Elastic moduli of polyelectrolyte multilayer films regulate endothelium-blood interaction under dynamic conditions

A broad spectrum of biomaterials has been explored in order to design cardiovascular implants of sufficient hemocompatibility. Most of them were extensively tested for the ability to facilitate repopulation by patient cells. It was shown that stiffness, surface roughness, or hydrophilicity of polyelectrolyte films have an impact on adhesion, proliferation, and differentiation of cells. At the same time, it is still unknown how these properties influence cell functionality and as a consequence interactions with blood components under dynamic conditions. In this study, we aimed to determine the impact of chemical cross-linking of Chitosan (Chi) and Chrondroitin Sulphate (CS) on endothelium-blood cross-talk. We have found that the morphology of the endothelium monolayer was not altered by changes in coating properties. However, free radical generation by endothelial cells varied depending on the elastic properties of the coating. Simultaneously, we have observed a significant decrease in the level of adhering and circulating active platelets as well as aggregates when the endothelium monolayer was formed on stiffer films than on the other coating variants. Moreover, the same type of films has promoted significantly higher adhesion of blood morphotic elements when they were not functionalized by endothelium. The observed changes in hemocompatibility indicate the importance of a design of coatings that will promote cellularization in vivo in a relatively short time and which will regulate cell function.</p

Elastic moduli of polyelectrolyte multilayer films regulate endothelium-blood interaction under dynamic conditions

A broad spectrum of biomaterials has been explored in order to design cardiovascular implants of sufficient hemocompatibility. Most of them were extensively tested for the ability to facilitate repopulation by patient cells. It was shown that stiffness, surface roughness, or hydrophilicity of polyelectrolyte films have an impact on adhesion, proliferation, and differentiation of cells. At the same time, it is still unknown how these properties influence cell functionality and as a consequence interactions with blood components under dynamic conditions. In this study, we aimed to determine the impact of chemical cross-linking of Chitosan (Chi) and Chrondroitin Sulphate (CS) on endothelium-blood cross-talk. We have found that the morphology of the endothelium monolayer was not altered by changes in coating properties. However, free radical generation by endothelial cells varied depending on the elastic properties of the coating. Simultaneously, we have observed a significant decrease in the level of adhering and circulating active platelets as well as aggregates when the endothelium monolayer was formed on stiffer films than on the other coating variants. Moreover, the same type of films has promoted significantly higher adhesion of blood morphotic elements when they were not functionalized by endothelium. The observed changes in hemocompatibility indicate the importance of a design of coatings that will promote cellularization in vivo in a relatively short time and which will regulate cell function.</p

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

Polyelectrolyte Multilayer Films Modification with Ag and rGO Influences Platelets Activation and Aggregate Formation under In Vitro Blood Flow

Surface functionalization of materials to improve their hemocompatibility is a challenging problem in the field of blood-contacting devices and implants. Polyelectrolyte multilayer films (PEMs), which can mimic functions and structure of an extracellular matrix (ECM), are a promising solution to the urgent need for functional blood-contacting coatings. The properties of PEMs can be easily tuned in order to provide a scaffold with desired physico-chemical parameters. In this study chitosan/chondroitin sulfate (Chi/CS) polyelectrolyte multilayers were deposited on medical polyurethane. Afterwards PEMs were modified by chemical cross-linking and nanoparticles introduction. Coatings with variable properties were tested for their hemocompatibility in the cone-plate tester under dynamic conditions. The obtained results enable the understanding of how substrate properties modulate PEMs interaction with blood plasma proteins and the morphotic elements