Well-defined poly(DL-lactide)-b-poly(N-vinylcaprolactam) copolymers: synthesis, solution properties and in vitro degradation

摘要: Well-defined thermoresponsive amphiphilic poly(DL-lactide)-b-poly(N- vinylcaprolactam) (PDLLA-b-PNVCL) block copolymers with various compositions were synthesized via a combination of ring-opening polymerization (ROP) and atom transfer radical (ATRP). Their structures confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR) gel permeation chromatography/multi-angle laser light scattering (GPC/MALLS) measurements. They exhibited reversible temperature-dependent aggregation behavior in aqueous media as characterized turbidity dynamic (DLS) lower critical solution temperatures (LCSTs) increased the increase chain length PNVCL decrease copolymer concentrations. These self-assembled into aggregates morphologies their solution, depending on copolymers. As content increased, morphology changed from spheres to large compound vesicles (LCVs)-like, irregularly spherical micelles. The viscosity measurement 1HNMR analyses proved that these hydrolytically degradable degradation process was accelerated under basic acidic environments, especially media.