Silver nanoparticles and calcium glycerophosphate: synthesis by conventional and phytochemical routes, antimicrobial analysis and evaluation of cytotoxicity.

Author(s)

Gabriela Lopes Fernandes

• Document type: Master's Dissertation
• Press: Araçatuba. 2016-04-28.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araçatuba
• Defense date: 2016-04-18
• Advisor: Debora Barros Barbosa; Aline Satie Takamiya

Abstract

The aim of this study was to synthesize and characterize nanomaterials compounds by silver nanoparticles (AgNP) and calcium glycerophosphate (CaGP) synthesized by chemical route using sodium borihidreto or sodium citrate, and phytochemical through pomegranate peel extract, and evaluate its antimicrobial effect against reference strains of Candida albicans (ATCC 10231) and Streptococcus mutans (ATCC 25175) and its cytotoxicity in fibroblast cells (L929). Besides, reducing agent for chemical syntheses, is varied the silver concentration (1 or 10%), the form of CAGP (micro or nanoparticulate), the solvent used in synthesis (deionized water or isopropanol) and the form of the nanocomposite ( suspended, dry in incubator or lyophilized). For the phytochemical synthesis, utilized the peel extract of pomegranate obtained by percolation in ethanol (70%) and total phenolic compounds was expressed in gallic acid standard and ellagic acid concentration respectively quantified by colorimetric method HPLC. The characterization of nanocomposites and controls containing only AgNP was made by UV-Vis spectroscopy, SEM and EDX. The antimicrobial activity was evaluated by the minimum inhibitory concentration according to the microdilution method (CLSI M27-M07-A2 and A9), whereas fibroblast cell viability was quantitated using fluorimetric method (Alamar Blue). These experiments were performed in triplicate on three different occasions and the cell viability percentage data were analyzed by one-way ANOVA followed by Bonferroni test (α = 5%). For all syntheses were associated between AgNP and CaGP. However only by microscopy at a concentration of 10% silver visualized the AgNP decorating the surface of CaGP (synthesis with sodium borihidreto and isopropanol) shrouded by CaGP or (synthesis with borihidreto and water and pomegranate peel). The nanocompounds synthesized by chemical route, were more effective against the microorganisms than synthesized by the phytochemical route, especially when used sodium citrate as reducing agent. Through the phytochemical route with the pomegranate, the AgNP-CaGP nanocomposite was more effective against C. albicans that AgNP and the opposite occurred to S. mutans. The use of pomegranate extract for the synthesis significantly (p <0.05) cytotoxicity both AgNP-CaGP nanocomposite of AgNP as compared to those synthesized chemically, regardless of the reducing agent used in the reaction. Yet, for all the syntheses, the CaGP reduced significantly (p <0.05) the cytotoxicity of nanocomposites AgNP-CaGP when compared with the isolated AgNP. It concludes that the nanocomposite formed by AgNP and CaGP has antimicrobial effectiveness against important pathogens related with caries and their cytotoxicity was reduced when used the pomegranate peel as reducing agent of silver. (AU)

• FAPESP's process: 14/08648-2 - Ag/²-calcium glycerophosphate nanocomposite: synthesis, and effect on Candida albicans and Streptococcus mutans biofilm and on odontoblasts MDPC-23 cells
• Grantee: Gabriela Lopes Fernandes
• Support Opportunities: Scholarships in Brazil - Master