Antibacterial Activity of Indolicidin-Coated Silver Nanoparticles in Oral Disease

Abstract

Featured Application: Indolicidin-coated silver nanoparticles could be used as platforms in the dental field as oral disease preventive drug. Furthermore, nanomaterials could prevent oral cancers and balance oral health care. Abstract:(1) Background: In dentistry, silver nanoparticles (AgNPs) have progressively earned great interest as antimicrobial drugs and are widely used in several biomedical fields. Recent progress in the analysis of complex bacterial communities has demonstrated the richness of the oral microbiota and the presence of numerous previously unexplained strains. Several efforts have been dedicated to the investigation of antimicrobial peptides (AMPs). Those peptides are a widespread group of small peptides against invading microbes. We report the production of a hybrid molecule composed of AgNPs and indolicidin, a well-known antibacterial peptide. (2) Methods: Spectroscopy and microscopy were used to analyze the optical features and to determine the size of the generated AgNPs. The AgNP antibacterial activity was evaluated versus oral Gram-positive and Gram-negative bacteria.(3) Results: The coated nanoparticles' antibacterial activity strongly inhibited the growth of microorganisms, with very low minimum inhibitory concentration (MIC) values in the range of 5-12.5 µg/mL. We hypothesize that this effect depended on the specific characteristics of the metal surface coated with indolicidin. The second result was that the coated nanoparticles observed cellular toxicity, was lower with respect to the toxicity of peptide and the naked AgNPs when used individually. (4) New investigations regarding antimicrobial effect of AgNPs coated with AMPs in oral infections are an urgent task.

Current Evidence on the Ocular Surface Microbiota and Related Diseases

“…Therefore, a complete swabbing at different levels is necessary to obtain a precise characterization of the ocular surface microbiome diversity [ 3 ]. The role of the ocular microbiota is very important and is similar to that of the other organism’s districts (e.g., skin, intestine, and upper respiratory tract) [ 27 ]. The commensal bacterial flora communicates with the epithelial and immune cells and coordinates different functions aimed at the maintenance of homeostasis and local well-being, such as preservation of barrier function, inhibition of apoptosis and inflammation, acceleration of wound healing, competitive exclusion of potential pathogens and maintenance of immunotolerance.…”

<p>Ecotoxicity Evaluation of Pristine and Indolicidin-coated Silver Nanoparticles in Aquatic and Terrestrial Ecosystem</p>

“…UV-Vis spectrometer was used to confirm the formation of AgNPs in colloidal solution already reported in a previous work. 16 The different sizes of the Ag nanoclusters were determined by TEM ( Figure 1 ). The particles were nearly spherical in shape and evenly distributed in size with an average dimension of 10–40 nm if they were uncoated or coated.…”

“…15 We previously reported that AgNPs coated with indolicidin have a good antibacterial activity also with low doses of indolicidin attached to nanoparticles, lower than those used with indolicidin or NPs alone. 16 Likewise, the opportunity to use AgNPs coated with indolicidin as a novel antimicrobial, determines the urgent need to better define their possible toxicological effects due to their potential release into the environment.…”

“… 15 We previously reported that AgNPs coated with indolicidin have a good antibacterial activity also with low doses of indolicidin attached to nanoparticles, lower than those used with indolicidin or NPs alone. 16 …”

First Report of the mcr-1 colistin Resistance Gene Identified in Escherichia coli Isolated from a Clinical Sample in Naples in 2020

“…This report should serve as a public health warning signal, however, to intensify surveillance efforts and identify mcr-1 tanks in sensitive populations. Environmental, food and clinical monitoring are essential in order to reduce the transfer of multi-strain resistant bacteria between animals and humans Finally, increased vigilance and the implementation of antimicrobial management programs are necessary and important in the health sector to slow the spread of antimicrobial resistance [22][23][24][25].…”