BSA-FITC-loaded microcapsules for in vivo delivery.
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.
Kim
Byung Soo
BS
Fusion Biotechnology Research Center, Korea Research Institute of Chemical Technology, PO Box 107, Yuseong, Daejeon 305-600, South Korea.
Oh
Jae Min
JM
Kim
Kyung Sook
KS
Seo
Kwang Soo
KS
Cho
Jae Song
JS
Khang
Gilson
G
Lee
Hai Bang
HB
Park
Kinam
K
Kim
Moon Suk
MS
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*
D002214:Capsules; D012710:Serum Albumin, Bovine; D016650:Fluorescein-5-isothiocyanate