Controllable growth of drug-encapsulated metal-organic framework (MOF) on porphyrinic MOF for PDT/chemo-combined therapy

To improve the therapeutic effect of tumors, developing well-defined hybrid metal-organic frameworks (MOFs) through MOF-on-MOF growth has attracted much attention. In this work, an in situ growth strategy was reported to assemble doxorubicin (DOX)-encapsulated zeolitic imidazolate frameworks (ZIF-8) on the surface of Zr(IV)-based porphyrinic MOFs. Such an approach offers a high controllability in the thickness of the ZIF-8 layer without any requirement of surface modifications on porphyrinic MOFs. Impressively, the acidic pH-response degradation of ZIF-8 promoted the release of DOX in the acidic tumor microenvironment. Upon light irradiation, porphyrinic MOFs can harvest photons to produce plentiful singlet oxygen, thus leading to amplified chemo/PDT therapeutic efficacy. This work paves the way to utilize the hybrid engineering of MOFs for synergistic cancer therapy.