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Bacteria-killing implant material

The two main problems in implant surgery are the slow survival of the implant and the risk of developing a bacterial infection at the site of its installation. Acceleration of survival is possible by making an implant from a bioactive material that stimulates the division of osteoblasts - the patient’s bone cells. Infection is fought with antibiotics, but bacteria quickly develop resistance to them. This problem requires the creation of new effective ways to fight infections, for example, the use of metal ions known for their bactericidal activity or the ability to generate reactive oxygen species (they are harmful to bacterial membranes).

Most modern implants are made of titanium - it is durable, bio-inert and not subject to corrosion. However, titanium does not have bioactive and antibacterial properties, and that is why scientists are actively working to create coatings that eliminate these shortcomings. A film of titanium oxide (TiO2) shows good results - because of the porous structure, it is most suitable for bone cell division, and the inclusion of calcium Ca and phosphorus P in its composition provides bioactivity. However, it is still an important task to give the implant antibacterial properties.

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The team of the scientific and educational center for self-propagating high-temperature synthesis NITU "MISiS" (NUTS SHS NITU "MISiS") has developed coatings for titanium implants based on titanium oxide with silver and platinum nanoparticles. The material developed by scientists allows accelerating proliferation, that is, active cell division by an average of 12-20%, as well as ensuring the destruction of up to 100% of bacteria after 72 hours and protection against the formation of a bacterial film.

« — „“ . (Ca = 6,3 P = 4,8 %), — 0,7 2,3 . — , . Pt Ag », — , «» .

Penetrating a depth of approximately 30 nanometers into the sample, individual ions formed atoms. As a result of the high concentration of atoms in this layer, some of them came to the surface of the implant and formed silver and platinum nanoparticles. Silver on the surface is already independently capable of providing an antibacterial effect due to its ions. But there is their maximum concentration above which toxic properties may appear.

Platinum as an element does not have any bactericidal properties. The presence of Ag and Pt in the form of nanoparticles on the surface of titanium oxide gives the material catalytic properties. As a result, under ordinary light and ultraviolet radiation, coatings are able to generate a large number of reactive oxygen species that destroy various bacterial strains.

To check the antibacterial properties of the material, the samples were placed in media with various strains of E. coli and Staphylococcus aureus. The results obtained allowed us to conclude that the synergistic effect of silver ions and reactive oxygen species allows you to quickly and effectively eliminate any bacterial infection without jeopardizing the patient. Samples with platinum nanoparticles destroy bacteria only due to reactive oxygen species.

In the future plans of scientists - to continue experiments to increase the bioactivity and bactericidal properties of implants. In particular, it is planned to saturate the open pores of titanium oxide with antibiotics, artificial blood and peptides.

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