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Bioactive nanocomposites were constructed, containing chitosan (Cht), extracted from shrimps’ wastes, and transformed into nanoparticles (NPs) using ionic-gelation. Selenium NPs (Se-NPs) were phytosynthesized using cinnamon (Cinnamomum zeylanicum) bark extract (CIE), characterized and evaluated with Cht-NPs as antimicrobial composites against bacterial food-borne pathogens “Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes” and as potential edible coating (EC) basements. The CIE-phytosynthesized Se-NPs had well-distributed and spherical shapes with 23.2 nm mean diameter. The CIE, CIE/Se-NPs, and innovative CIE/Se/Cht-NP composites exhibited distinguished antibacterial actions toward the entire screened pathogens; CIE/Se/Cht-NP composite was significantly the most potent. The formulated ECs from CIE/Se/Cht-NP nanocomposites had matching antibacterial manner, which was strengthened with CIE/Se-NP percentage increments. Scanning micrographs indicated the attachment of CIE/Se-NPs to bacterial cells to cause their complete lysis and death after 10 h of exposure. CIE/Se/Cht-NP composites are proposed as effectual control agents toward food-borne pathogens using efficient biological carriers and eco-friendly phytosynthesis protocol.

Cadmium-tolerant (6 mM) Aspergillus niger (RCMB 002002) biomass was challenged with aqueous cadmium chloride (1 mM) followed by sodium sulfide (9 mM) at 37°C for 96 h under shaking conditions (200 rpm), resulting in the formation of highly stable polydispersed cadmium sulfide nanoparticles (CdSNPs). Scanning electron microscopy revealed the presence of spherical particles measuring approximately 5 nm. A light scattering detector (LSD) showed that 100% of the CSNPs measure from 2.7 to 7.5 nm. Structural analyses by both powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed the presence of cubic CdS nanoparticles (CdSNPs) capped with fungal proteins. These CdSNPs showed emission spectra with a broad fluorescence peak at 420 nm and UV absorption onset at 430 nm that shifted to 445 nm after three months of incubation. The CdSNPs showed antimicrobial activity against E. coli, Pseudomonas vulgaris, Staphylococcus aureus, and Bacillus subtilis, and no antimicrobial activity was detected against Candida albicans. The biosynthesized CdSNPs have cytotoxic activity, with 50% inhibitory concentrations (IC50) of 190 μg mL-1 against MCF7, 246 μg mL-1 against PC3, and 149 μg mL-1 against A549 cell lines.

Helicobacter pylori can infect most people worldwide to cause hazardous consequences to health; the bacteria could not easily be controlled or disinfected. Toward exploring of innovative biocidal nanoformulations to control H. pylori , broccoli seeds ( Brassica oleracea var. italica ) mucilage (MBS) was employed for biosynthesizing selenium nanoparticles (MBS/SeNPs), which was intermingled with chitosan nanoparticles (NCT) to generate bioactive nanocomposites for suppressing H. pylori . The MBS could effectually generate and stabilize SeNPs with 13.61 nm mean diameter, where NCT had 338.52 nm mean diameter and positively charged (+ 39.62 mV). The cross-linkages between NCT-MBS-SeNPs were verified via infrared analysis and the nanocomposites from NCT:MBS/SeNPs at 1:2 (T1), 1:1 (T2) and 2:1 (T3) ratios had mean diameters of 204, 132 and 159 nm, respectively. The entire nanomaterials/composites exhibited potent anti- H. pylori activities using various assaying methods; the T2 nanocomposite was the utmost bactericidal agent with 0.08–0.10 mg/L minimal concentration and 25.9–27.3 mm inhibition zones. The scanning microscopy displayed the ability of nanocomposite to attach the bacterial cells, disrupt their membranes, and completely lyse them within 10 h. The NCT/MBS/SeNPs nanocomposites provided effectual innovative approach to control H. pylori .

Shrimps are highly valuable and perishable foodstuff that could be rapidly spoiled. Chitosan (Cht) was extracted and transformed into nanoparticles (NPs) via ionic gelation and fortified with cloves (Syzygium aromaticum) buds extract (CLE) for usage as antimicrobial composites against food-borne bacterial pathogens (Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus) and as edible coating (EC) for shrimp (Fenneropenaeus indicus) biopreservation throughout refrigerated storage. The synthesized CLE/Cht-NPs were electrostatically cross-linked and appeared with spherical shapes and homogenized distribution, with 159.4 nm mean size diameter and positive charge of 17.4 mV. The entire agents (Cht-NPs, CLE, and CLE/Cht-NPs) exhibited remarkable antibacterial activities toward all food-borne pathogens; CLE/Cht-NPs were significantly the most forceful. The scanning micrographs of treated S. typhimurium with CLE/Cht-NPs displayed NPs ability to attach and destroy bacterial cells. The ECs-treated shrimps exhibited sharp decrease in microbial groups load (aerobic microorganisms, E. coli, Enterobacteriaceae, and staphylococci) during refrigerated storage (4 ± 1°C) for 10 days. Additionally, the sensorial attributes (appearance, odor, color, and texture) of EC-treated samples preserved their elevated qualities for storage duration. The most effective EC blend contained 1.5% from Cht/NPs and 1.0% from CLE. The CLE/Cht-NPs could be impressively recommended as effectual natural composites for shrimps’ biopreservation during cold storage.

Aiming to boost the catfish fillet quality, the consequences of their treatment with Lepidium sativum seeds mucilage (LSSM) and with LSSM-mediated selenium nanoparticles (LSSM-Se NPs) were investigated. The LSSM assessment for phenolic acids contents emphasized higher concentrations. Green-synthesized Se NPs were conjugated with LSSM to form LSSM-Se NPs and characterized; the NPs had spherical shapes, negatively charged with 15.47 nm mean diameters. Fish fillets were immersed in coating solutions for 2 min, drained, and stored for 25 days at 4°C. The fish groups (C: untreated samples, M: LSSM-treated, and G: LSSM-Se NPs treated) were assessed for their physicochemical, bacteriological, and sensorial attributes. On the 25th day, the samples’ pH values were 6.96, 6.6, and 6.3; TVB-N values were 38.8, 28.4, and 16.4 mg/100 g; TBARS values were 1.7, 0.97, and 0.68 malondialdehyde/kg; and overall acceptability scores were 3.9, 5.6, and 8.3, for C, M and G groups, respectively. At day 16, the psychrophilic bacterial count was 6.2, 4.0, and 3.6 log CFU/g for C, M, and G groups, respectively. The application of LSSM and LSSM-Se NPs is recommended to compose active coatings for quality boost and shelf-life extension of stored catfish fillet.

Zinc oxide nanoparticles (ZnONPs) were the targets of numerous biological syntheses to attain their precious values in various biomedical fields. The phycosynthesis of ZnONPs were innovatively investigated using cell-free extract of the macroalgae, Ulva fasciata Delile. The phycosynthesized U. fasciata-zinc oxide nanoparticles (UFD-ZnONPs) had 77.81 nm mean size, with flower and sphere shapes and positive zeta potential. The UFD-ZnONPs infra-red analysis indicated their basic components’ cross-linkage. The antibacterial potentialities of UFD-ZnONPs were confirmed, qualitatively and quantitatively, against foodborne microorganisms (Escherichia coli plus Staphylococcus aureus); the bactericidal action was higher for UFD-ZnONPs than the annealed phycosynthesized ZnONPs. The scanning micrographs of S. aureus and E. coli cells treated with UFD-ZnONPs indicated the severe action of nanoparticles to destroy bacterial cells in time-dependent manners. Peeled shrimps (Fenneropenaeus indicus) were biopreservated through refrigerated storage (4 °C) with UFD-ZnONPs based solution for six days. The microbial examination of UFD-ZnONPs -treated shrimps displayed decrease in microbial loads throughout the storage days. Moreover, the UFD-ZnONPs-treated shrimps showed acceptable sensorial attributes (appearance, odor, color and texture) compared to untreated shrimps. UFD-ZnONPs nanocomposite concentration of 3% and 5% could be remarkably suggested as efficient procedure for shrimps’ biopreservation during refrigerated storage regarding sensorial quality and microbial profile of product.

Here we report the phycosynthesis of silver nanoparticles (Ag-NPs), using Codium capitatum extract, and the synthesis of fungal chitosan nanoparticles (FC-NPs), using extracted chitosan from Aspergillus niger mycelia. Then nanoconjugates from FC/Ag-NPs were produced and evaluated. The synthesized NPs had mean particles' size diameters of 37.2, 68.4 and 79.6 nm for Ag-NPs, FC-NPs and FC/Ag-NPs, respectively. The FTIR (Fourier-transform infrared spectroscopy) analysis of synthesized NPs indicated their cross-linkage and interaction. The antibacterial activity of each type of NPs was assayed against drug resistant pathogens of Salmonella Typhimurium and Staphylococcus aureus. All NPs had powerful inhibitory effect and FC/Ag nanoconjugates had stronger activity than the other types. Scanning micrographs of FC/Ag-NPs treated S. Typhimurium elucidated vigorous alterations in cell surfaces and lethal damage to bacterial structure after 8 h of treatment. The nanoconjugates form FC-NPs and Ag-NPs had minute particle size with increasing bioactivity as antimicrobial agents to control drug resistant bacterial pathogens, which recommends their further exploration for topical applications in biomedical sectors.

The surge in global utilization of petroleum-based plastics, which notably heightened during the COVID-19 pandemic, has substantially increased its harm to ecosystems. Considering the escalating environmental impact, a pivotal shift towards bioplastics usage is imperative. Exploring and implementing bioplastics as a viable alternative could mitigate the ecological burden posed by traditional plastics. Macroalgae is a potential feedstock for the production of bioplastics due to its abundance, fast growth, and high cellulose and sugar content. Researchers have recently explored various methods for extracting and converting macroalgae into bioplastic. Some of the key challenges in the production of macroalgae bioplastics are the high costs of large-scale production and the need to optimize the extraction and conversion processes to obtain high-quality bioplastics. However, the potential benefits of using macroalgae for bioplastic production include reducing plastic waste and greenhouse gas emissions, using healthier materials in various life practices, and developing a promising area for future research and development. Also, bioplastic provides job opportunities in free enterprise and contributes to various applications such as packaging, medical devices, electronics, textiles, and cosmetics. The presented review aims to discuss the problem of petroleum-based plastic, bioplastic extraction from macroalgae, bioplastic properties, biodegradability, its various applications, and its production challenges.

The antibacterial performance of sol-gel-derived inorganic-organic hybrid polymers filled with ZnO nanoparticles-chitosan against a gram-negative bacterium Escherichia coli and a gram-positive Micrococcus luteus has been investigated. Three different molecular weights (MW) of chitosan (CTS) 1.36 · 105, 2.2 · 105, and 3.0 · 105 Da with equal degree of deacetylation (DD, 85%) (coded as S 85-60, He 85-250, and He 85-500) with equal degree of deacetylation (DD, 85%) were examined. ZnO was prepared by the base hydrolysis of zinc acetate in isopropanol using lithium hydroxide (LiOH · H2O) to hydrolyze the precursor. Sol-gel-based inorganic-organic hybrid polymers were modified with these oxides and were applied to cellulosic cotton (100%) and cotton/polyester (65/35%) fabrics. Inorganic-organic hybrids polymers were based on 3-glycidyloxypropyltrimethoxysilane (GPTMS). Bacteriological tests were performed in nutrient agar media on solid agar plates and in liquid broth systems using ZnO nanoparticles with average particle size of (40 nm). Our study showed the enhanced antibacterial activity of ZnO nanoparticles chitosan (different MW) of against a gram-negative bacterium Escherichia coli DSMZ 498 and a gram-positive Micrococcus luteus ATCC 9341 in repeated experiments. The antibacterial activity of textile treated with ZnO nanoparticles chitosan increases with decreasing the molecular weight of chitosan.