The effect of biphasic electrical stimulation on osteoblast function at anodized nanotubular titanium surfaces

Over the past decade, nanotechnology (or the use of materials with dimensions less than 100 nm in at least one direction) has been proposed to improve the lifespan of many biomedical devices, including orthopedic implants. Specifically, to improve the cytocompatibility properties of currently used orthopedic implants, nanotechnology has been used to create nanometer surface features (through anodization) on titanium. In addition to this approach, another therapeutic method widely investigated to heal bone fractures is through electrical stimulation. Here, the coupling of such nanotechnology approaches and electrical stimulation were studied to maximize bone cell functions on titanium. Results showed that compared to unstimulated conventional titanium, bone forming cell (osteoblast) proliferation and long-term functions (alkaline phosphatase synthesis, collagen type I synthesis and calcium deposition) were improved upon both the creation of an anodized nanotubular titanium surface and biphasic electrical stimulation. Most importantly, when electrical stimulation was combined with anodized nanotubular titanium features, osteoblast long-term functions were improved the most. Therefore, coupling the positive effects of anodized nanotubular titanium topographies with currently used therapeutic electrical stimulation should be further studied to improve orthopedic implants.