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Unimolecular Photodynamic O2‑Economizer To Overcome Hypoxia Resistance in Phototherapeutics
journal contribution
posted on 2020-03-06, 20:42 authored by Mingle Li, Yujie Shao, Ji Hyeon Kim, Zhongji Pu, Xueze Zhao, Haiqiao Huang, Tao Xiong, Yao Kang, Guangzhe Li, Kun Shao, Jiangli Fan, James W. Foley, Jong Seung Kim, Xiaojun PengTumor hypoxia has
proven to be the major bottleneck of photodynamic
therapy (PDT) to clinical transformation. Different from traditional
O2 delivery approaches, here we describe an innovative
binary photodynamic O2-economizer (PDOE) tactic to reverse
hypoxia-driven resistance by designing a superoxide radical (O2•–) generator targeting mitochondria
respiration, termed SORgenTAM. This PDOE system is able to block intracellular
O2 consumption and down-regulate HIF-1α expression,
which successfully rescues cancer cells from becoming hypoxic and
relieves the intrinsic hypoxia burden of tumors in vivo, thereby sparing
sufficient endogenous O2 for the PDT process. Photosensitization
mechanism studies demonstrate that SORgenTAM has an ideal intersystem
crossing rate and triplet excited state lifetime for generating O2•– through type-I photochemistry,
and the generated O2•– can further
trigger a biocascade to reduce the PDT’s demand for O2 in an O2-recycble manner. Furthermore, SORgenTAM also
serves to activate the AMPK metabolism signaling pathway to inhibit
cell repair and promote cell death. Consequently, using this two-step
O2-economical strategy, under relatively low light dose
irradiation, excellent therapeutic responses toward hypoxic tumors
are achieved. This study offers a conceptual while practical paradigm
for overcoming the pitfalls of phototherapeutics.