title: Facile control of porous structures of polymer microspheres using an osmotic agent for pulmonary delivery.
abstract: It has been challenging to prepare polymeric microspheres with controlled porous structures for many biomedical applications, particularly for pulmonary drug delivery. Here, we report the use of bovine serum albumin (BSA) as an osmotic agent in order to control the porous structure of poly(D,L-lactide-co-glycolide) (PLGA) microspheres prepared by a double emulsion method. BSA was useful to induce osmosis between internal and external water phases during the double emulsion process, resulting in the fabrication of microspheres with controllable, uniform porous structures. The pore size of PLGA microspheres was controlled independently from the particle size by this approach. The use of BSA as an osmotic agent reduced the initial burst of model proteins (e.g., insulin and VEGF) entrapped in the porous microspheres, and the sustained release of VEGF was achieved for two weeks in vitro. This approach to controlling porous structures of polymer microspheres could be useful to develop novel pulmonary drug delivery systems.
authors.affiliation: Department of Bioengineering, Hanyang University, Seoul 133-791, Republic of Korea.
authors.forename: Jangwook
authors.initials: J
authors.lastname: Lee
authors.forename: Yu Jin
authors.initials: YJ
authors.lastname: Oh
authors.forename: Sang Kyung
authors.initials: SK
authors.lastname: Lee
authors.forename: Kuen Yong
authors.initials: KY
authors.lastname: Lee
mesh_terms: D000818:Animals; D001682:Biological Availability; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding; D004655:Emulsions; D005260:Female; D007328:Insulin / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D019344:Lactic Acid / Q000737:chemistry*; D008168:Lung / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D009995:Osmosis; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012995:Solubility; D014018:Tissue Distribution; D042461:Vascular Endothelial Growth Factor A / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D007328:Insulin; D011994:Recombinant Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D012710:Serum Albumin, Bovine; D019344:Lactic Acid