Chemical control of polyelectrolyte film properties for an effective cardiovascular implants endothelialization

The aim of this study was to improve properties of blood contacting materials such as polyurethane, in a form of intelligent, self-organizing and self-controlling coatings, which allow the selective mobilization and colonization of the endothelial cells on their surface. The prepared multilayer polyelectrolyte scaffolds were cross-linked chemically by EDC/NHS reagents in order to control their physicochemical properties and thus improving potential to endothelialization. Four types of coatings, i.e. non-cross-linked, cross-linked by 260 mM, 400 mM and 800 mM EDC reagent, were investigated. Their comparison was performed based on the results of the surface topography measurements using Atomic Force Microscopy (AFM), cellular morphology and proliferation analysis using Confocal Laser Scanning Microscopy (CLSM) and the mechanical properties examinations. The optimal multilayer rigidity and surface roughness parameters were found for an effective control of the endothelial cells growth. Surface topography analysis indicated an increase in the coating’s roughness due to application of higher EDC cross-linker concentrations. Mechanical studies revealed that cross-linking caused a significant increase in the hardness and elastic modulus. The results from the cellular experiments allowed the conformation that 400 mM cross-linked PLL/HA films possess desired properties.