BIOMATERIALS IN ORTHOPEDIC-SURGERY - EFFECTS OF DIFFERENT HYDROXYAPATITES AND DEMINERALIZED BONE-MATRIX ON PROLIFERATION RATE AND BONE-MATRIX SYNTHESIS BY HUMAN OSTEOBLASTS

The effects of different biomaterials, used in orthopaedic surgery for bone substitution and/or prosthesis coating to improve fixation and d urability of prosthetic implants, have been studied in vitro on cell g rowth and bone matrix synthesis by human osteoblasts. The materials we re a bovine collagen matrix (Osteovit, B. Braun Melsungen AG, Melsunge n, Germany) and two hydroxyapatite (Ceros 80, Robert Mathys Co, Instru mentenfabrik Bettlach, Germany and Ostilit, Howmedica International, S taines House, UK). Cell proliferation and bone matrix synthesis were a ssessed by incorporation of [H-3]thymidine and [H-3]proline, respectiv ely. Cell viability in the presence of the materials was also morpholo gically controlled using phase-contrast microscopy. Exposure to Osteov it caused increased proliferation of human osteoblasts, whereas both O stilit and Ceros 80 induced a decreased cell growth. Osteoblast bone m atrix synthesis was increased by all the materials tested.