To date, there are a strikingly growing number of patients who need various
orthopedic implants. However, traditional orthopedic implants face many
complications such as infection and implant loosening which may lead to
implant failures. Conventional metal implants such as titanium were chosen
for orthopedic applications mainly based on their excellent mechanical
properties and biological inertness. Since natural bone matrix is nanometer
in dimension, it is desirable to design a biologically inspired
nanostructured coating that can turn conventional inert titanium surfaces
into biomimetic active interfaces, thus enhance bone cell adhesion and
osseointegration. For this purpose, we designed a biomimetic nanostructured
coating based on nanocrystalline hydroxyapatites (nHA) and single wall
carbon nanotubes (SWCNTs). Specifically, nHA with good crystallinity and
biomimetic dimensions were prepared via a wet chemistry method and
hydrothermal treatment; and the SWCNTs were synthesized via an arc plasma
method with or without magnetic fields. TEM images showed that the
hydrothermally treated nHA possessed regular rod-like nanocrystals and
biomimetic nanostructure. In addition, the length of SWCNTs can be
significantly increased under external magnetic fields when compared to
nanotubes produced without magnetic fields. More importantly, our results
showed that the above nHA and SWCNTs nanomaterials can greatly promote
osteoblast (bone-forming cell) adhesion on titanium in
vitro, thus holding great promise to improve osseointegration
and lengthen the lifetime of current orthopedic implants.