Photodynamic tumor therapy of nanoparticles with chlorin e6 sown in poly(ethylene glycol) forester

We developed novel photosensitizing drug-carrying nanoparticles with poly(ethylene glycol) (PEG) forester. In this study, chlorin e6 (Ce6, a model photosensitizing drug) was grafted to a poly(L-lysine) [poly(Lys)] derivative containing multiple PEG segments and carboxylic acids at its pendant chain and 3,4-dihydroxyhydrocinnamic acid (DOHA) at one terminal site on its backbone. The conjugate was bound to the surface of gold nanoparticles (AuNPs) as a result of non-covalent interaction between its DOHA moiety and AuNPs. These nanoparticles enabled elevated singlet oxygen generation due to the dequenching event of Ce6 molecules shielded in PEG forester. This system resulted in highly improved in vitro/in vivo photodynamic tumor cell ablation over the nanoparticles without PEG forester. We believe that this system with PEG forester for photosensitizing drugs possesses great potential for tumor therapy.