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Evaluation of leukocyte adhesion on polyurethanes: the effects of shear stress and blood proteins

Paper ID Volume ID Publish Year Pages File Format Full-Text
13271 847 2000 9 PDF Available
Title
Evaluation of leukocyte adhesion on polyurethanes: the effects of shear stress and blood proteins
Abstract

Leukocytes are a central cell type in directing host inflammatory and immune processes; thus, its response to biomaterials is extremely important in understanding material–host interaction. Blood contacting biomaterials may activate the complement cascade, thus promote leukocyte adhesion and activation to the biomaterial surface. We hypothesize that the extent of complement-mediated leukocyte activation is modulated by the material chemical formulation and the presence of fluid shear stress. Medical-grade polyurethanes with or without 4,4′-butyldiene bis(6-tert-butyl-m-cresol) antioxidant additives and a rotating disk system were utilized to study cell adhesion under a well-characterized shear stress field. Radioimmunoassay and ELISA were employed to assess the extent of complement activity. The results showed that adherent leukocyte densities decreased with increasing shear stress and that leukocyte adhesion was decreased significantly further by the presence of the antioxidant in the polyurethanes. Cell adhesion under flow conditions was abolished when complement C3 protein was depleted from the test medium. An increase in complement Factor H adsorption was observed at high shear region; however, no change in the complete complement activation was observed in the presence of shear stress as indicated by the protein S-terminal complement complex level. Based on these results, oligopeptides designed from C3a, C5a, and fibronectin were grafted onto a cell-nonadhesive polymer surface to probe the molecular mechanisms of leukocyte adhesion as mediated by protein–receptor complexation. The results showed that C3a-derived peptides mediated higher adherent macrophage density when compared to that mediated by C5a- and fibronectin-derived peptides.

Keywords
Complement; C3 complement protein; Rotating disc; Fibronectin; Polyethyleneglycol
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Evaluation of leukocyte adhesion on polyurethanes: the effects of shear stress and blood proteins
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 21, Issue 22, 15 November 2000, Pages 2295–2303
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us