Improved biocompatability of silicone rubber by removal of surface entrapped air nuclei

✍ Scribed by Kalman, P. G. ;Ward, C. A. ;McKeown, N. B. ;McCullough, D. ;Romaschin, A. D.

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 694 KB
• Volume: 25
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820250207

✦ Synopsis

Biomaterials activate the complement system which is important since C3a promotes platelet aggregation and release, and C5a activates neutrophils that may augment coagulation. Tiny air nuclei (microbubbles) are found in the surface roughness of biomaterials on exposure to a liquid, therefore two interfaces exist: (a) a blood/biomaterial, and (b) a blood/ air interface. Experiments were carried out that documented that air bubbles activate complement and augment in vitro platelet aggregation in human plasma. The air nuclei were removed from the surface of silicone rubber by a technique termed denucleation to determine if com-plement activation and platelet aggregation could be reduced. We observed a significant reduction in C3a and C5a in the plasma samples incubated with denucleated silicone rubber as compared to the control samples ( p < 0.001, ANOVA). The plasma incubated with the denucleated silicone caused reduced platelet aggregation as compared to the plasma incubated with the control silicone when added to a platelet suspension ( p < 0.001, ANOVA).

Surface chemical analysis by x-ray photoelectron spectroscopy (XPS) showed no change in the silicone rubber surface after the denucleation procedure.