Adhesion and growth of osteoblast-like cells on laser-engineered porous titanium surface: expression and localization of N-cadherin and beta-catenin.

Response of different types of cells on biomaterials is crucial for the applications of tissue engineering and regenerative medicine. It is recognized that cell behaviour depends largely on material surface characteristics. The purpose of this study was to define the biologic response of MG63 cells to the innovative patented surface SYNTHEGRA. MG63 morphology and distribution on the three different titanium disk surfaces (sandblasted, smooth, and laser-treated) were evaluated by microscopy analysis after staining with hematoxylin and eosin. Cell adhesion was determined by crystal violet assay at 48 h while proliferation and cytotoxicity were performed by MTT assay at 24, 48, 72 and 240 h. The expression and localization of N-cadherin and beta-catenin were studied by immunofluorescence and confocal microscopy. At 48 h the adhesion was similar in all titanium surfaces, no difference in cell viability were observed in all titanium disks when compared with controls, while the cell growth on laser-treated disks was significantly higher at 240 h than at 24 and 72 h. Morphological analysis show that cells are aligned along the grooves and inside the cavities. beta-catenin signal appeared more diffuse and localized underneath the cell membrane, while N-cadherin signal was fainter in cells grown on SYNTHEGRA surface. This work put into evidence the performance of newly designed laser-micromachined surface for adhesion, growth and distribution of human osteoblast-like cells. SYNTHEGRA surface inducing modification of N-cadherin and beta-catenin expression and localization, are suggestive of cells undergoing differentiation towards osteocytes and could be particularly suited for immediate load implant procedures.