Amphiphilic core cross-linked star polymers as water-soluble, biocompatible and biodegradable unimolecular carriers for hydrophobic drugs

Abstract

Unimolecular polymeric architectures are ideal candidates for drug encapsulation. In this study we report the facile yet well-controlled formation of a series of biocompatible and biodegradable core cross-linked star (CCS) polymers via the easily scalable, metal free, one- or two- step ring-opening polymerization (ROP) of ε-caprolactone, using poly(ethylene glycol) (PEG) as initiator and [4,4-bioxepane]-7,7-dione (BOD) as cross-linker. The resulting CCS polymers, which exhibit hydrophilic PEG blocks in their outer shell and hydrophobic poly(ε-caprolactone) (PCL) and BOD segments in their inner core, are water-soluble and amphiphilic and exist in a unimolecular state, both in organic solvents..