Acrylic star block copolymers as hydrophobic drug carriers

Amphiphilic poly(methyl methacrylate)-b-poly(acrylic acid) (PMMA-b-PAA) copolymers with 4 and 6 arms were synthesized by atomic transfer radical polymerization (ATRP). The polymers were characterized by GPC, H-NMR and FTIR analysis. Polymer samples synthesized at various molecular weights between 18-80 kDa were investigated in terms of maximum loading capacity and critical micelle concentration by fluorescence spectroscopy. 4 arm PMMA-b-PAA (MW 30 kDa) was loaded with hydrophobic model drug indomethacin with an extremely high drug loading efficiency (22.5% drug content). Drug loaded polymer formed a stable and biodegradable complex in aqueous medium.