Hypoxia, a salient feature of most solid tumors, confers invasiveness and resistance to the tumor cells. Oxygen-consumption photodynamic therapy (PDT) suffers from the undesirable impediment of local hypoxia in tumors. Moreover, PDT could further worsen hypoxia. Therefore, developing effective strategies for manipulating hypoxia and improving the effectiveness of PDT has been a focus on antitumor treatment. In this review, the mechanism and relationship of tumor hypoxia and PDT are discussed. Moreover, we highlight recent trends in the field of nanomedicines to modulate hypoxia for enhancing PDT, such as oxygen supply systems, down-regulation of oxygen consumption and hypoxia utilization. Finally, the opportunities and challenges are put forward to facilitate the development and clinical transformation of PDT.
Keywords: 3O2, molecular oxygen; APCs, antigen-presenting cells; AQ4N, banoxantrone; CaO2, calcium dioxide; Cancer; Ce6, chlorin e6; CeO2, cerium oxide; DC, dendritic cells; DDS, drug delivery system; DOX, doxorubicin; EPR, enhanced permeability and retention; FDA, U.S. Food and Drug Administration; H2O, water; H2O2, hydrogen peroxide; HIF, hypoxia-inducible factor; HIF-1α, hypoxia-inducible factor-1α; HSA, human serum albumin; Hb, hemoglobin; Hypoxia; MB, methylene blue; MDR1, multidrug resistance 1; MDSC, myeloid derived suppressive cells; Mn-CDs, magnetofluorescent manganese-carbon dots; MnO2, manganese dioxide; NMR, nuclear magnetic resonance; Nanomedicine delivery systems; O2.−, superoxide anion; OH., hydroxyl radical; Oxygen; PDT, photodynamic therapy; PFC, perfluorocarbon; PFH, perfluoroethane; PS, photosensitizers; Photodynamic therapy; RBCs, red blood cells; ROS, reactive oxygen species; TAM, tumor-associated macrophages; TPZ, tirapazamine.
© 2020 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.