NON-SELF-RECOGNITION OF METALS IN BLOOD AND PERITONEAL-CAVITY

To explore the hypothesis that protein adsorption followed by platelet adhesion and activation has an effect on the nature of the subsequent inflammatory response, we studied the cell-implant reactions to Ti an d Au in blood and the peritoneal cavity. The metals were exposed to bl ood (in vitro) and peritoneal fluid (in vivo). In blood the adhesion a nd activation of platelets and leucocytes were studied by fluorescence microscopy using specific FITC-labeled antibodies or acridine orange. Intraperitoneal leucocyte adhesion was studied by scanning electron m icroscopy, transmission microscopy, or by staining with acridine orang e. The metallic surfaces were exposed to both blood and peritoneal flu id for times varying from 15 s to 4 h. The results show (a) that a sig nificantly larger number of platelets followed by a correspondingly la rge number of leucocytes initially adhere to Ti rather than to Au, (b) that the rate of the inflammatory response as manifested by the appea rance of leucocytes is more rapid in the peritoneal cavity than in blo od, and (c) that cells attach directly to the Au surfaces while being separated by an amorphous layer on the Ti surfaces. Thus an interestin g nexus exists between the composition of the adsorbed protein layer, platelet adsorption, and activation and the rate and nature of leucocy te recruitment and interaction with implanted materials. (C) 1996 Amer ican Vacuum Society.