Size-controllable covalent organic frameworks with high NIR absorption for targeted delivery of glucose oxidase

Targeted delivery of glucose oxidase (GOx) by covalent organic frameworks (COFs) has long been a great challenge due to their hydrophobic surface and large size. Herein, an effective strategy to synthesize COFs with well-controlled size and good water-dispersiblity was reported. The surface of COFs was further modified with biomolecule, which not only endowed COFs with good biocompatibility and selectivity towards cancer cells, but also made the system especially responsive to near infrared (NIR) light. The strong Vander Waals force and hydrogen interactions between COFs and GOx quenched the fluorescence of GOx, allowed high loading capacity and finally resulted into an excellent synergetic photothermal and starvation therapy mode, which fundamentally kill cancer cells and inhibit migration without using any chemical drugs or photothermal regents. This work provides a new prospect for synthesis and modification of COFs with controllable property, and sheds insight into designing new photothermal and starvation therapy to achieve much better therapeutic effect with negligible side effects.