Metabolic response of granulocytes and platelets to synthetic vascular grafts: preliminary results with an in vitro technique.

The metabolism of granulocytes as well as platelets evoked by incubation with different synthetic vascular grafts was monitored during 6-h batch experiments using microcalorimetry. Standard knitted Dacron grafts, ePTFE-grafts, knitted Dacron grafts with collagen impregnation, and knitted Dacron grafts with external collagen-coating were used. The heat production per cell was calculated. A rapid increase of metabolic activity followed by a gradual decrease was demonstrated with both granulocyte suspension and platelet concentrate. Significant differences were obtained between the materials with a maximum response of Dacron grafts with collagen impregnation for both granulocyte and platelet response. The materials had different surface morphologies regarding cell adhesion after incubation as demonstrated with scanning electron microscopy with more pronounced adhesion on the collagen-impregnated grafts. The results suggest that microcalorimetry may be useful for the evaluation of cellular reactions on different biomaterials. However, further studies have to reveal the specificity of the reactions.