A research and development team at Tel Aviv University, led by Professor Noam Eliaz, has developed a way to electrochemically deposit synthetic hydroxyapatite, the coating used on metal implants. The coating, which is similar to the main inorganic constituent of enamel, dentin and vertebrate bone is crucial to the implant’s functionality and life.

Images of electrochemically-deposited crystals from a scanning electron microscope

Eliaz and his team have successfully applied the coating by placing metal implants into a bath of electrolyte solution, to which an electric current is applied. The electrochemical process is said to allow synthetic hydroxyapatite to more closely mimic the body's own material, which helps the body accept a new implant. Since human bones naturally contain apatite, covering the implant with a synthetic version allows the body to register the implant as similar to a real bone. This ensures integration and fixation of the implant, and also prevents poisonous materials from leaking from the metal of the implant into the blood stream.

The next-generation coating will include nano-particles to reinforce the coating. It will also have the potential to incorporate biological material or drugs during the process itself. "We can incorporate biological materials" because the electrochemical process works at lower temperatures, says Prof. Eliaz. "The reinforcement of nanoparticles will improve the mechanical properties and may also improve the biological response. Drug incorporation may reduce the risk of post-surgery infection and even catalyze the growth of the bone."