Abstract 387: Bioengineering L-605 Cobalt Chromium Cardiovascular Stent Biomaterial With Plasma Activated Coating, for Proactive Biocompatibility
Introduction: Cobalt Chromium alloy L605 is an underlying biomaterial in new generation drug eluting stents (DES) and bare metal stents (BMS). Suboptimal biocompatibility of stents clinically manifest as thrombosis and restenosis. We optimized a plasma coating technology to activate an alloy L605 surface for enhanced biofunctionalization.
Objective: Alloy L605 flat metal surface modified with plasma activated coating (PAC), covalently binds tropoelastin (TE) in its bioactive state. In vitro studies were conducted to assess biocompatibility of modified PAC biomaterial compared to the bare metal alloy L605.
Methods and Results: The initial water contact angle (Kruss contact angle analyser, DS10) of PAC was 44.40±3.40 and correlating surface energy computed with the Owens-Wendt-Rabel-Ström kinetic model was 62.35±2.4 mJ/m2. Thrombogenicity studies with heparinised whole blood (0.5 U/mL, 370C), in a modified chandler loop showed significantly less clot formation at 60 mins for PAC, PAC+TE Vs. L605 surfaces; 2.2±1.01 mg, 3.6±0.85 mg and 10.3±3.26 mg respectively (P<0.05). Static blood assays with platelet rich plasma (PRP) on PAC and PAC+TE surfaces were compared to L605 (figure 1). Samples incubated with tropoelastin and treated with SDS-Elisa (900C, 10 mins), to assess covalent binding showed higher absorbance for PAC vs. L605. Robust adhesion of PAC polymer to L605 was quantified as surface element percentage with energy dispersive X-ray spectroscopy (2 kV, Xray 2000 cps). Future studies will be conducted on an alloy L605 coronary stent platform.
Conclusion: The plasma coating is hydrophilic and hemocompatible. The PAC technology will be translated to a commercially available alloy L-605 coronary stent platform to establish a pre-clinical model of hemocompatibility in vitro, as an alternative to animal model testing. Early events of coagulation and inflammation will be determined via biological evaluation assays of medical devices (ISO 10993-4).
Author Disclosures: T. Jeewandara: None. S.G. Wise: None. P.L. Michael: None. J. Hung: None. M. Santos: None. A. Kondyurin: None. A. Weiss: None. M.M. Bilek: None. M.K.C. Ng: None.
- © 2015 by American Heart Association, Inc.