Encapsulation, stabilization, and release of BSA-FITC from polyanhydride microspheres


Publication Type:

Journal Article


Journal of Controlled Release : official journal of the Controlled Release Society, Volume 100, Number 1, p.97-109 (2004)


0168-3659 (Print)<br/>0168-3659 (Linking)

Accession Number:



*Microspheres, derivatives/chemistry, Electrophoresis, Polyacrylamide Gel, Fluorescein-5-isothiocyanate/*administration & dosage/*analogs &, Polyanhydrides/*administration & dosage, Serum Albumin, Bovine/*administration & dosage/chemistry, Spectroscopy, Fourier Transform Infrared


<p>In order to determine the efficacy of using polyanhydrides as a carrier for therapeutic proteins, the model protein bovine serum albumin labeled with fluorescein isothiocyanate (BSA-FITC) was encapsulated in microspheres of poly sebacic anhydride (poly(SA)), and random copolymers of poly(SA) and poly(1,6-bis-p-carboxyphenoxy)hexane (poly(CPH)). The microspheres were fabricated via the double emulsion (water/oil/water) technique and were characterized using scanning electron microscopy, gel permeation chromatography, confocal microscopy, and a Coulter counter. The effect of protein loading, protein distribution, and change in polymer composition was examined in an in vitro release study. The secondary structure of the encapsulated BSA-FITC was determined with Fourier transform infrared spectroscopy. The primary structure of the released protein was analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Poly(SA) and 20:80 (CPH:SA) microspheres were found to conserve the primary structure of the released protein and the secondary structure of the encapsulated protein, and showed a sustained delivery for approximately 15 and 30 days, respectively. As the CPH content in the copolymer increased, the secondary structure of FITC-BSA was not conserved, as indicated by the steep decrease in the alpha-helix content.</p>


Determan, Amy S<br/>Trewyn, Brian G<br/>Lin, Victor S-Y<br/>Nilsen-Hamilton, Marit<br/>Narasimhan, Balaji<br/>Netherlands<br/>J Control Release. 2004 Nov 5;100(1):97-109.