The scientists responsible for the creation claim that implants treated using the new method will noticeably speed up and facilitate trauma recovery. Their study has been published inColloids and Surfaces B: Biointerfaces, an international journal devoted to fundamental and applied research on colloid and interfacial phenomena.
Life expectancy is increasing in most countries today, leading to an increasing number of bone injuries among the elderly. The mechanical properties of bone and its ability to heal significantly deteriorate with age, making such injuries require careful and time-consuming treatment. These factors create a demand for new implant materials that speed up and facilitate rehabilitation, the scientists at NUST MISIS said.
According to scientists, the use of implants made of unmodified metals and alloys can lead to complications, the most common being inflammation due to bacterial infections, which may require repeated surgical intervention. Materials capable of inhibiting bacterial activity would make internal prosthetic surgery safer and more reliable.
Scientists at NUST MISIS have developed a method of creating an antibacterial coating for one of the most promising titanium alloys, Ti-Zr-Nb. Experiments have shown that coating the implant surface using the new method completely suppresses the growth of E. coli bacteria.
“We make the surface of the alloy more porous to a depth of 100-120 nanometres by chemical etching, which allows nanoparticles to be evenly distributed, not only on the surface but also in the depth of the pores. Even at low doses of silver output, about 0.037 mg/l, which is completely safe for the body, we managed to achieve a superior antibacterial activity,” said Anton Konopatsky, co-author of the research work and senior researcher at the NUST MISIS Laboratory of Inorganic Nanomaterials.
Silver ions deliver the “blow” to the bacteria, the authors of the method explained. The nanoparticles emitting them have been chemically synthesised by the scientists in solutions of complex alcohols, achieving a size of only about 10 nanometres. The scientists explained that the silver is deposited in the material's pores at a depth of up to 60 nanometres, which significantly increases the coating's durability and antimicrobial effectiveness.
According to scientists at NUST MISIS, the porosity of the surface provides an additional factor in suppressing bacteria - it allows micro-organisms to come into contact with the silver more densely and evenly.
Although tests on most types of bacteria have yet to be conducted, the creators are confident that the new coating will be as effective against any micro-organism as it is against E. coli.
The work was carried out with the participation of scientists from the Pirogov Russian National Research Medical University and Lomonosov Moscow State University. In the future, the scientific team intends to develop new coatings as part of the proposed approach, which will reduce the dose of antibiotics used during surgery and the recovery period.