Single shot with tetanus toxoid in biodegradable microspheres protects mice despite acid-induced denaturation of the antigen

Enhancement of immune response of HBsAg loaded poly (L-lactic acid) microspheres against Hepatitis B through incorporation of alum and chitosan

“…Vaccines formulated using polymeric microspheres provide a promising carrier system for delivery of antigens and several investigations have been carried out in recent years into the pharmaceutical potential of such formulations (Langer and Folkman 1976;Mathiowitz et al 1990;O'Hagan et al 1993a;Alpar et al 1994;Coombes et al 1996;Kersten et al 1996;Singh et al 2006). Theoretically, single shot vaccines should be able to deliver the vaccine at a pre-programmed rate in a controlled release manner, upon administration of a single dose, thereby conferring lifelong protective immunity (Raghuvanshi et al 2002).…”

Potentiation of Immune Response from Polymer-Entrapped Antigen: Toward Development of Single Dose Tetanus Toxoid Vaccine

“…Results of antibody titers obtained from groups immunized with 2 injections of 5 Lf TT each on alum and equivalent doses of encapsulated TT showed that the conventional immunization schedule gives significantly higher antibody titer than immunization with encapsulated TT (Kersten et al 1996;Johansen et al 2001). There are reports that smaller size and hydrophobic polymeric particles improve the immunogenicity of the entrapped antigen (Eldridge et al 1991;Conway, Eyles, and Alpar 1997).…”

“…Extensive studies with the use of PLGA/PLA particles have been carried out to explore the possibilities of developing a single shot vaccine for tetanus toxoid (Alonso et al1994;Kersten et al 1996;Audran et al 1998;Tobio et al 2000;Higaki et al 2001;Diwan, Khar, and Talwar 2001). Results of antibody titers obtained from groups immunized with 2 injections of 5 Lf TT each on alum and equivalent doses of encapsulated TT showed that the conventional immunization schedule gives significantly higher antibody titer than immunization with encapsulated TT (Kersten et al 1996;Johansen et al 2001).…”

Formulation and Characterization of Immunoreactive Tetanus Toxoid Biodegradable Polymer Particles

“…In most of the reported observations on controlled release formulation of TT from PLA or PLGA polymers, the antibody response have always been lower than that obtained from two conventional doses of alum adsorbed TT (Xing et al 1996;Kersten et al 1996;Gupta et al 1997;Audran et al 1998;Tobio et al 2000). The low antibody response produced by PLA or PLGA encapsulated TT particles may be due to either altered immunological responses as a result of antigen degradation during particle formation or to biochemical changes in the toxoid originating from, particle loading and subsequent degradation during storage or following administration (Alonso et al 1993;Chang and Gupta 1996).…”

“…The low antibody response produced by PLA or PLGA encapsulated TT particles may be due to either altered immunological responses as a result of antigen degradation during particle formation or to biochemical changes in the toxoid originating from, particle loading and subsequent degradation during storage or following administration (Alonso et al 1993;Chang and Gupta 1996). Stability issues of encapsulated TT in the polymer matrix have been addressed with respect to aggregation (Schwendeman et al 1995) and acid induced denaturation (Kersten et al 1996;Chang and Gupta 1996). Recently, polymeric formulation for encapsulating immunogenic TT by incorporation of additives have been reported (Schwendeman et al 1998;Audran et al 1998;Tobio et al 1999).…”