The effects of surface chemistry and adsorbed proteins on monocyte/macrophage adhesion to chemically modified polystyrene surfaces

Monocytes and macrophages play critical roles in inflammatory responses to implanted biomaterials. Monocyte adhesion may lead to macrophage activation and the foreign body response. We report that surface chemistry, preadsorb ed proteins, and adhesion time all play important roles during monocyte adh esion bi vitro. The surface chemistry of tissue culture polystyrene (TCPS), polystyrene, Primaria, and ultra low attachment (ULA) used for adhesion st udies was characterized by electron spectroscopy for chemical analysis. Fib rinogen adsorption measured by I-125-labeled fibrinogen was the lowest on U LA, higher on TCPS, and the highest on polystyrene or Primaria. Monocyte ad hesion on protein preadsorbed surfaces for 2 h or 1 day was measured with a lactate-dehydrogenase method. Monocyte adhesion decreased over time. The a bility of preadsorbed proteins to modulate monocyte adhesion was surface de pendent. Adhesion was the lowest on ULA, higher and similar on TCPS or poly styrene, and the highest on Primaria. Monocyte adhesion on plasma or fibrin ogen adsorbed surfaces correlated positively and linearly to the amount of adsorbed fibrinogen. Preadsorbed fibronectin, immunoglobulin G, plasma, or serum also promoted adhesion compared with albumin preadsorbed or uncoated surfaces. Overall, biomaterial surface chemistry, the type and amount of ad sorbed proteins, and adhesion time all affected monocyte adhesion in vitro. (C) 2001 John Wiley & Sons, Inc.