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.

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.

Chitosan-stabilized gold nanoparticles (Au NPs-Chi) have emerged as promising platforms for combined chemo-photothermal therapy due to their tunable surface properties, colloidal stability, and ability to incorporate therapeutic molecules. Understanding how formulation parameters influence interfacial organization and drug interactions remains essential for optimizing their therapeutic performance.Au NPs-Chi loaded with 5-fluorouracil (5-FU) were synthesized using varying gold precursor and chitosan concentrations to investigate the relationship between formulation parameters, surface chemistry, and drug interaction behavior for combined chemo-photothermal therapy applications.The systems were characterized using surface and spectroscopic techniques. Morphological analysis showed that formulations prepared with intermediate precursor concentration exhibited the most uniform nanoparticle organization. Spectroscopic investigations indicated that 5-FU interactions occurred primarily within the chitosan interfacial layer and were not depended on Au.Drug release studies under physiological saline conditions revealed non-monotonic and time-dependent redistribution of 5-FU, suggesting dynamic reversible interactions. Increased chitosan concentration improved drug retention, with the 15Au-1Chi formulation showing the most favorable balance between nanoparticle organization and drug retention behavior. Future studies should focus on molecular-level computational analysis and optimization of photothermal performance for combined therapeutic applications.