将下面中文翻译成英文：摘要 释药可控的药物递送系统能够在特定刺激条件下, 在时间和空间上精确实现在病灶处释放包载的药物分子, 具 有药物利用率高、毒副作用低等诸多优点, 为各种重大疾病, 如肿瘤的精准治疗提供了新思路. 在众多的可控释药递送 系统中, 利用特定光照控制药物释放的光控释药型药物递送系统展现出广阔的应用潜力, 受到研究者的广泛关注. 近 年来, 基于不同光响应机理的光控释药型药物递送系统被设计开发用于药物的精确可控释放, 本文介绍了四种光敏感 基团的不同光响应机理, 对基于不同光响应机理的光控释药型药物递送系统的研究进展进行了综述, 指出现有光控释 药型药物递送系统存在的问题及对未来的研究方向进行了展望.

Summary: Controllable drug delivery systems can precisely release the drug molecules contained in the package at the lesion site under specific stimulus conditions, with many advantages such as high drug utilization and low side effects, providing a new idea for the precise treatment of various major diseases such as cancer. Among the many controllable drug delivery systems, the photocontrollable drug delivery system using specific illumination to control drug release has shown broad application potential and has received widespread attention from researchers. In recent years, photocontrollable drug delivery systems based on different photoresponse mechanisms have been developed for the precise and controllable release of drugs. This article introduces the different photoresponse mechanisms of four photoresponsive groups and reviews the research progress of photocontrollable drug delivery systems based on different photoresponse mechanisms. It points out the problems existing in the current photocontrollable drug delivery systems and looks forward to the research direction in the future.