Síntese de hidroxiapatita com a adição de íons Ag+ pelo método de precipitação: caracterização e avaliação da capacidade antimicrobiana

Abstract

Hydroxyapatite, Ca10(PO4)6(OH)2 is defined as a biomaterial made primarily of calcium phosphate and contains 30% of the mass of bone and teeth. For this reason, have received great attention from the scientific community since there is a constant search for bone substitutes, especially in the medical field. However, any procedure can be subject to infections and compromise the material implanted in the short and medium term and thus, alternatives are sought to reduce or even prevent these possible infections. One of these alternatives is to associate bactericidal metals with the biomaterial and in this context, silver has gained prominence as an ally in the control of post surgical infections. This work describes the synthesis of silver nitrate doped hydroxyapatite by chemical and wet precipitation and the results of X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. The results of XRD indicated the presence of metallic silver characterized by peaks at 2= 38.2º and 44.4º for the HAAg 0.1 mol L-1 sample and the majority phase of HA characterized by peaks at 2 = 25.9º; 31.6 °; 32.9 ° and 33.9 °. In the Infrared spectra the bands that characterize the phase of the HA related to PO4 3-, OH- and CO3 2- groups were verified. The latter being a phase formed due to the synthesis being performed in the open system. To evaluate the antimicrobial effect of silver, the diffusion disc test was performed for Escherichia coli, Staphylococcus epidermidis and Candida albicans strains. Escherichia coli is a gram-negative bacterium, and there was no inhibition at any concentration of silver. For Staphylococcus epidermidis, which is a Gram-positive bacterium, and for the yeast Candida Albicans there was inhibition only at the concentration of silver of 0.1 mol L-1.