Tetanus toroid loaded nanoparticles from sulfobutylated poly(vinyl alcohol)-graft-poly(lactide-co-glycolide): Evaluation of antibody response after oral and nasal application in mice

Purpose. Aim of the study was the evaluation of the potential of novel teta nus toroid (TT) loaded nanoparticles (NP) for electing an immune response i n mice against TT. Methods. Sis week-old female Balb/c mice were immunized by oral (p.o.), nas al (i.n.) and intraperitoneal (i.p.) application of TT NP loaded by adsorpt ion. As polymer a novel polyester, sulfobutylated poly(vinyl alcohol)-graft -poly(lactide-co-glycolide), SB(43)-PVAL-g-PLGA was used. Blood samples wer e collected 4 and 6 weeks after immunization and assayed for serum IgG- as well as IgA antibody titers by ELISA. NP formulations varying in size and l oading were compared to alum adsorbates as well as to TT solutions. Results, Both, p.o. and i.n. administration of TT associated NP increased s erum titers up to 3 x 10(3) (IgG) and 2 x 10(3) (IgA). While small NP induc ed significantly higher titers then larger ones after oral administration, intermediate NP induced antibodies after nasal application. Of the mucosal routes investigated, i.n. seems to be more promising compared to p.o. immun ization. Conclusions. Antigen loaded NP prepared from surface modified polyesters co mbined with CT show considerable potential as a vaccine delivery system for mucosal immunization. The results warrant further experiments to explore i n more detail the potential use of NP as mucosal vaccine delivery system.