Hybrid Nanospheres to Overcome Hypoxia and Intrinsic Oxidative Resistance for Enhanced Photodynamic Therapy
Leilei Shi, Fang Hu, Yukun Duan, Wenbo Wu, Jinqiao Dong, Xiangjun Meng, Xinyuan Zhu, Bin Liu
Abstract
Photodynamic therapy (PDT) has been a well-accepted clinical treatment for malignant tumors owing to its noninvasiveness and high spatiotemporal selectivity. However, the efficiency of PDT is still severely hindered by an inherent aggregation-caused quenching (ACQ) effect of traditional photosensitizers (PSs), the presence of B-cell lymphoma 2 (Bcl-2), an antiapoptosis protein in cells, and hypoxia in the tumor microenvironment. To address these issues, hybrid nanospheres containing Fe3+, aggregation-induced emission (AIE) PS, and Bcl-2 inhibitor of sabutoclax were constructed via coordination-driven self-assembly in aqueous media. Once the hybrid nanospheres are taken up by tumor cells, intracellular O2 concentration is observed to increase via Fenton reaction driven by Fe3+, whereas intracellular PDT resistance of the AIE PS was mitigated by sabutoclax. The design of the multifunctional hybrid nanospheres demonstrates a prospective nanoplatform for image-guided enhanced PDT of tumors.