Synthesis and property of nano-fumed silica derivative with quaternary ammonium group / 生物医学工程学杂志

Nano-fumed silica derivative with quaternary ammonium group was synthesized and the antimicrobial activity was investigated. The nano-fumed silica derivative was investigated by Fourier-transform infrared spectroscopy (FTIR). The zeta potential and the size of the nano-fumed silica derivative were measured. The antimicrobial properties of the nano-fumed silica derivative against selected microorganisms were tested by the quantitative suspension method. The zeta potential showed that the isoelectric points of nano-fumed silica and modified nano-fumed silica are pH=4. 8 and pH =10.5-10.8, respectively, and the shift of the isoelectric point is due to the quaternary ammonium salt. The obtained nano-fumed silica derivative inhibited the growth of Gram-negative (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and fungus (Candida albicans). The inhibiting effect of nano-fumed silica derivative on the microorganisms varied with the time of exposure. The bacteriostatic rates were noted to be 99.99%, 99.99% and 94.12% after 15 minutes' exposure, respectively. Thus the results indicate that nano-fumed silica derivative with quaternary ammonium group has significant inhibitory effect on the growth of bacteria.

Konjac glucomannan-collagen -chitosan blend films (I) / 生物医学工程学杂志

Konjac glucomannan-collagen-chitosan blend films were prepared successfully by the solvent-casting method and were characterized by FT-IR,X-ray diffraction, SEM and optical transmittance. Moreover, tensile strength, breaking extension, water absorption, water vapor permeation coefficients, adsorbability and penetrating rates were measured. The results indicated that some strong interaction and good compatibility existed among Konjac glucomannan /collagen and chitosan in the blend films. Some properties of the KCCS films were improved markedly in comparison with binary blend films or Konjac glucomannan, collagen and chitosan film. The results of culturing vessel endothelial cells on CKCS-5 film showed that the blend films have good cell compatibility which indicates the potential for a scalfold material in tissue engineering.