Rational design of biodegradable semiconducting polymer nanoparticles for NIR-II fluorescence imaging-guided photodynamic therapy
Xuxuan Gu, Jinlong Shen, Zhiwei Xu, Wenqi Wang, Ying Wu, Wen Zhou, Chen Xie, Quli Fan
Abstract
Semiconducting polymer nanoparticles (SPNs) have shown great promise in second near-infrared window (NIR-II) phototheranostics. However, the issue of long metabolic time significantly restricts the clinical application of SPNs. In this study, we rationally designed a biodegradable SPN (BSPN50) for NIR-II fluorescence imaging-guided photodynamic therapy (PDT). BSPN50 is prepared by encapsulating a biodegradable SP (BSP50) with an amphiphilic copolymer F-127. BSP50 is composed of NIR-II fluorescent diketopyrrolopyrrole (DPP) segment and degradable poly(phenylenevinylene) (PPV) segment with the ratio of 50/50. BSPN50 has both satisfactory degradability under myeloperoxidase (MPO)/hydrogen peroxide (H 2 O 2 ) and NIR-II fluorescence emission upon 808 nm laser excitation. Furthermore, BSPN50 shows good photodynamic efficacy under 808 nm laser irradiation. BSPN50 shows a faster degradation rate than BSPN100 which has no PPV segment both in vitro and in vivo . In addition, BSPN50 can effectively diagnose tumor via NIR-II fluorescence imaging and inhibit the tumor growth by PDT. Thus, our study provides a rational approach to construct biodegradable nanoplatforms for efficient tumor NIR-II phototheranostics.