Initial attachment of osteoblasts to an optimised HAPEX topography.

The interactions between an implant material and the surrounding tissue are of a complicated nature, and the initial attachment of cells to the surface is important in determining the implant success. HAPEX has been developed as a second-generation orthopaedic biomaterial, with both mechanical and biological characteristics that make it suitable for bone augmentation. Further optimisation of the material is being continued to increase the attachment of osteoblasts coupled with improving mechanical characteristics, so it may be used in load bearing applications. It has been previously observed that polishing followed by roughening the surface of HAPEX enhances osteoblast proliferation and phenotype. This article discusses the recruitment of primary human osteoblast cells onto the optimised surface, by examining morphology and cytoskeletal changes using scanning electron microscopy and confocal laser scanning microscopy. The results show that the cells attach in greater numbers to the optimised surface, and develop notably faster, than cells on machined HAPEX.