Effect of low-intensity pulsed ultrasound on the biological behaviors of bone marrow mesenchymal stem cells on titanium with different surface topographies.

The use of low-intensity pulsed ultrasound (LIPUS) is a promising approach to promote osteogenesis. However, few studies have reported the influence of this technique on the osseointegration of endosseous implants, especially regarding different implant topographies. We focused on how the initial interaction between cells and the titanium surface is enhanced by LIPUS and the potential regulatory mechanisms. The bone marrow mesenchymal stem cells (BMSCs) of rats were cultured on two types of titanium surfaces (polished surface, Flat and large grain blast acid etched, SLA) under LIPUS stimulation or control conditions. The cell proliferation on the implant surfaces was significantly promoted by LIPUS, which stimulated the increase in the number of microfilaments, pseudopodia formed and extracellular matrix mineralization nodules compared with those in the control group. The expression of osteogenesis-related genes, including OPN, OCN, BMP-2, ALP, Runx2 and Col-1, were up-regulated on all the surfaces by LIPUS stimulation. Our findings suggest that LIPUS enhances osteoblast differentiation from BMSCs on titanium surfaces. The use of LIPUS might be a potential adjuvant treatment to improve the osseointegration process.