New model of bioceramics for bone implants proposed by Lobachevsky University chemists
Biocompatible materials with antibacterial properties are based on hydroxyapatite which is a promising material for implants and has a structure similar to that of the human body's hard tissue. Scientists at the Faculty of Chemistry of Lobachevsky University have refined hydroxyapatite composition and structure to make it even stronger and safer, and to avoid possible post-operative complications. Bioceramics can stimulate the repair of bone defects and at the same time provide protection against the development of bacterial infections.
The classical hydroxyapatite composition Ca10(PO4)6(OH)2 was supplemented with bismuth (Bi) ions as an antibacterial agent, which minimises the risk of postoperative infections and reduces the likelihood of repeated operations. In this case, the bismuth is firmly locked into the crystal lattice of the compound and will not accumulate in body tissues outside of the implant.
The bioceramics were also modified with sodium (Na) ions to improve biocompatibility and with fluorine (F) ions, which make the material more stable and enhance its effectiveness in dentistry. Thus, the researchers obtained fluorapatite Ca10-2xBixNax(PO4)6F2, which can prove very useful in the production of medical ceramic materials or coatings for metallic biomaterials.
"Today, apatite-based materials are in limited use, as small 'spare parts'. We believe that if they are strengthened with bismuth and supplemented with various biogenic elements such as fluoride and sodium, the quality of the prosthetic parts can be significantly improved. This can be a breakthrough in controlling post-operative infections. Instead of filling the implant with antibiotics that would spread throughout the body, we can use just one compound, a crystallochemical analogue of the bone. The near-term tests we conducted have already demonstrated that our material poses no danger to human cells," explains Associate Professor of the UNN Department of Analytical and Medicinal Chemistry Evgeny Bulanov, a co-author of the study.
Because of the special crystalline structure, the bioceramics obtained by Nizhny Novgorod scientists demonstrate low in vitro cytotoxicity, which means that the substance will not attack healthy tissue outside of the implant. The round shape of fluorapatite particles helps them easily penetrate cell membranes and effectively attack pathogens. All this opens up a wide range of possibilities for the new material to be used in medicine.
The results of the study were published in the book Bioceramics: Advances in Applications and Research issued by Nova Science Publishers.
The project was carried out at the UNN Research Laboratory for Chemistry of Natural Compounds and their Synthetic Analogues within the framework of the Nizhny Novgorod Research and Education Centre.
