Obtenção e avaliação do potencial imunoadjuvante de nanopartículas de quitosana na produção de antissoro contra a peçonha da serpente Crotalus durissus cascavella

Abstract

Snakebite envenoming is a tropical disease neglected in many regions of the world world. In Brazil, the Crotalus durissus cascavella (CDC) snake belongs to a genus with venom of highest lethality. A search for new immunoadjuvants aimed to expand the therapeutic alternatives to improve vaccines and antivenom. Thus, this approach proposed to produce small and narrow-sized cationic CDC venom-loaded chitosan nanoparticles (CHNP), by the two association method: adsorption and incorporation, able to induce antibody response against the CDC venom. The ionic gelation method induced the formation of stable and slightly smooth spherical nanoparticles (< 160 nm) with protein loading efficiency superior to 90%. The interactions between venom proteins and CHNP assessed using Fourier transform infrared spectroscopy corroborated with the in vitro release behavior of proteins from nanoparticles. Finally, the immunization animal model using BALB/c mice demonstrated the higher effectiveness of CDC venom-loaded CHNP, mainly by the adsorption method, compared to aluminum hydroxide, from the dilution 1: 6400 to 1: 25600 for the concentration of 0.5% and up to the dilution of 1: 3200 to 1.0% of the venom. Thus, CHNPs loaded with CDC venom exhibited a promising biotechnological approach to immunoadjuvant future.