Gene expression of markers of osteogenic differentiation of human mesenchymal cells on collagen I-modified microrough titanium surfaces.

Microrough, doubly acid etched titanium surfaces (Ti) were further modified by amination and covalent coupling of fibrillar collagen type I (ColTi). Human Mesenchymal Cells (HMC) adhesion and growth, and relevant osteogenic differentiation in nonosteogenic (basal) medium were evaluated by fluorescence microscopy, scanning electron microscopy, and RT-PCR for a three-week period. Results show strongly enhanced HMC adhesion and cell density at short experimental time on ColTi, together with complete spreading of the cell body over the microrough surface topography. RT-PCR analysis of several genes involved in osteogenesis indicate, since the first week of culturing, significant progression of HMC on ColTi along the osteogenic pathway. These results indicate that the adopted process of surface immobilization of collagen, mandatory to impart collagenase resistance in implant sites, does not impair biospecific interactions between HMC and collagen. Thus, it is possible to upgrade properties arising from the control of Ti surfaces topography by surface-chemistry driven enhanced recruitment of precursor osteogenic cells and pro-osteogenic stimula.