Analysis of rat plasma proteins desorbed from gold and methyl- and hydroxyl-terminated alkane thiols on gold surfaces

It is believed that adsorbed blood or plasma components, such as water, pep tides, carbohydrates and proteins, determine key events in the concomitant inflammatory tissue response close to implants. The aim of the present stud y was to develop a procedure for the collection and analysis of minor amoun ts of proteins bound to solid metal implant surfaces. The combination of a sodium dodecyl sulfate washing method coupled with a polyacylamide gel elec trophoretic protein separation technique (SDS-PAGE), Western blot and image analysis enabled the desorption, identification and semiquantification of specific proteins. The analyzed proteins were albumin, immunoglobulin G, fi brinogen and fibronectin. Concentration procedures of proteins were not req uired with this method despite the small area of the test surfaces. The pla sma proteins were adsorbed to pure gold and hydroxylated and methylated gol d surfaces, which elicit different tissue responses in vivo and plasma prot ein adsorption patterns in vitro. The image analysis revealed that the pure gold surfaces adsorbed the largest amount of total and specific proteins. This is in accordance with previous ellipsometry/antibody experiments in vi tro. Further, the principles described for the protein analysis can be appl ied on implant surfaces ex vivo. (C) 2000 Kluwer Academic Publishers.