Functionalization of CoCr surfaces for cardiovascular applications

Mobilitat-IncomingCardiovascular diseases are major concerns in public health of developed countries and the first cause of death in the world. The treatment of coronary artery diseases using metallic stents has been one of the most revolutionary and most rapidly adopted medical interventions of these last years. During early development much of the investigation and debate revolved around stent design, including assessment of different materials and surface treatments. However, restenosis, incomplete endothelialization, and thrombosis hamper the long term clinical success. The biological events that lead to the appropriate response of already successfully proved biomaterial surfaces, such as Co-Cr alloy for cardiovascular stents, are mainly influenced by the interactions at the bio/non-bio interface. To improve the endothelial cells adhesion and growth, surface treatments have been developed to anchor REDV elastin-like polymers which enhances surface endothelization . The aim of the present project is to obtain a new family of biofunctionalized Co‐Cr alloy surface by covalently-anchoring the REDV elastin-like polymer. Different surface treatments have been performed on CoCr: O2 plasma treatment, silanization with CPTES and NaOH basic etching previously to chemically or physically attach the biopolymer. Then surface characterization has been performed, for each step, in termsof surface wettability, roughness, topography, chemistry, and charge. A biochemist characterization has been done to quantify the adsorbed biopolymer by means of fluorescent assays to evaluate the efficiency of the surface treatments. CoCr alloy surfaces were successfully biofunctionalized with REDV elastin–like polymer. The quantity of adsorbed biopolymer was influenced by surface characteristics. All surfaces revealed considerable quantities of attached biopolymer, but combination of NaOH+CPTES series attached the highest amount (0,008 μg/mm2± 0,002) compared to NaOH series (0,005 μg/mm2± 0,003), CPTES series (0,004 μg/mm2± 0,001), control samples (0,003 μg/mm2± 0,001) and O2 plasma series (0,002 μg/mm2± 0, 0005). The quantity of hydroxiles formed on the different surfaces influences biopolymer adsorption and then, cell response