Carbon Dots Based Nanoscale Covalent Organic Frameworks for Photodynamic Therapy

Abstract Covalent organic frameworks (COFs) have attracted much attention for various applications, while developing COFs with biomedical functions remains a big challenge. Most COFs are built purely from organic molecules, no carbon dots (CDs)‐based COFs have been exploited to date. In this work, diamine molecules p‐phenylenediamine and BODIPY are selected as model monomers to react with aldehyde‐containing CDs and construct nanoscale COFs, named CCOF‐1 and CCOF‐2, respectively. After the modification with poly(ethylene glycol) (PEG), the formed CCOF‐1@PEG and CCOF‐2@PEG are stable and well‐dispersible in aqueous media. The merits of CCOF‐2@PEG containing favorable physiological stability, good biocompatibility, and strong reactive oxygen species generation ability enable it to act as an excellent photodynamic therapy (PDT) agent for tumor treatment. The high PDT therapeutic efficiency for inhibiting cell proliferation and tumor growth was well shown by in vitro and in vivo experiments. This work demonstrates a new strategy for fabricating functional COF‐based platforms for biomedical applications.