title: BSA-FITC-loaded microcapsules for in vivo delivery.
abstract: Here we describe the preparation of BSA-FITC-loaded microcapsules as a model protein system for in vivo delivery. BSA-FITC-loaded microcapsules were prepared using a mono-axial nozzle ultrasonic atomizer, varying a number of parameters to determine optimal conditions. The preparation method chosen resulted in a BSA-FITC encapsulation efficiency of approximately 60% and a particle size of approximately 50 microm. An analysis of the microcapsules showed a BSA-FITC core surrounded by a poly(D,L-lactic-co-glycolic acid) (PLGA) shell. Injection of BSA-FITC-loaded microcapsules into rats resulted in a sustained release of BSA-FITC that maintained increased concentrations of BSA-FITC in plasma for up to 2 weeks. In contrast, the concentration of BSA-FITC in plasma after injection of BSA-FITC-only solution reached near-zero levels within 3 days. Fluorescence images of microcapsules removed at various times after implantation showed a gradual decrease of BSA-FITC in BSA-FITC-loaded microcapsules, confirming a sustained in vivo release of BSA-FITC. The duration of in vivo release and plasma concentration of BSA-FITC was correlated with the initial dose of BSA-FITC. BSA-FITC-loaded microcapsules maintained their structure for at least 4 weeks in the rat. The inflammatory response observed initially after injection declined over time. In conclusion, BSA-FITC-loaded microcapsules achieved sustained release of BSA-FITC, suggesting that microcapsules manufactured as described may be useful for in vivo delivery of pharmacologically active proteins.
authors.affiliation: Fusion Biotechnology Research Center, Korea Research Institute of Chemical Technology, PO Box 107, Yuseong, Daejeon 305-600, South Korea.
authors.forename: Byung Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Oh
authors.forename: Kyung Sook
authors.initials: KS
authors.lastname: Kim
authors.forename: Kwang Soo
authors.initials: KS
authors.lastname: Seo
authors.forename: Jae Song
authors.initials: JS
authors.lastname: Cho
authors.forename: Gilson
authors.initials: G
authors.lastname: Khang
authors.forename: Hai Bang
authors.initials: HB
authors.lastname: Lee
authors.forename: Kinam
authors.initials: K
authors.lastname: Park
authors.forename: Moon Suk
authors.initials: MS
authors.lastname: Kim
mesh_terms: D000818:Animals; D002214:Capsules / Q000008:administration & dosage* / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry*; D007249:Inflammation; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D051381:Rats; D012710:Serum Albumin, Bovine / Q000737:chemistry*
chemical_list: D002214:Capsules; D012710:Serum Albumin, Bovine; D016650:Fluorescein-5-isothiocyanate