title: Prolonged immune response evoked by a single subcutaneous injection of microcapsules having a monophasic antigen release.
abstract: A model antigen, bovine serum albumin (BSA), was successfully incorporated into microcapsules fabricated from blends of poly(d,l-lactide-co-glycolide) and poly(d,l-lactide). The microcapsules possessed diameters ranging from 10 to 100 microns and exhibited a continuous monophasic release of the protein in-vitro for 3 weeks. They were found to enhance its immunogenicity, thereby potentiating the anti-BSA antibody response following a single subcutaneous injection in mice and rabbits. Enzyme-linked immunosorbent assays demonstrated that the microcapsules provoked high-titre and long-lived immunoglobulin G immune responses over a period of 192 days in mice. When rabbits were immunized by a single subcutaneous injection of BSA-loaded microcapsules, a high level of anti-BSA antibody was still present in the sera obtained at 17 weeks post-injection. The immunization protocol using the BSA-loaded microcapsules was superior to that using BSA dissolved in saline or adsorbed to alum. These microcapsules providing the controlled release of antigens may be valuable in designing better vaccine formulations.
authors.affiliation: Controlled Drug-Delivery Research Center, College of Pharmacy, Rutgers, State University of New Jersey, Piscataway 08854, USA.
authors.forename: H
authors.initials: H
authors.lastname: Sah
authors.forename: Y W
authors.initials: YW
authors.lastname: Chien
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D002214:Capsules / Q000737:chemistry; D003692:Delayed-Action Preparations; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007279:Injections, Subcutaneous; D019344:Lactic Acid; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011091:Polyesters / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000008:administration & dosage / Q000276:immunology* / Q000378:metabolism
chemical_list: D000936:Antigen-Antibody Complex; D001672:Biocompatible Materials; D002214:Capsules; D003692:Delayed-Action Preparations; D007074:Immunoglobulin G; D011091:Polyesters; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D012710:Serum Albumin, Bovine; D019344:Lactic Acid; C033616:poly(lactide)