Ultrastructural study of an apatite layer formed by a biomimetic process and its bonding to bone

A dense and uniform apatite layer about 20μm thick was formed on a poly(ether sulphone) (PESF) substrate treated with glow discharge in O2 gas by a biomimetic process. The apatite-polymer composite obtained was implanted into a rabbit tibia and the structure of the PESF-apatite-bone interface was observed under a scanning and a transmission electron microscope 8 weeks after implantation. The apatite layer formed by the biomimetic process was confirmed to consist of small crystals of apatite with a structure similar to that of apatite in bone. The apatite layer remained on the substrate in the body, and bonded to the apatite in the bone directly. This type of apatite-organic polymer composite expected to be useful as bone-repairing material.