pH响应型纳米药物载体的释药机制及性能研究进展

Release Mechanisms and Properties of pH-responsive Drug Nanocarriers

pH响应型纳米载体因具有智能的酸敏或碱敏释药性能,已成为当前一类重要的多功能纳米载体,并得到了研究人员的广泛关注。特别是酸敏性纳米载体,可用于肿瘤弱酸微环境的药物控释,因而对药物的定点释放和癌症的靶向治疗等生物医学应用发挥了积极作用。本文综述了近年来各类pH响应型纳米载体的典型合成方法,系统地介绍了共价键、分子间作用力以及物理结构变化3种方式引发的pH响应释药机制。深入阐述了pH响应型纳米载体的载药性能、体外释药性能、体外细胞毒性、体内抗癌性能及体内分布性能,并详细列举了近年来pH响应型纳米载体的各类实验参数,进而为pH响应型纳米载体的深入研究提供了方法学的借鉴和性能参考。

pH-responsive drug nanocarriers are a kind of important multifunctional nanocarriers due to their intelligent properties of acid sensitive or alkali sensitive release, and have received extensive attention from researchers. Especially, acid sensitive nanocarriers can be applied for controlled release at weak acid microenvironment of tumor, wich play an active role at some biomedicine application such as targeted delivery of drugs and targeted therapy for cancer. In this paper, the typical fabrication methods for pH-responsive drug nanocarriers in recent years have been summarized, and the pH-responsive drug release mechanisms triggered by three ways have been systematically introduced. Firstly, pH-responsive mechanism triggered by covalent bond, in which imine bond, acetal bond, ester bond, coordination bond and others covalent bond can be used individually as pH initiator. Secondly, pH-responsive mechanisms triggered by intermolecular forces, in which both electrostatic interaction and hydrogen bond are applied for pH-responsive release drug. Thirdly, pH-responsive mechanism triggered by physical structure of nanocarries, in which both polymer swelling at diffirent pH values and calcium phosphate dissolving in the acid environment can result in controlled drug release. The loading properties, release properties in vitro, cytotoxicity in vitro, anticancer properties in vivo and distribution properties in vivo of pH-responsive drug nanocarriers are also expounded. Various experimental parameters of pH-responsive drug nanocarriers have been enumerated in detail, which provide the performance and methodological references for the in-depth studies of pH-responsive nanocarries.