Biocompatible surfaces by immobilization of heparin on diamond‐like carbon films deposited on various substrates

Abstract

Although graphitic carbon has been known and used as a biomaterial for a very long time, the excellent biocompatibility of diamond-like carbon (DLC) films has been addressed only in a few cases. We anticipate the combination of bioinert DLC films and surface-immobilized bioactive biomolecules with antithrombogenic properties, such as the polysaccharide heparin, as a straightforward concept to optimize the haemocompatibility of a wide variety of materials. Therefore, to assess this property in view of an application as vascular grafts, surface analytical studies on DLC-coated and heparinized polymer and silicon substrates were performed. The DLC films were deposited on polytetrafluoroethylene (PTFE), PTFE vascular prostheses, polystyrene and silicon wafers by an energetic acetylene plasma beam and subsequently exposed to an ammonia plasma before heparin was covalently coupled to such functionalized surfaces by an end-point attachment method. The biochemical characterization by thrombin tests revealed, in accordance with XPS measurements, a high amount of heparin on the surface and an extended blood coagulation time. Thus, the efficiency of the plasma treatment for functionalization and successful improvement of the haemocompatibility of DLC films could be shown.

Ultrananocrystalline diamond film as an optimal cell interface for biomedical applications

“…Most important for its use in bioMEMS is the inertness of diamond which ensures that there will be no inflammatory response, favorable blood compatibility, and lack of cytotoxicity (Gardos 1999;Steffen et al 2000). However, since diamond is the hardest know material available, and normally is available in expensive gem form, it is very difficult and cost inefficient to fabricate devices out of diamond.…”

Incorporation of Primary Amines via Plasma Technology on Biomaterials

“…Both improved hemocompatibility, adhesion and proliferation of endothelial cells were attributed to a combined effect of increased wettability and amine based surface chemistry. In another study [78], the improvement of hemocompatibility of polymeric vascular prosthesis such as polytetrafluoroethylene (PTFE), polystyrene and silicon was investigated. After depositing diamond-like carbon (DLC) films on the polymer substrates via acetylene plasma, functionalization was done using ammonia plasma.…”

Immobilization of Heparin: Approaches and Applications

“…Steffen and co workers reported heparinization of diamond-like carbon (DLC) deposited on various surfaces such as PTFE, PTFE vascular prostheses, polystyrene and silicon wafers [24]. Low molecular weight heparin (MW av 4000-6000) was used for this purpose.…”