IN-VITRO IMMUNOCOMPATIBILITY & CHARACTERIZATION AT NANOSCALE OF THIN FILMS AND VASCULAR MEDICAL DEVICES.

Immunocompatibility comprises a complex response which depends both on the physico-chemical characteristics of the biomaterial and on the hereditary and acquired ability of the recipient to react. Objective: The objective of the present work was the comparative study of the immunocompatibility of different materials and their morphological characterization. Methods: The three types of thin films used in this work were the titanium nitride [TiN],Titanium [Ti] and the amorphous hydrogenated diamond-like carbon [a-C:H], which are deposited onto a silicon substrate by Magnetron Sputtering and Plasma-Enhanced Chemical Vapor Deposition (PECVD), respectively. Medical devices used in this study, were the silicon coated Latex irrigation catheter and the endoprosthesis such as vascular grafts [Dacron, PTFE] and stent grafts [Nitinol stent graft, Cobalt Chromium stent graft]. Bare silicon substrate and serum were used as a ?negative? control and the Latex [elastomer-elastic hydrocarbon polymer] as a ?positive? control. Complement C5 convertase [C5c] activation was assessed using the sandwich enzyme immunoassay-sandwich ELISA for the specific time periods [0min, 15 min, 30 min and 60 min] at wavelength of 450nm. The morphological characterization of the materials was conducted by Scanning Electron Microscopy (SEM). The study of biomaterials topography was conducted by Atomic Force Microscopy (AFM) and their surface wettability properties by Contact Angle measurements. Results: Our results show that both groups of materials (the nanomaterials and the medical devices) are not likely to cause any immunological adverse reaction and as a result might be characterized and selected as excellent candidates for medical applications. Conclusions: The effectiveness of the study is attributed to the measurement of a single factor in serum in order to acquire important information about the materials? properties e.g immunological response. The possibility to modify the above tested parameters during material synthesis and manufacture could allow limiting their immunological response and improving their immunocompatibility.