Tumor microenvironment-sensitive polymeric nanoparticles for synergetic chemo-photo therapy

Nanoparticles that employ stimuli-responsive polymeric delivery carriers have emerged as intelligent nanoplatforms with great potential in cancer theranostics, mainly including cancer diagnosis, controlled/triggered drug delivery, and real-time monitoring of therapeutic response. Particularly, tumor microenvironment (TME)-responsive polymeric nanocarriers in response to weak acidity, hypoxia, reactive oxygen species (ROS), glutathione (GSH), or tumor enzymes in the TME show great promise in facilitating tumor accumulation, enhancing tumor penetration, prolonging tumor retention, and achieving controlled drug release, thereby improving the efficiency of tumor therapy. Besides, the combination of chemotherapy and phototherapy presents a promising endeavor for the treatment of tumors, which allows for the integration of the advantages of each treatment modality, addressing the shortcomings of the two methods, and amplifying the efficacy of tumor treatment while reducing adverse reactions. This review focuses on the latest progress in the development of TME-responsive polymeric nanoparticles for synergetic chemo-photo therapy, and discusses the critical challenges and future considerations involved in the fabrication of TME-responsive nanocarriers.