| Abstract
| - Protein adhesion plays a major role in determining the biocompatibility of materials. The firststage of implant integration is the adhesion of protein followed by cell attachment. Surface modification ofimplants (surface chemistry and topography) to induce and control protein and cell adhesion is currently ofgreat interest. This communication presents data on protein adsorption (bovine serum albumin andfibrinogen) onto model hydrophobic (CH3) and hydrophilic (OH) surfaces, investigated using a quartz crystalmicrobalance (QCM) and grazing angle infrared spectroscopy. Our data suggest that albumin undergoesadsorption via a single step whereas fibrinogen adsorption is a more complex, multistage process. Albuminhas a stronger affinity toward the CH3 compared to OH terminated surface. In contrast, fibrinogen adheresmore rapidly to both surfaces, having a slightly higher affinity toward the hydrophobic surface. Conformationalassessment of the adsorbed proteins by grazing angle infrared spectroscopy (GA-FTIR) shows that afteran initial 1 h incubation few further time-dependent changes are observed. Both proteins exhibited a lessorganized secondary structure upon adsorption onto a hydrophobic surface than onto a hydrophilic surface,with the effect observed greatest for albumin. This study demonstrates the ability of simple tailor-mademonochemical surfaces to influence binding rates and conformation of bound proteins through protein−surface interactions. Current interest in biocompatible materials has focused on surface modifications toinduce rapid healing, both of implants and for wound care products. This effect may also be of significanceat the next stage of implant integration, as cell adhesion occurs through the surface protein layer.
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