POLY(EPSILON-CAPROLACTONE) MICROSPHERES AS A VACCINE CARRIER

Poly(epsilon-caprolactone) (PCL), a biocompatible and biodegradable po lymer hitherto thought unsuitable for protein delivery because of its poor permeability to macromolecules, is shown to be sufficiently perme able to proteins to function as a vaccine carrier, Using a model antig en such as bovine serum albumin (BSA), we demonstrate that a single in jection of BSA-loaded PCL microspheres generates an immune response co mparable in magnitude and time kinetics to that of a conventional thre e-injection schedule of the antigen in a rat model, Unlike polyesters such as poly(lactic acid) (PLA) and poly(glycolic acid) (PGA), PCL deg rades slowly and therefore does not generate an acid environment adver sely affecting the antigenicity of vaccines and may prove to be promis ing as a vaccine carrier.