Anti-biofilm activity of biogenic selenium nanoparticles and selenium dioxide against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis

Characterization and biological activity of selenium nanoparticles biosynthesized by Yarrowia lipolytica

In this research, biogenic selenium nanoparticles were produced by the fungi Yarrowia lipolytica, and the biological activity of its nanoparticles was studied for the first time. The electron microscopy analyses showed the production of nanoparticles were intracellular and the resulting particles were extracted and characterized by XRD, zeta potential, FESEM, EDX, FTIR spectroscopy and DLS. These analyses showed amorphous spherical nanoparticles with an average size of 110 nm and a Zeta potential of -34.51 ± 2.41 mV. Signatures of lipids and proteins were present in the capping layer of biogenic selenium nanoparticles based on FTIR spectra. The antimicrobial properties of test strains showed that Serratia marcescens, Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis were inhibited at concentrations between 160 and 640 μg/mL, while the growth of Candida albicans was hindered by 80 μg/mL of biogenic selenium nanoparticles. At concentrations between 0.5 and 1.5 mg/mL of biogenic selenium nanoparticles inhibited up to 50% of biofilm formation of Klebsiella pneumonia, Acinetobacter baumannii, Staphylococcus aureus and Pseudomonas aeruginosa. Additionally, the concentration of 20-640 μg/mL of these bioSeNPs showed antioxidant activity. Evaluating the cytotoxicity of these nanoparticles on the HUVEC and HepG2 cell lines did not show any significant toxicity within MIC concentrations of SeNPs. This defines that Y. lipolytica synthesized SeNPs have strong potential to be exploited as antimicrobial agents against pathogens of WHO concern.

Hybrid nanoparticles combining nanoselenium-mediated Carica papaya extract and trimethyl chitosan for combating clinical multidrug-resistant bacteria

Multidrug-resistant bacterial infections pose a significant threat to human health, prompting the exploration of innovative solutions. In this study, a new series of antibacterial hybrid nanoparticles (HNPs) were developed. The HNPs are based on a combination of selenium nanoparticles (SeNPs), synthesized using Carica papaya leaf extract, and chitosan (CS/SeHNPs) or trimethyl chitosan (TMC/SeHNPs), respectively. Comprehensive characterization using UV-Vis, FTIR, XRD, SEM-EDX, DLS, TEM, and DSC confirmed the structure and properties of the developed HNPs. SeNPs, CS/SeHNPs, and TMC/SeHNPs showed average hydrodynamic size of 78.8, 91.3, and 122 nm, and zeta potentials of -6.35 mV, +32.8 mV, and +54.8 mV, respectively. Biological assessments were conducted, including antibacterial and antibiofilm assays against clinical strains (E. coli, S. aureus, and K. pneumoniae), along with antioxidant activity. TMC/SeHNPs demonstrated superior performance compared to SeNPs and CS/SeHNPs with the lowest minimum inhibition concentrations (MIC) against S. aureus and K. pneumoniae (3.9 μg/mL) and 62.5 μg/mL against E. coli in addition to robust antibiofilm activity. Furthermore, the TMC/SeHNPs exhibited potent DPPH free radical scavenging ability and demonstrated good biocompatibility, as evidenced by cell viability assays on HFB4 cells. Overall, TMC/SeHNPs emerged as promising candidates in nanomedicine, offering high antioxidant, antibacterial, and antibiofilm activities alongside excellent biocompatibility.

Antibiofilm and antivirulence activity of selenium nanoparticles synthesized from cell-free extract of moderately halophilic bacteria

Biofilm-forming microbes can pose a major health risk that is difficult to combat. Nanotechnology, on the other hand, represents a novel technique for combating and eliminating biofilm-forming microbes. In this study, the selenium nanoparticles (SeNPs) were biosynthesized from moderate halophilic bacteria isolated from Pichavaram mangrove sediments. The bacterial strain S8 was found to be efficient for SeNPs synthesis and hence identified by 16s r RNA sequencing as Shewanella sp. In UV- spectral analysis the SeNPs displayed a peak at 320 nm due to surface plasmon resonance (SPR). The cell-free extract of Shewanella sp. and SeNPs indicates that the various functional groups in the cell-free extract were mainly involved in the synthesis and stabilization of SeNPs. The SeNPs had a spherical form with average diameter of 49 ± 0.01 nm, according to the FESEM analysis. The EDX shows the distinctive peaks of selenium at 1.37, 11.22.12.49 Kev. In the agar well diffusion method, the SeNPs show inhibitory activity against all the test pathogens with the highest activity noted against P.aeruginosa with a zone of inhibition of 22.7 ± 0.3 mm. The minimal inhibitory concentration (MIC) value of 80 μg/ml, minimal bactericidal concentration (MBC) of 160 μg/ml, and susceptibility constant of 0.043 μg/ml show that SeNPs highly effective against P.aeruginosa. The Sub-MIC value of SeNPs of 20 μg/ml was found to inhibit P.aeruginosa biofilm by 85% as compared to the control. Further, the anti-virulence properties viz., pyocyanin, pyoverdine, hemolytic, and protease inhibition revealed the synthesized SeNPs from halophilic bacteria control the pathogenicity of P.aeruginosa.

Se-functionalized ZIF-8 nanoparticles: synthesis, characterization and disruption of biofilms and quorum sensing inSerratia marcescens

The majority of research on nanomaterials has been concentrated on metal nanoparticles since they are easily made and manipulated. Nanomaterials have shown a wide range of applications in biology. Nevertheless, their bioactivity declines due to their extreme susceptibility to and novel Se@ZIF-8 by chemical method. The sizes and morphologies of Se (0) and Se@ZIFchemical and physical stimuli. The goal of encapsulating these nanomaterials in a matrix is gradually being pursued, which boosts their affordability, stability, and usability. Metal-organic frameworks, often known as MOFs, have the potential to be the best platforms for encapsulating metal nanoparticles due to their well-defined frameworks, persistent porosity, and flexibility in modification. In this investigation, we report the synthesis and optimization of polyvinylpyrrolidone-stabilized Se(0) nanoparticles -8 were affected by the ratios of Se/Zn2+and [hmim]/Zn2+used. The optimized Se@ZIF-8 nanoparticles exhibited a particle size and zeta potential of 319 nm and -34 mv respectively. Transmission electron microscopy displayed spherical morphology for Se(0) nanoparticles, whereas the surface morphology of novel Se@ZIF-8 nanoparticles was drastically changed to hexagonal shaped structures with smooth surface morphologies in scanning electron microscopy (SEM). The DTA, TG/DTG, XRD analysis confirmed the presence of novel Se incorporated ZIF-8 nanoparticulate framework. The synthesized novel Se@ZIF-8 nanoparticles showed efficient antibacterial activity as evidenced by low MIC values. Interestingly, these Se@ZIF-8 NPs not only inhibited biofilm formation inS. marcescens,but also effectively eradicated mature biofilms by degrading the eDNA of the EPS layer. It was validated by confocal laser scanning microscopy and SEM analysis. It was observed that Se@ZIF-8 targeted the Quroum Sensing pathway and reduced its associated virulence factors production. This work opens up a different approach of Se@ZIF-8 nanoparticles as novel antibiotics to treat biofilm-associated infections caused byS. marcescensand offer a solution for antimicrobial resistance.

Biomedical Promise of Aspergillus Flavus-Biosynthesized Selenium Nanoparticles: A Green Synthesis Approach to Antiviral, Anticancer, Anti-Biofilm, and Antibacterial Applications

This study utilized Aspergillus flavus to produce selenium nanoparticles (Se-NPs) in an environmentally friendly and ecologically sustainable manner, targeting several medicinal applications. These biosynthesized Se-NPs were meticulously characterized using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), and UV-visible spectroscopy (UV), revealing their spherical shape and size ranging between 28 and 78 nm. We conducted further testing of Se-NPs to evaluate their potential for biological applications, including antiviral, anticancer, antibacterial, antioxidant, and antibiofilm activities. The results indicate that biosynthesized Se-NPs could be effective against various pathogens, including Salmonella typhimurium (ATCC 14028), Bacillus pumilus (ATCC 14884), Staphylococcus aureus (ATCC 6538), Clostridium sporogenes (ATCC 19404), Escherichia coli (ATCC 8739), and Bacillus subtilis (ATCC 6633). Additionally, the biosynthesized Se-NPs exhibited anticancer activity against three cell lines: pancreatic carcinoma (PANC1), cervical cancer (Hela), and colorectal adenocarcinoma (Caco-2), with IC50 values of 177, 208, and 216 μg/mL, respectively. The nanoparticles demonstrated antiviral activity against HSV-1 and HAV, achieving inhibition rates of 66.4% and 15.1%, respectively, at the maximum non-toxic concentration, while also displaying antibiofilm and antioxidant properties. In conclusion, the biosynthesized Se-NPs by A. flavus present a promising avenue for various biomedical applications with safe usage.

Nanomaterial in controlling biofilms and virulence of microbial pathogens

The escalating threat of antimicrobial resistance (AMR) poses a grave concern to global public health, exacerbated by the alarming shortage of effective antibiotics in the pipeline. Biofilms, intricate populations of bacteria encased in self-produced matrices, pose a significant challenge to treatment, as they enhance resistance to antibiotics and contribute to the persistence of organisms. Amid these challenges, nanotechnology emerges as a promising domain in the fight against biofilms. Nanomaterials, with their unique properties at the nanoscale, offer innovative antibacterial modalities not present in traditional defensive mechanisms. This comprehensive review focuses on the potential of nanotechnology in combating biofilms, focusing on green-synthesized nanoparticles and their associated anti-biofilm potential. The review encompasses various aspects of nanoparticle-mediated biofilm inhibition, including mechanisms of action. The diverse mechanisms of action of green-synthesized nanoparticles offer valuable insights into their potential applications in addressing AMR and improving treatment outcomes, highlighting novel strategies in the ongoing battle against infectious diseases.

Biogenic synthesis of selenium nanoparticles from Nyctanthes arbor-tristis L. and evaluation of their antimicrobial, antioxidant and photocatalytic efficacy

Biogenic synthesis of nanoparticles has been established as an environmentally benign and sustainable approach. This study emphasizes biosynthesis of selenium nanoparticles (SeNPs) utilizing leaf extract of Nyctanthes arbor-tritis L., well known for its abundant bioactive compounds. Various analytical techniques were employed for characterization of synthesized SeNPs. X-ray diffraction (XRD) spectroscopy confirmed the crystalline structure and revealed the average crystalline size of SeNPs to be 44.57 nm. Additionally, UV-Vis spectroscopy confirmed successful synthesis of SeNPs by validating the surface plasmon resonance (SPR) properties of SeNPs. FTIR analysis data revealed different bonds and their corresponding functional groups responsible for the synthesis and stability of synthesized SeNPs. DLS and zeta analysis revealed that 116.5 nm sized SeNPs were stable in nature. Furthermore, field emission scanning electron microscopy (FE-SEM) validated the spherical morphology of SeNPs with a size range of 60-80 nm. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) determined the concentration of SeNPs in the obtained colloidal solution. Antioxidant activity of synthesized SeNPs was evaluated employing DPPH and H2O2 assay, revealed that the synthesized SeNPs were effective antioxidant agent. Additionally, antimicrobial potential was evaluated against a panel of Gram-positive and Gram-negative bacteria and found to be effective at higher concentration of SeNPs. SeNPs also exhibited strong anti-biofilm activity while evaluated against various biofilm producing bacteria like Escherichia coli , Staphylococcus epidermidis and Klebsiella pneumonia. The cytotoxicity of the bio-synthesized SeNPs was evaluated against HEK 293 cell line, exhibited minimal toxicity even at concentration 100 μg/mL with 65% viable cells. SeNPs has also been evaluated for dye degradation which has indicated excellent photocatalytic activity of synthesized SeNPs. The experimental data obtained altogether demonstrated that synthesized SeNPs exhibited significant antimicrobial and anti-biofilm activity against various pathogens, and also showed significant antioxidant and photocatalytic efficiency.

Selenium Nanoparticles as Neuroprotective Agents: Insights into Molecular Mechanisms for Parkinson's Disease Treatment

Oxidative stress and the accumulation of misfolded proteins in the brain are the main causes of Parkinson's disease (PD). Several nanoparticles have been used as therapeutics for PD. Despite their therapeutic potential, these nanoparticles induce multiple stresses upon entry. Selenium (Se), an essential nutrient in the human body, helps in DNA formation, stress control, and cell protection from damage and infections. It can also regulate thyroid hormone metabolism, reduce brain damage, boost immunity, and promote reproductive health. Selenium nanoparticles (Se-NPs), a bioactive substance, have been employed as treatments in several disciplines, particularly as antioxidants. Se-NP, whether functionalized or not, can protect mitochondria by enhancing levels of reactive oxygen species (ROS) scavenging enzymes in the brain. They can also promote dopamine synthesis. By inhibiting the aggregation of tau, α-synuclein, and/or Aβ, they can reduce the cellular toxicities. The ability of the blood-brain barrier to absorb Se-NPs which maintain a healthy microenvironment is essential for brain homeostasis. This review focuses on stress-induced neurodegeneration and its critical control using Se-NP. Due to its ability to inhibit cellular stress and the pathophysiologies of PD, Se-NP is a promising neuroprotector with its anti-inflammatory, non-toxic, and antimicrobial properties.

PLGA and PDMS-based in situ forming implants loaded with rosuvastatin and copper-selenium nanoparticles: a promising dual-effect formulation with augmented antimicrobial and cytotoxic activity in breast cancer cells

Breast cancer is among the most prevalent tumors worldwide. In this study, in-situ forming implants (ISFIs) containing rosuvastatin calcium were prepared using three types of poly (D, L-lactic-co-glycolic acid) (PLGA), namely, PLGA 50/50 with ester terminal and PLGA 75/25 with ester or acid terminal. Additionally, polydimethylsiloxane (PDMS) was added in concentrations of 0, 10, 20, and 30% w/v to accelerate matrix formation. The prepared ISFIs were characterized for their rheological behaviors, rate of matrix formation, and in-vitro drug release. All the prepared formulations revealed a Newtonian flow with a matrix formation rate between 0.017 and 0.059 mm/min. Generally, increasing the concentration of PDMS increased the matrix formation rate. The prepared implants' release efficiency values ranged between 46.39 and 89.75%. The ISFI containing PLGA 50/50 with 30% PDMS was selected for further testing, as it has the highest matrix formation rate and a promising release efficiency value. Copper-selenium nanoparticles were prepared with two different particle sizes (560 and 383 nm for CS1 and CS2, respectively) and loaded into the selected formulation to enhance its anticancer activity. The unloaded and loaded implants with rosuvastatin and copper-selenium nanoparticles were evaluated for their antibacterial activity, against Gram-positive and negative microorganisms, and anticancer efficacy, against MCF-7 and MDA-MB-231 cell lines. The results confirmed the potency of rosuvastatin calcium against cancer cells and the synergistic effect when loaded with smaller particle sizes of copper-selenium nanoparticles. This formulation holds a considerable potential for efficient breast cancer therapy.

Polyethyleneimine surface-modified silver-selenium nanocomposites for anti-infective treatment of wounds by disrupting biofilms

Bacterial biofilm formation is associated with the pathogenicity of pathogens and poses a serious threat to human health and clinical therapy. Complex biofilm structures provide physical barriers that inhibit antibiotic penetration and inactivate antibiotics via enzymatic breakdown. The development of biofilm-disrupting nanoparticles offers a promising strategy for combating biofilm infections. Hence, polyethyleneimine surface-modified silver-selenium nanocomposites, Ag@Se@PEI (ASP NCs), were designed for synergistic antibacterial effects by destroying bacterial biofilms to promote wound healing. The results ofin vitroantimicrobial experiments showed that, ASP NCs achieved efficient antibacterial effects againstStaphylococcus aureus (S. aureus)andEscherichia coli (E. coli)by disrupting the formation of the bacterial biofilm, stimulating the outbreak of reactive oxygen species and destroying the integrity of bacterial cell membranes. Thein-vivobacterial infection in mice model showed that, ASP NCs further promoted wound healing and new tissue formation by reducing inflammatory factors and promoting collagen fiber formation which efficiently enhanced the antibacterial effect. Overall, ASP NCs possess low toxicity and minimal side effects, coupled with biocompatibility and efficient antibacterial properties. By disrupting biofilms and bacterial cell membranes, ASP NCs reduced inflammatory responses and accelerated the healing of infected wounds. This nanocomposite-based study offers new insights into antibacterial therapeutic strategies as potential alternatives to antibiotics for wound healing.

Metal-based nanoparticles: an alternative treatment for biofilm infection in hard-to-heal wounds

Metal-based nanoparticles (MNPs) are promoted as effective compounds in the treatment of bacterial infections and as possible alternatives to antibiotics. These MNPs are known to affect a broad spectrum of microorganisms using a multitude of strategies, including the induction of reactive oxygen species and interaction with the inner structures of the bacterial cells. The aim of this review was to summarise the latest studies about the effect of metal-based nanoparticles on pathogenic bacterial biofilm formed in wounds, using the examples of Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Pseudomonas aeruginosa, as well as provide an overview of possible clinical applications.

Assessment of the growth inhibition and anti-biofilm activity of aptamer (PmA2G02) against Proteus mirabilis 1429T

Proteus mirabilis is known to cause Catheter-associated urinary tract infections (CAUTIs), which exhibit virulence factors linked to forming biofilms. Aptamers have recently been explored as potential anti-biofilm agents. This study demonstrates the anti-biofilm activity of aptamer (PmA2G02) targeting P. mirabilis 1429T, a pathogenic bacteria known to cause Catheter-associated urinary tract infections (CAUTIs). The studied aptamer inhibited biofilm formation, swarming motility, and cell viability at a concentration of 3 μM. The study also showed that the PmA2G02 had a binding affinity towards fimbrial outer membrane usher protein (PMI1466), flagellin protein (PMI1619), and regulator of swarming behavior (rsbA), which are responsible for adhesion, motility, and quorum sensing, respectively. Crystal violet assay, SEM, and confocal imaging confirmed the effectiveness of the PmA2G02 as an anti-biofilm agent. Moreover, as verified by qPCR, the expression levels of fimD, fliC2, and rsbA were significantly reduced compared to the untreated group. This study suggests that aptamer may be a potential alternative to traditional antibiotics for the treatment of CAUTIs caused by P. mirabilis. These findings shed light on the mechanisms by which the aptamer inhibits biofilm formation.

Janus silk fibroin/polycaprolactone-based scaffold with directionally aligned fibers and porous structure for bone regeneration

To promote bone repair, it is desirable to develop three-dimensional multifunctional fiber scaffolds. The densely stacked and tightly arranged conventional two-dimensional electrospun fibers hinder cell penetration into the scaffold. Most of the existing three-dimensional structural materials are isotropic and monofunctional. In this research, a Janus nanofibrous scaffold based on silk fibroin/polycaprolactone (SF/PCL) was fabricated. SF-encapsulated SeNPs demonstrated stability and resistance to aggregation. The outside layer (SF/PCL/Se) of the Janus nanofiber scaffold displayed a structured arrangement of fibers, facilitating cell growth guidance and impeding cell invasion. The inside layer (SF/PCL/HA) featured a porous structure fostering cell adhesion. The Janus fiber scaffold containing SeNPs notably suppressed S. aureus and E. coli activities, correlating with SeNPs concentration. In vitro, findings indicated considerable enhancement in alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts and upregulation of genes linked to osteogenic differentiation with exposure to the SF/PCL/HA/Se Janus nanofibrous scaffold. Moreover, in vivo, experiments demonstrated successful critical bone defect repair in mouse skulls using the SF/PCL/HA/Se Janus nanofiber scaffold. These findings highlight the potential of the SF/PCL-based Janus nanofibrous scaffold, integrating SeNPs and nHA, as a promising biomaterial in bone tissue engineering.

Improving the structural, optical, and electrical properties of carboxymethyl cellulose/starch/selenium oxide nanocomposites for flexible electronic devices

Nanocomposites based on biopolymers are interesting materials owing to their multifunctionality and ease of preparation. In this study, the solution casting method was used to mix selenium oxide nanoparticles (SeO2 NP) made by a solvothermal method into a bio-blend of carboxymethyl cellulose and starch (CMC/St). XRD analysis showed that SeO2 NP increased the amorphous portion inside the blend. HR-TEM revealed the spherical morphology of these NP with an average diameter of 16.88 nm. The FE-SEM indicated a satisfactory uniform distribution and homogeneity in the surface morphology of the films. FTIR confirmed the interaction between SeO2 and the blend functional groups. The films preserved good transmission after doping, and their direct and indirect band gaps decreased. The refractive index, absorption index, optical conductivity, and other dispersion parameters were improved after SeO2 loading. The DC conductivity of the blend is in the range of 3.8 × 10-7 to 5.6 × 10-4 S/m and improved after loading SeO2 NP. The IV characteristic curves in the temperature range of 300-415 K were studied to figure out the conduction mechanism in the CMC/St/SeO2 composites. Because the optical and electrical properties improved, these nanocomposites could be used for coatings and other things like waveguides, photovoltaic cells, and light-emitting diodes.

Selenium Nanoparticles: A Comprehensive Examination of Synthesis Techniques and Their Diverse Applications in Medical Research and Toxicology Studies

Selenium is a trace and necessary micronutrient for human, animal, and microbial health. Many researchers have recently been interested in selenium nanoparticles (SeNPs) due to their biocompatibility, bioavailability, and low toxicity. As a result of their greater bioactivity, selenium nanoparticles are widely employed in a variety of biological applications. Physical, chemical, and biological approaches can all be used to synthesize selenium nanoparticles. Since it uses non-toxic solvents and operates at a suitable temperature, the biological technique is a preferable option. This review article addresses the processes implemented in the synthesis of SeNPs and highlights their medicinal uses, such as the treatment of fungi, bacteria, cancer, and wounds. Furthermore, we discuss the most recent findings on the potential of several biological materials for selenium nanoparticle production. The precursor, extract, process, time, temperature, and other synthesis criteria will be elaborated in conjunction with the product's physical properties (size, shape, and stability). The synergies of SeNP synthesis via various methods aid future researchers in precisely synthesizing SeNPs and using them in desired applications.

Improved titer and stability of selenium nanoparticles produced by engineered Saccharomyces cerevisiae

Selenium nanoparticles (SeNPs) have gained significant attention in the fields of medicine and healthcare products due to their various biological activities and low toxicity. In this study, we focused on genetically modifying the Saccharomyces cerevisiae strain YW16 (CICC 1406), which has the ability to efficiently reduce sodium selenite and produce red SeNPs. By overexpressing genes involved in glutathione production, we successfully increased the glutathione titer of the modified strain YJ003 from 41.0 mg/L to 212.0 mg/L. Moreover, we improved the conversion rate of 2.0 g/L sodium selenite from 49.3% to 59.6%. Furthermore, we identified three surface proteins of SeNPs, and found that overexpression of Act1, one of the identified proteins, led to increased stability of SeNPs across different acid-base and temperature conditions. Through a 135-h feed fermentation process using 5.0 g/L sodium selenite, we achieved an impressive conversion rate of 88.7% for sodium selenite, and each gram of SeNPs contained 195.7 mg of selenium. Overall, our findings present an efficient method for yeast to synthesize SeNPs with high stability. These SeNPs hold great potential for applications in nanomedicine or as nutritional supplements to address selenium deficiency.

Selenium Nanoparticles: Green Synthesis and Biomedical Application

Selenium nanoparticles (SeNPs) are extremely popular objects in nanotechnology. "Green" synthesis has special advantages due to the growing necessity for environmentally friendly, non-toxic, and low-cost methods. This review considers the biosynthesis mechanism of bacteria, fungi, algae, and plants, including the role of various biological substances in the processes of reducing selenium compounds to SeNPs and their further packaging. Modern information and approaches to the possible biomedical use of selenium nanoparticles are presented: antimicrobial, antiviral, anticancer, antioxidant, anti-inflammatory, and other properties, as well as the mechanisms of these processes, that have important potential therapeutic value.

Selenite bioreduction with concomitant green synthesis of selenium nanoparticles by a selenite resistant EPS and siderophore producing terrestrial bacterium

Environmental bacterial isolates play a very important role in bioremediation of metals and toxic metalloids. A bacterial strain with high selenite (SeO32-) tolerance and reducing capability was isolated from electronic waste dump site in Banaras Hindu University, Varanasi, India. Based on 16 S rRNA sequencing and BLAST search, this bacterial isolate was identified as Bacillus paramycoides and designated as strain MF-14. It tolerated Sodium selenite up to 110 mM when grown aerobically in LB broth and reduced selenite into elemental selenium (Se0) significantly within 24 h with concomitant biosynthesis of selenium nanoparticles as clearly revealed by brick red precipitate and specific surface plasmon resonance peak at 210 nm using UV-Visible spectrophotometer. Scanning electron microscopy (SEM) analysis of this bacterial strain exposed to 1mM and 5 mM selenite also demonstrated morphological alterations as cell enlargement due to accumulation and bioprecipitation of elemental selenium (Se0). The FTIR analysis clearly demonstrated that functional groups present on the surface of biogenic selenium nanoparticles (SeNPs) play a significant role in the stabilization and capping of SeNPs. Furthermore, these SeNPs were characterized using spectroscopic analysis involving Dynamic light scattering, zeta potential, XPS, FTIR, XRD and Raman spectroscopy which clearly revealed particle size 10-700 nm, amorphous nature, stability as well as it's oxidation state. The biochemical studies have demonstrated that membrane bound reductase enzyme may be responsible for significant reduction of selenite into elemental selenium. Therefore, we may employ Bacillus paramycoides strain MF-14 successfully for bioremediation of selenite contaminated environmental sites with concomitant green synthesis of SeNPs.

Unleashing the Potential of Benincasa hispida Peel Extract: Synthesizing Selenium Nanoparticles with Remarkable Antibacterial and Anticancer Properties

In this study, we successfully synthesized selenium nanoparticles (P-SeNPs) using an environment-friendly approach. This method involves utilizing the aqueous peel extract of Benincasa hispida (ash gourd) in combination with selenium salt. Through our innovative procedure, we harnessed the impressive bio-reduction capabilities, therapeutic potential, and stabilizing attributes inherent in B. hispida. This results in the formation of P-SeNPs with distinct and noteworthy qualities. Our findings were thoroughly substantiated through comprehensive characterizations employing various techniques, including ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential analysis, and Fourier transform infrared spectroscopy (FTIR). The nanoparticles exhibited a spherical shape, considerable size (22.32 ± 2 nm), uniform distribution, and remarkable stability (-24 mV), all of which signify the effective integration of the phytoconstituents of B. hispida. Furthermore, P-SeNPs displayed robust antibacterial efficacy against pathogenic bacterial strains, as indicated by their low minimum inhibitory concentration values. Our research also revealed the remarkable ability of P-SeNPs to fight cancer, as demonstrated by their impressive IC50 value of 0.19 µg/mL against HeLa cells, while showing no harm to primary human osteoblasts, while simultaneously demonstrating no toxicity toward primary human osteoblasts. These pivotal findings underscore the transformative nature of P-SeNPs, which holds promise for targeted antibacterial treatment and advancements in cancer therapeutics. The implications of these nanoparticles extend to their potential applications in therapies, diagnostics, and various biomedical contexts. Notably, the environmentally sustainable synthesis process and exceptional properties established this study as a significant milestone in the field of nanomedicine, paving the way for a more promising and health-enhancing future.

Selenium-Fortified Kombucha-Pollen Beverage by In Situ Biosynthesized Selenium Nanoparticles with High Biocompatibility and Antioxidant Activity

Biogenic selenium nanoparticles (SeNPs) have been shown to exhibit increased bioavailability. Fermentation of pollen by a symbiotic culture of bacteria and yeasts (SCOBY/Kombucha) leads to the release of pollen content and enhances the prebiotic and probiotic effects of Kombucha. The aim of this study was to fortify Kombucha beverage with SeNPs formed in situ by Kombucha fermentation with pollen. Response Surface Methodology (RSM) was used to optimize the biosynthesis of SeNPs and the pollen-fermented Kombucha beverage. SeNPs were characterized by Transmission electron microscopy energy-dispersive X-ray spectroscopy (TEM-EDX), Fourier-transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), and Zeta potential. The pollen-fermented Kombucha beverage enriched with SeNPs was characterized by measuring the total phenolic content, antioxidant activity, soluble silicon, saccharides, lactic acid, and the total content of Se0. The polyphenols were identified by liquid chromatography-mass spectrometry (LC-MS). The pollen and the bacterial (nano)cellulose were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), FTIR, and X-Ray diffraction (XRD). We also assessed the in vitro biocompatibility in terms of gingival fibroblast viability and proliferation, as well as the antioxidant activity of SeNPs and the pollen-fermented Kombucha beverage enriched with SeNPs. The results highlight their increased biological performance in this regard.

A review on synthesis and antibacterial potential of bio-selenium nanoparticles in the food industry

Effective control of foodborne pathogen contamination is a significant challenge to the food industry, but the development of new antibacterial nanotechnologies offers new opportunities. Notably, selenium nanoparticles have been extensively studied and successfully applied in various food fields. Selenium nanoparticles act as food antibacterial agents with a number of benefits, including selenium as an essential trace element in food, prevention of drug resistance induction in foodborne pathogens, and improvement of shelf life and food storage conditions. Compared to physical and chemical methods, biogenic selenium nanoparticles (Bio-SeNPs) are safer and more multifunctional due to the bioactive molecules in Bio-SeNPs. This review includes a summarization of (1) biosynthesized of Bio-SeNPs from different sources (plant extracts, fungi and bacteria) and their antibacterial activity against various foodborne bacteria; (2) the antibacterial mechanisms of Bio-SeNPs, including penetration of cell wall, damage to cell membrane and contents leakage, inhibition of biofilm formation, and induction of oxidative stress; (3) the potential antibacterial applications of Bio-SeNPs as food packaging materials, food additives and fertilizers/feeds for crops and animals in the food industry; and (4) the cytotoxicity and animal toxicity of Bio-SeNPs. The related knowledge contributes to enhancing our understanding of Bio-SeNP applications and makes a valuable contribution to ensuring food safety.

Oxidative stress generated due to photocatalytic activity of biosynthesized selenium nanoparticles triggers cytoplasmic leakage leading to bacterial cell death

The present work investigates the role of oxidative stress generated at biosynthesized selenium nanoparticles (SeNPs) interface in defining the antimicrobial and anti-biofilm activity. To this end, SeNPs with average size of 119 nm were synthesized rapidly during the growth of Staphylococcus aureus using the principle of green chemistry. The synthesis of SeNPs was confirmed by using different biophysical techniques like UV-vis spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), EDX and zeta potential analysis. The obtained data from antimicrobial study revealed strong antimicrobial activity against both Gram-positive bacteria like Bacillus subtilis (MTCC 441) and Gram-negative bacteria like Escherichia coli (MTCC 443) and anti-biofilm activity against biofilm forming bacteria. The mechanism behind antimicrobial activity of biosynthesized SeNPs was explored by evaluating the amount of reactive oxygen species (ROS) generated at SeNPs interface due to photocatalytic activity. The experimental data obtained altogether concluded that, the ROS generated at SeNPs interface put stress on bacterial cell membrane causing leakage of cytoplasmic contents, leading to bacterial cell death.

Inhibition of Adherence and Biofilm Formation of Pseudomonas aeruginosa by Immobilized ZnO Nanoparticles on Silicone Urinary Catheter Grafted by Gamma Irradiation

Nosocomial infections caused by microbial biofilm formation on biomaterial surfaces such as urinary catheters are complicated by antibiotic resistance, representing a common problem in hospitalized patients. Therefore, we aimed to modify silicone catheters to resist microbial adherence and biofilm formation by the tested microorganisms. This study used a simple direct method to graft poly-acrylic acid onto silicone rubber films using gamma irradiation to endow the silicone surface with hydrophilic carboxylic acid functional groups. This modification allowed the silicone to immobilize ZnO nanoparticles (ZnO NPs) as an anti-biofilm. The modified silicone films were characterized by FT-IR, SEM, and TGA. The anti-adherence ability of the modified silicone films was evidenced by the inhibition of biofilm formation by otherwise strong biofilm-producing Gram-positive, Gram-negative, and yeast clinical isolates. The modified ZnO NPs grafted silicone showed good cytocompatibility with the human epithelial cell line. Moreover, studying the molecular basis of the inhibitory effect of the modified silicone surface on biofilm-associated genes in a selected Pseudomonas aeruginosa isolate showed that anti-adherence activity might be due to the significant downregulation of the expression of lasR, lasI, and lecB genes by 2, 2, and 3.3-fold, respectively. In conclusion, the modified silicone catheters were low-cost, offering broad-spectrum anti-biofilm activity with possible future applications in hospital settings.

Physiological Benefits of Novel Selenium Delivery via Nanoparticles

Dietary selenium (Se) intake within the physiological range is critical to maintain various biological functions, including antioxidant defence, redox homeostasis, growth, reproduction, immunity, and thyroid hormone production. Chemical forms of dietary Se are diverse, including organic Se (selenomethionine, selenocysteine, and selenium-methyl-selenocysteine) and inorganic Se (selenate and selenite). Previous studies have largely investigated and compared the health impacts of dietary Se on agricultural stock and humans, where dietary Se has shown various benefits, including enhanced growth performance, immune functions, and nutritional quality of meats, with reduced oxidative stress and inflammation, and finally enhanced thyroid health and fertility in humans. The emergence of nanoparticles presents a novel and innovative technology. Notably, Se in the form of nanoparticles (SeNPs) has lower toxicity, higher bioavailability, lower excretion in animals, and is linked to more powerful and superior biological activities (at a comparable Se dose) than traditional chemical forms of dietary Se. As a result, the development of tailored SeNPs for their use in intensive agriculture and as candidate for therapeutic drugs for human pathologies is now being actively explored. This review highlights the biological impacts of SeNPs on growth and reproductive performances, their role in modulating heat and oxidative stress and inflammation and the varying modes of synthesis of SeNPs.

An insight into biofabrication of selenium nanostructures and their biomedical application

Evidence shows that nanoparticles exert lower toxicity, improved targeting, and enhanced bioactivity, and provide versatile means to control the release profile of the encapsulated moiety. Among different NPs, inorganic nanoparticles (Ag, Au, Ce, Fe, Se, Te, Zn, etc.) possess a considerable place owing to their unique bioactivities in nanoforms. Selenium, an essential trace element, played a vital role in the growth and development of living organisms. It has attracted great interest as a therapeutic factor without significant adverse effects in medicine at recommended dose. Selenium nanoparticles can be fabricated by physical, biological, and chemical approaches. The biosynthesis of nanoparticles is shown an advance compared to other procedures, because it is environmentally friendly, relatively reproducible, easily accessible, biodegradable, and often results in more stable materials. The effect of size, shape, and synthesis methods on their applications in biological systems investigated by several studies. This review focused on the procedures for the synthesis of selenium nanoparticles, in particular the biogenesis of selenium nanoparticles and their biomedical characteristics, such as antibacterial, antiviral, antifungal, and antiparasitic properties. Eventually, a comprehensive future perspective of selenium nanoparticles was also presented.

Antimicrobial materials for endotracheal tubes: A review on the last two decades of technological progress

Ventilator-associated pneumonia (VAP) is an unresolved problem in nosocomial settings, remaining consistently associated with a lack of treatment, high mortality, and prolonged hospital stay. The endotracheal tube (ETT) is the major culprit for VAP development owing to its early surface microbial colonization and biofilm formation by multiple pathogens, both critical events for VAP pathogenesis and relapses. To combat this matter, gradual research on antimicrobial ETT surface coating/modification approaches has been made. This review provides an overview of the relevance and implications of the ETT bioburden for VAP pathogenesis and how technological research on antimicrobial materials for ETTs has evolved. Firstly, certain main VAP attributes (definition/categorization; outcomes; economic impact) were outlined, highlighting the issues in defining/diagnosing VAP that often difficult VAP early- and late-onset differentiation, and that generate misinterpretations in VAP surveillance and discrepant outcomes. The central role of the ETT microbial colonization and subsequent biofilm formation as fundamental contributors to VAP pathogenesis was then underscored, in parallel with the uncovering of the polymicrobial ecosystem of VAP-related infections. Secondly, the latest technological developments (reported since 2002) on materials able to endow the ETT surface with active antimicrobial and/or passive antifouling properties were annotated, being further subject to critical scrutiny concerning their potentialities and/or constraints in reducing ETT bioburden and the risk of VAP while retaining/improving the safety of use. Taking those gaps/challenges into consideration, we discussed potential avenues that may assist upcoming advances in the field to tackle VAP rampant rates and improve patient care. STATEMENT OF SIGNIFICANCE: The use of the endotracheal tube (ETT) in patients requiring mechanical ventilation is associated with the development of ventilator-associated pneumonia (VAP). Its rapid surface colonization and biofilm formation are critical events for VAP pathogenesis and relapses. This review provides a comprehensive overview on the relevance/implications of the ETT biofilm in VAP, and on how research on antimicrobial ETT surface coating/modification technology has evolved over the last two decades. Despite significant technological advances, the limited number of gathered reports (46), highlights difficulty in overcoming certain hurdles associated with VAP (e.g., persistent colonization/biofilm formation; mechanical ventilation duration; hospital length of stay; VAP occurrence), which makes this an evolving, complex, and challenging matter. Challenges and opportunities in the field are discussed.

Biofilm Lifestyle in Recurrent Urinary Tract Infections

Urinary tract infections (UTIs) represent one of the most common infections that are frequently encountered in health care facilities. One of the main mechanisms used by bacteria that allows them to survive hostile environments is biofilm formation. Biofilms are closed bacterial communities that offer protection and safe hiding, allowing bacteria to evade host defenses and hide from the reach of antibiotics. Inside biofilm communities, bacteria show an increased rate of horizontal gene transfer and exchange of resistance and virulence genes. Additionally, bacterial communication within the biofilm allows them to orchestrate the expression of virulence genes, which further cements the infestation and increases the invasiveness of the infection. These facts stress the necessity of continuously updating our information and understanding of the etiology, pathogenesis, and eradication methods of this growing public health concern. This review seeks to understand the role of biofilm formation in recurrent urinary tact infections by outlining the mechanisms underlying biofilm formation in different uropathogens, in addition to shedding light on some biofilm eradication strategies.

Antibacterial and Antibiofilm Potential of Microbial Polysaccharide Overlaid Zinc Oxide Nanoparticles and Selenium Nanowire

Here, we report on the synthesis of zinc oxide nanoparticles (ZnO NPs) and selenium nanowires (Se NWs) using microbial exopolysaccharides (EPS) as a mediator and then examine their antibacterial and ecotoxicity effects in vitro and in vivo, respectively. At 100 µg/mL, EPS, EPS-ZnO NPs, and EPS-Se NWs all exhibited potent in vitro antibacterial properties, drastically inhibiting the development of aquatic Gram(-) pathogens. In addition, antibiofilm studies using a microscope revealed that EPS, EPS-ZnO NPs, and EPS-Se NWs at 75 µg/mL prevented biofilm development. Furthermore, the in vivo toxicity was carried out via Danio rerio embryos and Ceriodaphnia cornuta. Danio rerio embryos were determined at different time intervals (6 hpf, 12 hpf, 24 hpf and 48 hpf). The maximum survival rate (100%) was obtained in a control group. Correspondingly, EPS, EPS-ZnO NPs and EPS-Se NWs treated embryos showed a considerable survival rate with 93.3%, 86.7% and 77.2%, respectively, at 100 µg/mL for 48 hpf. The total mortality of C. cornuta was seen at 100 µg/mL, with 56.7% in EPS, 60.0% in EPS-ZnO NPs, and 70.0% in EPS-Se NWs. For C. cornuta, the LC50 values for EPS, EPS-ZnO NPs, and EPS-Se NWs were 90.32, 81.99, and 62.99 µg/mL, respectively. Under a microscope, morphological alterations in C. cornuta were analyzed. After 24 h, an amount of dark substance was seen in the guts of C. cornuta exposed to 100 µg/mL, but in the control group, all of the living C. cornuta were swimming as usual. Our results show that EPS and EPS-ZnO NPs were less harmful than EPS-Se NWs, and that they were successfully employed to shield freshwater crustaceans from the toxins in aquatic environments.

Selenium Improved Phenylacetic Acid Content in Oilseed Rape and Thus Enhanced the Prevention of Sclerotinia sclerotiorum by Dimethachlon

Sclerotinia sclerotiorum is a broad-spectrum necrotrophic phytopathogen that can infect many plant species worldwide. The application of fungicides is a common measure for controlling Sclerotinia sclerotiorum. Due to the risk of developing resistance to fungicides, it is imperative to find ways to be environmentally friendly and even effective. Using bioactive compounds in plants to reduce the amounts of fungicides has become a clean and sustainable strategy of controlling Sclerotinia sclerotiorum. Our study found that selenium in soil mediated the phenylacetic acid-related metabolic pathway in oilseed rape and reduced the incidence rate of Sclerotinia sclerotiorum. The growth-inhibition rates of Sclerotinia sclerotiorum were observed at 25.82%, 19.67%, and 52.61% for treatments of 0.8 mg·L-1 dimethachlon, 0.1 mg·mL-1 phenylacetic acid, and dimethachlon (0.8 mg·L-1) + phenylacetic acid (0.1 mg·mL-1), respectively. Phenylacetic acid reduced the application amount of dimethachlon and enhanced the inhibition effect for Sclerotinia sclerotiorum. Results also suggested that phenylacetic acid severely damaged the morphological structure, changed the electrical conductivity, and reduced the capacity of acid production and oxalic acid secretion of Sclerotinia sclerotiorum mycelium. Further studies revealed that phenylacetic acid increased the gene-expression level of Ssodc1, Ssodc2, CWDE2 and CWDE10 in mycelium while decreasing the expression level of SsGgt1, and phenylacetic acid + dimethachlon reduced the relative expression level of SsBil. These findings verified that phenylacetic acid could partially replace the amount of dimethachlon, as well as enhance the prevention of Sclerotinia sclerotiorum by dimethachlon, which provides evidence for developing an environment-friendly method for Sclerotinia sclerotiorum control.

Biogenesis of selenium nanospheres using Halomonas venusta strain GUSDM4 exhibiting potent environmental applications

Selenite reducing bacterial strain (GUSDM4) isolated from Mandovi estuary of Goa, India was identified as Halomonas venusta based on 16S rRNA gene sequence analysis. Its maximum tolerance level for sodium selenite (Na₂SeO₃) was 100 mM. The 2, 3-diaminonaphthalene-based spectroscopic analysis demonstrated 96 and 93% reduction of 2 and 4 mM Na₂SeO₃ respectively to elemental selenium (Se⁰) during the late stationary growth phase. Biosynthesis of Se nanoparticles (SeNPs) commenced within 4 h during the log phase, which was evident from the brick red color in the growth medium and a characteristic peak at 265 nm revealed by UV-Vis spectrophotometry. The intracellular periplasmic synthesis of SeNPs in GUSDM4 was confirmed by transmission electron microscopy (TEM). Characterization of SeNPs by X-ray crystallography, TEM and energy-dispersive X-ray analysis (EDAX) clearly demonstrated spherical SeNPs of 20-80 nm diameter with hexagonal crystal lattice. SeNPs (0.8 and 1 mg/L) primed seeds under arsenate [As(V)] stress showed increase in shoot length, root length and biomass by 1.4-, 1.5- and 1.1-fold respectively, as compared to As(V) primed seeds alone. The proline and phenolic content in seeds primed with SeNPs under arsenate stress showed alleviated levels proving its ameliorative potential. SeNPs also demonstrated anti-biofilm activity at 20 µg/mL against human pathogens which was evident by scanning electron microscopic (SEM) analysis. SeNPs interestingly revealed mosquito larvicidal activity also. Therefore, these studies have clearly demonstrated amazing potential of the marine bacterium, Halomonas venusta in biosynthesis of SeNPs and their applications as ameliorative, anti-biofilm and mosquito larvicidal agents which is the first report of its kind.

Recent advances in carbon-based nanomaterials for combating bacterial biofilm-associated infections

The prevalence of bacterial pathogens among humans has increased rapidly and poses a great threat to health. Two-thirds of bacterial infections are associated with biofilms. Recently, nanomaterials have emerged as anti-biofilm agents due to their enormous potential for combating biofilm-associated infections and infectious disease management. Among these, relatively high biocompatibility and unique physicochemical properties of carbon-based nanomaterials (CBNs) have attracted wide attention. This review presented the current advances in anti-biofilm CBNs. Different kinds of CBNs and their physicochemical characteristics were introduced first. Then, the various potential mechanisms underlying the action of anti-biofilm CBNs during different stages were discussed, including anti-biofouling activity, inhibition of quorum sensing, photothermal/photocatalytic inactivation, oxidative stress, and electrostatic and hydrophobic interactions. In particular, the review focused on the pivotal role played by CBNs as anti-biofilm agents and delivery vehicles. Finally, it described the challenges and outlook for the development of more efficient and bio-safer anti-biofilm CBNs.

Growth Response in Oryctolagus cuniculus to Selenium Toxicity Exposure Ameliorated with Vitamin E

The adverse impacts of high temperature during the summer season on the rabbit industry have gained increased global attention. In this study, the comparative effects of biological (BIO) and chemical (CH) nanoselenium (nano-Se) combined with vitamin E on the growth and immune performances of rabbits were observed. A total of 200 white male rabbits of similar age (90 days) were divided into five treatment groups (T0, T1, T2, T3, and T4), 40 animals in each treatment. The rabbits in the first treatment group (T0) was fed basal diet; (T1) basal diet supplemented with 35 mg biological synthesized nanoselenium/kg diet; (T2) basal diet with 35 mg biological nanoselenium/kg diet+150 mg Vit. E/kg; (T3) basal diet+35 m chemically synthesized nanoselenium/kg diet; and (T4) basal diet+35 mg of chemical nanoselenium/kg diet+150 mg Vit. E/kg. The duration of this experiment was 63 days. The body weight of each rabbit was recorded weekly. Results revealed a significant (P < 0.05) increase in live body weight (LBW), total body gain (TBG), and feed conversion ratio (FCR) of rabbits treated with BIO-Se+Vit. E (T2) compared to the other groups. Selenium concentrations in the kidneys and liver were significantly higher (P < 0.05) in animals fed with BIO-Se+Vit. E (T2). The concentrations of serum urea, glutamyl transferase (GGT), and triglycerides (TG) were lower in untreated (T0) and treated groups (T1, T2, T3, and T4). From the results of this study, it can be concluded that biological nano-Se gave maximum improvement for the parameters under study compared to the chemically synthesized nanoselenium by playing a role in alleviating heat stress, increasing the growth performance, and enhancing the immunity of growing white male rabbits. Further addition of Vit. E is an alternative method to maximize productivity with no adverse effects during the fattening period of growing white male rabbits.

Investigation of the Antibacterial and Antibiofilm Activity of Selenium Nanoparticles against Vibrio cholerae as a Potent Therapeutics

Vibrio cholerae is a major cause of severe diarrhea, which is ecologically flexible, and remains as a major cause of death, especially in developing countries. Consecutive emergence of antibiotic-resistant strains is considered to be as one of the major concerns of the World Health Organization (WHO). Nanoparticles as a new nonantibiotic therapeutic strategy have been widely used in recent years to treat bacterial infections. The present study aimed to investigate the antibacterial and antibiofilm effect of selenium nanoparticles (SeNPs) in vitro against V. cholerae O1 ATCC 14035 strain. SeNPs were prepared and characterized using ultraviolet-visible (UV-Vis) spectroscopy, DLS (dynamic light scattering), zeta potential measurement, and Fourier transform infrared (FTIR) analysis. The concentration of SeNPs was calculated by ICP (inductively coupled plasma) method. Also, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was employed to assess the cytotoxic effect of SeNPs on Caco-2 cells. Antibacterial and antibiofilm activity of SeNPs was determined by broth microdilution and crystal violet assays, respectively. The average particle size of SeNPs was 71.1 nm with zeta potential −32.2 mV. The SEM images supported the uniform spherical morphology of the prepared nanoparticles. The antibiofilm effect of SeNPs was evident at concentrations of 50–200 μg/mL. This study results provided evidence that SeNPs are safe as an antibacterial and antibiofilm agent against V. cholerae O1 ATCC 14035 strain.

Novel Antiviral and Antibacterial Durable Polyester Fabrics Printed with Selenium Nanoparticles (SeNPs)

The COVID-19 pandemic has clearly shown the importance of developing advanced protective equipment, and new antiviral fabrics for the protection and prevention of life-threatening viral diseases are needed. In this study, selenium nanoparticles (SeNPs) were combined with polyester fabrics using printing technique to obtain multifunctional properties, including combined antiviral and antibacterial activities as well as coloring. The properties of the printed polyester fabrics with SeNPs were estimated, including tensile strength and color fastness. Characterization of the SeNPs was carried out using TEM and SEM. The results of the analysis showed good uniformity and stability of the particles with sizes range from 40-60 nm and 40-80 nm for SeNPs 25 mM and 50 mM, respectively, as well as uniform coating of the SeNPs on the fabric. In addition, the SeNPs-printed polyester fabric exhibited high disinfection activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an inhibition percentage of 87.5%. Moreover, a toxicity test of the resulting printed fabric revealed low cytotoxicity against the HFB4 cell line. In contrast, the treated fabric under study showed excellent killing potentiality against Gram-positive bacteria (Bacillus cereus) and Gram-negative bacteria (Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli). This multifunctional fabric has high potential for use in protective clothing applications by providing passive and active protection pathways.

Nanoparticle, a promising therapeutic strategy for the treatment of infective endocarditis

Infective endocarditis (IE) has been recognized as a biofilm-related disease caused by pathogenic microorganisms, such as bacteria and fungi that invade and damage the heart valves and endocardium. There are many difficulties and challenges in the antimicrobial treatment of IE, including multi-drug resistant pathogens, large dose of drug administration with following side effects, and poor prognosis. For the past few years, the development of nanotechnology has promoted the use of nanoparticles as antimicrobial nano-pharmaceuticals or novel drug delivery systems (NDDS) in antimicrobial therapy for chronic infections and biofilm-related infectious disease as these molecules exhibit several advantages. Therefore, nanoparticles have a potential role to play in solving problems in the treatment of IE, including improving antimicrobial activity, increasing drug bioavailability, minimizing frequency of drug administration, and preventing side effects. In this article, we review the latest advances in nanoparticles against drug-resistant bacteria in biofilm and recommends nanoparticles as an alternative strategy to the antibiotic treatment of IE.

Green synthesis of selenium nanoparticles using Rosmarinus officinalis and investigated their antimicrobial activity

The interest of many has been attracted by plant-mediated synthesizing procedures for nanoparticles since they provide certain qualities including being cost-effective, quick, and compatible with the environment. In this regard, this work introduces the production of selenium-nanoparticles (Se-NPs) in a biological manner utilizing aqueous extracts of Rosmarinus officinalis (R. officinalis). Production of Se-NPs was confirmed using UV-visible (UV-Vis) spectrophotometry. Also, dynamic light scattering (DLS) analysis was used for determination particle size distribution, while we distinguished the identification of crystalline construction of nanoparticles through the means of X-ray diffraction (XRD) pattern, DLS, and transmission electron microscopy (TEM) examination indicated that Se-NPs are often spherical with a size about 20 to 40 nm. The minimum inhibitory concentration (MIC) of the synthesized Se-NPs by R. officinalis extract against Mycobacterium tuberculosis (M. tuberculosis), Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) was 256, 16, 32, 128, and 64 µg/mL, respectively. The synthesized Se-NPs had no significant effect on Mycobacterium simiae (M. simiae) and had exhibited a strong antimicrobial functionality towards the gram-positive and gram-negative bacteria and can stand as a potent antibacterial agent.

Simultaneous Sonochemical Coloration and Antibacterial Functionalization of Leather with Selenium Nanoparticles (SeNPs)

The development of antibacterial coatings for footwear components is of great interest both from an industry and consumer point of view. In this work, the leather material was developed taking advantage of the intrinsic antibacterial activity and coloring ability of selenium nanoparticles (SeNPs). The SeNPs were synthesized and implemented into the leather surface by using ultrasonic techniques to obtain simultaneous coloring and functionalization. The formation of SeNPs in the solutions was evaluated using UV/Vis spectroscopy and the morphology of the NPs was determined by transmission electron microscopy (TEM). The treated leather material (leather/SeNPs) was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The effects of SeNPs on the coloration and antibacterial properties of the leather material were evaluated. The results revealed that the NPs were mostly spherical in shape, regularly distributed, and closely anchored to the leather surface. The particle size distribution of SeNPs at concentrations of 25 mM and 50 mM was in the range of 36–77 nm and 41–149 nm, respectively. It was observed that leather/SeNPs exhibited a higher depth of shade compared to untreated ones, as well as excellent fastness properties. The results showed that leather/SeNPs can significantly enhance the antibacterial activity against model of bacteria, including Gram-positive bacteria (Bacillus cereus) and Gram-negative bacteria (Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli). Moreover, the resulting leather exhibited low cytotoxicity against HFB4 cell lines. This achievement should be quite appealing to the footwear industry as a way to prevent the spread of bacterial infection promoted by humidity, poor breathability and temperature which promote the expansion of the microflora of the skin.

Selenium nanoparticles from Lactobacillus paracasei HM1 capable of antagonizing animal pathogenic fungi as a new source from human breast milk

The current study was performed to develop a simple, safe, and cost-effective technique for the biosynthesis of selenium nanoparticles (SeNPs) from lactic acid bacteria (LAB) isolated from human breast milk with antifungal activity against animal pathogenic fungi. The LAB was selected based on their speed of transforming sodium selenite (Na2SeO3) to SeNPs. Out of the four identified LAB isolates, only one strain produced dark red color within 32 h of incubation, indicating that this isolate was the fastest in transforming Na2SeO3 to SeNPs; and was chosen for the biosynthesis of LAB-SeNPs. The superior isolate was further identified as Lactobacillus paracasei HM1 (MW390875) based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and phylogenetic tree analysis of 16S rRNA sequence alignments. The optimum experimental conditions for the biosynthesis of SeNPs by L. paracasei HM1 were found to be pH (6.0), temperature (35˚C), Na2SeO3 (4.0 mM), reaction time (32 h), and agitation speed (160 rpm). The ultraviolet absorbance of L. paracasei-SeNPs was detected at 300 nm, and the transmission electron microscopy (TEM) captured a diameter range between 3.0 and 50.0 nm. The energy-dispersive X-ray spectroscopy (EDX) and the Fourier-transform infrared spectroscopy (FTIR) provided a clear image of the active groups associated with the stability of L. paracasei-SeNPs. The size of L. paracasei-SeNPs using dynamic light scattering technique was 56.91 ± 1.8 nm, and zeta potential value was -20.1 ± 0.6 mV in one peak. The data also revealed that L. paracasei-SeNPs effectively inhibited the growth of Candida and Fusarium species, and this was further confirmed by scanning electron microscopy (SEM). The current study concluded that the SeNPs obtained from L. paracasei HM1 could be used to prepare biological antifungal formulations effective against major animal pathogenic fungi. The antifungal activity of the biologically synthesized SeNPs using L. paracasei HM1 outperforms the chemically produced SeNPs. In vivo studies showing the antagonistic effect of SeNPs on pathogenic fungi are underway to demonstrate the potential of a therapeutic agent to treat animals against major infectious fungal diseases.

Phyto-fabricated Nanoparticles and Their Anti-biofilm Activity: Progress and Current Status

Biofilm is the self-synthesized, mucus-like extracellular polymeric matrix that acts as a key virulence factor in various pathogenic microorganisms, thereby posing a serious threat to human health. It has been estimated that around 80% of hospital-acquired infections are associated with biofilms which are found to be present on both biotic and abiotic surfaces. Antibiotics, the current mainstream treatment strategy for biofilms are often found to be futile in the eradication of these complex structures, and to date, there is no effective therapeutic strategy established against biofilm infections. In this regard, nanotechnology can provide a potential platform for the alleviation of this problem owing to its unique size-dependent properties. Accordingly, various novel strategies are being developed for the synthesis of different types of nanoparticles. Bio-nanotechnology is a division of nanotechnology which is gaining significant attention due to its ability to synthesize nanoparticles of various compositions and sizes using biotic sources. It utilizes the rich biodiversity of various biological components which are biocompatible for the synthesis of nanoparticles. Additionally, the biogenic nanoparticles are eco-friendly, cost-effective, and relatively less toxic when compared to chemically or physically synthesized alternatives. Biogenic synthesis of nanoparticles is a bottom-top methodology in which the nanoparticles are formed due to the presence of biological components (plant extract and microbial enzymes) which act as stabilizing and reducing agents. These biosynthesized nanoparticles exhibit anti-biofilm activity via various mechanisms such as ROS production, inhibiting quorum sensing, inhibiting EPS production, etc. This review will provide an insight into the application of various biogenic sources for nanoparticle synthesis. Furthermore, we have highlighted the potential of phytosynthesized nanoparticles as a promising antibiofilm agent as well as elucidated their antibacterial and antibiofilm mechanism.