Biomimetic O2-Evolving metal-organic framework nanoplatform for highly efficient photodynamic therapy against hypoxic tumor

Improving the supply of O-2 and the circulation lifetime of photosensitizers for photodynamic therapy (PDT) in vivo would be a promising approach to eliminate hypoxic tumors. Herein, by taking advantage of the significant gas-adsorption capability of metal-organic frameworks (MOFs), a biomimetic O-2-evolving photodynamic therapy (PDT) nanoplatform with long circulating properties was fabricated. Zirconium (IV)-based MOF (UiO-66) was used as a vehicle for O-2 storing, then conjugated with indocyanine green (ICG) by coordination reaction, and further coated with red blood cell (RBC) membranes. Upon 808 nm laser irradiation, the initial singlet oxygen (O-1(2)) generated by ICG would decompose RBC membranes. At the same time, The photothermal property of ICG could facilitate the burst release of O-2 from Ui0-66. Subsequently, the generated O-2 could significantly improve the PDT effects on hypoxic tumor. Owing to the advantages of long circulation and O-2 self-sufficient, the designed nanotherapeutic agent can improve the efficiency of treatment against hypoxia tumor via PDT. Hence, this study presents a new paradigm for co-delivery of O-2 and photosensitizers, and provides a new avenue to eliminate hypoxic tumors. (C) 2018 Elsevier Ltd. All rights reserved.