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Introduction: The material of a bandage plays an important role in wound management. Microorganisms can colonize the dressing and release toxins, which create dead cells in the wound. This allows the microorganisms to bind the dead cells and infect the wound. Thus, a dressing is needed that kills bacteria in the bandage. To combat health care-associated infections, antimicrobial treatment of medical textiles, such as gauze, uniforms, curtains, bed sheets, gowns, and masks, is required. Besides, antimicrobial resistance is another major problem of this century. Antibacterial overuse has contributed to drug-resistant bacteria. To combat these two problems, we synthesized new organo-selenium compounds that can be attached to the cotton of the dressing. We then used an in vivo wound model, which allowed us to measure the effectiveness of selenium attached to a cotton dressing, to prevent bacteria from infecting a wound., Materials and Methods: Organo-selenium was attached to cotton fabric, resulting in a fabric with 0.1% selenium covalently attached to it. Staphylococcus aureus (as well as methicillin-resistant S. aureus [MRSA]), Stenotrophomonas maltophilia, Enterococcus faecalis, Staphylococcus epidermidis, and Pseudomonas aeruginosa were chosen for the wound infection study. All the bacteria were enumerated in the wound dressing and in the wound tissue under the dressing. Wounds were made on the backs of mice. The material was used as a bandage over the wound. Bacteria were injected into the wound under the bandage. The amount of bacteria in the wound after 5 days was determined. A similar study was performed using dressing material that was soaked in phosphate buffered saline at 37 °C for 3 months before use., Results: Cotton dressing with selenium attached showed complete inhibition (7 logs, as compared with control dressing) of different bacterial strains, in both the dressing and "the tissue" of the wound. Similar results were obtained using selenium cotton dressing that was soaked for 3 months before use. Control cotton with no selenium showed complete infiltration of bacteria into the wound and the dressing. In addition, a study was performed under Food and Drug Administration standard methods to show the ability of the selenium to kill bacteria in the fabric, using material that was washed 5 times in detergent. This also showed complete killing of bacteria in the fabric., Conclusions: The results show that the selenium remains in the dressing after washing and is able to completely protect the wound from bacterial infection. In the selenium bandage, no bacteria were found in the bandage or the wound after 5 days., (Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2024. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Bleached and cationized cotton fabrics were chemically modified with reactive organoselenium compounds through the nucleophilic aromatic substitution (S N Ar) reaction, which allowed for organo-selenium attachment onto the surface of cotton fabrics via covalent bonds and, in the case of the cationized cotton fabric, additional ionic interactions. The resulting textiles exhibited potent bactericidal activity against S. aureus (99.99% reduction), although only moderate activity was observed against E. coli . Fabrics treated with reactive organo-selenium compounds also exhibited fungicidal activities against C. albicans , and much higher antifungal activity was observed when organo-selenium compounds were applied to the cationized cotton in comparison to the bleached cotton. The treatment was found to be durable against rigorous washing conditions (non-ionic detergent/100 °C). This paper is the first report on a novel approach integrating the reaction of cotton fabrics with an organo-selenium antimicrobial agent. This approach is attractive because it provides a method for imparting antimicrobial properties to cotton fabrics which does not disrupt the traditional production processes of a textile mill.

Purpose: Catheter-associated urinary tract infections are of significant medical burden in cost, morbidity, and mortality. Experimental selenium-coated medical devices have demonstrated non-toxic in vitro and in vivo antimicrobial activity. While antimicrobial-coated catheters have shown efficacy in preventing CAUTIs, selenium has not been tested in this context. The purpose of this in vitro study is to evaluate selenium-incorporated urinary catheters for inhibition of uropathogenic bacterial growth and biofilm formation., Methods: Urinary catheters incorporated with 1% organo-selenium and standard (uncoated) catheters were incubated in vitro with E. coli, K. pneumoniae, P. aeruginosa, H. influenzae, and combinations of these bacteria. Growth was evaluated by colony-forming unit count and visualized with confocal laser and scanning electron microscopy. Organo-selenium catheter material integrity was also tested by soaking the tubing in phosphate-buffered saline for 12 weeks at 37 °C., Results: Organo-selenium-incorporated catheters demonstrated total reduction (100%) of in vitro bacterial growth and biofilm formation for E. coli, K. pneumoniae, H. influenzae, and a combination of these species when compared to control. P. aeruginosa growth was inhibited by approximately 4 logs (99.99%). Complete inhibition of E. coli growth was maintained after long-term phosphate-buffered saline soaking., Conclusion: The results demonstrate that organo-selenium was stably incorporated into catheter tubing and inhibited bacterial attachment, growth, and biofilm formation for multiple uropathogenic organisms. Furthermore, long-term soaking of organo-selenium tubing in phosphate-buffered saline did not show any decline in bacterial growth inhibition or biofilm formation. These findings suggest that organo-selenium-incorporated catheters may be advantageous in preventing catheter-associated urinary tract infections and warrant further in vivo and clinical evaluation., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Objective: Dental plaque is a complex structure (called a biofilm) that is produced by a community of oral bacteria. As microorganisms accumulate in the oral cavity, bacteria can assemble into biofilms that protect them from antibiotics and disinfectants, which contribute to dental cavities and oral infections that acts as the seed for further infections throughout the body. Therefore, there is great interest in developing dental sealants that can effectively eliminate biofilms formed from an assortment of oral bacteria species., Methods: In previous papers, it was shown that both in vivo and in vitro use of organo-selenium dental sealants have the potential to be an effective method for preventing dental caries and plaque formation. However, our previous in vitro study only examined the effect of the organo-selenium sealants on Streptococcus mutans and salivarius. Since that time, this organo-selenium sealant has been changed to improve its curing time., Results: We showed a selenium containing sealant (SeLECT-DefenseTM) can completely eliminate biofilm formation on the sealant at selenium concentrations of 0.25% and higher, by S. salivarius, S. sanguinis, or S. mutans, individually or in combination. This selenium containing sealant can also completely inhibit the same bacteria from growing under the sealant, while control sealant cannot. The selenium containing sealant was tested for stability and it was found to still kill these same bacteria after soaking for the equivalent of one year in PBS (pH 7.4). It was also found that the combination of the three bacteria were also killed by the selenium sealant, thus ruling out potential synergism of the bacteria in forming resistance., Significance: The following study showed that this modified selenium dental sealant effectively eliminates species of bacteria both on and under the dental sealant., (Copyright © 2022 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Purpose: Although silicone hydrogel materials have produced many corneal health benefits to patients wearing contact lenses, bacteria that cause acute red eye or corneal ulcers are still a concern. A coating that inhibits bacterial colonization while not adversely affecting the cornea should improve the safety of contact lens wear. A covalent selenium (Se) coating on contact lenses was evaluated for safety using rabbits and prevention of bacterial colonization of the contact lenses in vitro., Methods: Contact lenses coated with Se were worn on an extended-wear schedule for up to 2 months by 10 New Zealand White rabbits. Corneal health was evaluated with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. Lenses worn by the rabbits were analyzed for protein and lipid deposits. In addition, the ability of Se to block bacterial colonization was tested in vitro by incubating lenses in a Pseudomonas aeruginosa broth followed by scanning electron microscopy of the contact lens surface., Results: The covalent Se coating decreased bacterial colonization in vitro while not adversely affecting the corneal health of rabbits in vivo. The Se coating produced no noticeable negative effects as observed with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. The Se coating did not affect protein or lipid deposition on the contact lenses., Conclusion: The data from this pilot study suggest that a Se coating on contact lenses might reduce acute red eye and bacterial ulceration because of an inhibition of bacterial colonization. In addition, our safety tests suggest that this positive effect can be produced without an adverse effect on corneal health.

To further investigate the inhibition of Pseudomonas aeruginosa's in vitro growth and biofilm formation by an organo-selenium-incorporated polyurethane (PU) catheter material. P. aeruginosa, Staphylococcus aureus, and Candida albicans were incubated in vitro with organo-selenium and control polyurethane catheter materials in the presence of glutathione. Growth was evaluated by a colony-forming-unit (CFU) count and visualized with confocal laser scanning microscopy. Two different PU catheter materials were used. Using tin-catalyzed PU catheter material, complete inhibition of S. aureus was seen at 1% selenium (Se), whereas no inhibition was seen for P. aeruginosa at up to 3.0% Se. Whereas, using a thermoplastic PU catheter material, 1.5% Se and 2% Se organo-selenium caused several logs of growth inhibition of P. aeruginosa, and 2.5% selenium, incorporation showed complete inhibition (8 logs). Samples with lower than 1.5% selenium did not show adequate growth inhibition for P. aeruginosa. Similar in vitro growth inhibition was achieved against a multidrug-resistant C. albicans strain. It was concluded that optimal inhibition of P. aeruginosa in vitro growth and biofilm formation occurs with 2.5% selenium incorporated as organo-selenium in a thermoplastic PU catheter material. These results suggest that reduced incidence of CAUTIs (catheter associated urinary tract infections) with P. aeruginosa and other bacteria and fungi can be achieved by using organo-selenium-incorporated catheters. [ABSTRACT FROM AUTHOR]

Modern epidemics quickly spread across borders and continents with devastating effects on both human health and the world economy. This issue is made worse by the various ways that infections are spread, including through aerosol, droplets, and fomites. The antibacterial qualities of various surface materials and coatings have been the subject of much research. However, the antiviral activity of metal coatings can be heavily influenced by imbalances in metal distribution and the presence of other metal impurities. As such, there is interest in developing novel surface coatings that can reduce the transmission of active viral particles in healthcare facilities. In recent years, the non-metals, such as selenium and nanoparticles, have acquired greater interest from the medical and scientific community for their antiviral surface activity. In this review, we will discuss the cellular and physiological functions of selenium in mammalian cells and against viral infections. We then discuss the mechanism behind selenium coated surfaces and their efficacy against bacterial infections. Lastly, we examine the antiviral activity of selenium, and the potential antiviral activity of selenium nanoparticles and coatings. [ABSTRACT FROM AUTHOR]

This study examines the use of a covalently selenium-bonded peptide and phage that binds to the Yersinia pestis F1 antigen for the targeting and killing of E. coli expressing this surface antigen. Using a Ph.D.-12 phage-display library for affinity selection of the phage which would bind the F1 antigen of Y. pestis, a phage displaying a peptide that binds the F1 antigen with high affinity and specificity was identified. Selenium was then covalently attached to the display phage and the corresponding F1-antigen-binding peptide. Both the phage and peptides with selenium covalently attached retained their binding specificity for the Y. pestis F1 antigen. The phage or peptide not labeled with selenium did not kill the targeted bacteria, while the phage or peptide labeled with selenium did. In addition, the seleno-peptide, expressing the F1 targeting sequence only, killed cells expressing the F1 antigen but not the parent strain that did not express the F1 antigen. Specifically, the seleno-peptide could kill eight logs of bacteria in less than two hours at a 10-µM concentration. These results demonstrate a novel approach for the development of an antibacterial agent that can target a specific bacterial pathogen for destruction through the use of covalently attached selenium and will not affect other bacteria. [ABSTRACT FROM AUTHOR]

Methylselenol from selenium metabolism is postulated to be and most experimental evidence now indicates that it is the selenium metabolite responsible for the dietary chemoprevention of cancers. Using the recombinant enzyme methioninase, methylselenol-generating chemiluminesence by superoxide (O2⋅−) is shown to be catalytically produced from l-selenomethionine and d,l-selenoethionine, but not from methionine or l-Se-methylselenocysteine (SeMC). Methylselenol enzymaticaly generated by methioninase activity from the substrate selenomethionine arises from an initial putative selenium radical as measured by chemiluminesence in the absence of glutathione (GSH). In the presence of GSH, superoxide was generated as measured by chemiluminesence and superoxide dismutase inhibition of chemiluminescence. Ascorbic acid also quenched the chemiluminesence from the activity of methioninase with selenomethionine. Methylselenol and other redox cycling selenium compounds are almost assuredly accountable for inducing cell-cycle arrest and apoptosis in cancer cells in vitro and in vivo. Methylselenol generated from selenomethionine by methioninase is catalytic alone in oxidizing thiols, i.e. GSH, generating superoxide and inducing oxidative stress in direct proportion to its concentration. Se-methylselenocysteine in vivo is very likely carcinostatic in like manner to selenomethionine by generating methylselenol from other enzymatic activity, i.e. beta-lyase or amino acid oxidases. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to determine the inhibitory effect of selenocystamine coated intraocular lenses (IOLs) on the formation of posterior capsule opacification (PCO) in an ex vivo canine lens capsular bag assay. Selenocystamine was covalently bound to the surface of poly(2-hydroxyethyl methacrylate) (poly(HEMA)) discs. Three groups of canine lens capsules (6 coated IOLs (SeIOLs), 7 non-coated control IOLs and 8 empty capsules) were cultured for 10 days. During the culture period PCO was scored based on visual inspection of the capsules using phase contrast microscopy. On day 10 all the capsules were prepared for light microscopic examination and lens epithelial cells (LECs) were quantified. Proliferating cell nuclear antigen (PCNA), α-smooth muscle actin (α-SMA) and cleaved caspase-3 were examined by immunohistochemistry. Additionally, cell viability assays were performed on LECs cultured in tissue culture medium pre-incubated with either a SeIOL or control IOL. The viability assays demonstrated that no detectable cytotoxic leachables were associated with the functionalized IOLs. The central posterior capsule was free of cells underneath all SeIOLs, although large numbers of LECs populated the capsular periphery. Apoptotic cells were observed underneath the periphery of some SeIOLs. Both the PCO scores and LEC counts of SeIOL containing capsules were significantly lower than those of control group capsules (p < 0.01 and p = 0.0004, respectively). The use of selenium functionalized IOLs resulted in a significant reduction of PCO in this ex vivo model. Binding of selenocystamine to a foldable IOL may provide an effective method to prevent population of the central posterior capsule with LECs. [Copyright &y& Elsevier]

Among the most difficult bacterial infections encountered in treating patients are wound infections, which may occur in burn victims, patients with traumatic wounds, necrotic lesions in people with diabetes, and patients with surgical wounds. Within a wound, infecting bacteria frequently develop biofilms. Many current wound dressings are impregnated with antimicrobial agents, such as silver or antibiotics. Diffusion of the agent(s) from the dressing may damage or destroy nearby healthy tissue as well as compromise the effectiveness of the dressing. In contrast, the antimicrobial agent selenium can be covalently attached to the surfaces of a dressing, prolonging its effectiveness. We examined the effectiveness of an organoselenium coating on cellulose discs in inhibiting Pseudomonas aeruginosa and Staphylococcus aureus biofilm formation. Colony biofilm assays revealed that cellulose discs coated with organoselenium completely inhibited P. aeruginosa and S. aureus biofilm formation. Scanning electron microscopy of the cellulose discs confirmed these results. Additionally, the coating on the cellulose discs was stable and effective after a week of incubation in phosphate-buffered saline. These results demonstrate that 0.2% selenium in a coating on cellulose discs effectively inhibits bacterial attachment and biofilm formation and that, unlike other antimicrobial agents, longer periods of exposure to an aqueous environment do not compromise the effectiveness of the coating. [ABSTRACT FROM AUTHOR]