Application of poly(amidoamine) dendrimer as transfer agent to synthesize poly(amidoamine)-b-poly(methyl acrylate) amphiphilc block copolymers: Self-assembly in aqueous media and drug delivery

Abstract

Herein, second generation cystamine-cored poly(amidoamine) (PAMAM) dendrimer has been synthesized and used as transfer agent in atom transfer radical polymerization (ATRP) of poly(methyl acrylate) (PMA). Transfer reaction to dendrimer has been resulted in synthesis of PAMAM-b-PMA block copolymers with different degree of polymerization of PMA block. Synthesized block copolymers have been self-assembled in aqueous media to prepare cubic/hexagonal and spherical supramolecular structures with nanoscale particle size. Finally, the behavior of drug release from supramolecular structures as nanocarriers of the anticancer drug, doxorubicin (DOX), has been investigated under different conditions. Results showed that in block copolymers with shorter length of hydrophobic block, drug loading capacity was increased due to predominant interactions between dendrimer and drug molecules. Higher hydrophobic block length led to higher cumulative release of drug due to presence of hydrophobic interactions between PMA block and DOX molecules. Moreover, nanocarriers showed significant drug release in acidic media whereas no remarkable release was observed at pH = 7.4.