MODULATION OF THE TISSUE REACTION TO BIOMATERIALS - II - THE FUNCTIONOF T-CELLS IN THE INFLAMMATORY REACTION TO CROSS-LINKED COLLAGEN IMPLANTED IN T-CELL-DEFICIENT RATS

Unwanted tissue reactions are often observed resulting in events such as early resorption of the biomaterial, loosening of the implant, or a chronic (immunologic) response. From immunologic studies it is known that inflammatory reactions can be modulated by use of (anti)-growth f actors or anti-inflammatory drugs. Before this can be employed with re spect to biomaterials, the role of individual factors (humoral and cel lular) has to be studied. In this part of the investigation, the role of T cells was studied by use of T-cell-deficient (nude) rats and cont rol (AO) rats. Hexamethylenediisocyanate-crosslinked dermal sheep coll agen (HDSC) was selected as the test material. The results showed that T cells or T cell-related factors played a prominent role in the attr action of macrophages and the formation of giant-cells, their antigen presentation, and their phagocytotic capacity. As a consequence, degra dation of HDSC was strongly delayed. This study also showed that infil tration of fibroblasts and creation of stromal areas in HDSC was restr icted to areas subjected to degradation. However, in time, absence of T cells resulted in increased formation and maturation of autologous r at collagen. Results obtained suggest that the inflammatory reaction t o biomaterials might be modulated by controlling T-cell activation. (C ) 1998 John Wiley & Sons, Inc.