ABSTRACT
34 nm gold nanoparticles with good stability were synthesized and characterized and their effect (as a function of concentration) on the proliferation of keratinocytes was evaluated by means of MTT and nucleolar organizer region (AgNOR) count (silver staining). The cell morphology was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results demonstrate that a low concentration of gold nanoparticles enhances the proliferation of keratinocytes. Specifically, a concentration of 5.0 ppm gold nanoparticle has the best effect on the promotion of cell growth. In the experiment group, the AgNOR-positive areas and AgNOR area/nuclear area ratios of keratinocytes co-cultured with 5.0 ppm gold nanoparticles were greater than those in the control group (p<0.01). At a level greater than 10.0 ppm, gold nanoparticles were found to have a cytotoxic effect on keratinocytes. It is concluded that a low concentration of gold nanoparticles may be used as a biomedical material in skin tissue engineering.
Subject(s)
Gold/pharmacology , Keratinocytes/cytology , Keratinocytes/drug effects , Metal Nanoparticles/chemistry , Animals , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Gold/chemistry , Rats , Rats, Sprague-Dawley , Skin/cytology , Structure-Activity RelationshipABSTRACT
A novel hydrogen peroxide (H2O2) biosensor was developed by immobilizing hemoglobin on the gold colloid modified electrochemical pretreated glassy carbon electrode (PGCE) via the bridging of an ethylenediamine monolayer. This biosensor was characterized by UV-vis reflection spectroscopy (UV-vis), electrochemical impendence spectroscopy (EIS) and cyclic voltammetry (CV). The immobilized Hb exhibited excellent electrocatalytic activity for hydrogen peroxide. The Michaelis-Menten constant (K(m)) was 3.6 mM. The currents were proportional to the H2O2 concentration from 2.6 x 10(-7) to 7.0 x 10(-3) M, and the detection limit was as low as 1.0 x 10(-7) M (S/N = 3).
Subject(s)
Biosensing Techniques/instrumentation , Carbon/chemistry , Gold Colloid/chemistry , Hemoglobins/chemistry , Hydrogen Peroxide/chemistry , Animals , Cattle , Electrochemical Techniques , Electrodes , Ethylenediamines/chemistry , Hydrogen-Ion Concentration , Nanostructures/chemistry , Reproducibility of Results , Spectrophotometry, UltravioletABSTRACT
A novel wound dressing composed of nano-silver and chitosan was fabricated using a nanometer and self-assembly technology. Sterility and pyrogen testing assessed biosafety, and efficacy was evaluated using Sprague-Dawley rats with deep partial-thickness wounds. Silver sulfadiazine and chitosan film dressings were used as controls. At intervals wound areas were measured, wound tissues biopsied and blood samples taken. Compared with the controls, the silver nanocrystalline chitosan dressing significantly (p<0.01) increased the rate of wound healing and was associated with silver levels in blood and tissues lower than levels associated with the silver sulfadiazine dressing (p<0.01). Sterility and pyrogen tests of the silver nanocrystalline chitosan dressing were negative. Thus this dressing should have wide application in clinical settings.
