Laser modified functional carbon-based coatings on titanium substrate for cardiac tissue integration and blood clotting inhibition

The work focused on developing functional coatings on titanium substrates that would facilitate the integration with the cardiac tissue and with a specific form of connective tissue like blood. Surface modifications consisted in the laser evaporation of part of the biocompatible layer, thus creating a suitable environment for a particular tissue. For the myocardium integration, the metal surface was refined by biohemocompatible coatings. Such surfaces were the starting point for further modifications in the form of channels. The channeled surfaces enabled a controlled cell migration and proliferation. The interaction of endothelial cells with the material was highly dependent on the surface characteristics such as: topography, microstructure or mechanical properties. The controlled cellular response was achieved by modifying the surface to obtain a network of wells or channels of different dimensions via the laser interference lithography. This technique determined a high resolution shape, size and distribution patterns. As a result, it was possible to control cells in the scale corresponding to biological processes. The surface periodization ensured the optimal flow of oxygen and nutrients within the biomaterial, which was of a key importance for the cell adhesion and proliferation. The work attempted at producing the surface networks mimicking natural blood vessels. To stimulate the formation of new blood vessel the finishing resorbable synthetic coatings were applied on the surface to act as a drug carrier. Therefore, the initial trial to introduce factors stimulating the blood vessels growth was performed.