HA and double-layer HA-P2O5/CaO glass coatings: influence of chemical composition on human bone marrow cells osteoblastic behavior

Human osteoblastic bone marrow derived cells were cultured for 28 days onto the surface of a glass reinforced hydroxyapatite (HA) composite and a comm ercial type HA plasma sprayed coatings, both in the "as-received" condition and after an immersion treatment with culture medium during 21 days. Cell proliferation and differentiation were analyzed as a function of the chemic al composition of the coatings and the immersion treatment. Cell attachment, growth and differentiation of osteoblastic bone marrow cel ls seeded onto "as-received" plasma sprayed coatings were strongly affected by the time-dependent variation of the surface structure occurring during the first hours of culture. Initial interactions leading to higher amounts of adsorbed protein and zeta potential shifts towards negative charges appe ared to result in surface structures with better biological performance. Cu ltures grown onto the pretreated coatings showed higher rate of cell prolif eration and increased functional activity, as compared to those grown onto the corresponding "as-received" materials. However, the cell behavior was s imilar in the glass composite and HA coatings. The results showed that the glass composites present better characteristics for bone cell growth and function than HA. In addition, this work also pro vide evidence that the biological performance of the glass composites can b e modulated and improved by manipulations in the chemical composition, name ly in the content of glass added to HA. (C) 2001 Kluwer Academic Publishers .