[In vitro testing of thrombocyte adhesion to different collagenous hemostyptic agents]

The aim of the present study was to evaluate the adhesion of thrombocytes to different collagenous hemostyptics in a new blood flow chamber.

Three hemostyptics were tested: (1) Resorba (RE, native equine collagen, Resorba Wundversorgung GmbH, Nürnberg, Germany), (2) Hemocol (HE, native porcine collagen, Medical Biomaterial Products GmbH, Neustadt-Gleve, Germany), and (3) an experimental sponge (ES, chemically cross-linked porcine collagen, Geistlich Biomaterials, Wolhusen, Switzerland). Ten specimens of each sponge were exposed to a laminar 40 ml/h anticoagulated blood flow and adhering thrombocytes were examined using a confocal laser scanning microscope (CLSM). Pure collagen (Kollagen S, Roche) served as positive control and fetal calf serum (FKS, Roche) as negative control. Examination time was set at 0, 60, 120, and 180 s. Furthermore, pH measurements of defined sponge volumes were evaluated after incubation with NaCl and human blood serum after 3, 30, and 60 min.

All specimens showed a comparable amount of fluorescence units on the surface over time which was statistically not significantly different from the positive control (p>0.05, ANOVA). Nevertheless, acidity of all specimens could be observed after incubation with NaCl and in cases of HE and ES after incubation with human blood serum.

Within the limits of the present in-vitro study it was concluded that (1) all hemostyptics examined showed similar results in thrombocyte adhesion; (2) chemical cross-linking of collagen does not affect the thrombogenicity of the tested collagen; (3) however, the acidity might have a negative effect on thrombus formation in vivo.