Evaluation of the antimicrobial activity of polyamide 6 nanocomposite biomaterials with trimetaphosphate nanoparticles decorated with silver nanoparticles

Author(s)

Leonardo Antonio de Morais

• Document type: Master's Dissertation
• Press: Araçatuba. 2021-03-04.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araçatuba
• Defense date: 2021-02-25
• Advisor: Alberto Carlos Botazzo Delbem; Débora Barros Barbosa

Abstract

The use of new nanocomposite materials for the manufacture of prosthetic devices, matrices for filling bone defects, protection of the pulp tissue of exposed teeth and dentinal tubules can significantly contribute to the quality of life of the population. Objective: To perform the processing of the polymeric matrix of polyamide. 6 (P6) impregnated with trimetaphosphate nanoparticles (TMP) and silver nanoparticles (AgNP), evaluate the antimicrobial activity against Streptococcus mutans and Candida albicans and the release of TMP and Ag +. Methods: The minimum inhibitory concentration (MIC) of AgNP was determined with or without the presence of NH3 for S. mutans and C. albicans. Then, the synthesis and characterization of the nanocomposites (P6, P6-2.5, 5 and 10% TMP associated or not with AgNP), quantification of colony forming units (CFU), determination of the inhibition halo and quantification of TMP and Ag + released during 1, 2, 3, 4, 5, 10, 12, 14, 16, 18, 20 and 24 hours in deionized water. The data were submitted to bidirectional analysis of variance, followed by the Fisher LSD test (p <0.05). Results: The MIC for C. albicans was 9.40 mg / mL with or without the presence of NH3 and for S. mutans it was 601.9 mg / mL with NH3 and 300.9 mg / mL without NH3. In the characterization tests it was possible to incorporate the P6 with TMP without changing its properties. The highest amount of Ag + released occurred in the first three hours for all groups decorated with AgNP. There was TMP release in the first three hours for the P6-5% TMP and P6-10% TMP groups and for the other membranes, no releases were detected. In the agar diffusion assay, halos formed for C. albicans and S. mutans showed AgNP action for both microorganisms. The P6-Ag-2.5% TMP and P6-Ag-5% TMP groups with AgNP show a greater reduction in CFU for S. mutans when compared to the other groups, with a greater reduction in the time of 18 hours. For C. albicans, all groups showed a reduction in CFU when compared to the control, with no statistical difference between them. Conclusion: It was possible to develop a polymeric matrix of P6 impregnated with TMP and AgNP with antimicrobial action against the microorganisms tested. (AU)

• FAPESP's process: 18/16041-1 - Evaluation of antimicrobial activity of polyamide 6 nanocomposite biomaterials and trimetaphosphate nanoparticles decorated with silver nanoparticles
• Grantee: Leonardo Antônio de Morais
• Support Opportunities: Scholarships in Brazil - Master