JERUSALEM, Sept. 2 (Xinhua) -- Israeli researchers have developed a method of antibacterial coating for metal medical implants to prevent infections, the Hebrew University of Jerusalem (HUJI) reported on Monday.
Metallic and plastic implants are available for various purposes, ranging from bone-connecting screws to coils that prevent arterial occlusions.
However, the insertion of any foreign body into the human body has risks of infection and fusion difficulties between the implant and the tissue.
In the new study published in the journal Nano Materials, the researchers presented a coating combined of antioxidant zinc particles with antibacterial activity and hydroxyapatite, a calcium and phosphate mineral which forms the bones and teeth and helps the implant's absorption process.
The researchers first created the zinc oxide nanoparticles ZnO and hydroxyapatite, adding a small amount of organic additive which expands and stabilizes them in solution and gives them a positive charge.
Finally, the team exerted a negative voltage on a metallic implant, and the positive charge generated on the particles causes them to sink in the metal.
Unlike other methods, the new method makes it possible to evenly coat conductive substrates of complex geometry, such as screws.
In addition, the drug can be introduced at one stage as part of the hydroxyapatite coating, and can be introduced at one phase as part of the hydroxyapatite coating process.
Testing the new coating, the team found that on exposed titanium surface, there was a significant growth of bacteria, while on the surface with the new coating no bacteria grew at all.
In addition, in a toxicity test, the coating did not interfere with cell growth, indicating a high level of coating suitability for implants.
In a similar method, the researchers hope to add more hydroxyapatite substances like growth factors.
The new approach may be applied to coating implants of various types, such as dental implants which may lead to production of "smart" implants in a simple and effective way.