奈米銀與幾丁聚醣的抗菌性研究

Abstract

銀的抗菌性已被發現數千年之久，本篇選用具有生物相容性的幾丁聚醣在鹼性環境下還原硝酸銀成為奈米銀(CS-AgNPs)，所形成的CS-AgNPs與銀離子(Ag+)、奈米銀(AgNPs)比較其抗菌性與細胞毒性；除此之外生物實驗中也另外比較幾丁聚醣(CS)與奈米幾丁聚醣(CS-TPP NPs)。 物性測試的部分分別以粒徑分析儀、穿透式電子顯微鏡、紫外光/可見光光譜儀、紅外線分光光譜儀、火焰式原子吸收光譜進行分析。在生物性實驗的部分，以L929細胞進行細胞毒性試驗並利用細胞存活率計算IC50；抗菌性實驗檢測大腸桿菌與金黃色葡萄球菌的最小抑菌濃度(MIC)、最小殺菌濃度(MBC)與抑制圈大小。 CS-AgNPs系列中的AgNPs大小約為10 nm左右，而AgNPs與CS-TPP NPs的大小分別為40~50 nm與200~300 nm。生物性實驗比較細菌抗性與細胞毒性的結果發現，含銀系列樣品的抗菌效果與細胞毒性皆大於幾丁聚醣系列。在含銀樣品的結果中Ag+和AgNPs相互比較，MBC與抑制圈的結果呈現Ag+優於AgNPs，在細胞毒性上48小時的毒性比較未見統計差異；Ag+與CS-AgNPs相互比較，在MIC與MBC的結果發現，CS-AgNPs的抗菌性更勝Ag+，而48小時細胞毒性中Ag+與CS-AgNPs的IC50數值皆在0.3~0.5 µg/mL區間，但CS-AgNPs的IC50多小於Ag+。當CS與CS-TPP NPs相比較，在最高劑量下皆未見其細胞毒性，而抗菌性的部分則觀察到CS的抗菌效果優於CS-TPP NPs的現象。

The antibacterial property of silver has been discovered for thousand years. This study used biocompatible chitosan to reduce silver ion and form silver nanoparticles (CS-AgNPs). The antibacterial activity and cell toxicity among Ag+, AgNPs, and CS-AgNPs were compared. Moreover, chitosan (CS) and chitosan nanoparticles (CS-TPP NPs) were also evaluated, too. The properties of samples were determined by using Zetasizer, TEM, UV-Vis spectroscope, FT-IR , and Flame Atomic Absorption Spectrometer. The cytotoxicity was preformed in L929 cell line and IC50 values were calculated. The antibacterial activity was evaluated in the Escherichia coli as well as Staphylococcus aureus, and the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and inhibition zone were measured. The size of AgNPs in CS-AgNPs was about 10 nm.The particle diameter of AgNPs and CS-TPP NPs was about 40~50 nm and 200~300 nm. The bacterial activity and cell cytotoxicity of silver products were higher than those of chitosan products. According to the MBC and inhibition zone results, the antibacterial activity of the Ag+ was higher than AgNPs. However, the was no significant difference in 48-hours cell toxicity. In addition, CS-AgNPs had higher antibacterial activity than Ag+ according to MIC and MBC results. The half maximal inhibitory concentrations (IC50) of Ag+ and CS-AgNPs were 0.3-0.5 µg/mL in 48-hours cell experiment, and most of the CS-AgNPs were less than Ag+. There was no cytotoxicity of CS and CS-TPP NPs, even at the highest concentration. The antibacterial activity of CS are higher than CS-TPP NPs.