Strength of cellular adhesion to specific biomaterial surfaces

The jet impingement method was used to discover the variation in strength of cellular adhesion between different biomaterial surfaces. Fibroblasts were cultured on circular discs of each material such that the surface was covered but the layer was subconfluent. A fluid jet of known temperature and flow conditions was used to erode the cells from the surface by perpendicular impingement. The lesions formed were viewed and measured using a fluorescent microscopy technique and a digitizing tablet. From these measurements the maximum shear stress that the cells could resist before being washed off was calculated according to theoretical principles previously described. Calculated shear stresses for three materials, Ti-6Al-4V, tissue culture polystyrene (TCP) and glass, showed noticeable differences between materials with the glass showing the lowest stress to erosion and the Ti-6Al-4V showing the highest. The glass result was as expected, since cell culture specialists consider this material to be suboptimal in terms of encouraging cell growth and proliferation on this material. The comparison of the Ti-6Al-4V results with the TCP indicates that the cells adhere better to the metal. In general, the results show that the jet impingement method is a useful technique for quantifying the strength of cellular adhesion.