There is a growing interest in the use of biopolymers for the development of new pharmaceutical, veterinary and food products. In this context, our work was focused initially in the characterization of the interactions among positively charged biopolymers with lipid and protein complexes. Those studies led to the development of new methods for the concentration of caseins from whole milk and for the production of fiber-enriched cheeses. As another aspect of the characterization of the potential incorporation of cationic polymers as food additives we studied their effects in the homeostasis of the mucosal immune system. Thus, we determined that early after feeding, chitosan (a cationic polymer of N-acetyl-D-glucosamine and D-glucosamine) enhances the release of anti-inflammatory cytokines such as IL-10, IL-4 and TGF-b at the inductive sites of mucosal immune system. These results opened the possibility to explore the potential uses of this polymer in animal models of intestinal injury and autoimmune diseases.
We have recently shown that a cationic acrylic polymer (eudragit E100) is able to interact with DNA forming stable complexes, and with protein complexes like casein micelles, with a biphasic aggregation-dissociation effect, disrupting structures of 200 nm to structures of 4 nm (average diameter of casein molecules). These results indicated that this polymer presents detergent-like amphipathic properties and led us to the characterization of its membrane-destabilizing properties, confirmed by its lytic activity on liposomes, red blood cells and by an important antiviral effect of E100 on Herpes simplex virus type 2. We are currently exploring the possibility to use this polymer for the inactivation of enveloped viruses in cell free hemoderivatives.
The improvements in Artificial Insemination (AI) and Embryo Transference (ET) had the greatest impact in the development of new Reproductive Technologies. Within this context, we started a project that led to the development of new controlled-release systems for steroid (progesterone) and peptidic (FSH) hormones for the control of the estrus cycle in livestock. We also conducted studies on the effects of polymeric macromolecules as substitutes of proteins and/or surfactants in solutions currently used in washing, collection and freezing/thawing of embryos.
More details of these and other recent achievements by our group will be presented.
