Non-invasive monitoring of the in situ drug release in a real-time manner is crucial for the clinical cancer treatment. In this work, a polymeric prodrug, P(HPMA-co-(CPT-SS-CyN)), composed of N-(2-hydroxypropyl) methacrylamide (HPMA) and a functional monomer (a near-infrared fluorescent cyanine-amine dye (CyN) and camptothecin (CPT) linked by disulfide bond) was reported for the non-invasive and real-time reporting drug release. The cleavage of the disulfide bond intracellularly could lead to the release of free CPT as well as the blue shift of the dye (CyN conjugated polymer), enabling facile monitoring of the drug release. Moreover, the percentage of the released drug showed a linear correlation with the normalized increase in the fluorescence intensity, which can be further used for the quantification of the local drug concentration. In vitro cell study showed that the fluorescence intensity gradually increased with the prolongation of incubation time, and P(HPMA-co-(CPT-SS-CyN)) exhibited the same inhibition efficiency of tumor cell proliferation as CPT. This work may guide researchers for the precise design and development of various pharmaceutical formulations.

实时地对原位药物释放进行无创监测对于临床癌症治疗至关重要。在这项工作中，聚合前药P（HPMA- co-（CPT-SS-CyN）），由N-（2-羟丙基）甲基丙烯酰胺（HPMA）和功能性单体（通过二硫键连接的近红外荧光花青胺染料（CyN）和喜树碱（CPT））组成据报道是非侵入性和实时报告药物释放的。细胞内二硫键的裂解可导致游离CPT的释放以及染料（CyN共轭聚合物）的蓝移，从而可以轻松监控药物的释放。此外，释放的药物的百分比与荧光强度的标准化增加呈线性相关，可以进一步用于定量局部药物浓度。体外细胞研究表明，随着培养时间的延长，荧光强度逐渐增加，P（HPMA-co-（CPT-SS-CyN））对肿瘤细胞的增殖抑制作用与CPT相同。这项工作可以指导研究人员进行各种药物制剂的精确设计和开发。