title: Optimization of entrapping conditions to improve the release of BMP-2 from PELA carriers by response surface methodology.
abstract: A microcapsule prepared from triblock copolymer poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA, PELA) was investigated as a controlled release carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2). The rhBMP-2/PELA microspheres were prepared using the water-in-oil-in-water (W/O/W) solvent evaporation method. This work was conducted to optimize the entrapping conditions of the rhBMP-2 loaded PELA copolymer. The effects on encapsulation efficiency (EE) of different molecular weights (MW) of PEG in the copolymer, the amount of PELA, the amount of rhBMP-2, the span-20 concentration, the polyvinyl alcohol (PVA) concentration and stirring time were tested. On the basis of single-factor experiments, the optimum parameters were achieved using response surface methodology (RSM). The results showed that the highest EE of BMP-2 was achieved with a span-20 concentration of 0.5%, PEG MW 4000 Da, a stirring time of 30 min at 800 rpm min(-1), 282.3 mg of PELA, 1 μg of rhBMP-2 and PVA concentration 0.79%. Under these optimal conditions, it was predicted that the highest EE to be achieved would be 76.5%; the actual EE achieved was 75%.
authors.affiliation: Department of Orthopaedics, Zhujiang Hospital affiliated with Southern Medical University Guangzhou, Guangzhou 510282, People's Republic of China.
authors.forename: Xialin
authors.initials: X
authors.lastname: Li
authors.forename: Shaoxiong
authors.initials: S
authors.lastname: Min
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhao
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Lu
authors.forename: Anmin
authors.initials: A
authors.lastname: Jin
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D004337:Drug Carriers; D004655:Emulsions; D006801:Humans; D008863:Microspheres; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties; D016212:Transforming Growth Factor beta / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D004337:Drug Carriers; D004655:Emulsions; D011091:Polyesters; D011994:Recombinant Proteins; D012997:Solvents; D016212:Transforming Growth Factor beta; C507889:polylactide-polyethylene glycol-polylactide; C499469:recombinant human bone morphogenetic protein-2; D011092:Polyethylene Glycols; D011142:Polyvinyl Alcohol