UV-stabilized self-assembled amphiphilic triblock terpolymers supramolecular structures with low cytotoxicity as doxorubicin carriers

Amphiphilic polystyrene-b-poly[(7-(Allyloxy)-2H-chromen-2-one)-co-(2-hydroxyethyl methacrylate)]-b-poly(2-(dimethylamino)ethyl methacrylate) (PS-b-P(AC-co-HEMA)-b-P(DMAEMA)) triblock terpolymers were synthesized by atom transfer radical polymerization (ATRP). PS-b-P(AC-co-HEMA)-b-PDMAEMA triblock terpolymers were characterized using proton nuclear magnetic resonance (H-1 NMR) and gel permeation chromatography (GPC). The effect of various pH values on solution self-assembly behavior of PS-b-P(AC-co-HEMA)-b-P (DMAEMA) triblock terpolymers was investigated. Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), fluorescence microscopy, and dynamic light scattering (DLS) were used to observe the size and morphology of the assembled triblock terpolymers. With altering pH value, different morphologies were obtained including spherical micelles, Janus snowman, and spherical Janus as well as cubic-hexagonal structures. UV light was used to stabilize the self-assembled morphologies and FE-SEM results showed that morphology remained unchanged after photo-dimerization. The self-assembled triblock terpolymers before and after photo-crosslinking were loaded with doxorubicin (DOX) and drug release behavior was examined at different conditions. Due to photo-crosslinking of self-assembled terpolymers, cumulative release was decreased. Thus, they might be more controllable drug carriers in drug delivery systems.