Green Synthesis, Characterization and Antimicrobial Evaluation of Silver Nanoparticles for an Intracanal Dressing

Abstract

Green chemistry has been applied in different areas due to the growing demands for renewable processes and one of them is nanotechnology. The aim of this study was to characterize a formulation containing silver nanoparticles (AgNPs) produced by a green synthesis and to evaluate its antimicrobial activity. The formulation will be used as an intracanal dressing exploiting the AgNPs’ antimicrobial properties, which are crucial to prevent infections and bacterial reinfections that can compromise endodontic treatments. In the green synthesis, silver nitrate was employed as the precursor salt, maltose as a reducing agent, and gelatin as a stabilizing agent. The formulation was prepared mixing 50 % of a liquid containing the AgNPs and 50 % of hydroxyethylcellulose gel at 1.5 % with proper evaluation of the process inherent parameters. Techniques such as molecular absorption spectrometry and dynamic light scattering were used in characterization step. The antimicrobial activity of the AgNPs against Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Streptococcus mutans ATCC 25175 was verified according to National Comittee for Clinical Laboratory Standards (NCCLS) by determining minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The obtained results indicated the formulation containing AgNPs produced by a green synthesis was properly characterized by the selected techniques. Furthermore, the formulation assessment proved that it is suitable for the proposal as well as it has potential to be used as an intracanal dressing since presented antimicrobial activity against all bacterial strains evaluated.

Antimicrobial Properties of Silver Nitrate Nanoparticle and Its Application in Endodontics and Dentistry: A Review of Literature

“…The synthesis of Ag NPs is of enormous concern to investigators because of their wide range of uses. The Ag NPs were first produced by reducing Ag NO 3 (silver nitrate) 0.500 mol/L with maltose 1.000 mol/L and then stabilizing them with 1.0 g gelatin [29]. Physical, chemical, and biological approaches are used to make Ag NPs [30].…”

Síntese verde e caracterização de nanopartículas de prata em curcumina e extrato de cajueiro (Anacardium occidentale)

“…Os resultados encontrados convergem com diversos autores que afirmam ser possível produzir extratos com atividades redutoras e estabilizadoras, apenas com a utilização do processo hidroalcoólico dispensando, dessa forma, o uso de solventes mais tóxicos e consequentes nocivos ao meio ambiente e os seres vivos (Álvarez et al, 2017). O processo pelo método de síntese verde além de ser um processo rápido e econômico não requer produtos tóxicos e ainda é compatível com produtos biomédicos de aplicação farmacêutica (Bruniera et al, 2020).…”

“…A maioria dos métodos descritos na literatura para o desenvolvimento das nanopartículas usam solventes tóxicos que causam danos ambientais e aos sistemas biológicos (Jiang et al, 2020). Para diminuir os riscos ambientais e aos seres vivos, a síntese verde se apresenta como alternativa viável e eficiente no desenvolvimento das nanopartículas (Bruniera et al, 2020).…”

“…Pois as biomoléculas presentes nas plantas reduzem ativamente os íons metálicos, atuam como agentes protetores e estabilizadores das nanopartículas (Rai, 2013). A síntese verde além de ser um processo rápido e econômico não requer produtos tóxicos e ainda é compatível com produtos biomédicos de aplicação farmacêutica (Bruniera et al, 2020).…”

Molecular mechanisms of the antibacterial activity of polyimide fibers in a skin-wound model with Gram-positive and Gram-negative bacterial infection in vivo

“…15 This increases morbidity and mortality and leads to a high economic burden of caring for patients infected with multidrug-resistant bacteria. 16 Silver nanoparticles display bactericidal activity against a large number of bacteria (such as E. coli ATCC 25922 , Enterococcus faecalis NCTC 775 , Pseudomonas aeruginosa ATCC 27853 , Staphylococcus aureus ATCC 25923, and Streptococcus mutans ATCC 25175 ); 17 unfortunately, silver nanoparticles still stimulate the potency of microbial resistance 18 and easily enter the human body through various biological barriers such as skin and tissues, and can cause serious toxicity to the human cells. 19,20 Natural honey, 21 essential oils, 22 and chitosans 23 and its modified derivatives such as adenine-modified chitosan (AC) hydrogels displayed excellent antibacterial activities against Gram-negative bacteria, Gram-positive bacteria, fungi, and drug-resistant bacteria.…”