Synthesis of multifunctional miktoarm star polymers via an RGD peptide-based RAFT agent

Miktoarm star (MAS) polymers are polymers with a number of distinct arms connected to a central core. Owing to their exclusive structure, MAS polymers have been extensively studied in recent years. To exploit their biomedical applications the combination of nucleic acids, peptides and saccharides are desired. In this study, RAFT polymerization of three monomers with markedly different properties, N,N-dimethylaminoethyl methacrylate (DMAEMA, cationic), n-butyl methacrylate (BMA, hydrophobic) and oligo(ethylene glycol) methyl ether methacrylate (OEGMA, hydrophilic) was conducted using an RGD peptide based RAFT agent as a chain transfer agent (RGD-CTA). With a disulphide dimethacrylate (DSDMA) redox-cleavable cross-linker, the above linear polymers were combined via an arm-first technique to access MAS polymers containing peptide arms. These MAS polymers showed excellent biocompatibility, cell staining performance and rapid redox responsiveness. The novel MAS polymers have potential as a prospective platform for intracellular drug/gene delivery for cancer therapy.