title: Preparation of thermosensitive microgels via suspension polymerization using different temperature protocols.
abstract: A thermosensitive and biodegradable microgel for protein drug release was synthesized from a thermosensitive macromer via inverse suspension polymerization. Preparation was made under a constant temperature or under variable temperatures. In the latter protocol, dispersion was performed at a low temperature below lower critical solution temperature of the macromer aqueous solution and polymerization was performed at a high temperature above lower critical solution temperature. According to the experiments, the constant-temperature method was not suitable for preparation of microgels when the macromer concentration was high, because early physical gelation at the preparation temperature seriously influenced formation of dispersed droplets. If the macromer concentration was low, both temperature protocols resulted in spherical hydrogel microparticles, but the properties of the resulting microgels were different to a certain degree. In both cases, the model protein bovine serum albumin was loaded into microgels by a postfabrication encapsulation technique, which takes advantage of the microgels' negative thermosensitivity. The results demonstrate that, in microgel preparation, the variable-temperature protocol is useful in suspension polymerization of negatively thermosensitive macromers at a wide rage of monomer concentrations.
authors.affiliation: Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wen
authors.initials: W
authors.lastname: Zhu
authors.forename: Jiandong
authors.initials: J
authors.lastname: Ding
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D004337:Drug Carriers; D020100:Hydrogels / Q000737:chemistry / Q000378:metabolism; D010316:Particle Size; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D020100:Hydrogels; D011108:Polymers; D012710:Serum Albumin, Bovine