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

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.