Bio/Polymer Research Group, School of Biotechnology & Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
Biotechnol Lett. 2011 Feb;33(2):417-21. doi: 10.1007/s10529-010-0435-1. Epub 2010 Oct 16.
Chitosan is a promising biomaterial for biomedical applications and is currently applied as wound dressings. While chitosan solutions demonstrate strong bactericidal activity against a range of medically important bacteria, the study here reports a loss of this beneficial property in thin films cast from the same solutions. Chitosan films (20 microm) showed no inhibitory effects against Escherichia coli, Staphylococcus aureus or S. epidermidis species. In contrast, solutions used to prepare the films showed almost complete inhibition (approximately 98 ± 2%) when tested on bacterial lawns and in liquid cultures. Increased acidity of the chitosan solutions (pH 5) was shown to promote the bactericidal effects of this biopolymer. The concept that devices fabricated from chitosan have an inherent antimicrobial activity is suggested as an important misconception.
壳聚糖是一种有前途的生物医学材料，目前用作伤口敷料。虽然壳聚糖溶液对多种重要的医学细菌表现出强烈的杀菌活性，但本研究报告称，由相同溶液浇铸而成的薄膜中丧失了这种有益的特性。壳聚糖薄膜（20 微米）对大肠杆菌、金黄色葡萄球菌或表皮葡萄球菌没有抑制作用。相比之下，当在细菌菌苔和液体培养物中进行测试时，用于制备薄膜的溶液显示出几乎完全的抑制作用（约 98±2%）。增加壳聚糖溶液的酸度（pH5）被证明可以促进这种生物聚合物的杀菌作用。从壳聚糖制造的设备具有固有抗菌活性的概念被认为是一个重要的误解。
