This January was the time to summary results of cytotoxicity experiments. Thus multilayer polyelectrolyte films consist of chitosan/chondroitin sulfate polymers exhibit a fast biodegradability in the environment of human tissues. Lifetime extension of this material type could be implemented by its structure stabilization through the introduction of nanoparticles. Transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) methods were used to determine the microstructure and localization of the silicon carbide nanoparticles introduced to the extracellular like structure of the polymer coatings. Modified coatings biocompatibility was analyzed in cytotoxicity assay and microscopic observations of endothelial cells growth on the material surface.