Author/Authors :
Abbaszadegan, Abbas Department of Endodontics - Dental School, Shiraz University of Medical Sciences, Shiraz , Gholami, Ahmad Department of Pharmaceutical Biotechnology - School of Pharmacy, Shiraz University of Medical Sciences, Shiraz , Abbaszadegan, Sara Department of Endodontics - Dental School, Shiraz University of Medical Sciences, Shiraz , Aleyasin, Zeynab Sadat Department of Oral Medicine - Dental School, Shiraz University of Medical Sciences, Shiraz , Ghahramani, Yasamin Department of Endodontics - Dental School, Shiraz University of Medical Sciences, Shiraz , Dorostkar, Samira Department of Chemistry - Shiraz University, Shiraz , Hemmateenejad, Bahram Department of Pharmaceutical Biotechnology - School of Pharmacy, Shiraz University of Medical Sciences, Shiraz , Ghasemi, Younes Department of Pharmaceutical Biotechnology - School of Pharmacy, Shiraz University of Medical Sciences, Shiraz , Sharghi, Hashem Department of Oral Medicine - Dental School, Shiraz University of Medical Sciences, Shiraz
Abstract :
Introduction: The antibacterial efficacy and toxicity of silver nanoparticles (AgNPs) depends on
their physicochemical properties including size, shape, surface charge and surface coatings. The
Objectives of this study were: i) To synthesize and characterize positively charged AgNPs coated by
different ionic-liquids with different alkyl chain lengths, ii) To evaluate the antimicrobial activity of
these nanoparticles against Enterococcus faecalis compared to sodium hypochlorite (NaOCl) and
chlorhexidine (CHX), iii) To compare the cytocompatibility of these solutions against L929 mouse
fibroblasts. Methods and Materials: AgNPs with positive surface charges capped by two different
ionic liquids [imidazolium (Im) and pyridinium (Py)] with two alkyl chain lengths (C12 and C18)
were synthesized. Im and Py were also tested as control groups. The characterization revealed
synthesis of spherical NPs in the size range of 6.7-18.5 nm with a surface charge ranging from +25
to +58 mV. To standardize the comparisons, the surface charge to radius ratio of each nanoparticle
was calculated. The minimum inhibitory concentrations (MIC) of the AgNP solutions, NaOCl and
CHX were determined against E. faecalis by a microdilution test. An MTT-based cytotoxicity assay
evaluated the cytotoxicity of the solutions in different concentrations on L929 fibroblasts. One-way
and two-way ANOVA were used for statistical analysis. Results: All tested AgNPs reached MIC90 in
significantly lower concentrations compared to CHX and NaOCl. C12 Py-coated AgNPs had the
lowest MIC90 value. CHX and NaOCl were more toxic on fibroblasts than all tested AgNPs. Imcoated
AgNPs had better compatibility with fibroblasts than Py-coated particles; and C12 Im AgNPs
had the best biocompatibility. Variations in alkyl chain length had no effects on the biocompatibility
of AgNPs. Conclusion: Py improved the antibacterial efficacy of AgNPs compared to Im; however,
it had a negative effect on cytocompatibility. Alkyl chain length had no effects on AgNPs’ bioactivity.
Keywords :
Antibacterial Agents , Chlorhexidine , Cytotoxicity , Metal Nanoparticles , Sodium Hypochlorite
