具高穩定性之奈米矽片銀水溶液及其抗菌性探討

Abstract

本研究設計一新型奈米複合材料-奈米矽片銀，使用奈米矽片水溶液分散奈米銀粒子，並將其應用至抗菌生醫領域。奈米銀粒子之尺寸由3.8奈米至35奈米可藉由控制固態分散劑，即厚度為1奈米之奈米矽片，得到良好之可操控性。而奈米矽片帶有高表面電荷及高表面積之特殊性質為奈米銀粒子帶來不只良好可操控性，也是其具高穩定性與抗菌效果。本研究中，我們將不同比例之奈米矽片銀水溶液進行抗菌測試，發現抗菌能力對無論革蘭氏陰性菌或革蘭氏陽性菌均與奈米銀粒子大小成反比。更進一步以SEM觀察可發現表面細菌之形態，奈米矽片銀會由於表面帶有電荷而貼附至細菌表面，造成細菌之表面型態由原本飽滿轉化成萎縮更甚破裂之構形，且奈米矽片使銀粒子固定在表面而可能不經由穿透細胞即造成死亡。

A new class of nanohybrids were synthesized by complexing silver nanoparticles (AgNPs) with clay silicate platelets and evaluated for antibacterial activities. Various silver particle sizes in the range of 3.8 to 35 nm diameter were tailored by using nanoscale silicate platelets (NSP) at 1.0 nm thickness as supports. High stability and antibacterial activity were achieved. The efficacy of AgNPs on NSP was highly dependent on the silver particle size in the tests of controlling dermal pathogens including Gram-positive and Gram-negative bacteria. Scanning electron microscope had directly observed the adherence of the nanohybrids to the surface of individual bacteria. The role of NSP as surface supports for immobilizing AgNPs was elucidated by varying the AgNP/NSP weight ratio and testing for their differences in antibacterial efficacy. It is concluded that that hybridization of AgNPs on NSP surface allows the enhancement of AgNP activities and mitigation of their adversary effects on cells.