Stable Plasma-Engineered Films for Surface Modification of Blood-Contacting Medical Devices

Abstract

This thesis investigated the role of ion-assisted plasma polymerization (IPP) in facilitating effective biofunctionalization of non-degradable cardiovascular stents composed of stainless steel (SS) and cobalt-chromium (CoCr), as well as biodegradable magnesium (Mg) stents. IPP enabled either direct covalent immobilization or indirect hydrogel-mediated attachment of recombinantly expressed human perlecan biomolecules on SS and CoCr substrates, with successful translation to clinically used CoCr stents. In the hydrogel-mediated strategy, different hydrogels—without cross-linkers—were strongly and stably anchored to the surface, forming robust and durable solid–hydrogel interfaces enabled by IPP. In vitro and ex vivo evaluations demonstrated significantly improved hemocompatibility of the biofunctionalized substrates. In the case of biodegradable Mg stents, IPP not only enabled the direct attachment of heparin biomolecules but also enhanced corrosion resistance by forming an effective barrier layer on the surface.

The findings of this thesis demonstrate the effectiveness of IPP in enabling the covalent immobilization of therapeutic biomolecules and the robust attachment of hydrogels for surface biofunctionalization. Moreover, IPP simplifies the overall process by eliminating the need for complex wet-chemical methods. The approach developed here offers broad applicability to other blood-contacting medical devices, providing a streamlined and clinically relevant platform for the next generation of biomedical technologies.