Rockets with a vaccine

Vaccines against infectious diseases have saved millions of lives, while no one likes injections, which prompted specialists to work on creating vaccines for oral use. However, in order to remain effective, such a vaccine must pass through the digestive tract and enter the immune cells inhabiting the intestinal walls.

In addition to avoiding needles and syringes, oral vaccines can provide a wider range of immune responses by stimulating immune cells of the intestinal mucosa that produce a special class of antibodies of the immunoglobulin A class (IgA).

Researchers at the University of California at San Diego, working under the leadership of Professor Liangfang Zhang, have suggested that they can use magnesium particles as tiny "jet engines" to deliver an oral vaccine against Staphylococcus aureus, which is one of the most common bacterial pathogens. When applied to a large part of the surface of magnesium microparticles of titanium dioxide, peculiar nozzles are obtained that use water as fuel for the synthesis of hydrogen bubbles that provide the reactive movement of the particle.

To obtain an oral vaccine, the authors coated such microparticles with erythrocyte membranes expressing staphylococcal alpha toxin, as well as a layer of chitosan that provides attachment to the intestinal mucosa. After that, a coating was applied to the particles, protecting them from the acidic environment of the intestine.

In experiments on mice, the particles swallowed by animals successfully passed through the stomach, after which their protective coating dissolved in the intestines, activating the engines. Subsequent visualization demonstrated that particles with "motors" accumulated in the intestinal wall more efficiently than "non-motorized" ones. In addition, the production of IgA class antibodies to staphylococcal alpha toxin stimulated by them was approximately 10 times higher than the production triggered by static particles.

Article by Xiaoli Wei et al. Biomimetic Micromotor Enables Active Delivery of Antigens for Oral Vaccination published in the journal Nano Letters.

Evgenia Ryabtseva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of the American Chemical Society: Micromotors deliver oral vaccines.