肿瘤酸度活化的纳米药物载体

pH响应性的纳米粒（nanoparticles，NPs）作为药物输送载体用于肿瘤治疗倍受关注。实体瘤的弱酸性肿瘤微环境（pHe约为6.8）为抗肿瘤药物纳米载体的设计提供了新思路和发展契机。相对于靶向基团介导的肿瘤靶向策略，对pHe响应的纳米载体更具有普适性。本文概述了pHe活化纳米药物载体在肿瘤治疗中的设计和应用现状，重点介绍pHe触发表面电荷反转的纳米颗粒用于抗肿瘤药物和小干扰RNA（siRNA）输送的研究进展，并展望这种新型载体在增强肿瘤疗效方面的应用潜力。 

Tumor extracellular acidity-activated nanoparticles as drug delivery systems

pH-responsive nanoparticles (NPs) are currently under intense development as carriers of drug delivery systems for cancer therapy. Of these NPs, those that are designed to target the slightly acidic extracellular pH environment (pHe ~ 6.8) of solid tumors offer a new paradigm of tumor-targeted drug delivery. Compared with conventional, specific, surface-targeting approaches, the pHe-targeting strategy is considered to be more general because of the common occurrence of an acidic microenvironment in solid tumors. This review mainly focuses on the design and applications of pHe-activated NPs, particularly on pHe-activated surface-charge reversal NPs, for drug and siRNA delivery to tumors. The novel development of NPs described in this review has high potential for achieving stronger therapeutic effects in cancer treatment.