Plasma mediated collagen-I-coating of metal implant materials to improve biocompatibility

This study describes the collagen-I coating of titanium and steel implants via cold low-pressure gas plasma treatment. To analyze the coatings in terms of bio-compatibility osteoblast-like osteosarcoma cells and human leukocytes were cultivated on the metal surfaces. Two different implant materials were assessed (Ti6Al4V, X2CrNiMo18) and four different surface properties were evaluated: (a) plasma pretreated and collagen-I coated implant materials; (b) collagen-I dip-coated without plasma pretreatment; (c) plasma treated but not collagen-I coated; (d) standard implant materials served as control. The different coating characteristics were analyzed by scanning electron microscopy (SEM). For adhesion and viability tests calcein-AM staining of the cells and Alamar blue assays were performed. The quantitative analysis was conducted by computer assisted microfluorophotography and spectrometer measurements. SEM analysis revealed that stable collagen-I coatings could not be achieved on the dip-coated steel and titanium alloys. Only due to pretreatment with low-pressure gas plasma a robust deposition of collagen I on the surface could be achieved. The cell viability and cell attachment rate on the plasma pretreated, collagen coated surfaces was significantly (p < 0.017) increased compared to the non coated surfaces. Gas plasma treatment is a feasible method for the deposition of proteins on metal implant materials resulting in an improved biocompatibility in vitro. (C) 2010 Wiley Periodicals, Inc. J Biomed Mater Res 94A: 19-26, 2010