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1.
Int J Biol Macromol ; 50(3): 603-12, 2012 Apr 01.
Article in English | MEDLINE | ID: mdl-22260903

ABSTRACT

Silver nanoparticles have received attention as novel antimicrobial agents due to their high surface area to volume ratio and the unique chemical and physical properties. In order to study the effects of capping agents on silver nanoparticles (AgNPs), the nanoparticles were synthesized via chemical reduction method using different concentrations (0.3 mM, 0.6 mM and 0.9 mM) of polyethylene glycol (PEG) and Triton X-100 (TX). Also, AgNPs capped by the combinations of both PEG and TX were synthesized. These coated AgNPs were incorporated into collagen, lyophilized to form scaffolds and characterized by FTIR and FT-Raman spectroscopy. Results on mechanical property of all the scaffolds displayed no significant difference in the percentage elongation at break. However, the maximum percentage of 46.67% was observed with the combinations (0.9 mM PEG+0.9 mM TX). This implies that the combinations of surfactants increase the elasticity, which is useful for biomedical applications, e.g., Heart-valve preparations.


Subject(s)
Collagen/chemistry , Cyanoacrylates/chemistry , Metal Nanoparticles/chemistry , Polyethylene Glycols/chemistry , Silver/chemistry , Spectrum Analysis , Animals , Capsules , Cattle
2.
Colloids Surf B Biointerfaces ; 90: 191-6, 2012 Feb 01.
Article in English | MEDLINE | ID: mdl-22063757

ABSTRACT

Silver nanoparticles have received attention as novel antimicrobial agents. In order to study the effects of silver nanoparticles on both Gram positive and negative bacteria, the nanoparticles were synthesized via chemical reduction method using different concentrations (0.3, 0.6 and 0.9 mM) of poly(ethylene) glycol (PEG) and TritonX-100 (TX). Also, mixed PEG/TX systems with equimolar concentrations capped silver nanoparticles were synthesized and confirmed by UV-vis, fluorescence spectroscopy and particle size analysis. These coated silver nanoparticles were incorporated into collagen, lyophilized to form scaffolds and characterized by SEM, XRD, ATR-FTIR, DSC, TGA and zeta potential. Results on mechanical property of all the scaffolds displayed no significant difference in the percentage elongation at break. However, the maximum percentage of 46.67% was observed with the combinations (0.9 mM PEG+0.9 mM TX). This implies that the combinations of surfactants increase the elasticity, which is useful for biomedical applications, e.g., heart-valve preparations. Furthermore, the antimicrobial activities of these capped silver nanoparticles homogenized with collagen were tested against both Gram positive and negative bacteria. Minimum inhibitory concentration values obtained for the combination (0.9 mM PEG+0.9 mM TX) were found to be better than others and thus provide strong antibacterial property to the collagen scaffolds prepared for tissue regeneration applications.


Subject(s)
Anti-Bacterial Agents/chemistry , Biocompatible Materials/chemistry , Collagen/chemistry , Metal Nanoparticles/chemistry , Silver/chemistry , Tissue Engineering/methods , Tissue Scaffolds , Animals , Anti-Bacterial Agents/pharmacology , Biocompatible Materials/metabolism , Cattle , Collagen/metabolism , Freeze Drying , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/growth & development , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/growth & development , Humans , Metal Nanoparticles/ultrastructure , Microbial Sensitivity Tests , Microscopy, Electron, Scanning , Octoxynol/chemistry , Oxidation-Reduction , Particle Size , Polyethylene Glycols/chemistry , Silver/pharmacology , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction
3.
Article in English | MEDLINE | ID: mdl-11837047

ABSTRACT

Dielectric properties of supersaturated alpha-D-glucose aqueous solutions (45-56% w/w) at 2.45 GHz were investigated at temperatures ranging from 25 degrees C to 85 degrees C. Penetration depth was calculated as well. At each temperature tested, there exists a concentration range at which the dielectric constants or loss factors for supersaturated glucose solutions are independent of concentration. These results will be helpful in studies of the Maillard reaction as it occurs in a microwave field.


Subject(s)
Glucose Solution, Hypertonic , Microwaves , Electrochemistry , Temperature
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