title: Production of microspheres with surface amino groups from blends of Poly(Lactide-co-glycolide) and Poly(epsilon-CBZ-L-lysine) and use for encapsulation.
abstract: Microspheres were formed from blends of the biodegradable polymer poly(DL-lactic-co-glycolic acid) (PLGA) together with poly(epsilon-CBZ-L-lysine) (PCBZL) by a double-emulsification/solvent evaporation technique. The size of the microspheres formed by this method was dependent both on the total concentration of the polymers and on the ratio of PLGA to PCBZL. The use of the microspheres for encapsulation was demonstrated by the inclusion of a solution of Texas Red fluorescent dye. Lysine epsilon-amino groups on the surface of the microspheres were deprotected by acid hydrolysis or lithium/liquid ammonia reduction. Acid hydrolysis damaged the surface of the microspheres as assessed by scanning electron microscopy, whereas deprotection by lithium/ammonia produced less damage and allowed the retention of encapsulated dye solution. The surface lysine groups made available on the surface of the microspheres could be used to covalently link a variety of biologically active molecules to alter their in vivo properties and allow targeting to specific cell types.
authors.affiliation: Huffington Center on Aging and Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zheng
authors.forename: P J
authors.initials: PJ
authors.lastname: Hornsby
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002214:Capsules; D004655:Emulsions; D005456:Fluorescent Dyes; D019344:Lactic Acid / Q000737:chemistry*; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D012997:Solvents; D013499:Surface Properties; D014966:Xanthenes
chemical_list: D001672:Biocompatible Materials; D002214:Capsules; D004655:Emulsions; D005456:Fluorescent Dyes; D011108:Polymers; D012997:Solvents; D014966:Xanthenes; C077785:N(epsilon)-carbobenzoxylysine; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C034657:Texas red; D008239:Lysine