Modular Design of Supramolecular Organic Frameworks for Image‐Guided Photodynamic Therapy

Inspired by the efficient modular design of contemporary engineering, a design philosophy is proposed for the construction of molecular building blocks. Here, modular design of supramolecular organic frameworks (SOFs) for image-guided photodynamic therapy (PDT) in vivo is presented. The closo-dodecaborate cluster (B-12) can selectively bind with the convex exterior of cucurbit[8]uril (CB[8]) with a molar ratio of 1:3 through chaotropic effect, which enables the CB[8]-B(12)based SOFs with exchangeable units/functions. After the B(12)is modified with polyethylene glycol (PEG) and RGD sequence as target ligand and the CB[8] is loaded with methylene blue (MB) as supramolecular photosensitizer, the SOFs can be easily prepared with wide engineering range. A uniform nanoshuttle (NanoSOF) with excellent water dispersibility and bioavailability can be prepared by simply mixing the B-12-PEG-RGD and MB@CB[8] in aqueous solution. As a proof of concept, the NanoSOF is applied as smart nanomedicine for targeted tumor imaging and PDT of tumor, and excellent tumor targeting ability as well as tumor ablation ability can be achieved in vivo. This work highlights the modular design of SOFs with exchangeable units/functions based on chaotropic effect, which may arouse research interests in many other fields.