| AVS 65th International Symposium & Exhibition | |
| Biomaterial Interfaces Division | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterial Interfaces Division Poster Session |
| Presenter: | Bill Theilacker, Medtronic |
| Authors: | B. Theilacker, Medtronic J. Ho, Interface Biologics J. Swenor, Interface Biologics M.F. Wolf, Medtronic J.L. Kalscheue, Medtronic S. Thinamany, Medtronic S. Ubl, medtronic |
| Correspondent: | Click to Email |
Blood represents one of the most complex biochemical systems in living organisms. As a result, the design of medical device materials is often tailored to reduce platelet adhesion and activation, protein adsorption, and thrombus formation. With roughly 50% or more of Medtronic products contacting vascular tissue, medical device materials that show evidence of biocompatibility with blood (aka ‘hemocompatibility’) are of high interest. The Endexo™ surface treatment from Interface Biologics is asserted to show improved hemocompatibility through the action of low molecular weight fluoro-oligomeric additives that bloom to the surface and reduce or inhibit blood platelet activation and procoagulant protein formation. Incorporating Endexo technology into materials is straightforward and does not change the mechanical or functional properties of the underlying medical device.
Through a collaborative effort, we examined the IBI fluoro-oligomeric additive added to a common copolyester base polymer used in blood-contact applications and evaluated the platelet and coagulation protein activating capacity. Tritan™ polyester (Eastman) was formulated with several different concentrations of Endexo™ fluoro-oligomeric additive. The surface chemistry of the samples was characterized by Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). An in vitro vacuum test tube model developed at Medtronic was employed to asses hemocompatibility. Complete blood count analysis, platelet activation (via ELISA immunoassay for platelet plasma protein βTG), and coagulation protein formation (via ELISA immunoassay for the thrombin coagulation protein indicator TAT) was evaluated in the exposed blood.
The Endexo™ surface modifying agent appeared to show improved interaction with blood platelets. Similar favorable performance as assessed by TAT and βTG indicators of hemocompatibility may suggest a viable avenue for incremental improvement in the hemocompatibility of blood contacting devices and device materials. Surface analysis results show the Endexo formulated materials are modified with F-rich chemistry with no change in surface morphology. Medical devices that show improved performance in in vitro studies of hemocompatibility have potential to show improved performance in the in vivo clinical setting.