An in vitro focus on doxorubicin hydrochloride delivery of novel pH-responsive poly(2-succinyloxyethylmethacrylate) and poly[(N-4-vinylbenzyl),N,N-diethylamine] diblock copolymers

Novel pH-responsive poly(2-succinyloxyethylmethacrylate)-b-poly[(N-4-vinylbenzyl),N,N-diethylamine] [poly(SEMA-b-VEA)] diblock copolymers were synthesized via reversible addition fragmentation transfer (RAFT) polymerization to investi- gate their self-assembly micellar behavior. The self-assembly behaviors of synthesized diblock copolymers with distinct molecular weights (labeled (1) to) were confirmed by 1H NMR spectroscopy, TEM and dynamic light scattering mea- surements. Doxorubicin hydrochloride (DOX) loading capacity was evaluated, and the in vitro cytotoxicity effect of DOX-loaded diblock copolymer was also studied by assessing the survival rate of the breast cancer cell line MCF-7 with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. The results exhibited remarkable controlled release in the MTT assay. The DOX encapsulation efficiency was calculated to be 96.4%. The size and zeta potential of DOX-loaded poly(SEMA-b-VEA) diblock copolymers were 204 nm and +5.7mV at a pH of 7.4. DOX release values after 440 h at pH7.4, 5.4 and 4 were 22.15%, 31.43% and 47.06%, respectively. The released values of DOX-loaded poly(SEMA-b-VEA) and at pH7.4 were 22.15%, 20.5%and 17.5%, respectively. Cell survival ratios were 18.9%, 23.16%and 16.92%after 72 h. Poly(SEMA-b-VEA) copolymers can be considered in nanomedicine applications due to their excellent pH-responsivemicellar behavior. © 2017 Society of Chemical Industry

pH-responsive; diblock copolymer; drug delivery; MTT assay