title: Osmogen-Mediated One-Step Technique of Fabricating Hollow Microparticles for Encapsulation and Delivery of Bioactive Molecules.
abstract: Microparticulate systems composed of biodegradable polymers, such as poly(d,l-lactic-co-glycolic acid) (PLGA), are widely used for controlled release of bioactive molecules. However, the acidic microenvironment within these microparticles, as they degrade, has been reported to perturb the configuration of most encapsulated proteins. In addition, these polymer particles are also reported to suffer from unrealistically slow and incomplete release of proteins. To address these drawbacks, hollow PLGA microparticles are fabricated through a novel one-step oil-in-water emulsion solvent evaporation technique, by capitalizing on the osmotic property of an osmogen. The effects of fabrication para-meters on particle size and morphology, i.e., volume space of hollow cavity and shell thickness, are also studied. These hollow microparticles are subsequently loaded with bovine insulin microcrystals. It is shown that insulin release profiles can be tuned by simply changing the amount of osmogen in the formulation. At the same time, these hollow microparticles are shown to be effective in maintaining the bioactivity of the encapsulated protein.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798.
authors.forename: Sharad
authors.initials: S
authors.lastname: Kharel
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798.
authors.forename: Wei Li
authors.initials: WL
authors.lastname: Lee
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798.
authors.forename: Xuan Yi
authors.initials: XY
authors.lastname: Lee
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798.|Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, 637551.
authors.forename: Say Chye Joachim
authors.initials: SC
authors.lastname: Loo
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects; D002942:Circular Dichroism; D004339:Drug Compounding / Q000379:methods*; D016503:Drug Delivery Systems / Q000379:methods*; D065546:Drug Liberation; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D019344:Lactic Acid / Q000737:chemistry; D061986:MCF-7 Cells; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012965:Sodium Chloride / Q000494:pharmacology*; D012997:Solvents
chemical_list: D001672:Biocompatible Materials; D007328:Insulin; D012997:Solvents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D012965:Sodium Chloride
keywords: PLGA; acidic microenvironment; hollow; microparticles; osmogen; protein