Effects of polymer surface molecular structure and force-field characteristics on blood interfacial phenomena. I
Version of Record online: 13 SEP 2004
Copyright © 1977 John Wiley & Sons, Inc.
Journal of Biomedical Materials Research
Volume 11, Issue 1, pages 51–68, January 1977
How to Cite
Nyilas, E., Morton, W. A., Cumming, R. D., Lederman, D. M., Chiu, T.-H. and Bailer, R. E. (1977), Effects of polymer surface molecular structure and force-field characteristics on blood interfacial phenomena. I. J. Biomed. Mater. Res., 11: 51–68. doi: 10.1002/jbm.820110107
- Issue online: 13 SEP 2004
- Version of Record online: 13 SEP 2004
To quantify the effects of major surface structural factors influencing interfacial reactions induced by polymers in native blood, model surfaces of solvent-cast films of two analogous poly (ether urethanes) and three homologous polyamides (nylon 4, 6/6, and 12) were exposed ex vivo to canine blood under the well-defined hemodynamic conditions of the Stagnation Point Flow Experiment. The selected surfaces allow for incremental changes in properties and were characterized by their “Composite Surface Free Energy Function,” γ′s, which describes the surface force field as the sum of the mean dispersion (sd) and polar (sp) contributions and is computed from wettability spectra obtained with ultrapure diagnostic liquids. Blood interfacial effects were measured by the shear-limited diameter of the white cell circle formed around the stagnation point, the flow parameter at which symmetric aggregation occurred, and the surface-number density of platelets, [Ps], remaining adherent under fixed conditions. At identical flows, within each group of polymers, both the WBC-circle diameter and [Ps] scale with sp/γ′s, implying that (1) only the magnitude but not the interaction mechanism varies as a function of incremental structural and surface changes, (2) the primary determinant of surface-induced effects is the polar force contribution, and (3) the magnitude of γ′s is secondary if sd/γ′s is sufficiently great.