Single-Crystal to Single-Crystal Transformation of Metal–Organic Framework Nanoparticles for Encapsulation and pH-Stimulated Release of Camptothecin

Abstract

The phenomenon of single-crystal to single-crystal transformation and the performance change along with the transformation have been widely discovered, whereas the efficient utilization of the crystal transformation process is less reported. Herein, we present an interesting thermally driven single-crystal to single-crystal transformation of HNU-43. During transformation, the effective encapsulation of camptothecin (CPT) has been achieved as CPT-HNU-43 converts into CPT-HNU-43(T), which cannot directly encapsulate CPT owing to the small channel size of HNU-43(T). Following the successful packaging, the CPT can be triggered to gradually release as pH = 6.0 which is quite close to the acid environment of cancer cells. Furthermore, CPT-HNU-43(T) nanoparticles show excellent biocompatibility, and the cancer cells can be effectively inhibited through the release of CPT.