Construction of Multiform Hollow‐Structured Covalent Organic Frameworks via a Facile and Universal Strategy for Enhanced Sonodynamic Cancer Therapy

Abstract

The special structural morphology of hollow covalent organic frameworks (HCOFs) has an important influence on their applications. However, the rapid and precise control of morphology for HCOFs still remains largely challenging. Herein, we present a facile and universal two-step strategy based on solvent evaporation and oxidation of imine bond for the controllable synthesis of HCOFs. The strategy enables to prepare HCOFs in a greatly shortened reaction time and seven kinds of HCOFs are fabricated by the oxidation of imine bond via hydroxyl radicals ( * OH) generated from Fenton reaction. Importantly, a fascinating library of HCOFs with diverse nanostructures, including bowllike, yolk-shell, capsule-like and flower-like morphologies, has been ingeniously constructed. Owing to the large cavities, the obtained HCOFs are ideal candidates for drug delivery, which are employed to load five small molecule drugs, achieving the enhanced sonodynamic cancer therapy in vivo.

Strategies for utilizing covalent organic frameworks as host materials for the integration and delivery of bioactives

“…Liu and coworkers proposed a fascinating strategy for the controllable synthesis of a series of hollow COFs via the oxidation of the imine bond via hydroxyl radicals (˙OH) generated from the Fenton reaction. 47 The whole procedure included two steps (Fig. 5(C)), where firstly, a solvent evaporation strategy was proposed for the synthesis of high crystallinity COFs, by which the solvent (ACN) and catalysis (acetic acid) were evaporated when exposed in an uncovered vessel at mild temperature (room temperature to 60 °C) with stirring.…”