An amphiphilic block copolymer conjugated with carborane and a NIR fluorescent probe for potential imaging-guided BNCT therapy

A carborane-containing triblock copolymer conjugated with a near infrared (NIR) fluorescence probe has been synthesized via reversible addition fragmentation chain transfer (RAFT), ring open polymerization (ROP), and conjugations of a cyanine NIR dye. Reactions were traced by means of 1H-NMR, GPC and FT-IR. The NIR amphiphilic copolymer with polycaprolactone and polycarborane as hydrophobic segments and poly(ethylene glycol)methyl ether methacrylate as the hydrophilic segment could self-assemble into micelles in aqueous solution, and was characterized by means of DLS and TEM. In the copolymer, carborane works as a boron neutron capture therapy (BNCT) agent while the aminocyanine (Cy) dye works as a NIR bioimaging agent, and the nanoparticles of the copolymers are a potential theranostic BNCT system for cancer therapy, which was supported by MTT experiments and in vitro fluorescence microscopy studies.