| 초록 |
pH-sensitive and biodegradable polyaspartamide derivatives were synthesized by a successive graft reaction of O-(2-aminoethyl)-O'-methylpoly(ethylene glycol) 5000, 1-(3-aminopropyl)imidazole and lactic acid oligomers(LAs) on polysuccinimide for drug delivery systems. LAs were synthesized by ring-opening polymerization of L-lactide using 1-dodecanol as initiator, and stannous octoate as catalyst. LAs were activated with succinic anhydride, and were nodified N-hydroxysuccimide/1,3-Dicyclohexylcar bodiimide. The structure and the degree of substitution of the prepared polymer was confirmed using FT-IR and 1H NMR spectroscopy. Their pH-sensitive properties were characterized by light transmittance measurements, and the effect of the degree of substitution(DS) of MPEG/LAs/API on the selfassociation properties of MPEG/LAs/API grafted polyaspartamide derivatives in aqueous solution were investigated by dynamic light scattering measurements(DLS) |
