Síntese, avaliação das propriedades antimicrobianas, caracterização e aplicação de vidros borato, fosfato e borofosfatos

Abstract

The difficulties in controlling pathogenic microorganisms have become a serious public health problem that directly influences the population's quality of life. Due to the emergence of drug-resistant microorganisms, the use and discovery of antimicrobial materials are gaining importance every day. Among them, the glass has stability and good shelf life and has been applied in several areas, mainly health. Of the existing glass network formers, we have those made of glassy phosphorus and boron, which by themselves present stability problems, but when combined, form borophosphate glasses that are more stable and less hygroscopic. Therefore, in this study, borates, phosphates and borophosphates glasses were synthesized (with or without the addition of zinc oxide) by the melting/quenching technique. The glasses were submitted to microbiological tests with bacteria of the species Escherichia coli, Staphylococcus aureus and yeasts of the species Candida albicans and Candida glabrata. All tested glasses showed bacteriostatic and fungistatic activity, and the borates, phosphates and borophosphates P/B=2, P/B=0.5 and P/B=1 showed to be fungicidal. The glass that showed the best inhibition results against the microorganisms tested was the one composed only of boric acid, but it was classified in this study as unfeasible for application, since it has chemical instability. Thus, borophosphate glass P/B = 0.5 classified as the most promising sample of the others, including fungicidal activity against C. albicans. After performing physicochemical characterization analyses, borophosphate glass P/B=0.5 was used in a prototype test, in which its activity against C. albicans in female sanitary napkins was tested, since this species of Candida causes vaginal infections, a worldwide health problem that affects most women, especially in their fertile life. The application of glass in intimate absorbents showed promising results, since the number of Colony Forming Units (CFU) observed in the absorbents with the vitreous sample showed a significant difference compared to the growth control, showing a reduction of more than 80% in mean value of CFU/mL, when compared to the growth control that did not have the sample. Therefore, the results obtained in this study open the way for a diversity of applications of the synthesized vitreous samples against the tested microorganisms.