In situ synthesis of a functional ZIF-8 nanocomposite for synergistic photodynamic–chemotherapy and pH and NIR-stimulated drug release.

In this paper, we designed and synthesized a novel pH and NIR light responsive UCNP/TiO2/Cur@ZIF-8 nano-composite. The newly synthesized nano-platform was characterized using spectroscopic methods. Here, upconversion nanoparticles (UCNPs) and titanium dioxide nanoparticles (TiO2 NPs) were encapsulated to upconvert energy through the photosensitizing phenomenon where the chemotherapeutic agent curcumin (Cur) and TiO2 synergistically achieved therapeutic effects. At first, ZIF-8 decomposed in the acidic microenvironment of tumors that assisted TiO2 NPs to efficiently convert the irradiated near infrared (NIR) 808 nm light into UV visible light, thus producing a large number of reactive oxygen species to effectively inhibit tumor growth. Furthermore, in vitro and in vivo data demonstrated that UCNP/TiO2/Cur@ZIF-8 is an excellent nanoplatform that can be used as NIR-mediated photodynamic as well as chemotherapeutic therapy for tumors. [ABSTRACT FROM AUTHOR]