Facile fabrication of highly soluble, extremely small-sized drug carriers using globular poly(ethylene glycol)

Abstract

We report extremely small-sized drug-carrying globular poly(ethylene glycol) particles. These particles were prepared using fullerene (C-60) as a backbone structure and poly(ethylene glycol) as a hydrophilic shell. All - carbon bonds in C-60 were combined with poly(ethylene glycol), which form a globular nano-cage with a hollow core (originating from the soccer-ball-shaped truncated icosahedron of C-60) and the poly(ethylene glycol) shell. Subsequently, we constructed chlorin e6-conjugated globular poly(ethylene glycol). The obtained globular poly(ethylene glycol)-chlorin e6 (average 3.6nm in diameter) was soluble in aqueous solution and enabled improved singlet oxygen generation. The preferential cellular uptake of globular poly(ethylene glycol)-chlorin e6 resulted in significant enhancement of in vitro or in vivo photodynamic tumor cell ablation under light illumination. Our approach offers a versatile strategy to create extremely small-sized drug carriers using a biocompatible polymer for various biomedical applications.