title: Synthesis and characterization of poly(lactic acid-co-glycolic acid) complex microspheres as drug carriers.
abstract: Poly(lactic-co-glycolic) acid (PLGA) is synthesized via melt polycondensation directly from lactic acid and glycolic acid with a feed molar ratio of 75/25. Bovine serum albumin, which is used as model protein, is entrapped into the poly(lactic-co-glycolic acid) microspheres with particle size of 260.9 ± 20.0 nm by the double emulsification method. Then it is the first report of producing more carboxyl groups by poly(lactic-co-glycolic acid) surface hydrolysis. The purpose is developing poly(lactic-co-glycolic acid) microspheres surface, which is modified with chitosan by chemical reaction between carboxyl groups and amine groups. The particle size and the positive zeta potential of the poly(lactic-co-glycolic acid)/chitosan microspheres are 388.2 ± 35.6 nm and 10.4 ± 2.9 mV, respectively. The drug loading ratio and encapsulation efficacy of poly(lactic-co-glycolic acid)/chitosan microspheres are 36.3% and 57.5%, which are higher than PLGA microspheres. Furthermore, the drug burst release of poly(lactic-co-glycolic acid)/chitosan microspheres at 10 h is decreased to 21.72% while the corresponding value of the poly(lactic-co-glycolic acid) microsphere is 64.56%. These results reveal that surface hydrolysis modification of poly(lactic-co-glycolic acid) is an efficient method to improve the negative potential and chemical reaction properties of the polymer. And furthermore, this study shows that chitosan-modified poly(lactic-co-glycolic acid) microspheres is a promising system for the controlled release of pharmaceutical proteins.
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, PR China Department of Mechanical Engineering, University of Delaware, Newark, United States wangfang@njfu.edu.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, PR China.
authors.forename: Xiuxiu
authors.initials: X
authors.lastname: Liu
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yuan
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, PR China.
authors.forename: Siqian
authors.initials: S
authors.lastname: Yang
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, PR China.
authors.forename: Yueqin
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing, PR China.
authors.forename: Qinwei
authors.initials: Q
authors.lastname: Gao
mesh_terms: D065966:Absorption, Physicochemical; D002214:Capsules / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000737:chemistry*; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012710:Serum Albumin, Bovine / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D012710:Serum Albumin, Bovine; D019344:Lactic Acid
keywords: Poly(lactic-co-glycolic) acid; chitosan; drug delivery system; hydrolysis; microspheres; synthesis