title: Spray-drying preparation of microparticles containing cationic PLGA nanospheres as gene carriers for avoiding aggregation of nanospheres.
abstract: Preparation of nano-sized particles using lyophilization, which is a standard drying technique for high-molecular-weight compounds such as bioactive peptides, proteins, plasmid DNA and siRNA, often results in particle aggregation. In this study, spray-drying was applied for preparation of cationic PLGA nanospheres as gene delivery vectors in order to minimize aggregation and loss of gene transfection efficiency. PLGA nanoparticle emulsions were prepared by dropping an acetone/methanol mixture (2/1) containing PLGA and a cationic material, such as PEI, DOTMA, DC-Chol or CTAB, into distilled water with constant stirring. The PLGA nanosphere emulsion was dried with mannitol by spray-drying, and mannitol microparticles containing PLGA nanospheres were obtained. Mean particle diameter of spray dried PLGA particles was 100-250 nm, which was similar to that of the nano-emulsion before drying, whereas the lyophilized PLGA particles showed increased particle diameter due to particle aggregation. PEI, DOTMA and DC-Chol were useful for maintaining nanoparticle size and conferring positive charge to nanospheres. Transfection of pDNA (pCMV-Luc) using these spray-dried cationic PLGA nanospheres yielded high luciferase activity in COS-7 cells, particularly with PLGA/PEI nanospheres. The present spray-drying technique is able to provide cationic PLGA nanospheres, and may improve redispersal and handling properties.
authors.affiliation: Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi Hachioji, Tokyo 192-0392, Japan. takasima@ps.toyaku.ac.jp
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Takashima
authors.forename: Ryo
authors.initials: R
authors.lastname: Saito
authors.forename: Azusa
authors.initials: A
authors.lastname: Nakajima
authors.forename: Motoko
authors.initials: M
authors.lastname: Oda
authors.forename: Aki
authors.initials: A
authors.lastname: Kimura
authors.forename: Takanori
authors.initials: T
authors.lastname: Kanazawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okada
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004247:DNA / Q000008:administration & dosage / Q000737:chemistry; D004339:Drug Compounding / Q000379:methods*; D005260:Female; D005612:Freeze Drying; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D019344:Lactic Acid / Q000008:administration & dosage / Q000737:chemistry*; D008156:Luciferases / Q000378:metabolism; D008353:Mannitol / Q000008:administration & dosage / Q000737:chemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D054118:Nanospheres / Q000737:chemistry*; D010316:Particle Size; D010957:Plasmids; D011094:Polyethyleneimine / Q000008:administration & dosage / Q000737:chemistry; D011100:Polyglycolic Acid / Q000008:administration & dosage / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000008:administration & dosage / Q000737:chemistry*; D014018:Tissue Distribution; D014162:Transfection / Q000379:methods
chemical_list: D011108:Polymers; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D008353:Mannitol; D011094:Polyethyleneimine; D004247:DNA; D008156:Luciferases