Encapsulation into amphiphilic polyanhydride microparticles stabilizes Yersinia pestis antigens

The design of biodegradable polymeric delivery systems based on polyanhydrides that would provide for improved structural integrity of Yersinia pesos antigens was the main goal of this study Accordingly, the full-length Y pesos fusion protein (F1-V) or a recombinant Y pesos fusion protein (F1(B2T1)-V10) was encapsulated and released from microparticles based on 1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic acid (SA) copolymers and 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) and CPH copolymers fabricated by cryogenic atomization. An enzyme-linked immunosorbent assay was used to measure changes in the antigenicity of the released proteins The recombinant F1(B2T1)-V10 was unstable upon release from the hydrophobic CPH SA microparticles. but maintained its structure and antigenicity in the amphiphilic CPTEG CPH system The full-length F1-V was stably released by both CPH SA and CPTEG CPH microparticles. In order to determine the effect of the anhydride monomers on the protein structure, changes in the primary, secondary, and tertiary structure, as well as the antigenicity of both Y pestis antigens, were measured after incubation in the presence of saturated solutions of SA. CPH, and CPTEG anhydride monomers The results indicated that the amphiphilic environment provided by the CPTEG monomer was Important to preserve the structure and antigenicity of both proteins These studies offer an approach by which a thorough understanding of the mechanisms governing antigenic instability can be elucidated in order to optimize the in vivo performance of biodegradable delivery devices as protein carriers and/or vaccine adjuvants (C) 2010 Acta Materialia Inc Published by Elsevier Ltd All rights reserved