AVS 46th International Symposium
    Biomaterial Interfaces Group Tuesday Sessions
       Session BI-TuP

Paper BI-TuP11
The Effects of Surface Chemistry and Adsorbed Proteins on Monocyte/Macrophage Adhesion to Surfaces

Tuesday, October 26, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: M. Shen, University of Washington
Authors: M. Shen, University of Washington
T.A. Horbett, University of Washington
Y.V. Pan, University of Washington
B.D. Ratner, University of Washington
K.D. Hauch, University of Washington
Correspondent: Click to Email
Adherent macrophages play a central role in inflammatory responses to implanted biomaterials. Human monocyte adhesion to surfaces was therefore studied to determine the effects of surface chemistry, adsorbed proteins, and adhesion time. The surface chemistry of a series of commercially available modified polystyrene (PS) surfaces, fluorinated ethylene-propylene polymer (FEP), and plasma-polymerized-tetraglyme (PPT) coated FEP was analyzed by ESCA. The surfaces were preadsorbed with plasma, serum, fibrinogen, fibronectin, or albumin. Human monocytes in 10% serum were allowed to adhere to the surfaces for 2 hours or 1 day. Adhesion was measured by an LDH method. After 2 hours, monocytes adhered to most surfaces under all conditions examined. Adhesion was greater on charged hydrophilic TCPS, Plastek C, or Primaria than on hydrophobic PS, Plastek A, Plastek B, or FEP. Adhesion was lowest on uncharged hydrophilic PPT-coated FEP or Costar's Ultra Low Attachment hydrogel, which were also shown to resist fibrinogen adsorption. Monocyte adhesion was greater on surfaces preadsorbed with fibrinogen or fibronectin than on surfaces preadsorbed with albumin. However, 2-hour adhesion to surfaces preadsorbed with serum was similar to surfaces preadsorbed with plasma, despite the lack of fibrinogen. Preadsorption of dilute plasma or serum increased adhesion to TCPS but did not increase adhesion to PS. After 1 day, monocyte adhesion decreased and was lowest to surfaces without preadsorbed proteins. One-day adhesion was greater on plasma than on serum preadsorbed surfaces and was much greater on fibrinogen or fibronectin than on albumin preadsorbed surfaces. Overall, monocytes adhered to all surfaces and preadsorbed fibrinogen and fibronectin significantly promoted monocyte adhesion. Non-fouling surfaces that minimize protein adsorption may minimize overall macrophage adhesion and activation.