A hybrid drug delivery system was successfully fabricated by attaching a camptothecin (CPT)-based polymeric prodrug onto the surface of silver nanoparticles (AgNPs). PEG was employed as a macro-RAFT agent in RAFT polymerization to synthesize a branched star copolymer, to which CPT is linked through the photo-responsive o-nitrobenzyl linkage. In vitro tests indicate that the fluorescence of CPT in the polymeric prodrug is quenched by AgNPs based on the nanomaterial surface energy transfer (NSET) effect and the fluorescence recovers when the CPT molecules are released from hybrid nanoparticles. Thus, the variation of fluorescence intensity is bound up with the drug release behaviours, which may enable this AgNP-based drug delivery system to trace the intracellular drug release process and observe the distribution of released CPT in cells.

中文翻译：

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光响应性喜树碱基聚合物前药涂层的银纳米颗粒，用于通过纳米材料表面能传递（NSET）效应跟踪药物释放行为†

通过将基于喜树碱（CPT）的聚合物前药附着到银纳米颗粒（AgNPs）的表面上，成功制造了一种混合药物递送系统。PEG被用作RAFT聚合反应中的大分子RAFT剂，以合成支链星形共聚物，CPT通过光响应性邻硝基苄基键合而与之连接。体外测试表明，基于纳米材料表面能转移（NSET）效应，AgNPs可以使聚合前药中的CPT荧光猝灭，并且当CPT分子从杂化纳米颗粒中释放时，荧光会恢复。因此，荧光强度的变化与药物释放行为有关，这可能使基于AgNP的药物释放系统能够追踪细胞内药物释放过程并观察释放的CPT在细胞中的分布。