title: Action of silver nanoparticles towards biological systems: cytotoxicity evaluation using hen's egg test and inhibition of Streptococcus mutans biofilm formation.
abstract: This study aimed to evaluate the cytotoxicity and bactericidal properties of four silver nanoparticle (AgNP) colloids and their ability to inhibit Streptococcus mutans biofilm formation on dental enamel. The cytotoxicity of AgNPs was evaluated based on signs of vascular change on the chorioallantoic membrane using the hen's egg test (HET-CAM). Bactericidal properties and inhibition of S. mutans biofilm formation were determined using a parallel-flow cell system and a dichromatic fluorescent stain. The percentage of viable cells was calculated from regression data generated from a viability standard. AgNP colloids proved to be non-irritating, as they were unable to promote vasoconstriction, haemorrhage or coagulation. AgNP colloids inhibited S. mutans biofilm formation on dental enamel, and cell viability measured by fluorescence was 0% for samples S1, S2, S3 and S4 and 36.5% for the positive control (diluted 30% silver diamine fluoride). AgNPs are new products with a low production cost because they have a lower concentration of silver, with low toxicity and an effective bactericidal effect against a cariogenic oral bacterium. Moreover, they do not promote colour change in dental enamel, which is an aesthetic advantage compared with traditional silver products.
authors.affiliation: Faculty of Dentistry, University of Pernambuco, Av. Gal. Newton Cavalcanti, n° 1650, CEP: 54753-020, Camaragibe, PE, Brazil. Electronic address: perezila@hotmail.com.
authors.forename: Priscila L L
authors.initials: PL
authors.lastname: Freire
authors.affiliation: Federal University of Pernambuco, Av. Profª Morais Rego, n° 1235, Cidade Universitária, CEP: 50670-901, Recife, PE, Brazil.
authors.forename: Thayza C M
authors.initials: TC
authors.lastname: Stamford
authors.affiliation: Federal University of Paraíba, Campus Universitário I, Cidade Universitária, CEP: 58059-900, João Pessoa, PB, Brazil.
authors.forename: Allan J R
authors.initials: AJ
authors.lastname: Albuquerque
authors.affiliation: Federal University of Paraíba, Campus Universitário I, Cidade Universitária, CEP: 58059-900, João Pessoa, PB, Brazil.
authors.forename: Fabio C
authors.initials: FC
authors.lastname: Sampaio
authors.affiliation: Federal University of Paraíba, Campus Universitário I, Cidade Universitária, CEP: 58059-900, João Pessoa, PB, Brazil.
authors.forename: Horacinna M M
authors.initials: HM
authors.lastname: Cavalcante
authors.affiliation: Federal University of Paraíba, Campus Universitário I, Cidade Universitária, CEP: 58059-900, João Pessoa, PB, Brazil.
authors.forename: Rui O
authors.initials: RO
authors.lastname: Macedo
authors.affiliation: Federal University of Pernambuco, Av. Profª Morais Rego, n° 1235, Cidade Universitária, CEP: 50670-901, Recife, PE, Brazil; Center of Strategic Technologies of Northeast, Campus MCTI Nordeste, Av. Prof. Luiz Freire, n° 01, CEP: 50740-540, Recife, PE, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Galembeck
authors.affiliation: Center of Strategic Technologies of Northeast, Campus MCTI Nordeste, Av. Prof. Luiz Freire, n° 01, CEP: 50740-540, Recife, PE, Brazil.
authors.forename: Miguel A P
authors.initials: MA
authors.lastname: Flores
authors.affiliation: Faculty of Dentistry, University of Pernambuco, Av. Gal. Newton Cavalcanti, n° 1650, CEP: 54753-020, Camaragibe, PE, Brazil.
authors.forename: Aronita
authors.initials: A
authors.lastname: Rosenblatt
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D002645:Chickens; D005260:Female; D053768:Metal Nanoparticles / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013295:Streptococcus mutans / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D012834:Silver
keywords: Antibacterial activity; Antifouling; Colloids; Dental caries; HET-CAM or irritation delay