Charles University, Faculty of Pharmacy, Department of Inorganic and Organic Chemistry, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
Curr Pharm Des. 2011;17(32):3596-607. doi: 10.2174/138161211798194468.
Chitosan is a linear polysaccharide with a good biodegradability, biocompatibility, and no toxicity, which provide it with huge potential for future development. The chitosan molecule appears to be a suitable polymeric complex for many biomedical applications. This review gathers current findings on the antibacterial, antifungal, antitumour and antioxidant activities of chitosan derivatives and concurs with our previous review presenting data collected up to 2008. Antibacterial activity is based on molecular weight, the degree of deacetylation, the type of substitutents, which can be cationic or easily form cations, and the type of bacterium. In general, high molecular weight chitosan cannot pass through cell membranes and forms a film that protects cells against nutrient transport through the microbial cell membrane. Low molecular weight chitosan derivatives are water soluble and can better incorporate the active molecule into the cell. Gram-negative bacteria, often represented by Escherichia coli, have an anionic bacterial surface on which cationic chitosan derivatives interact electrostatically. Thus, many chitosan conjugates have cationic components such as ammonium, pyridinium or piperazinium substituents introduced into their molecules to increase their positive charge. Gram-positive bacteria like Staphylococcus aureus are inhibited by the binding of lower molecular weight chitosan derivatives to DNA or RNA. Chitosan nanoparticles exhibit an increase in loading capacity and efficacy. Antitumour active compounds such as doxorubicin, paclitaxel, docetaxel and norcantharidin are used as drug carriers. It is evident that chitosan, with its low molecular weight, is a useful carrier for molecular drugs requiring targeted delivery. The antioxidant scavenging activity of chitosan has been established by the strong hydrogen-donating ability of chitosan. The low molecular weight and greater degree of quarternization have a positive influence on the antioxidant activity of chitosan. Phenolic and polyphenolic compounds with antioxidant effects are condensed with chitosan to form mutual prodrugs.
壳聚糖是一种具有良好生物降解性、生物相容性和无毒的线性多糖，这为其未来的发展提供了巨大的潜力。壳聚糖分子似乎是许多生物医学应用的合适聚合物复合物。本综述汇集了壳聚糖衍生物的抗菌、抗真菌、抗肿瘤和抗氧化活性的最新发现，并与我们之前的综述一致，该综述介绍了截至 2008 年收集的数据。抗菌活性基于分子量、脱乙酰度、取代基的类型，这些取代基可以是阳离子的或容易形成阳离子的，以及细菌的类型。一般来说，高分子量壳聚糖不能穿透细胞膜，并形成一层膜，保护细胞免受营养物质通过微生物细胞膜的运输。低分子量壳聚糖衍生物是水溶性的，可以更好地将活性分子掺入细胞中。革兰氏阴性菌，通常以大肠杆菌为代表，其细菌表面带负电荷，与阳离子壳聚糖衍生物发生静电相互作用。因此，许多壳聚糖缀合物引入了带正电荷的铵、吡啶鎓或哌嗪鎓取代基等阳离子成分，以增加其正电荷。革兰氏阳性菌如金黄色葡萄球菌则被低分子量壳聚糖衍生物与 DNA 或 RNA 的结合所抑制。壳聚糖纳米粒子表现出载药量和疗效的增加。阿霉素、紫杉醇、多西他赛和去甲斑蝥素等抗肿瘤活性化合物被用作药物载体。显然，低分子量的壳聚糖是需要靶向递送的分子药物的有用载体。壳聚糖的强供氢能力使其具有抗氧化清除活性。低分子量和更大程度的季铵化对壳聚糖的抗氧化活性有积极的影响。具有抗氧化作用的酚类和多酚类化合物与壳聚糖缩合形成相互前药。
