering. A highly porous 3-D β-tricalcium phosphate (β-TCP) scaffolds, inside of which two perpendicular canals were created, was fabricated using foam-casting technique. Then, scaffolds were coated with gelatin layer. Next, BMP2-loaded chitosan (CS) nanoparticles were dispersed into collagen hydrogel and filled into the scaffold canals. Physical characteristics of fabricated constructs were evaluated. Moreover, the capability of given construct for bone regeneration has been evaluated in vitro in interaction with human buccal fat pad-derived stem cells (hBFPSCs). The results showed that gelatin-coated TCP scaffold with rhBMP2 delivery system not only could act as a mechanically and biologically compatible framework, but also act as an osteoinductive graft by sustained delivering of rhBMP2 in a therapeutic window for differentiation of hBFPSCs towards the osteoblast lineage. The proposed scaffold model can be suggested for delivering of cells and other growth factors such as vascular endothelial growth factor (VEGF), alone or in combination, for future investigations.

Different techniques have been employed to produce chitosan nanoparticles; thus, suitable alternatives and easy-handling production methods are highly desired. We used a tank reactor with baffles and mechanical stirring with Cowles impellers that can feasibly be up-scaled and allows for the production of homogenous chitosan nanoparticles. First, we explored the effects of temperature on the produc- tion of chitosan (CHI)/pentasodium tripolyphosphate (TPP) nanoparticles. We compared the effect of gradual temperature decrease between 40 to 55◦C with the effect of isothermal processes (25, 45 and 55◦C). CHI/TPP nanoparticles produced by the gradual temperature decrease technique had polydis- persity indices (PDIs) that were significantly smaller than the nanoparticles produced by isothermal processes. To further control the production process, we employed an experimental design to determine the effects of CHI and TPP concentrations and CHI/TPP mass ratios in the gradual temperature decrease technique. Under all conditions, the sizes of the CHI/TPP nanoparticles were on the nanoscale. Gene deliv- ery capacities of the nanoparticles were evaluated; the plasmid pEGFP-N1 was incorporated (10 and 40% of the chitosan weight) into the nanoparticles and incubated with 293A cells. The in vitro transfection efficiencies were evaluated over 120 h and indicated sustained gene delivery at 10% pDNA. The poly- plexes demonstrated some cytotoxicity after 120 h. These findings will contribute to the development of processes for generating CHI/TPP nanoparticles for gene delivery applications.

Background and Objectives: The most prevalent and worldwide oral disease is dental caries that affects a significant proportion of the world population. There are some classical approaches for control, prevention and treatment of this pathologic condition; however, the results are still not completely successful. Therefore new methods are needed for better management of this important challenge. Chitosan is a natural and non-toxic polysaccharide with many biological applications, particularly as an antimicrobial agent. Chitosan nanoparticle is a bioactive and environment friendly material with unique physicochemical properties. The aim of the present study was to investigate the antimicrobial effect of chitosan and nano-chitosan on the most important cariogenic streptococci. Materials and Methods: For evaluation of antimicrobial effect of chitosan and nano-chitosan against oral streptococci broth micro-dilution method was carried out for four bacterial species; Streptococcus mutans,...

Introduction: Antibiotic-carrying nanoparticles have cytotoxic effects on drug-resistant bacteria. The aim of the present study was to evaluate the effect of chitosan nanoparticles carrying amoxicillin and clavulanic acid on the viability of staphylococcus aureus strains.

Materials & Methods: In this study, chitosan nanoparticles were prepared by ionic gelation method and were loaded by amoxicillin and clavulanic acid leading to the production of nanoparticles with dimension less than 100 nm. To evaluate the effect of different nanoparticle concentration on the bacteria, chitosan and amoxicillin concentrations of 0.25-8 and 1-128 µg/ml were prepared, respectively, using the microdilution method. Subsequently, 100 nm of different chitosan nanoparticle concentration with antibiotic was transferred to each well and 1 μl of bacterial suspension was added to the wells.  Turbidity in the wells was observed without armed eye and the light absorbance was read in the wavelength range of 630 nm by enzyme-linked immunosorbent assay.

Findings: The results showed that minimum inhibitory concentrations of chitosan nanoparticles carrying amoxicillin and clavulanic were 0.9 and 3.6 µg/ml in susceptible and resistant specimens, respectively.  Moreover, their minimum destructive concentrations were obtained at 1.8 and 7.2 µg/ml, respectively.

Discussion & Conclusions: According to the results, the obtained combination showed more antibacterial effectiveness, compared to chitosan and amoxicillin alone. This reveals the synergistic effect of amoxicillin with clavulanic acid and chitosan.

Zea mays is an important crop and an essential source of fatty acids. Hence, increasing and adding new fatty acids led to the enhancement of these properties. Transformation of external Acetyl-CoA gene (Aco) can enhance fatty acid components, as ACo is expressed into Acetyl-CoA carboxylase (ACCase) enzyme, which is the first essential step in the fatty acid production process. Chitosan nanoparticles are safe and fast polymer nanoparticles that are applied for gene transformation. Conventional PCR was performed for the detection of the ACo gene in both transgenic and nontransgenic maize lines. The results confirm the presence of the gene in the transgenic lines and absence in non-transgenic lines. The Gas chromatography-mass spectrometry (GC-MS) analysis for fatty acid contents in transgenic and non-transgenic maize lines showed an increase in fatty acid contents in transgenic lines compared to non-transgenic ones. Besides, the transgenic maize's lines produced extra new fatty acids not found in non-transgenic ones.

Background and Objectives: The most prevalent and worldwide oral disease is dental caries that affects a significant proportion of the world population. There are some classical approaches for control, prevention and treatment of this pathologic condition; however, the results are still not completely successful. Therefore new methods are needed for better management of this important challenge. Chitosan is a natural and non-toxic polysaccharide with many biological applications, particularly as an antimicrobial agent. Chitosan nanoparticle is a bioactive and environment friendly material with unique physico-chemical properties. The aim of the present study was to investigate the antimicrobial effect of chitosan and nano-chitosan on the most important cariogenic streptococci. Materials and Methods: For evaluation of antimicrobial effect of chitosan and nano-chitosan against oral streptococci broth micro-dilution method was carried out for four bacterial species; Streptococcus mutans, Streptococcus sobrinus, Streptococ-cus sanguis and Streptococcus salivarius. Also the effect of these materials on adhesion of above bacteria was evaluated. One-way ANOVA and post hoc Tukey test were used for statistical analysis. Results: The MICs of chitosan for S. mutans, S. sanguis, S. salivarius and S. sobrinus were 1.25, 1.25, 0.625 and 0.625 mg/ mL, respectively. The MIC of chitosan nanoparticle for S. mutans, S. salivarius and S. sobrinus was 0.625 mg/mL and for S. sanguis was 0.312 mg/mL. Chitosan and chitosan nanoparticles at a concentration of 5 mg/mL also reduced biofilm formation of S. mutans up to 92.5% and 93.4%, respectively. Conclusion: The results of this study supported the use of chitosan and chitosan nanoparticles as antimicrobial agents against cariogenic Streptococci.