Antimicrobial and cytotoxicity evaluation of colloidal chitosan – silver nanoparticles – fluoride nanocomposites

Abstract

The present study aimed to evaluate the antimicrobial activity and cytotoxicity of colloidal chitosan - silver nanoparticle - fluoride nanocomposites (CChAgNpFNc), with different silver nanoparticle shapes and sizes. The syntheses of CChAgNpFNc were performed with silver nitrate added to a chitosan solution, addition of a sodium borohydride solution and solid sodium fluoride. Solution of ascorbic acid was added to synthesize larger silver nanoparticles. CChAgNpFNc obtained: S1- 100% spherical, 8.7±3.1nm; S2- 97% spherical, 15.0±7.9nm and 2.5% triangular, 22.2±9.5nm; S3- 77.3% spherical, 31.8±10.4nm, 15.9% triangular, 27.1±10.1nm and 6.8% elliptical, 33.2±7.8nm; and S4- 75.2% spherical, 43.2±14.3nm; 23.3% triangular 38.2±14.8nm, and 1.5% elliptical 38.4±11.6nm. The CChAgNpFNc showed antimicrobial activity against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans, by microdilution technique. The influence on the growth of microorganisms was evaluated using a fluorescence assay, and showed an increasing lag phase and a decreasing log phase. Cytotoxicity was investigated using Artemia salina and MTT assays. The S3 and S4 samples exhibited low cytotoxicity. The S1 and S2 samples inhibited murine macrophages and revealed lethal dose concentrations above 1000mg/mL that were classified as moderately toxic. Thus, CChAgNpFNc are potential options for the control of multiple-drug-resistant microorganisms and do not represent substantial risks to human health.

Low molecular weight chitosan-coated silver nanoparticles are effective for the treatment of MRSA-infected wounds

“…In addition, AgNPs/chitosan materials could promote wound healing. 3,17,[28][29][30] In comparison with long-chain high molecular weight chitosan, the short-chain LMWC is better in terms of water solubility and biocompatibility. Besides, it has been confirmed that LMWC enhances the physical and chemical stability of many drugs such as insulin 31 and siRNA, 32 and works as a suitable carrier for the delivery and controlled release of drugs.…”

Biomedical Applications of Silver Nanoparticles: An Up-to-Date Overview

“…Because the oral cavity is an active ecosystem usually colonized by various pathogenic microorganisms, dental materials and implants have an increased risk of contamination and subsequent colonization processes [ 155 ]. In terms of superior antimicrobial activity, promising results were reported with respect to the incorporation of silver-based nanosystems within adhesive resins [ 156 , 157 ], orthodontic cements [ 158 , 159 ], and dental composites [ 160 , 161 , 162 ]. In addition to being used as antimicrobial filling agents within multifunctional biomaterials, another attractive and challenging dental application of AgNPs relies on their potential use as biostatic or biocide coatings for conventional titanium-based dental implants [ 163 , 164 ].…”

Bacillus amyloliquefaciens levan and its silver nanoparticles with antimicrobial properties

“…The result showed that the cell inhibition was below 25% at the presence of 20 lg/mL AgNPs ( Figure 5). Freire et al [32] thought that colloidal chitosan-silver nanoparticle-fluoride nanocomposites were non-toxic at a concentration of 50 mg/mL, since in their presence, the RAW 264.7 cell inhibition was below 50%. According to their report, our result indicated that AgNPs from levan are able to display antibacterial activity without being harmful to macrophages.…”