title: Fabrication and in vitro drug release study of microsphere drug delivery systems based on amphiphilic poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide]-g-poly(L-lactide) graft copolymers.
abstract: Biodegradable amphiphilic graft copolymers with different compositions were synthesized by grafting poly(L-lactide) (PLLA) sequences onto a water-soluble poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA) backbone. The critical micelle concentration (CMC) of the graft polymers was determined by fluorescence probe technique. Using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, the graft polymers were proved to have low cytotoxicity. Based on the specific physicochemical property of the graft copolymers, submicron sized microsphere drug delivery systems were prepared by a very convenient "ultrasonic dispersion method", which did not involve toxic organic solvents. The drug-loaded microspheres had a regular spherical shape with a narrow size distribution. A hydrophobic drug, prednisone acetate, was encapsulated into polymeric microspheres and the in vitro drug release was studied.
authors.affiliation: Key Laboratory of Biomedical Polymers of Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China.
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Zhou
authors.forename: Song-Lin
authors.initials: SL
authors.lastname: Li
authors.forename: Hui-Li
authors.initials: HL
authors.lastname: Fu
authors.forename: Si-Xue
authors.initials: SX
authors.lastname: Cheng
authors.forename: Xian-Zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Ren-Xi
authors.initials: RX
authors.lastname: Zhuo
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D016503:Drug Delivery Systems; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D041681:NIH 3T3 Cells; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D011241:Prednisone / Q000737:chemistry; D011506:Proteins / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D011091:Polyesters; D011108:Polymers; D011506:Proteins; C527879:poly-alpha,beta-(N-(2-hydroxyethyl)aspartamide)-g-polylactide; D011241:Prednisone