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

A novel approach for enhancing the color and antimicrobial properties of pine and beech wood using Se-NPs

Pine wood (PW) and beech wood (BW) are the most used wood in furniture and other applications owing to their unique characteristics and low machining cost. However, their biodegradability and varied moisture content limit their wider use and durability. Therefore, in this study, nanotechnology was used as a novel eco-friendly approach to enhance the durability, antimicrobial properties, and color of wood. Selenium nanoparticles (Se-NPs) were prepared in spherical shape at varied concentrations (25 and 50 mM) using an eco-friendly method in the range of 35-80 and 40-155 nm, respectively. Se-NPs formation at the nanoscale was confirmed using UV/Vis analysis, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The prepared Se-NPs were then impregnated into PW and BW for different periods ranging from 2 h to 1 week. The treated wood were then leached in distilled water for 14 days to eliminate excess Se-NPs from the wood surface. The treated wood surfaces were examined using energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). In addition, the depth of Se-NPs penetration into the treated wood at both tangential and radial sides was determined. Se-NPs impacts on the color properties, density, moisture content and antimicrobial activities of the treated wood were evaluated. PW treated with Se-NPs showed better antimicrobial and color characteristics than treated BW. PW samples immersed in 50 mM Se-NPs for 2 h showed the highest K/S values, whereas the highest antimicrobial values were obtained for those immersed at the same concentration for 2 days, and 1 week.

A Review of the Antibacterial, Fungicidal and Antiviral Properties of Selenium Nanoparticles

The resistance of microorganisms to antimicrobial drugs is an important problem worldwide. To solve this problem, active searches for antimicrobial components, approaches and therapies are being carried out. Selenium nanoparticles have high potential for antimicrobial activity. The relevance of their application is indisputable, which can be noted due to the significant increase in publications on the topic over the past decade. This review of research publications aims to provide the reader with up-to-date information on the antimicrobial properties of selenium nanoparticles, including susceptible microorganisms, the mechanisms of action of nanoparticles on bacteria and the effect of nanoparticle properties on their antimicrobial activity. This review describes the most complete information on the antiviral, antibacterial and antifungal effects of selenium nanoparticles.

Antibacterial and Antifungal Fabrication of Natural Lining Leather Using Bio-Synthesized Silver Nanoparticles from Piper Betle L. Leaf Extract

Leather is often used to make comfortable shoes due to its soft and breathable nature. However, its innate ability to retain moisture, oxygen and nutrients renders it a suitable medium for the adsorption, growth, and survival of potentially pathogenic microorganisms. Consequently, the intimate contact between the foot skin and the leather lining surface in shoes, which are subject to prolonged periods of sweating, may result in the transmission of pathogenic microorganisms and cause discomfort for the wearer. To address such issues, we modified pig leather with silver nanoparticles (AgPBL) that were bio-synthesized from Piper betle L. leaf extract as an antimicrobial agent via the padding method. The evidence of AgPBL embedded into the leather matrix, leather surface morphology and element profile of AgPBL-modified leather samples (pLeAg) was investigated using colorimetry, SEM, EDX, AAS and FTIR analyses. The colorimetric data confirmed that the pLeAg samples changed to a more brown color with higher wet pickup and AgPBL concentration, owing to the higher quantity of AgPBL uptake onto the leather surfaces. The antibacterial and antifungal activities of the pLeAg samples were both qualitatively and quantitatively evaluated using AATCC TM90, AATCC TM30 and ISO 16187:2013 test methods, approving a good synergistic antimicrobial efficiency of the modified leather against Escherichia coli and Staphylococcus aureus bacteria, a yeast Candida albicans and a mold Aspergillus niger. Additionally, the antimicrobial treatments of pig leather did not negatively impact its physico-mechanical properties, including tear strength, abrasion resistance, flex resistance, water vapour permeability and absorption, water absorption and desorption. These findings affirmed that the AgPBL-modified leather met all the requirements of upper lining according to the standard ISO 20882:2007 for making hygienic shoes.

An eco-friendly method of extracting alizarin from Rubia tinctorum roots under supercritical carbon dioxide and its application to wool dyeing

Because of its low critical temperature and pressure levels, supercritical carbon dioxide (scCO₂) is the most widely used supercritical fluid in the supercritical fluid extraction (SFE) technique. Alizarin was extracted from madder roots (Rubia tinctorum) using scCO₂ under different conditions of co-solvent ratio (0-50%), temperature (45-95 °C), pressure (150-250 bar), extraction time (15-120 min), and flow rate (5-9 mL/min). Based on alizarin recovery and minimization of environmental risk, the optimum conditions were determined. SFE was optimum at 90% CO₂:10% methanol (Me), 65 °C, 250 bar, 45 min, and 9 mL/min. The alizarin recovery, and its content in R. tinctorum extract (RE) under the optimum conditions were 1.34 g/kg roots, and 6.42%, respectively. Using conventional dyeing methods, wool fabrics were dyed with RE at different concentrations (2-6%). Various types of mordants were also used in the dyeing process, including chemical and bio-mordants. Color and fastness properties of dyed wool fabrics were evaluated based on RE concentration and mordant type. A higher RE concentration and the use of mordants, specifically Punica granatum (P. granatum) peels, increased the color characteristics. RE and dyed fabrics exhibited good antibacterial activity against the tested bacterial strains, especially Pseudomonas aeruginosa and Escherichia coli.

Enhancing the Activity of Carboxymethyl Cellulase Enzyme Using Highly Stable Selenium Nanoparticles Biosynthesized by Bacillus paralicheniformis Y4

The inorganic selenium is absorbed and utilized inefficiently, and the range between toxicity and demand is narrow, so the application is strictly limited. Selenium nanoparticles have higher bioactivity and biosafety properties, including increased antioxidant and anticancer properties. Thus, producing and applying eco-friendly, non-toxic selenium nanoparticles in feed additives is crucial. Bacillus paralicheniformis Y4 was investigated for its potential ability to produce selenium nanoparticles and the activity of carboxymethyl cellulases. The selenium nanoparticles were characterized using zeta potential analyses, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Additionally, evaluations of the anti-α-glucosidase activity and the antioxidant activity of the selenium nanoparticles and the ethyl acetate extracts of Y4 were conducted. B. paralicheniformis Y4 exhibited high selenite tolerance of 400 mM and the selenium nanoparticles had an average particle size of 80 nm with a zeta potential value of −35.8 mV at a pH of 7.0, suggesting that the particles are relatively stable against aggregation. After 72 h of incubation with 5 mM selenite, B. paralicheniformis Y4 was able to reduce it by 76.4%, yielding red spherical bio-derived selenium nanoparticles and increasing the carboxymethyl cellulase activity by 1.49 times to 8.96 U/mL. For the first time, this study reports that the carboxymethyl cellulase activity of Bacillus paralicheniforis was greatly enhanced by selenite. The results also indicated that B. paralicheniformis Y4 could be capable of ecologically removing selenite from contaminated sites and has great potential for producing selenium nanoparticles as feed additives to enhance the added value of agricultural products.

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.