THE EFFECT OF SUBSTRATUM ROUGHNESS ON OSTEOCLAST-LIKE CELLS IN-VITRO

Calcium phosphate powders were used to produce three groups of experimental substrata for the culture of primary rat bone marrow cells in conditions which permitted the survival and function of osteoclasts. Each of the three experimental groups were subdivided by differences in substratum surface roughness and following a culture period of 7 to 11 days, the culture units were stained for tartrate-resistant acid phosphatase activity. In all samples both small, sometimes mononuclear, and large multinucleate cells stained positive for tartrate-resistant acid phosphatase activity and the numbers and types of cells were quantified and statistically analyzed. Following histochemical staining the samples were dehydrated and gold coated for examination by scanning electron microscopy. Cells were found to create distinct resorption lacunae in most substrata, but not on the dense, high temperature sintered hydroxyapatite, and cells responsible for this activity were confirmed as exhibiting positive tartrate resistant acid phosphatase activity. Statistical analyses showed that both the total number of tartrate-resistant acid phosphatase positive cells and the number of multinucleate tartrate-resistant acid phosphatase positive cells was greater on the rougher than the smoother surfaces.