Enhanced catalytic and antibacterial efficiency of biosynthesized Convolvulus fruticosus extract capped gold nanoparticles (CFE@AuNPs)

Bio-fabrication of chitosan-stabilized magnesium oxide nanomaterials: Investigation of photocatalytic, in vitro cytotoxicity activities and apoptosis in oral squamous carcinoma cells

A bio-fabrication approach is a novel way to develop chitosan-stabilized magnesium oxide nanomaterials (cMgO-NMs). The process involves utilizing polymeric chitosan as the reducing and stabilizing agent. The characteristics of the developed cMgO-NMs were determined using various spectroscopical techniques. Fourier-transform infrared spectroscopy (FTIR) analysis revealed crucial functional groups, Ultraviolet-visible spectroscopy (UV-Vis) spectrum showed nanomaterial development with a peak at 358 nm, and powder X-ray diffraction (PXRD) pattern confirmed a pure cubic crystalline structure. Field emission scanning electron microscopy (FE-SEM) images depicted spherical shape, while energy dispersive X-ray analysis (EDX) confirmed Mg presence. The photocatalytic efficacy of these nanomaterials in degrading dye methylene blue (MB) was examined, and the findings demonstrated the remarkable proficiency of cMgO-NMs in breaking down the dye. The cytotoxic effects of cMgO-NMs were assessed for the first time on PCI-9A and PCI-13 cancer cell lines, yielding an IC50 value of 51 μg/mL and 42 μg/mL. The cMgO-NMs treated PCI-9A and PCI-13 cancer cells morphological changes were observed via acridine orange and ethidium bromide and DAPI staining assay, and apoptotic mode of cell death was examined through flow cytometry and comet assay. Polymeric chitosan proved effective in extensive cMgO-NMs production, showing potential as an anticancer drug, although requiring further preclinical development.

Synthesis, characterization, anticancer, antibacterial and antifungal activities of nanocomposite based on tertiary metal oxide Fe2O3@CuO@ZnONPs, starch, ethylcellulose and collagen

This study aimed to synthesize a nanocomposite based on tertiary metal oxide Fe2O3@CuO@ZnONPs, starch, ethylcellulose, and collagen, as well as evaluate its biological activities. The prepared nanocomposites were characterized using physicochemical analysis, which included FTIR, XRD, and DLS. Additionally, topographical analysis using FI-SEM, EDX, mapping, HR-TEM, and SAED affirmed the molecular structure and nanosized of formulated nanocomposites. Moreover, DLS performed a size of free nanocomposite (Bnanocomp) and trimetallic loaded nanocomposite (Lnanocomp) as 158 and 105 nm, respectively. The synthesized loaded nanocomposite with metal oxides (Lnanocomp) was assessed for cytotoxicity on normal and cancerous cell lines. Results revealed that the IC50 of Lnanocomp toward Wi-38 normal cell line was 196.4 μg/mL; this confirms that Lnanocomp is non-toxic and safe in use. Moreover, Lnanocomp displayed anticancer activity against Hep-G2 with IC50 53.7 μg/mL. Furthermore, Lnanocomp displayed potential antibacterial activity toward E. coli, P. aeruginosa, S. typhimurium, S. aureus, and B. subtilis with MICs 50, 50, 12.5, 50, and 25 μg/mL, respectively. Also, Lnanocomp exhibited antifungal activity where MIC was 200, 50, and 100 μg/mL toward C. albicans, A. fumigatus, and A. brasilienisis respectively. In conclusion, the prepared Fe2O3@CuO@ZnONPs-based nanocomposite shows promising synergetic antibacterial, antifungal, and anticancer activities with state biocompatibility.

Physalis peruviana heteropolysaccharide-conjugated selenium nanoparticles: Preparation, characterization, and promising applications in cancer therapy

Selenium nanoparticles (SeNPs) have attracted considerable attention in the field of cancer therapy due to their remarkable biological activities and advantageous nanoscale properties. However, their inherent instability presents a considerable challenge for broader applications. To address this issue, the heteropolysaccharide extracted from golden berries (the fruits of Physalis peruviana), designated as DLG, was utilized to synthesize heteropolysaccharide-conjugated selenium nanoparticles, named DLG-SeNP3. Subsequent characterization showed that the nanoparticles DLG-SeNP3 were spherical, with an average particle size of 77 nm, a zeta potential of -14.4 mV, and excellent stability under physiological pH conditions. Further biological investigations showed that DLG-SeNP3 effectively inhibited tumor cell proliferation, exhibiting an IC50 value of 41.60 μg/mL against A549 cells, and induced apoptosis, with a proportion of 31.30 % at 100 μg/mL. Moreover, in vivo experiments demonstrated that DLG-SeNP3 not only inhibited angiogenesis, resulting in a 26.51 % decrease at 2 μg/mL, but also suppressed tumor growth and invasion, with reductions of 76.90 % and 66.67 % in the intensity and foci of red fluorescence, respectively, at 2 μg/mL. In conclusion, DLG-SeNP3, stabilized with polysaccharides derived from golden berries, shows promising potential for application in cancer treatment.

Biosynthesis of a range of ZnO nanoparticles utilising Salvia hispanica L. seed extract and evaluation of their bioactivity

Zinc deficiency precipitates considerable health problems in developing countries, affecting development, growth, and immunological function. The main issue is that zinc exhibits limited bioavailability in diets, sometimes compounded by the high concentration of phytate molecules in staple foods, which impedes zinc absorption. Nanoparticles offer a promising approach to improve zinc bioavailability and address deficiency through the application of advanced agricultural techniques. The study introduces a novel method for synthesizing Zinc oxide (ZnO) biometallic nanoparticles by employing aqueous extracts of Salvia hispanica L. (Chia seed) as a reducing and capping agent in an environmentally sustainable way. Their active phytoconstituents acted as a stabilising agent and facilitated the conversion of ionic zinc (Zn2+) into elemental zinc. The study synthesized the diverse forms of zinc oxide nanoparticles (NP-α, NP-β, NP-γ, NP-δ, NP-ε, and NP-η) utilising various molar concentrations (0.5mM, 1.0mM, 3.0mM, 5.0mM, 7.0mM, and 9.0mM) of a precursor solution, zinc nitrate [(ZnNO3)2]. The synthesized NPs were evaluated using UV-Vis spectroscopy, FTIR spectroscopy, XRD, SEM, EDX, TEM, SAED, and HR-TEM methods to determine their characteristics. The standard particle size varies from 40 to 80 nm, exhibiting a consistent hexagonal morphology and a polydispersed characteristic with minimal size fluctuation. The molarity substantially influenced the shape of NPs, particularly concerning their size and surface area. An in vitro evaluation was performed to investigate the antibacterial activity against Staphylococcus aureus and the possible degradation of the hazardous dye Congo red. The particles exhibited antibacterial efficacy at a concentration of 40 ppm ZnO, antidiabetic qualities at 10 µl/ml ZnONPs, antioxidant activity at concentrations ranging from 100 to 900 µl/ml showing 89.47 ± 0.022 µg AAE/mg, maximum activity with total antioxidant capacity (TAC), and dye degradation potential at a concentration of 50 mg ZnONPs, revealed 50.78% CR degradation after 90 min of irradiation. Additionally, it had significant inhibitory effects on the enzymes α-amylase (72.93%) and α-glucosidase (60.48%) by ZnONP-η. The efficacy of dye degradation with synthesized nanoparticles seems to enhance with increased particle sizes and reduced specific surface areas. The antioxidant, antidiabetic, and catalytic capabilities improved with an increase in particle size. Nevertheless, it was found that an increase in particle size corresponded with a substantial reduction in antibacterial activity. The study presents an efficient approach for the eco-friendly synthesis of ZnONPs, highlighting their significant potential for many biological applications.

The prospect of using nanotechnology to prevent and treat infections caused by Listeria monocytogenes

Listeria monocytogenes (L. monocytogenes) is an opportunistic intracellular pathogen that causes listeriosis in human and leads to high mortality rate. L. monocytogenes is resistant to various antibiotics due to its ability to form biofilm. Designing a new generation of antibiotics is a very expensive and time-consuming process. Moreover, the protection of antibiotics via drug delivery system can promote their effectiveness and bioavailability. Nanomedicine can be a promising tool for treating intracellular bacteria and preventing the recurrence of infections. Nanocarriers can be employed as antibacterial agents or as a carrier for antibacterial agents. In the present review, the application of nanotechnology has been discussed for the prevention and treatment of Listeria infection. According to the studies, the application of nanomaterials can be a potential strategy to eradicate infections caused by L. monocytogenes.

Studying the properties of green synthesized silver oxide nanoparticles in the application of organic dye degradation under visible light

In present study the green synthesis of silver oxide nanoparticles has been effectively achieved using novel plant extract Phragmanthera Macrosolen. This method provides sustainable alternative for nanoparticle synthesis, demonstrating the potential of Phragmanthera Macrosolen as a reducing and stabilizing agent in the production of Ag2O NPs. The synthesized nanoparticles were characterized for their structural, morphological, and optical properties, confirming their successful formation and potential applications in various fields. The effects of different pH values and annealing temperature of the samples on the properties of Ag2O NPs formations, as well as photo-catalytic activities towards Toluidine Blue dye degradations, were studied. Powder XRD reveals that the crystallite natures of Ag2O NPs a long with crystalline size ranges from 25.85 to 35.90 nm. FIB-SEM and HR-TEM images displayed that the Ag2O NPs as spherical shapes. UV-vis spectroscopy displayed that Ag2O NPs belong to a direct-band gap of 2.1-2.6 eV. FTIR- study shown that the green synthesized Ag2O NPs may be steadied via the interfaces of -OH as well as C = O groups in the carbohydrate, flavonoid, tannin, as well as phenolic acid existing in P. macrosolen L. leaf. The chemical states, electron-hole recombinations and purity of Ag and O in the synthesized Ag2O NPs were confirmed through X-ray Photoelectron Spectroscopy (XPS) and PL analysis respectively. Fascinatingly, the synthesized Ag2O NPs at pH 12 displayed high photo-catalytic degradations for TB dyes. The photo-catalytic degradations of the TB dyes were monitored spectro-photo-metrically in wave-length ranges of 200-900 nm, as well as high efficiency (98.50%) with half-life of 9.5798 min and kinetic rate constant of 0.07234 min-1, was obtained after 45 min of reactions. From this study, it can be concluded that Ag2O NPs synthesized from Phragmanthera Macrosolen aqueous extract are promising in the remediation of environmental pollution and water treatment. In this light, the study reports that Phragmanthera Macrosolen green synthesis of Ag2O NPs can effectively address environmental pollution in cost-effective, eco-friendly, and sustainable ways.

Exploring structural and optical properties of iodine-doped TiO2 nanoparticles in Rhodamine-B dye degradation: Experimental and theoretical investigation

Energy conversion and pollutant degradation are critical for advancing sustainable technologies, yet they often encounter challenges related to charge recombination and efficiency limitations. This study explores iodine-doped TiO2 nanoparticles as a potential solution for enhancing both energy conversion and pollutant degradation. The nanoparticles were synthesized via the sol-gel method with varying iodine precursor concentrations (0.025-0.1 M) and were characterized for their structural, compositional, and optical properties, particularly in relation to their photocatalytic performance in Rhodamine-B dye degradation. X-ray diffraction confirmed a tetragonal anatase crystal structure, with the average crystallite size decreasing from 10.06 nm to 8.82 nm with increase in iodine concentration. Selected area electron diffraction patterns verified the polycrystalline nature of the nanoparticles. Dynamic light scattering analysis showed hydrodynamic radii ranging from 95 to 125 nm. Fourier-transform infrared spectroscopy identified metal-oxygen vibrations at 441 cm⁻1, and electron microscopy confirmed the spherical morphology of the nanoparticles. Elemental analysis detected the presence of Ti, O, and I in the samples. Diffuse reflectance spectroscopy indicated the optical absorption edges for the doped samples in the visible region from which the corresponding band gap values were deduced. Photoluminescence spectroscopy revealed that the sample with 0.1 M iodine exhibit the lowest emission intensity, suggesting reduced charge recombination. Notably, 0.1 M iodine doped TiO2 samples demonstrated the highest photocatalytic efficiency, achieving 82.36% degradation of Rhodamine-B dye within 140 min under visible light. Additionally, ab-initio density functional theory calculations were performed to investigate the structural, optical, and adsorption properties of TiO2, iodine-doped TiO2, Rhodamine-B, and their composites, providing further insight into the enhanced photocatalytic activity observed in the experiments.

Alkaline protease functionalized hydrothermal synthesis of novel gold nanoparticles (ALPs-AuNPs): A new entry in photocatalytic and biological applications

Researchers are consistently investigating novel and distinctive methods and materials that are compatible for human life and environmental conditions This study aimed to synthesize gold nanoparticles (ALPs-AuNPs) using for the first time an alkaline protease (ALPs) derived from Phalaris minor seed extract. A series of physicochemical techniques were used to inquire the formation, size, shape and crystalline nature of ALPs-AuNPs. The nanoparticles' ability to degrade methylene blue (MB) through photocatalysis under visible light irradiation was assessed. The findings demonstrated that ALPs-AuNPs exhibited remarkable efficacy by destroying 100 % of MB within a mere 30-minute irradiation period. In addition, the ALPs-AuNPs demonstrated remarkable effectiveness in inhibiting the growth of gram-positive (S. aureus) and gram-negative (E. coli) bacteria. The inhibition zones examined against the two bacterial strains were 23(±0.3) mm and 19(±0.4); 13(±0.3) mm and 11(±0.5) mm under light and dark conditions respectively. The ALPs-AuNPs exhibited significant antioxidant activity by effectively scavenging 88 % of stable and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. As a result, the findings demonstrated that the environmentally friendly ALPs-AuNPs showed a strong potential for MB degradation and bacterial pathogen treatment.

Cellulase activity of a novel bacterial strain Arthrobacter woluwensis TDS9: its application on bioconversion of paper mill sludge

Background

Lignocellulosic biomasses produced from agriculture and forest-based industries are the cheapest or negative-cost biomass with a great potential for biotransformation to value-added bioproducts. Paper mill sludge, an important lignocellulosic biomass creates an environmental threat, which requires financial input for disposal. Thus, this study was aimed to isolate a novel bacterial strain capable of degrading cellulosic biomass including paper mill sludge to produce reducing sugar and other value-added bioproducts.

Results

A novel bacterial strain Arthrobacter woluwensis TDS9 isolated from the soil was screened for its cellulolytic activity using carboxymethyl cellulose (CMC) as the sole carbon source. The incubation period, temperature, pH, carbon, and nitrogen sources are the most important factors ruling the CMCase and sugar productions of the strain A. woluwensis TDS9, and an alkaline pH (pH 8.0) led to enhanced sugar production up to 1100.09 μg/mL after 72 h of incubation at 25°C in a medium containing 1.5% CMC and 1.25% beef extract. The optimal conditions for maximum CMCase activity were defined, and the potassium ion boosted the CMCase activity up to 1.06 U/mL when the enzymatic reaction was performed for 30 min at 50°C and pH 8 using CMC as a substrate. Moreover, the strain A. woluwensis TDS9 produced 433.33 μg/mL reducing sugar from 1% pretreated paper mill sludge. Significant alterations in the structural arrangement of cellulosic fiber of paper mill sludge observed under microscope after each step of chemical treatment process helped for loosening the cellulose fibers and increased the saccharification for enzymatic hydrolysis. Endoglucanase IV (33 KDa) and beta-glucosidase II (53 KDa) were identified in crude enzyme based on the zymogram analysis and substrate specificity.

Conclusions

The research has for the first time proved that this A. woluwensis TDS9 strain can efficiently convert cellulose. Therefore, the strain TDS9 could be a potential candidate for cellulase production in an industrial biotransformation process of paper mill sludge to produce reducing sugar. This sugar stream can be further used as a substrate to produce biofuels and other organic acids using another microorganism, which represents a greener alternative to add value to the paper production helping paper mill industries.

A Critical Review of the Antimicrobial and Antibiofilm Activities of Green-Synthesized Plant-Based Metallic Nanoparticles

Metallic nanoparticles (MNPs) produced by green synthesis using plant extracts have attracted huge interest in the scientific community due to their excellent antibacterial, antifungal and antibiofilm activities. To evaluate these pharmacological properties, several methods or protocols have been successfully developed and implemented. Although these protocols were mostly inspired by the guidelines from national and international regulatory bodies, they suffer from a glaring absence of standardization of the experimental conditions. This situation leads to a lack of reproducibility and comparability of data from different study settings. To minimize these problems, guidelines for the antimicrobial and antibiofilm evaluation of MNPs should be developed by specialists in the field. Being aware of the immensity of the workload and the efforts required to achieve this, we set out to undertake a meticulous literature review of different experimental protocols and laboratory conditions used for the antimicrobial and antibiofilm evaluation of MNPs that could be used as a basis for future guidelines. This review also brings together all the discrepancies resulting from the different experimental designs and emphasizes their impact on the biological activities as well as their interpretation. Finally, the paper proposes a general overview that requires extensive experimental investigations to set the stage for the future development of effective antimicrobial MNPs using green synthesis.

Construction of a Silver Nanoparticle Complex and its Application in Cancer Treatment

Nanomedicine has been used in tumor treatment and research due to its advantages of targeting, controlled release and high absorption rate. Silver nanoparticle (AgNPs), with the advantages of small particle size, and large specific surface area, are of great potential value in suppressing and killing cancer cells. Methods: AgNPs–polyethyleneimine (PEI) –folate (FA) (AgNPs–PF) were synthesised and characterised by several analytical techniques. The ovarian cancer cell line Skov3 was used as the cell model to detect the tumor treatment activity of AgNPs, AgNPs–PF and AgNPs+ AgNPs–PF. Results: Results shown that AgNPs–PF were successfully constructed with uniform particle size of 50–70 nm. AgNPs, AgNPs–PF, AgNPs–PF+ AgNPs all showed a certain ability to inhibit cancer cell proliferation, increase reactive oxygen species and decrease the mitochondrial membrane potential. All AgNPs, AgNPs–PF, AgNPs+ AgNPs–PF promoted DNA damage in Skov3 cells, accompanied by the generation of histone RAD51 and γ-H2AX site, and eventually leading to the apoptosis of Skov3 cells. The combination of AgNPs–PF and AgNPs had a more pronounced effect than either material alone. Conclusion: This study is to report that the combination of AgNPs+ AgNPs–PF can cause stronger cytotoxicity and induce significantly greater cell death compared to AgNPs or AgNPs–PF alone in Skov3 cells. Therefore, the combined application of drugs could be the best way to cancer treatment.

Enhancing Antioxidant Activities and Anti-Aging Effect of Rice Stem Cell Extracts by Plasma Treatment

Plant-derived substances exhibit antioxidant and antibacterial activities and have been proven to have beneficial effects in wound healing and skin regeneration. Plant stem cells have recently received much attention as research materials in cosmetic development because they promote regeneration after damage. In this paper, we demonstrate for the first time that the plasma treatment of stem cells obtained from rice-seed embryos can be effective in enhancing antioxidant activity and in regenerating human skin. We investigated this potential utilizing micro-DBD (Dielectric Barrier Discharge) plasma as a pretreatment technique to enhance the vitality and functional activity of rice stem cells. The results of the cell culture experiments show that plasma-treated rice stem cell extracts (RSCE) have promising antioxidant and anti-skin aging activities. The results of quantitative real-time PCR (qRT-PCR) for major antioxidant enzymes and anti-aging genes confirm that the plasma technique used in the pretreatment of RSCE was able to enhance cell activities in skin regeneration, including cell survival, proliferation, and collagen enhancement for Human Fibroblast (HFB) degraded by oxidative stress. These results show that the relatively low energy of less than 300 W and an amount of NOx-based reactive nitrogen species (RNS) from plasma discharge of about 3 μL/L were the key factors and that RSCE, of which the antioxidant activity was enhanced by plasma treatment, appeared to be a major contributor to the protective effect of HFB against oxidative stress. Plasma-treated RSCE induced excellent anti-aging properties by stimulating HFB to promote collagen synthesis, thereby promoting skin regeneration. These properties can protect the skin from various oxidative stresses. This study demonstrates that plasma-treated extracts of stem cells derived from rice-seed embryos have an excellent regenerative effect on aging-treated HFB. Our results demonstrate the potential utility of plasma-treated RSCE as a skin anti-aging agent in cosmeceutical formulations for the first time.

AuNPs/NiFe-LDHs-assisted laser desorption/ionization mass spectrometry for efficient analysis of metronidazole and its metabolites in water samples

Gold nanoparticles (AuNPs) have been widely used as laser desorption/ionization mass spectrometry (LDI-MS) nanomaterials for the analysis of low-molecular-weight samples. Nickel/iron-layered double hydroxides (NiFe-LDHs) nanosheets can support the anchoring of AuNPs and enhance the ability of desorption/ionization. Their hybrid nanocomposites are expected to produce synergistic effects to improve the performance of LDI-MS. In this work, a novel AuNPs/NiFe-LDHs nanomaterial was synthesized by self-assembly method and characterized based on TEM, SEM, XPS, UV-vis and FTIR-ATR. AuNPs/NiFe-LDHs assisted LDI-TOF MS exhibited higher peak intensity and lower background noise compared with conventional organic matrices. Furthermore, excellent salt and protein tolerance, good repeatability and quantification were observed when MNZ and its metabolites were detected in the range of 1-50 ng·μL^-1 (R² > 0.98), with LODs and LOQs of 0.5 ng·μL^-1 and 1 ng·μL^-1, respectively. This nanocomposite could also be used for the analysis of some other small molecules, such as antibiotics, sugars, amino acids and pesticides, demonstrating the potential to detect a variety of environmental chemicals. Taken together, the developed method combined the advantages of two nanomaterials and can provide rapid and accurate analysis of MNZ and its metabolites in water samples, as well as some other small molecules.

Facile Synthesis of Gold Nanoparticles for Anticancer, Antioxidant Applications, and Photocatalytic Degradation of Toxic Organic Pollutants

In the current study, a facile, rapid, and ecologically safe photosynthesis of gold nanoparticles (AuNPs) that remained stable for 3 months is reported to advocate the main aspects of green chemistry, such as safer solvents and auxiliaries, and the use of renewable feedstock. Zi-AuNPs were phytosynthesized by the aqueous extract of Ziziphus spina-christi leaves, and numerous techniques were employed for their characterization. The results demonstrated the successful phytofabrication of crystalline AuNPs with brownish-black color, spherical nanoparticles with a size between 0 and 10 nm, a plasmon peak at 540 nm, and a surface charge of -25.7 mV. Zi-AuNPs showed an effective photodegradation efficiency (81.14%) against malachite green and a good recycling capacity of 69.2% after five cycles of regeneration. The cytotoxicity test by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay signified a high anticancer efficiency for both Zi-AuNPs and Z. spina-christi extract against human breast cancer cells (MCF7 cell line) with IC₅₀'s of 48 and 40.25 μg/mL, respectively. Highly efficient antioxidant capabilities were proven with 2,2-diphenyl-1-picrylhydrazyl (DPPH) removal percentages of 67.5% for Zi-AuNPs and 92.34% for Z. spina-christi extract.

Comparison of Phytochemical Contents, Antioxidant and Antibacterial Activities of Various Solvent Extracts Obtained from 'Maluma' Avocado Pulp Powder

Although avocado is a superfood rich in phytochemicals with high antioxidant activities, studies on the antibacterial properties of its pulp are limited, except for seed and peel portions. In this study, three types of solvent (acetone, methanol, and diethyl ether) were used to obtain the extracts from "Maluma" avocado pulp powder prepared by infrared drying. The extracts were analyzed for total polyphenols, phytopigments (total chlorophylls and carotenoids), antioxidant activities (ferric-reducing antioxidant power (FRAP), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays), and antibacterial activities against seven pathogens (Shigella sonnei ATCC 9290, Escherichia coli ATCC 8739, Salmonella typhi ATCC 6539, Vibrio parahaemolyticus ATCC 17802, Proteus mirabilis ATCC 25933, Staphylococcus aureus ATCC 6538, and Bacillus cereus ATCC 11778). The results showed that the acetone solvent could extract the highest polyphenols and chlorophylls with the highest antioxidant activity in terms of ABTS and DPPH assays. In contrast, diethyl ether exhibited the most significant content of carotenoids and FRAP values. However, the methanol extract was the best solvent, exerting the strongest antibacterial and meaningful antioxidant activities. For the bacterial activities, Gram-positive pathogens (Bacillus cereus and Staphylococcus aureus) were inhibited more efficiently by avocado extracts than Gram-negative bacteria. Therefore, the extracts from avocado powder showed great potential for applications in food processing and preservation, pharmaceuticals, and cosmetics.

Synthesis of silver nanoparticles using Ziziphus nummularia leaf extract and evaluation of their antimicrobial, antioxidant, cytotoxic and genotoxic potential (4-in-1 system)

This study reports the synthesis of silver nanoparticles (AgNPs) from silver nitrate by leaf extract of a medicinal plant Ziziphus nummularia. The leaf extract acts as a reducing and stabilizing agent for the formation of nanoparticles. The green synthesized AgNPs were characterized by ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FITR) spectroscopy, Thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) analysis and evaluated their antimicrobial, antioxidant, cytotoxic and genotoxic potential. The UV-Vis spectroscopy showed a characteristic absorption peak at 430 nm due to surface plasma resonance. TEM analysis showed that synthesized AgNPs were spherical and oval with an average size of 25.96 nm. AgNPs showed effective antimicrobial activity (lowest MIC-0.625 µg/mL against Escherichia coli), synergistic antimicrobial activity (lowest ΣFIC 0.09 with chlormaphenicol against Corynebacterium rubrum) and antibiofilm activity. AgNPs showed strong DPPH activity with IC50 - 520 µg/mL and ABTS activity IC50 - 55 µg/mL and reducing capacity assessment. In vitro cytotoxic effect was evaluated by MTT assay against HeLa cells, breast cells and fibroblast cells. Genotoxic effect was evaluated by comet assay. AgNPs displayed dose-dependent cytotoxic and genotoxic effect. Our findings indicated that synthesized AgNPs could be considered as multifunctional and have great potential for use in biomedical applications.HighlightsSilver nanoparticles were synthesized using leaf extract of Ziziphus nummulariaCharacterization was done by various spectral techniquesAntimicrobial efficacy was demonstrated against an array of bacteriaAgNPs exhibited significant cytotoxic effect against HeLa cell lineAgNPs showed cytotoxicity and genotoxicity in a dose-dependent manner.

Investigation of the Characteristics and Antibacterial Activity of Polymer-Modified Copper Oxide Nanoparticles

The proliferation of drug-resistant pathogens continues to increase, giving rise to serious public health concerns. Many researchers have formulated metal oxide nanoparticles for use as novel antibacterial agents. In the present study, copper oxide (CuO) was synthesized by simple hydrothermal synthesis, and doping was performed to introduce different polymers onto the NP surface for bacteriostasis optimization. The polymer-modified CuO NPs were analyzed further with XRD, FTIR, TEM, DLS and zeta potential to study their morphology, size, and the charge of the substrate. The results indicate that polymer-modified CuO NPs had a significantly higher bacteriostatic rate than unmodified CuO NPs. In particular, polydopamine (PDA)-modified CuO (CuO-PDA) NPs, which carry a weakly negative surface charge, exhibited excellent antibacterial effects, with a bacteriostatic rate of up to 85.8 ± 0.2% within 3 h. When compared to other polymer-modified CuO NPs, CuO-PDA NPs exhibited superior bacteriostatic activity due to their smaller size, surface charge, and favorable van der Waals interactions. This may be attributed to the fact that the CuO-PDA NPs had relatively lipophilic structures at pH 7.4, which increased their affinity for the lipopolysaccharide-containing outer membrane of the Gram-negative bacterium Escherichia coli.

Novel manganese carbon quantum dots as a nano-probe: Facile synthesis, characterization and their application in naproxen delivery (Mn/CQD/SiO2@naproxen)

This study for the first time pursues two crucial aims of using Naproxen as a non-steroidal anti-inflammatory drug in a better, non-invasive setting and introducing a simple and biocompatible nano-carrier (Mn/CQD/SiO₂) which is a magneto carbon quantum dots modified with mesoporous silica probe which can be served as a drug delivery and tracer system. SiO₂modification was doneby mesoporous silica which improves biocompatibility and provideslow cytotoxicity. Naproxen was conjugated to the nano-probe to form Mn/CQD/SiO₂@naproxen and biodistribution was investigated. Physicochemical characteristics of the Mn/CQD/SiO₂@naproxen were investigated using FT-IR, SEM, TEM, UV-Vis and BET. Antiproliferation assay using MTT assay was performed on HEK-293 cells to determine the cytotoxity of Mn/CQD/SiO₂@naproxen. Relaxivity of Mn/CQD/SiO2 was examined thereafter. To investigate the imaging capability of Mn/CQD/SiO₂@naproxen and biodistribution of Naproxen, fluorescent imaging was done. To confirm the data, then the levels of COX Gene expression was determined. The specific surface area, pore volume, and pore radius were 44.4 m²/g, 10.23 cm³/g, and 25.9 nm respectively. MTT assay showed no cytotoxicity. Relaxivity of Mn/CQD/SiO₂ was higher than conventional Gd-based contrast agent. Fluorescence imaging of Mn/CQD/SiO₂@naproxen showed the biodistribution of naproxen. COX Gene expression confirmed the biodistribution data. By increasing the accumulation in liver COX production reduced. All in all, unique features of Mn/CQD/SiO₂ including biocompatibility, low toxicity, magnetic and fluorescence properties showed that it can be used in biomedical sciences.

Novel Dy2O3/ZnO-Au ternary nanocomposites: Green synthesis using pomegranate fruit extract, characterization and their photocatalytic and antibacterial properties

In this study for the first time, high efficient, eco-friendly and novel Dy₂O₃/ZnO-Au ternary nanocomposites (Dy/ZnO-AuNCs) were prepared in presence of pomegranate fruit (PF) extract as capping and reducing agents (Dy/ZnO-AuNCs@PF). The influence of various parameters such as basic agents, reducing agents, sonication power, and sonication time were performed to reach the optimum condition. The formation of the products was characterized by FT-IR, HRTEM, XRD, FE-SEM, TEM, EDX and DRS techniques. The XRD and TEM analysis showed that the morphology and crystallite size of nanocomposites were spherical morphology and 85-90 nm, respectively. The obtained Dy/ZnO-AuNCs@PF were investigated as a nanocatalyst for degradation of erythrosine (ES) as anionic dye and basic violet 10 (BV10) as cationic dye under UV and visible light irradiations. The Dy/ZnO-AuNCs@PF exhibited higher photodegradation against ES (89.6%) and BV10 (91.3%) than pure Dy₂O₃ (63.1% for ES, 66.5% for BV10) and Dy₂O₃/ZnO (64.5% for ES, 70.8% for BV10) under UV irradiation. It was found that gold nanoparticles have significant effect on Dy/ZnO-AuNCs@PF catalytic performance for decomposition of organic pollutants. In addition, Dy/ZnO-AuNCs@PF showed excellent in-vitro antibacterial activity against A. baumannii, S. aureus and P. mirabilis with MIC and MBC values of (5, 80 mg/ml), (5, 40 mg/ml) and (2.5, 20 mg/ml), respectively. Generally, according to its excellent antibacterial and catalytic activity, Dy/ZnO-AuNCs@PF can be used in biomedical and environmental applications.

Facile green synthesis of zero-valent iron nanoparticles using barberry leaf extract (GnZVI@BLE) for photocatalytic reduction of hexavalent chromium

In this study, zero-valent iron (GnZVI) was synthesized using barberry leaf extract (GnZVI@BLE). The physicochemical properties of the final products were characterized by FT-IR, SEM, TEM, and EDS techniques. The results of TEM analysis showed that the obtained iron zero-valent nanoparticles with a diameter between 20 and 40 nm and shell-core structures were successfully synthesized. The results of FT-IR confirmed the presence of various functional groups. The photocatalytic activity of synthesized nanoparticles was investigated by reduction of hexavalent chromium. Laboratory data showed that the presence of GnZVI@BLE as a nanocatalyst in the photocatalytic process could be reduction the hexavalent chromium (Cr (VI)). Photocatalytic data revealed that, when the dosage of nanoparticles was 0.675 g/L, the reduction efficiency of hexavalent chromium was 100%. The kinetics of the reaction follows a pseudo-second-order equation. The constant of reaction rate was 0.4 at pH 2 and 0.5 g/L concentration of GnZVI@BLE.

Green synthesis, in vivo and in vitro pharmacological studies of Tamarindus indica based gold nanoparticles

The current investigation aims to synthesize gold nanoparticles (AuNPs) from aqueous extract of Tamarindus indica and to evaluate the in vitro anti-bacterial and in vivo sedative and anelgescic activities of crude extract as well as synthesized AuNPs. Several methods have been reported to synthesize AuNPs; however, most of them were not ecofriendly. In the present study, the green synthesis of AuNPs has been carried out. Using the green synthesis method, AuNPs of T. indica were synthesized at room temperature (25 °C) by mixing 5 mL of HAuCl₄ (1 mM) with 1 mL of T. indica seed extract solution. This extract solution was prepared by taking 5 gm dry seeds in 100 mL of double deionized water with continuous stirring for up to 24 h at 80 °C. The stability of AuNPs was confirmed with the help of relevant experimental techniques including ultraviolet-visible (UV/Vis) showing maximum absorbance at 535-540 nm, Fourier transform infrared showing a broad signal at 3464 cm^-1 which can be attributed to either amide or hydroxyl functionalities and atomic force microscopy analysis showed that the biomaterial surrounding AuNPs was agglomerated which proves the formation of discrete nanostructutres. These AuNPs have been evaluated for their antibacterial potential. The results revealed good antibacterial activity of the samples against. Klebsiella pneumonia, Bacillus subtilis and Staphylococcus epidermidis with 10-12 mm zone of inhibition range. The AuNPs were also found stable at high temperature, over a range of pH and in 1 mM salt solution. Moreover, the crude extract and respective AuNPs also exhibited interesting sedative and analgesic activities. Hence, we focused on phytochemicals-mediated synthesis of AuNPs considered as greatest attention in the treatment of anti-bacterial, analgesic, and sedative.