Designing and developing processes for plasma immersion ion implantation of metallic surfaces for improving bio- and hemo-compatibility for biomedical devices

点击翻译按钮获取中文摘要

The interaction between an implanted device and the biological environment inside the human body is a critical issue due to the high and increasing number of biomedical implants realized every year. This is dramatically true especially for cardiac, vascular and neurologic applications for stents, where hemo- and biocompatibility play a key role in the final outcome of the implant. Failure of the device occurs when there is an incorrect integration of metallic devices in the vascular system; this cause can lead to localized coagulation, inflammation, cellular damage and hyperplasia, conducing to a final restenosis of the vessel because of clotting. While non-absorbable alloys need to be corrosion resistant, to avoid the release of toxic ions, absorbable alloy share required to have their corrosion rate controlled. Surface modification by plasma immersion ion implantation and magnetron sputtering is an innovative way to provide both absorbable and non-absorbable materials excellent biological properties while bulk ones are preserved. Since the surface of a material is the place where interactions with body tissues develop, plasma modification can both create a barrier layer to hamper the diffusion of toxic ions (Ni+, Cr6+, Mn2+, etc.) and provide a more favorable environment to cell viability. It is possible in this case to tailor surface chemical composition and physical structure so that a better biological response is obtained. The final goal of this project is the designing and validation of ion-implantation-based plasma surface processes conferring to the material effective biocompatibility. This overall objective will be attained through a multidisciplinary approach, namely the study of the plasma parameters and processes, their correlation with surface chemistry and structure of the modified alloys, the assessment of corrosion and biological properties and the transfer of the defined processes to different products. The participation of Plasmionique in the project will be fundamental for the application of the found procedures to semifinished products and to scaling up, so that consistent medical, scientific and industrial benefits will arise for Canada society and economy.