Basic fibroblast growth factor production in vitro by macrophages exposed to Dacron and polyglactin 910

Macrophage activation by implanted blood-contacting biomaterials modulates smooth muscle cell and endothelial cell ingrowth. The present study evaluates the in vitro interactions between Dacron or polyglactin 910 with macrophages derived from rabbits fed either normal or atherogenic diets. Peritoneal macrophages were cultured in the presence or absence (negative controls) of either biomaterial for 7 weeks. Conditioned media was evaluated for mitogenic activity using a rabbit aortic smooth muscle cell bioassay with or without preincubation with neutralizing anti-basic-FGF antibody. Results demonstrated increased mitogen release from macrophages harvested from the atherosclerotic rabbits. Only macrophages harvested from normal diet fed rabbits increased their mitogen release following exposure to either polyglactin 910 (p < 0.05) or to Dacron (p < 0.005) over controls. The stimulation of mitogen release by polyglactin 910 did not significantly exceed that in response to Dacron. In rabbits fed normal diets neutralization with the anti-basic-FGF antibody inhibited 100% of the Dacron induced mitogen release as compared to 36% of the polyglactin 910 induced mitogen release (p < 0.01). These results demonstrate significant induced mitogen release from macrophages exposed to biomaterials in vitro, much of the smooth muscle cell mitogen represented by basic-FGF.