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

Abstract

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.