Self-Assembled PEGylated Nanocubes Based on Hydrophobic Camptothecin and Doxorubicin for Combinational Therapy of Colorectal Cancer

Nanoassemblies based on drug conjugates with high drug loading efficiency and stability have been regarded as promising candidates for the next generation of drug formulations. However, they are mostly amphiphilic. Here, a dual-hydrophobic drug conjugate-based nanoassembly has been created for enhanced synergistic antiproliferation against colorectal cancer cells. Camptothecin (CPT) and doxorubicin (DOX) were chosen as the hydrophobic drugs and covalently linked with a disulfide bond (-ss-). The synthesized CPT-ss-DOX can self-assemble into nanocubes (NCs) in an aqueous solution with the assistance of a small amount of polyethylene glycol (PEG), named PEGylated CPT-ss-DOX NCs. The PEGylated CPT-ss-DOX NCs were approximately 111.8 nm, possessing a crystal structure and a very low critical aggregation concentration (8.36 μg·mL