Better osteoblast adhesion on nanoparticulate selenium- A promising orthopedic implant material

Apart from problems such as poor osseointegration, stress shielding, and wear debris-associated bone cell death, a major concern of metallic orthopedic implants is that they slowly corrode under in vivo environments. It is possible that continuous tissue exposure to metallic corrosion products limits orthopedic implant efficacy; this is especially true for patients receiving implants due to bone cancer. To date, there is no metallic orthopedic implant available in the market that specifically deals with the prevention and/or recurring cancer that may happen in these patients. The objective of this study was to deal with these problems in an integrated way by introducing a new biomaterial to the orthopedic community with anticancer chemistry: selenium (Se). In this study, six types of Se compacts were tested for bone cell (osteoblast) adhesion under in vitro conditions. Two types of cylindrical compacts were made with conventional Se metal particles in the micron (6.539 +/- 1.364-microm diameter) and submicron (0.963 +/- 0.139-microm diameter) range. These two types of compacts were chemically etched with different concentrations of NaOH to create two additional types of Se particles in each category: conventional size particles with nanosurface roughness and nanometer particles (0.204- to 0.264-microm diameter). Results showed for the first time, enhanced osteoblast adhesion on particulate surfaces of the compacts made from conventional Se compared with reference nonparticulate wrought titanium sheets. More importantly, this study provided the first evidence that osteoblast density was further increased on the surfaces of the Se compacts with nanometer particles. These initial findings indicate that there may be a promising future for nanoparticulate Se as an anticancer biocompatible orthopedic material.