CHARACTERIZATION OF BOVINE OSTEOCLASTS ON AN IONOMERIC CEMENT INVITRO

Primary bovine osteoclasts were obtained by an outgrowth method from b ovine periosteum and cultured for 7 days on an ionomeric cement for bi omaterial testing. Osteoclasts cultured on slices of bovine bone and o n glass microscope cover-slides served as a control. The cells were ch aracterised as osteoclasts by a number of tests. Osteoclasts showed po sitive staining for tartrate resistant acid phosphatase and reactivity with the antibodies 13C2 and 23C6, which react with the alpha-chain o f the vitronectin receptor. Addition of salmon calcitonin to the cultu re medium led to sudden cessation of lamellipodial activity. The cells resorbed bone by making pits. In mixed cultures with osteoblasts, the morphology of the osteoclasts on the smooth ionomeric cement surface was comparable to the one on glass cover-slides, revealing broad cytop lasmatic extensions on the material. Acridine orange staining demonstr ated viability of cells until the end of the culture period and increa sed acidification after parathyroid hormone (PTH) stimulation. Scannin g electron microscopy did not reveal erosion of the material by osteoc lasts. No signs of aluminium toxicity on osteoclasts could be detected during the 7 day culture period, although an increased uptake of alum inium into the cell was demonstrated.