POLYLACTIC ACID NANOPARTICLES INFLUENCE ON IMMUNOGENICITY OF THE PROTEIN BOUND WITH THEM

We investigated immunogenic properties of proteins bound with nanoparticles. A process for producing spherical nanoparticles having size of 20 microns by polymerization of lactic acid and an optimal method of nanoparticle surface activation were described. Activated nanoparticles were used for covalent binding of model fusion protein comprising sequences of human beta-2 microglobulin and green fluorescent protein. It is shown that the nanoparticles were able to bind 3 micrograms of the protein per 1 mg of the polymer. According to the results of confocal microscopy and electrophoresis the protein is firmly adsorbed on the surface of the granules. F1 (CBA x C57BL) mice were subjected to intraperitoneal immunization with fusion protein modified nanoparticles and equivalent mixture of unmodified nanoparticles and unbound fusion protein. Blood was taken at 2 weeks after three-time intraperitoneal immunization. Antibody level to model protein was determined in mouse sera using enzyme-linked immunosorbent assay. Each of experimental and control groups comprised 39 animals. The validity of the results was evaluated using the Mann–Whitney test. It is shown that the average antibody level in the control group was 1.8 times greater than that in the experimental group. The diffe rence was significant (p 0.004). We discuss the significance of the results in terms of development traps capable to bind virus particles in blood and to provide immune response.