At 3434 and 3399 cm−1, the characteristic band of the hydroxyl group (OH) is recorded, overlapping with N–H stretch at 3270 cm−1. At 1646 cm−1 the characteristic bands of chitosan

appear with high intensity that correspond to the vibration of amid. At 1380 cm−1 the C–H stretch of the CH3 group is recorded. At 1322 cm−1 the C–N stretch is recorded and finally at 1080 cm−1 the band of C–O stretch group appears (Costa and Mansur, 2008 and Papadimitriou et al., 2008). The success in the production of the cross-linked nanoparticles may be demonstrated by the reduced particle size obtained, which remained smaller than BGJ398 in vitro 200 nm for all formulations. The experimental data obtained for size and zeta potential are shown in Table 1. In addition, a high value of encapsulation efficiency was obtained for different venom:chitosan ratios used (5 and 10%) (Table 1). The mice were immunized for 6 weeks with 100 μL of subcutaneous injections of T. serrulatus venom proteins in different concentrations (0; 5.0 and 10.0%), encapsulated in chitosan nanoparticles or associated with the aluminum hydroxide. The experimental mice were bled by cardiac puncture, and the serum was obtained. Antigen-specific serum antibody responses

were measured 1 week see more following the vaccination boosters by ELISA. The results displayed in Fig. 3 demonstrate that significant difference was found in the mice group of immune protection of vaccines with the adjuvant chitosan associated with the venom in the concentration 5.0% and the adjuvant aluminum hydroxide associated with the venom in the concentration 10.0% (P < 0.05). However, the group that received hydroxide associated with the venom in the concentration 10.0% when compared with the adjuvant chitosan associated

with the venom in the concentration (-)-p-Bromotetramisole Oxalate 10.0% did not exhibit significant difference in the antibody title produced ( Table 2). The data also reveal that when the control group immunized with chitosan nanoparticles was compared with the adjuvant chitosan nanoparticles associated with the venom in both concentrations (5.0 and 10.0%) a significant difference of immune protection was found in the mice. The same was shown when comparing the title of antibody in animals vaccinated with the adjuvant aluminum hydroxide associated with the venom in both concentrations (5.0 and 10.0%) and groups of animals, which received only aluminum hydroxide ( Table 2). All effective vaccines need a suitable antigen-presenting system that depends on adjuvant or vehicle (Xie et al., 2007). The development of a novel adjuvant is necessary to decrease the side effects and maximize the efficacy of new or available vaccines and serums. The chitosan is a non-toxic and biodegradable copolymer with low immunogenicity that has been extensively investigated for formulating carrier and delivery systems for therapeutic macromolecules (Janes et al., 2001 and Richardson et al., 1999).