Poly[(N-isopropylacrylamide-co-acrylamide-co-(hydroxyethylmethacrylate))] thermoresponsive microspheres: An accurate method based on solute exclusion technique to determine the volume phase transition temperature

摘要: Abstract Poly[(N-isopropylacrylamide-co-acrylamide-co-(hydroxyethylmethacrylate))] [poly(NIPAAm-co-AAm-co-HEMA)] copolymer was synthesized as a new thermoresponsive material possessing lower critical solution temperature (LCST) around 37 °C in phosphate buffer, pH 7.4, at concentration of 1%, w/v. The influence polymer on LCST determined by cloud point measurements and microcalorimetric analysis. transformed hydrogel microspheres suspension reticulation OH groups with glutaraldehyde. volume phase transition (VPTT) approach, which involves measurement the increase blue dextran (BD) different temperatures presence dry microspheres. minimum BD that gives reliable reproducible results to be 1 mg/ml. However, higher is smaller error. Contrary linear displays sharp temperature, dependence water regain lasts from 4 °C 50 °C.