Selenium (Se) nanoclusters were coated on three different orthopedic materials: Titanium, stainless steel and ultra high molecular weight polyethylene (UHMWPE). There different coating densities were achieved on each type of substrate. The uncoated and coated Ti and SS substrates were then used in experiments with either normal healthy osteoblasts (bone-forming cells) or cancerous osteoblasts (osteosarcoma) or a combination of both. For the first time, it was shown that the substrates coated with Se nanoclusters promoted (or at least maintained) normal osteoblast proliferation and inhibited cancerous osteoblast growth in both separate culture experiments and co-culture experiments. Thus, this study introduced to the orthopedic cancer community for the first time a coating material (Se) which may inhibit bone cancer growth and promote normal bone growth.