| Titanium and its alloys have been widely used in orthopedic field on behalf of biomaterials. The stability of endoprosthetic implants depends on a stable connection between the implant material surface and the surrounding bone tissue. But the intractable problem has not been solved finely up to now. In recent years, some researches have demonstrated that the bone-implant interface is very important for long-term implant bonding and the implant surface topography has a great influence on osteoblastic cell response, especially the micro-topography. The detailed investigates of osteoblast response to varied surface topographies might be essential to overcome the problem of bone-implant interface. This study was focused on the influence of four various surface micro-topographies on cell morphology, adhesion, proliferation and differentiation, which is to find the optimal surface micro-topography to increase the clinical performance of titanium-based implants.1. A modified method for isolating and culturing pure osteoblasts from rabbit calvaria in vitroObjective Pure osteoblasts are important in studies concerning the osteoblasts in vitro. For obtaining pure osteoblasts, a simple and tried method is needed. Methods A modified method is presented for isolating osteoblasts from newborn rabbit calvaria. The procedure is based on the former methods. To strip away periostea from calvaria by enzymes digesting separation and then culture explant in DMEM supplemented with 10% fetal calf serum. The new method is named floating explant culture. Cultured cells were examined by morphological observation and histochemical staining. Results Rabbit osteoblasts were obtained by migrating from bone onto culture flasks, and the biological behaviors of the osteoblast were observed under a phase-contrast microscope. Histochemical staining of alkaline phosphatase demonstrated 100% purity of cultured osteoblasts. The presence of calcium deposit activity in cultured cells was demonstrated by Van Kossa staining and alizarin red staining. Growth curve of the cells revealed the presence of strong proliferation activity. Conclusion The results showed isolated osteoblasts were pure and retained their unique property in culture. The modified method, floating explant culture, provides a useful and simple method for the studies of bone biology and bone tissue engineering.2. Effect of surface micro-topography of titanium material on the behaviors of rabbit osteoblastic cells in vitroObjective Studies on interactions of osteoblastic cells on various topography surfaces of titanium material through in vitro systems, can give lucid insights to osseo-integrative efficacies of when in vivo implants. Methods In the present investigation four micro-topography surfaces of titanium material, laser-scanned surface (LS), sandblasted surface (SS), machine-tooled surface (MS) and polished surface (PS) were compared through in vitro measurement. The titanium samples were seeded with osteoblastic cells and maintained for a period of 1–12 days. Adhesion in 24h, proliferation in 12 days and ALP activity in 11days were assessed. The cell morphologies were observed by scanning electron microscopy and fluorescence microscopy. Results Implant surface micro-topography can influence osteoblastic cells adhesion, proliferation, differentiation and morphology. The investigation showed better cell proliferation and best cell differentiation on the micro-grooved surface (LS) at the cell scale (50μm). Further, osteoblastic cells on the micro-grooved surfaces also displayed a more similar morphology to osteoblastic cells in vivo. Conclusion Surface micro-texture at the cell scale can more greatly influence cell responses than rough surface and surface texture above the cell scale (>100μm). The regular micro-grooved titanium surface at the cell scale can offer a better cell growth environment compared with the other titanium surfaces. |
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