title: Chitosan-HPMC-blended microspheres as a vaccine carrier for the delivery of tetanus toxoid.
abstract: The purpose of this research was to develop a suitable and alternate adjuvant for the tetanus toxoid (TT) vaccine that induces long term immunity after a single-dose immunization. In our study, the preformulation studies were carried out by using different ratios (7/3, 8/2, and 9/1) of chitosan-hydroxypropyl methylcellulose (HPMC)-blended empty microspheres. Moreover, TT was stabilized with heparin (at heparin concentrations of 1%, 2%, 3%, and 4% w/v) and encapsulated in ideal chitosan - HPMC (CHBMS) microspheres, by the water-in-oil-in-water (W/O/W) multiple emulsion method. The vaccine entrapment and the in vitro release efficiency of the CHBMS was evaluated for a period of 90 days. The release of antigens from the microspheres was determined by ELISA. Antigen integrity was investigated by SDS-PAGE. From the optimization studies, it was found that a chitosan/HPMC ratio of 8/2 produced a good yield, with microspheres that were spherical, regular and uniformly-sized. In the CHBMS, a heparin concentration of 3% w/v resulted in well-sustained antigen delivery for a period of 90 days. It was found that the characteristics of initial release could be observed in 2 days, followed by a constant release, and an almost 100% complete release in 90 days. From the in vitro release characteristics, the ideal batch of CHBMS (3% w/v heparin) was evaluated for in vivo studies by the antibody induction method. The antibody levels were measured for different combinations for the period of 9 months, and finally, with a second booster dose after 1 year. In conclusion, it was observed that CHBMS (combination-1) resulted in the antibody level of 4.5 IU/mL of guinea pig serum, and the level was 3.5 IU/mL for the Central Research Institute's alum-adsorbed tetanus toxoid (CRITT) (combination 2), after 1 year, with a second booster dose. This novel approach of using CHBMS may have potential advantages for single-step immunization with vaccines.
authors.affiliation: a Department of Chemical Engineering , Hanseo University , Seosan, Chungcheongnam-do , South Korea.
authors.forename: Saravanakumar
authors.initials: S
authors.lastname: Arthanari
authors.affiliation: a Department of Chemical Engineering , Hanseo University , Seosan, Chungcheongnam-do , South Korea.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Mani
authors.affiliation: a Department of Chemical Engineering , Hanseo University , Seosan, Chungcheongnam-do , South Korea.
authors.forename: Mei Mei
authors.initials: MM
authors.lastname: Peng
authors.affiliation: a Department of Chemical Engineering , Hanseo University , Seosan, Chungcheongnam-do , South Korea.
authors.forename: Hyun Tae
authors.initials: HT
authors.lastname: Jang
mesh_terms: D000818:Animals; D048271:Chitosan / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D006168:Guinea Pigs; D065347:Hypromellose Derivatives / Q000737:chemistry*; D008863:Microspheres; D013745:Tetanus Toxoid / Q000737:chemistry* / Q000276:immunology
chemical_list: D004337:Drug Carriers; D013745:Tetanus Toxoid; D065347:Hypromellose Derivatives; D048271:Chitosan
keywords: adjuvant; biodegradable polymers; chitosan microspheres; tetanus toxoid; vaccine delivery systems