Bone formation on carbon nanotube composite.

The effects of a layer-by-layer assembled carbon nanotube composite (CNT-comp) on osteoblasts in vitro and bone tissue in vivo in rats were studied. The effects of CNT-comp on osteoblasts were compared against the effects by commercially pure titanium (cpTi) and tissue culture dishes. Cell proliferation on the CNT-comp and cpTi were similar. However, cell differentiation, measured by alkaline phosphatase activity and matrix mineralization, was better on the CNT-comp. When implanted in critical-sized rat calvarial defect, the CNT-comp permitted bone formation and bone repair without signs of rejection or inflammation. These data indicate that CNT-comp may be a promising substrate for use as a bone implant or as a scaffold for tissue engineering.