Cell morphology, markers, spreading, and proliferation on orthopaedic biomaterials. An innovative cellular model for the "in vitro" study.

The aims of tissue engineering are the in vitro reconstruction of functionally active tissues, and the in vivo induction of their appropriate development. The great progresses in the fields of biology and biomaterials represent key events, which allowed the recent improvement of tissue engineering. In the orthopaedic perspective, tissue engineering is focused on the development of innovative materials, whose action consists in recruiting bone progenitor cells and in stimulating their proliferation. In this context, it should remind that these materials should not only allow cells adhesion and proliferation, but also ensure that attached cells maintain the cellular properties of the original tissue. In this study, a new cellular model, suitable for the rapid in vitro determination of the above parameters, is presented. The cell model derives from a human osteosarcoma cell line, Saos-2, which maintained the cytological features of the osteoblast cells. The cell line was genetically modified to express constitutively the enhanced green fluorescent protein. The engineered cell line Saos-eGFP represents a suitable in vitro mode for studying the biocompatibility, the cell adhesion, spreading, and proliferation on biomaterials developed for clinical applications.