BIOCOMPATIBILITY ANALYSIS OF DIFFERENT BIOMATERIALS IN HUMAN BONE-MARROW CELL-CULTURES

A cell culture system for biocompatibility testing of hip implant mate rials is described. Human bone marrow cells have been chosen because t hese cells are in direct contact with the biomaterial after implantati on in situ. The sensitivity of this method is evaluated for materials which are already being used as implants in humans and animal, e.g., h ydroxyapatite (HA) ceramic, pure titanium, and ultra-high-molecular-we ight polyethylene (UHMWPE). As indicative parameters of biocompatibili ty primary cell adherence, cell number, cell proliferation, production of extracellular matrix, cell vitality, and cell differentiation are described. After 2 weeks in culture, obvious differences between the b iomaterials with respect to the indicative parameters could be observe d. Cell numbers were greatest on the HA specimens. Ln the case of tita nium alloys, we observed a decreased number of cells. The production o f extracellular matrix was high for the HA ceramics but reduced for ti tanium specimens. The polymers allowed only a few adherent cells and s howed no signs of extracellular matrix production. The results can be correlated astonishingly well to animal experiments and clinical exper iences. Therefore, we suggest that this cell culture system seems to b e a useful tool for biocompatibility testing of bone implantation mate rials. It also helps reduce animal experiments. With the help of flow cytophotometry, we analyzed the influence of biomaterials on large num bers of cells with respect to differentiation. There were similar popu lations of T cells and monocytes on all specimens tested. Extended B-c ell and granulocyte populations, however, were observed with titanium and UHMWPE. Most osteocalcin-containing cells adhered to the HA cerami cs. (C) 1998 John Wiley & Sons, Inc.