Photocatalytic activity of silver nanoparticles@cellulose nanocomposites, from pistachio husk, in the toxic azo commercial dye degradation.

In this work, an over-the-counter commercial dye, containing direct blue 151 in its composition, which is also discarded without any environmental regulation, was efficiency photodegraded using a green chemistry-synthesized nanocomposites type silver nanoparticles (AgNPs) supported on pistachio husk (PH). The green synthesis (GS) of the nanocomposites was carried out using the Anemopsis californica leaf extract (ExAc) as a reducing-stabilizing agent (AgNPs/ExAc-PH), for the first time. The presence of AgNPs on the nanocomposite surface was corroborated by field emission transmission electron microscope (FE-TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The synthesized AgNPs/ExAc-PH has a bimodal size of 24 and 25 nm (4.86 % each) and a 0.72 % of AgNPs on its surface. AgNPs were adhered to the PH surface, through secondary bonds between the Ag and the cellulose of the PH. The optimum conditions, for efficient photocatalytic degradation, were 5 mg of nanocomposite, 3.18 × 10-2 M of NaBH4, natural sunlight, and stirring; this results in a photodegradation efficiency of 100 % almost instantaneously. Furthermore, it was shown that the dye degradation process is primarily due to the photocatalytic degradation of the dye, which occurs almost instantaneously.

Green synthesis of silver nanoparticles by using Allium sativum extract and evaluation of their electrical activities in bio-electrochemical cell.

An electrical application of green synthesized silver nanoparticles (Ag NPs) by developing a unique bio-electrochemical cell (BEC) has been addressed in the report. Here, garlic extract (GE) has been used as a reducing agent to synthesize Ag NPs, and as a bio-electrolyte solution of BEC. Ag NPs successfully formed into face-centered cubic structures with average crystallite and particle sizes of 8.49 nm and 20.85 nm, respectively, according to characterization techniques such as the UV-vis spectrophotometer, XRD, FTIR, and FESEM. A broad absorption peak at 410 nm in the UV-visible spectra indicated that GE played a vital role as a reducing agent in the transformation of Ag+ions to Ag NPs. After that four types of BEC were developed by varying the concentration of GE, CuSO4. 5H2O, and Ag NPs electrolyte solution. The open circuit voltage and short circuit current of all cells were examined with the time duration. Moreover, different external loads (1 Ω, 2 Ω, 5 Ω, and 6 Ω) were used to investigate the load voltage and load current of BEC. The results demonstrated that the use of Ag NPs on BEC played a significant role in increasing the electrical performance of BEC. The use of GE-mediated Ag NPs integrated the power, capacity, voltage efficiency, and energy efficiency of BEC by decreasing the internal resistance and voltage regulation. These noteworthy results can take a frontier forward to the development of nanotechnology for renewable and low-cost power production applications.

Green synthesized silver nanoparticles using the plant-based reducing agent Matricaria chamomilla induce cell death in colorectal cancer cells.

OBJECTIVE: There is a need to treat cancer cells with safe and natural nanoparticles to avoid the side effects of chemotherapeutic agents. Chamomile is considered a safe, natural plant with anticancer activity. We synthesize simple, inexpensive, and eco-friendly silver nanoparticles (SNs) using Chamomile (CHM) to tune their anticancer properties. MATERIALS AND METHODS: SN-CHM was synthesized by reducing 1 mM silver nitrate aqueous solution in 100 mL with the aqueous ethanolic flower extract of CHM (18 mg/mL, w/v). The reaction proceeded overnight at 600 rpm and 28°C. SN-CHM was characterized for their % yield, average diameter, charge, morphology, and silver release. Moreover, SN-CHM was investigated for its antioxidant and anticancer activities at 200 µg/mL and 5 mg/ mL, respectively. RESULTS: A 59.12% yield and a uniform SN-CHM size of 115 ± 3.1 nm with a ζ-potential of -27.67 ± (-3.92) mv were observed. The UV-visible absorption showed shifts from 379.5 to 383.5 nm for CHM and SN-CHM, respectively. Moreover, Ag+ was ultimately released from SN-CHM after 5 h. Fourier Transform Infrared Spectroscopy (FT-IR) showed characteristic absorption peaks of CHM and produced SN-CHM. Furthermore, SN-CHM showed moderate antioxidant activity. SN-CHM inhibited the % viability of SW620 and HT-29 cell lines at 20 µM. SN-CHM may also greatly upregulate the apoptotic gene BAX while considerably downregulating the anti-apoptotic genes BCL2 and BCL-Xl. CONCLUSIONS: CHM can be a safe soft drink, especially when conjugated with Ag ions as anticancer NPs. SN-CHM is considered potent anticancer activity against SW620, and HT-29 cell lines.

Green Synthesis of Metal and Metal Oxide Nanoparticles: A Review of the Principles and Biomedical Applications.

In recent years, interest in nanotechnology has increased exponentially due to enhanced progress and technological innovation. In tissue engineering, the development of metallic nanoparticles has been amplified, especially due to their antibacterial properties. Another important characteristic of metal NPs is that they enable high control over the features of the developed scaffolds (optimizing their mechanical strength and offering the controlled release of bioactive agents). Currently, the main concern related to the method of synthesis of metal oxide NPs is the environmental impact. The physical and chemical synthesis uses toxic agents that could generate hazards or exert carcinogenicity/environmental toxicity. Therefore, a greener, cleaner, and more reliable approach is needed. Green synthetic has come as a solution to counter the aforementioned limitations. Nowadays, green synthesis is preferred because it leads to the prevention/minimization of waste, the reduction of derivatives/pollution, and the use of non-toxic (safer) solvents. This method not only uses biomass sources as reducing agents for metal salts. The biomolecules also cover the synthesized NPs or act as in situ capping and reducing agents. Further, their involvement in the formation process reduces toxicity, prevents nanoparticle agglomeration, and improves the antimicrobial activity of the nanomaterial, leading to a possible synergistic effect. This study aims to provide a comprehensive review of the green synthesis of metal and metal oxide nanoparticles, from the synthesis routes, selected solvents, and parameters to their latest application in the biomedical field.

Revisiting the Green Synthesis of Nanoparticles: Uncovering Influences of Plant Extracts as Reducing Agents for Enhanced Synthesis Efficiency and Its Biomedical Applications.

Background: Conventional nanoparticle synthesis methods involve harsh conditions, high costs, and environmental pollution. In this context, researchers are actively searching for sustainable, eco-friendly alternatives to conventional chemical synthesis methods. This has led to the development of green synthesis procedures among which the exploration of the plant-mediated synthesis of nanoparticles experienced a great development. Especially, because plant extracts can work as reducing and stabilizing agents. This opens up new possibilities for cost-effective, environmentally-friendly nanoparticle synthesis with enhanced size uniformity and stability. Moreover, bio-inspired nanoparticles derived from plants exhibit intriguing pharmacological properties, making them highly promising for use in medical applications due to their biocompatibility and nano-dimension. Objective: This study investigates the role of specific phytochemicals, such as phenolic compounds, terpenoids, and proteins, in plant-mediated nanoparticle synthesis together with their influence on particle size, stability, and properties. Additionally, we highlight the potential applications of these bio-derived nanoparticles, particularly with regard to drug delivery, disease management, agriculture, bioremediation, and application in other industries. Methodology: Extensive research on scientific databases identified green synthesis methods, specifically plant-mediated synthesis, with a focus on understanding the contributions of phytochemicals like phenolic compounds, terpenoids, and proteins. The database search covered the field's development over the past 15 years. Results: Insights gained from this exploration highlight plant-mediated green synthesis for cost-effective nanoparticle production with significant pharmacological properties. Utilizing renewable biological resources and controlling nanoparticle characteristics through biomolecule interactions offer promising avenues for future research and applications. Conclusion: This review delves into the scientific intricacies of plant-mediated synthesis of nanoparticles, highlighting the advantages of this approach over the traditional chemical synthesis methods. The study showcases the immense potential of green synthesis for medical and other applications, aiming to inspire further research in this exciting area and promote a more sustainable future.

Biosynthesis of copper oxide nanoparticles using Caesalpinia sappan extract: In vitro evaluation of antifungal and antibiofilm activities against Candida albicans.

Synthesis of nanoparticles using natural organic substances has attracted more attention due to avoiding inorganic toxicity. This work aimed to synthesize copper oxide nanoparticles (CuONPs) using Caesalpinia sappan heartwood extract as a reducing agent. The effects of pH of synthesis reaction were investigated. The obtained CuONPs were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Their particle size, size distribution, and zeta potential were determined using photon correlation spectrophotometry. Candida albicans is a major cause of chronic fungal infections due to its biofilms leading to severe drug resistance problems. In this study, in vitro antifungal and antibiofilm activities as well as killing kinetics of the synthesized CuONPs against C. albicans were investigated. Additionally, fungal biofilm was observed by using confocal laser scanning microscopy. The results showed that the pH of the synthesis reaction played an important role in the physicochemical properties and antifungal activities of the obtained CuONPs. CuONPs synthesized at pH 10 and 12 showed the relatively small and narrow size distribution with high negative zeta potential and time-dependent killing kinetics. Confocal laser scanning microscopy confirms obvious fungal biofilm reduction and increased fungal cell death after exposure to CuONPs. These findings suggest the optimal pH of CuONPs synthesis using C. sappan extract as a reducing agent. The results on antifungal and antibiofilm activities indicate that the obtained CuONPs can be a promising agent for treating fungal infection.

Antibacterial and Antibiofilm Activity of Ficus carica-Mediated Calcium Oxide (CaONPs) Phyto-Nanoparticles.

The significance of nanomaterials in biomedicines served as the inspiration for the design of this study. In this particular investigation, we carried out the biosynthesis of calcium oxide nanoparticles (CaONPs) by employing a green-chemistry strategy and making use of an extract of Ficus carica (an edible fruit) as a capping and reducing agent. There is a dire need for new antimicrobial agents due to the alarming rise in antibiotic resistance. Nanoparticles' diverse antibacterial properties suggest that they might be standard alternatives to antimicrobial drugs in the future. We describe herein the use of a Ficus carica extract as a capping and reducing agent in the phyto-mediated synthesis of CaONPs for the evaluation of their antimicrobial properties. The phyto-mediated synthesis of NPs is considered a reliable approach due to its high yield, stability, non-toxicity, cost-effectiveness and eco-friendliness. The CaONPs were physiochemically characterized by UV-visible spectroscopy, energy-dispersive X-ray (EDX), scanning-electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The biological synthesis of the calcium oxide nanoparticles revealed a characteristic surface plasmon resonance peak (SPR) at 360 nm in UV-Vis spectroscopy, which clearly revealed the successful reduction of the Ca2+ ions to Ca0 nanoparticles. The characteristic FTIR peak seen at 767 cm-1 corresponded to Ca-O bond stretching and, thus, confirmed the biosynthesis of the CaONPs, while the scanning-electron micrographs revealed near-CaO aggregates with an average diameter of 84.87 ± 2.0 nm. The antibacterial and anti-biofilm analysis of the CaONPs showed inhibition of bacteria in the following order: P. aeruginosa (28 ± 1.0) > S. aureus (23 ± 0.3) > K. pneumoniae (18 ± 0.9) > P. vulgaris (13 ± 1.6) > E. coli (11 ± 0.5) mm. The CaONPs were shown to considerably inhibit biofilm formation, providing strong evidence for their major antibacterial activity. It is concluded that this straightforward environmentally friendly method is capable of synthesizing stable and effective CaONPs. The therapeutic value of CaONPs is indicated by their potential as a antibacterial and antibiofilm agents in future medications.

Antimicrobial evaluation of silver nanoparticles using extracts of Crescentia cujete L.

New natural reducing agents with a lower negative impact on the environment and with a high antimicrobial potential are required for the process of obtaining silver nanoparticles through the chemical reduction method. The use of plant extracts can be a fast track in the formation of nanoparticles. In this case, organic compounds such as terpenes, flavonoids, enzymes, proteins, and cofactors present in plants act as reducing agents for nanomaterials. This research evaluated the antimicrobial property of silver nanoparticles from extracts of Crescentia cujete L. The presence of quercetin (flavonoid) was determined by high-performance liquid chromatography (HPLC); the production of silver nanoparticles (AgNPs) was established by green synthesis; the size and morphology of the nanomaterials were evaluated by scanning electron microscope (SEM). The antimicrobial capacity was studied by two analysis methods: modified culture medium and surface seeding. The presence of quercetin (26.55 mg L-1) in the crude extract of Crescentia cujete L., identified by HPLC, was evidenced. Nanoparticle formation was spherical, with an average size of 250 ± 3 and 460 ± 6 nm. Microbiological cultures with treatment showed 94% microbial inhibition. It was concluded that the Crescentia cujete L., leaves shoed an acceptable concentration of quercetin to be used as a useful adjuvant to enhance the reduction of NPs synthesis. The nanoparticles produced by green synthesis proved to have a positive effect to combat pathogenic microorganisms.

Contact lenses that transform gold into nanoparticles for prophylaxis of light-related events and photothermal therapy.

This work describes for first time how anisotropic gold nanoparticles (AuNPs) can be spontaneously formed inside preformed contact lenses (CLs) avoiding the use of additional reductant agents (reagent-free) through a precise tunning of the monomeric composition, the saline concentration, and the application of steam heat sterilization. Protocols to generate AuNPs in solution using inorganic or small organic reductants are widely available. Differently, gold precursors interactions with polymer networks have been overlooked and, thus, the interest of chemically cross-linked hydrogels as organic reductants is still to be elucidated. In the ocular field, incorporation of AuNPs to CLs may expand their applications in prophylaxis, therapy and diagnosis. To carry out the work, a variety of hydrogels and commercially available CLs were incubated with gold salt solution without any other chemical reagent. AuNPs formation was monitored by changes in localized surface plasmon resonance (LSPR) bands and quantifying the gold sorbed. Only silicone hydrogels induced AuNPs formation at room temperature in few days; methacrylic acid red-shifted the LSPR band (550-600 nm), while monomers bearing F hindered the reduction. Storage of hydrogels in the gold precursor solution allowed a gradual formation of anisotropic AuNPs, which could be stopped at any time by washing the hydrogel with water. The developed CLs behave as efficient filters against highly penetrant light and also exhibit photoresponsiveness as demonstrated as rapid (10 s), focused mild hyperthermia when irradiated with green, red and NIR lasers.

Innovative methodology for green synthesis of iridium nanoparticles of rod shapes by reduction of iridium (IV) using sustainable pectin with formation of keto-pectin derivatives.

A prospective novel technique has been developed for green synthesis of iridium nanoparticles of rod shapes for the first time with simultaneous formation of keto-derivative oxidation product with a yield of 98.3 %. This takes place by reduction of hexacholoroiridate (IV) by using sustainable pectin as a powerful reducing agent biomacromolecule in acidic media. The formation of nanoparticles (IrNPS) was identified by Fourier transform infrared (FTIR), Transmission electron microscope (TEM), X-ray diffraction (XRD), and Scanning electron microscope (SEM) investigations. The TEM morphology showed that the iridium nanoparticles were of crystalline rod shapes on contrary to the spherical shapes reported on all synthesized IrNPS earlier. The rates of nanoparticles growth were followed kinetically using a conventional spectrophotometer. The kinetic measurements revealed a unity order reaction in [IrCl6]2- as oxidant and fractional first-order in [PEC] as a reducing agent, respectively. A decrease in the reaction rates was noticed with increasing the acid concentration. Kinetic evidence reveals the creation of intermediate complex as transient species prior to the slow step. Such complex formation may be facilitated by the participation of one chloride ligand from [IrCl6]2- oxidant forming a bridge between the oxidant and reductant in such formed intermediate complex. Plausible reaction mechanisms for electron transfer pathway routes consistent with the kinetics observations were discussed.

Exploring the potential of eco-friendly silver nanoparticles to inhibit azole-resistant clinical isolates of Candida spp.

The antimicrobial activity and biological efficiency of silver nanoparticles (AgNps) have been widely described and can be modeled through stabilizing and reducing agents, especially if they exhibit biocidal properties, which can enhance bioactivity against pathogens. The selective action of AgNps remains a major concern. In this regard, the use of plant extracts for the green synthesis of nanoparticles offers advantages because it improves the toxicity of Nps for microorganisms and is harmless to normal cells. However, biological evaluations of the activity of AgNps synthesized using different reducing agents are determined independently, and comparisons are frequently overlooked. Thus, we investigated and compared the antifungal and cytotoxic effects of two ecological AgNps synthesized from Moringa oleifera aqueous leaf extract (AgNp-M) and glucose (AgNp-G) against azole-resistant clinical isolates of Candida spp. and nontumor mammalian cells. Synthesized AgNps exhibited an antifungal effect on planktonic cells of drug-resistant C. albicans and C. tropicalis (MIC 0.21-52.6 µg/mL). The toxicity was influenced by size. However, the use of M. oleifera extracts allows us to obtain AgNps that are highly selective and nongenotoxic to Vero cells due to modifications of the shape and surface. Therefore, these results suggest that AgNp-M has antimicrobial potential and deserves further investigation for biomedical applications.

Green route synthesis of ZnO nanoparticles using Senna auriculata aqueous flower extract as reducing agent and evaluation of its antimicrobial, antidiabetic and cytotoxic activity.

The nanoparticles have unique and superior properties which make them applicable in almost every field of human life. Among the various methods that exist for the synthesis of nanoparticles, green synthesis is one of the best economic and eco-friendly methods compared with other conventional chemical methods. The nanoparticles synthesized by this method are also free from toxicity properties. This paper describes one such green synthesis method for zinc oxide nanoparticles (ZnO NPs) using the aqueous flower extract of Senna auriculata. The synthesized nanoparticles (SA-ZnO NPs) have been examined using UV-Vis spectrophotometer, photoluminescence spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The antibacterial and antifungal activities of the synthesized NPs were evaluated against gram-positive bacteria (S. aureus, B. subtilis), gram-negative bacteria (E. coli, S. typhi) and fungal organisms (C. albicans, A. nigar) using disc diffusion method. Furthermore, the antidiabetic and anticancer activities of the NPs were also been examined by α-amylase inhibition assay and MTT assay, respectively. These studies ensured that the SA-ZnO NPs have significant antimicrobial, antidiabetic and anticancer activities.

Physico-chemical properties and antimicrobial activity of silver nanoparticles fabricated by green synthesis.

A proper understanding of silver (Ag) nanoparticles properties is fundamental for developing new antimicrobial agents. In this study, Ag nanoparticles were obtained by green synthesis methods using natural reducing agents present in extracts of apples, oranges, potatoes, red pepper, white onion, garlic and radish. The antimicrobial properties of respective nanoparticles, expressed as the minimum inhibitory concentration, were assessed against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Candida krusei. Characterization of Ag nanoparticles was done with the application of transmission electron microscopy, X-ray diffraction and UV-vis spectroscopy. The obtained results led to the conclusions that in each extract (pH from 2.1 to 6.2) were obtained specific particles (size from 9 to 30 ± 2 nm) with different antimicrobial activity. Our study indicates that plant extracts gives the Ag nanoparticles specific properties, yet the best antimicrobial properties show nanoparticles obtained in the presence of potato extract.

Effective removal of phosphorus from high phosphorus steel slag using carbonized rice husk.

High phosphorus steel slag and carbonized rice husk are two common wastes characterized by high generation and low secondary use values. Through the reduction of high phosphorus steel slag by biomass, both wastes were fully utilized, thus reducing the negative impact on the environment. In this study, variables such as temperature, time, and amount of reactants were changed to determine the optimal conditions for the reaction of steel slag with carbonized rice husk at high temperatures. The actual amount of reducing agent consumed during the reduction was significantly greater than that predicted by theoretical calculations. Adding three carbon equivalent of carbonized rice husk and maintaining at 1500°C for 30 min could remove 79.25% of P2O5 in the slag. By modeling the material cycle in which high phosphorus steel slag was treated with biomass, the product could be used for crop growth. Meanwhile, the reduced iron and residual steel slag can be used to make steel again, thereby leading to a sharp reduction in fossil fuel usage and greenhouse gas emissions in this process.

Green synthesis of copper oxide and manganese oxide nanoparticles from watermelon seed shell extract for enhanced photocatalytic reduction of methylene blue.

In the current study, copper oxide (CuO) and manganese oxide (MnO) nanoparticles (NPs) were synthesized through a simple, cost-efficient, and green method using watermelon seed shell extract as a stabilizing and reducing agent. The synthesized CuO and MnO NPs were characterized by using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet spectroscopy (UV). The particle sizes of CuO and MnO NPs were determined to be in the range of 15-97 and 6-51 nm, respectively, by TEM and XRD analysis. The photocatalytic performance of the CuO and MnO NPs used as catalysts were investigated for the photocatalytic reduction of methylene blue in an aqueous solution. In the photocatalytic reduction of methylene blue, sodium borohydride (NaBH4) was used as the reducing agent. The CuO and MnO NPs were capable to remove 96.58% (in 70 min) and 96.60% (in 140 min) of methylene blue from aqueous media, respectively. Besides, the kinetics of the photocatalytic reaction was investigated by a pseudo-first order model, and the reaction rate coefficient for methylene blue with CuO and MnO NPs were calculated as 0.0426 and 0.0235 min-1, respectively. The results demonstrated that the synthesized CuO and MnO NPs through the green method were promising catalysts to improve the photocatalytic reduction performance of methylene blue.

Synthesis and Characterization of Silver Nanoparticles from Rhizophora apiculata and Studies on Their Wound Healing, Antioxidant, Anti-Inflammatory, and Cytotoxic Activity.

Silver nanoparticles (AgNPs) have recently gained interest in the medical field because of their biological features. The present study aimed at screening Rhizophora apiculata secondary metabolites, quantifying their flavonoids and total phenolics content, green synthesis and characterization of R. apiculata silver nanoparticles. In addition, an assessment of in vitro cytotoxic, antioxidant, anti-inflammatory and wound healing activity of R. apiculata and its synthesized AgNPs was carried out. The powdered plant material (leaves) was subjected to Soxhlet extraction to obtain R. apiculata aqueous extract. The R. apiculata extract was used as a reducing agent in synthesizing AgNPs from silver nitrate. The synthesized AgNPs were characterized by UV-Vis, SEM-EDX, XRD, FTIR, particle size analyzer and zeta potential. Further aqueous leaf extract of R. apiculata and AgNPs was subjected for in vitro antioxidant, anti-inflammatory, wound healing and cytotoxic activity against A375 (Skin cancer), A549 (Lung cancer), and KB-3-1 (Oral cancer) cell lines. All experiments were repeated three times (n = 3), and the results were given as the mean ± SEM. The flavonoids and total phenolics content in R. apiculata extract were 44.18 ± 0.086 mg/g of quercetin and 53.24 ± 0.028 mg/g of gallic acid, respectively. SEM analysis revealed R. apiculata AgNPs with diameters ranging from 35 to 100 nm. XRD confirmed that the synthesized silver nanoparticles were crystalline in nature. The cytotoxicity cell viability assay revealed that the AgNPs were less toxic (IC50 105.5 µg/mL) compared to the R. apiculata extract (IC50 47.47 µg/mL) against the non-cancerous fibroblast L929 cell line. Antioxidant, anti-inflammatory, and cytotoxicity tests revealed that AgNPs had significantly more activity than the plant extract. The AgNPs inhibited protein denaturation by a mean percentage of 71.65%, which was equivalent to the standard anti-inflammatory medication diclofenac (94.24%). The AgNPs showed considerable cytotoxic effect, and the percentage of cell viability against skin cancer, lung cancer, and oral cancer cell lines was 31.84%, 56.09% and 22.59%, respectively. R. apiculata AgNPs demonstrated stronger cell migration and percentage of wound closure (82.79%) compared to the plant extract (75.23%). The overall results revealed that R. apiculata AgNPs exhibited potential antioxidant, anti-inflammatory, wound healing, and cytotoxic properties. In future, R. apiculata should be further explored to unmask its therapeutic potential and the mechanistic pathways of AgNPs should be studied in detail in in vivo animal models.

Keratin-Based Composite Bioactive Films and Their Preservative Effects on Cherry Tomato.

In this study, keratins were extracted from pig nail waste through the reduction method using L-cysteine as a reductant. Curcumin was successively incorporated in a mixed solution including keratin, gelatin, and glycerin to prepare different kinds of keratin/gelatin/glycerin/curcumin composite films. The morphology of the keratin/ gelatin/glycerin/curcumin composite films were examined using scanning electron microscopy. The structures and the molecular interactions between curcumin, keratin, and pectin were examined using Fourier transform infrared spectroscopy and X-ray diffraction, and the thermal properties were determined through thermogravimetric analysis. The tensile strengths of keratin/gelatin/glycerin/curcumin and keratin/gelatin/curcumin composite films are 13.73 and 12.45 MPa, respectively, and their respective elongations at break are 56.7% and 4.6%. In addition, compared with the control group (no film wrapped on the surface of tomato), the ratio of weight loss of the keratin (7.0%)/gelatin (10%)/glycerin (2.0%)/curcumin (1.0%) experimental groups is 8.76 ± 0.2%, and the hardness value of the tomatoes wrapped with composite films is 11.2 ± 0.39 kg/cm3. Finally, the composite films have a superior antibacterial effect against Staphylococcus aureus and Escherichia coli because of the addition of curcumin. As the concentration of curcumin reaches 1.0%, the antibacterial activity effect of the film is significantly improved. The diameter of the inhibition zone of E. coli is (12.16 ± 0.53) mm, and that of S. aureus is (14.532 ± 0.97) mm. The multifunctional keratin/gelatin/glycerin/curcumin bioactive films have great potential application in the food packaging industry.

An Evaluation of Antimicrobial, Anticancer, Anti-Inflammatory and Antioxidant Activities of Silver Nanoparticles Synthesized from Leaf Extract of Madhuca longifolia Utilizing Quantitative and Qualitative Methods.

In the current decade, nanoparticles are synthesized using solvents that are environmentally friendly. A number of nanoparticles have been synthesized at room temperature using water as a solvent, such as gold (Au) and silver (Ag) nanoparticles. As part of nanotechnology, nanoparticles are synthesized through biological processes. Biological methods are the preferred method for the synthesis of inorganic nanoparticles (AgNPs) as a result of their simple and non-hazardous nature. Nanoparticles of silver are used in a variety of applications, including catalysts, spectrally selective coatings for solar absorption, optical objectives, pharmaceutical constituents, and chemical and biological sensing. Antimicrobial agents are among the top uses of silver nanoparticles. In the current study, silver nanoparticles were biologically manufactured through Madhuca longifolia, and their antibacterial activity against pathogenic microorganisms, anticancer, anti-inflammatory, and antioxidant activities were assessed. UV-Vis spectroscopy, XRD (X-ray diffraction), transmission electron microscopy, Zeta Potential, and FTIR were used to characterize silver nanoparticles. The current work describes a cheap and environmentally friendly method to synthesize silver nanoparticles from silver nitrate solution by using plant crude extract as a reducing agent.

New Green Approaches in Nanoparticles Synthesis: An Overview.

Nanotechnology is constantly expanding, with nanomaterials being more and more used in common commercial products that define our modern life. Among all types of nanomaterials, nanoparticles (NPs) occupy an important place, considering the great amount that is produced nowadays and the diversity of their applications. Conventional techniques applied to synthesize NPs have some issues that impede them from being appreciated as safe for the environment and health. The alternative to these might be the use of living organisms or biological extracts that can be involved in the green approach synthesis of NPs, a process that is free of harmful chemicals, cost-effective and a low energy consumer. Several factors, including biological reducing agent concentration, initial precursor salt concentration, agitation, reaction time, pH, temperature and light, can influence the characteristics of biologically synthesized NPs. The interdependence between these reaction parameters was not explored, being the main impediment in the implementation of the biological method on an industrial scale. Our aim is to present a brief review that focuses on the current knowledge regarding how the aforementioned factors can control the size and shape of green-synthesized NPs. We also provide an overview of the biomolecules that were found to be suitable for NP synthesis. This work is meant to be a support for researchers who intend to develop new green approaches for the synthesis of NPs.

Dietary-derived vitamin B12 protects Caenorhabditis elegans from thiol-reducing agents.

BACKGROUND: One-carbon metabolism, which includes the folate and methionine cycles, involves the transfer of methyl groups which are then utilised as a part of multiple physiological processes including redox defence. During the methionine cycle, the vitamin B12-dependent enzyme methionine synthetase converts homocysteine to methionine. The enzyme S-adenosylmethionine (SAM) synthetase then uses methionine in the production of the reactive methyl carrier SAM. SAM-binding methyltransferases then utilise SAM as a cofactor to methylate proteins, small molecules, lipids, and nucleic acids. RESULTS: We describe a novel SAM methyltransferase, RIPS-1, which was the single gene identified from forward genetic screens in Caenorhabditis elegans looking for resistance to lethal concentrations of the thiol-reducing agent dithiothreitol (DTT). As well as RIPS-1 mutation, we show that in wild-type worms, DTT toxicity can be overcome by modulating vitamin B12 levels, either by using growth media and/or bacterial food that provide higher levels of vitamin B12 or by vitamin B12 supplementation. We show that active methionine synthetase is required for vitamin B12-mediated DTT resistance in wild types but is not required for resistance resulting from RIPS-1 mutation and that susceptibility to DTT is partially suppressed by methionine supplementation. A targeted RNAi modifier screen identified the mitochondrial enzyme methylmalonyl-CoA epimerase as a strong genetic enhancer of DTT resistance in a RIPS-1 mutant. We show that RIPS-1 is expressed in the intestinal and hypodermal tissues of the nematode and that treating with DTT, ß-mercaptoethanol, or hydrogen sulfide induces RIPS-1 expression. We demonstrate that RIPS-1 expression is controlled by the hypoxia-inducible factor pathway and that homologues of RIPS-1 are found in a small subset of eukaryotes and bacteria, many of which can adapt to fluctuations in environmental oxygen levels. CONCLUSIONS: This work highlights the central importance of dietary vitamin B12 in normal metabolic processes in C. elegans, defines a new role for this vitamin in countering reductive stress, and identifies RIPS-1 as a novel methyltransferase in the methionine cycle.