Biodegradable and Biocompatible Chitosan-Protein Nanoparticles in Drug Delivery

纳米粒子疗法以天然聚合物和合成聚合物与水溶性聚合物为基础，为改善抗癌药物的输送提供了新的途径。这有助于药物的溶解，通过长循环增加治疗过程，并通过实现渗透性和滞留效果增强对肿瘤的摄取。在用于药物递送系统的天然阳离子聚合物中，壳聚糖是一种生物相容性、可生物降解性和多功能的聚合物，因此在纳米生物医学技术领域引起了人们的极大兴趣。壳聚糖及其衍生物作为药物给药工具具有安全使用所需的性能。利用壳聚糖及其衍生物作为药物载体的主要目的是提高治疗药物(多肽、蛋白质、抗原和质粒DNA)在体内的生物利用度。然而，壳聚糖只溶于酸性溶液，不能在中性pH条件下溶解，这给药物载体的制备带来了很大的困难。为了提高壳聚糖的溶解性和亲和力，需要对聚合物结构进行修饰。壳聚糖-蛋白质偶联将增加聚合物在生理pH中的溶解度，并将显著提高壳聚糖在药物输送系统中的效率。

Nanoparticle therapeutics, based on natural and synthetic polymers with water-soluble polymers, offer new routes to improve cancer drug delivery. This aids the drug solubility, increases the therapeutic process through long circulation and enhances the uptake into tumors by achieving the permeability and retention effect. Among natural cationic polymers used in drug delivery systems, chitosan has attracted a major interest in the nanobiomedical technology sector since it is a biocompatible, biodegradable and versatile polymer. Chitosan and its derivatives have the desired properties for safe use as pharmaceutical drug delivery tools. The principal interest in using chitosan and its derivatives as a pharmaceutical carrier is to enhance the bioavailability of therapeutic drugs (peptides, proteins, antigens and plasmid DNAs) in vivo. However, chitosan is only soluble in acidic solution and not at neutral pH, which causes a major problem for drug-carrier formulation. Modifications of polymer structure are needed, in order to increase chitosan solubility and affinity. Chitosan-protein conjugation will increase polymer solubility in physiological pH and will enhance markedly chitosan efficiency in a drug delivery system.