| 초록 |
Smart drug delivery with site-specific and time-controlled manner is critical for maximizing the therapeutic efficacy with reduced side-effect. Here, we describe an efficient approach to control the degradation kinetics of block copolymer micelles in acidic condition synthesized from the two novel epoxide monomers with different acetal groups. The amphiphilic block random copolymers, poly(ethylene glycol)-block-poly(ethoxyethyl glycidyl ether-co-tetrahydropyranyl glycidyl ether)s (PEG-b-P(EEGE-co-TGE))s were synthesized with pH-responsive epoxide monomers, ethoxyethyl glycidyl ether (EEGE) and tetrahydropyranyl glycidyl ether (TGE).1 A series of random copolymers, PEG-b-P(EEGE-co-TGE) was synthesized by controlling the ratio of two functional epoxide monomers, EEGE and TGE with acyclic and cyclic acetal moiety by anionic ring-opening polymerization. The block copolymers were successfully characterized by NMR, GPC, and DSC and the copolymerization kinetics between the two monomers was further studied by in situ 1H NMR analysis. The micelles prepared from a series of PEG-b-P(EEGE-co-TGE) copolymers exhibited the controlled critical micelle concentration values, loading efficiency and degradation kinetics with respect to the fraction of the TGE monomer. Interestingly, the micelles of PEG-b-P(EEGE-co-TGE) copolymers showed the highly tunable release profiles in mild acidic condition and biological condition, which are attributed to the changes in the hydrophobicity and packing density owing to the cyclic TGE side chains. The tunable release properties coupled with the high biocompatibility clearly demonstrate the significant potential of the prepared copolymers in smart drug delivery. We anticipate that the novel approach developed in this study will broaden the smart drug delivery system and offer promising monomer choices to the biomaterials and biomedical applications. (1) J. Song, L. Palanikumar, Y. Choi, I. Kim, T. Heo, E. Ahn, S.-H. Choi, E. Lee, Y. Shibasaki, J.-H. Ryu, and B.-S. Kim, Polym. Chem., 8, 7119 (2017). |
