Biosynthesis of metallic nanoparticles using mulberry fruit (Morus alba L.) extract for the preparation of antimicrobial nanocellulose film

Green synthesis and anthelmintic activity of silver nanoparticles using Morus Alba Fruit extract against different stages of equine strongyles

The current study was designed to green synthesize silver nanoparticles (GRAgNPs) using Morus alba fruit extract and evaluate their nematicidal effects against strongyle nematodes compared to commercial silver nanoparticles (CAgNPs) in vitro. The nanoparticles were characterized by Ultraviolet-visual absorption spectrography, transmission electron microscopy, and X-ray diffraction. Next, uptake of AgNPs by the first stage larvae (L1), egg hatch inhibition (EHI) and the motility of infectious larvae (L3s), and the ultrastructural analysis of the eggs and worms were conducted. Moreover, some of oxidative/nitrosative stress indicators, including total antioxidant status content (TAC), protein carbonylation (PCO), lipid peroxidation (MDA), and DNA damage were assessed in the homogenized samples of strongyle L3s. We found that the GRAgNPs had spherical shape, 20-30 nm in diameter with rough surface. Following incubation with GRAgNPs at concentrations of 43.40, 21.70 and 10.85 ppm and CAgNPs at concentrations of 43.40 and 21.70, EHI was more than 90%. In addition, concentrations of 43.40 and 21.70 ppm of GRAgNPs led to inhibition of larval motility by more than 90%. The LC50 at 24 h of treatment for GRAgNPs and CAgNPs was determined to be 8.62 and 10.34 ppm, respectively. GRAgNPs and CAgNPs, in a concentration-dependent manner, resulted in the induction of oxidative/nitrosative stress evidenced by decreased TAC levels, and increased levels of MDA and PCO, together with increased DNA damage. The uptake of AgNPs by the L1 larvae revealed that FITC labeled GRAgNPs fluoresced with high intensity largely in the intestinal area. Scanning Electron Microscopy analysis of eggs and larvae revealed that GRAgNPs penetrated the cuticle of larvae, changed the tegmentum, and ultimately killed the worm. In conclusion, GRAgNPs had more robust anthelminthic effects than the standard antiparasitic and CAgNPs. They could be considered as a promising antiparasitic agent.

Unlocking sustainable solutions: Nanocellulose innovations for enhancing the shelf life of fruits and vegetables - A comprehensive review

Regarding food security and waste reduction, preserving fruits and vegetables is a vital problem. This comprehensive study examines the innovative potential of coatings and packaging made of nanocellulose to extend the shelf life of perishable foods. The distinctive merits of nanocellulose, which is prepared from renewable sources, include exceptional gas barrier performance, moisture retention, and antibacterial activity. As a result of these merits, it is a good option for reducing food spoilage factors such as oxidation, desiccation, and microbiological contamination. Nanocellulose not only enhances food preservation but also complies with industry-wide environmental objectives. This review explores the many facets of nanocellulose technology, from its essential characteristics to its use in the preservation of fruits and vegetables. Furthermore, it deals with vital issues including scalability, cost-effectiveness, and regulatory constraints. While the use of nanocellulose in food preservation offers fascinating potential, it also wants to be cautiously careful to assure affordability, effectiveness, and safety. To fully use the potential of nanocellulose and advance the sustainability plan in the food business, collaboration between scientists, regulatory bodies, and industry stakeholders is important as we stand on the cusp of a revolutionary era in food preservation.

Carbon dots embedded bacterial cellulose membrane as active packaging: Toxicity, in vitro release and application in minced beef packaging

Antimicrobial bacterial cellulose (BC) membranes incorporated with carbon dots (CDs) were developed to improve the shelf life and ensure the safety of minced beef during 9 days of storage at 4 °C. An ex-situ method was used to develop BC-CDs with different CDs loading capacities (16.50, 22.50, and 38.50 mg/cm3). Only BC-CDs38.50 membrane exhibited toxicity in human embryonic kidney cells, and BC-CDs membranes had the slowest release rate of CDs in 95% ethanol. Significant differences were noted in the chemical and sensory attributes of samples packaged with BC-CDs16.50 and BC-CDs22.50, compared to the control. The microbial counts in samples with BC-CDs were significantly lower than those in samples with pristine BC membranes or the control. Notably, the BC-CDs22.50 membrane exhibited a substantial reduction (4.7 log10 CFU/g) in Escherichia coli counts by the end of storage. These findings highlight the potential of BC-CDs membranes as effective antimicrobial materials in meat packaging.

A Novel Indicator Based on Polyacrylamide Hydrogel and Bromocresol Green for Monitoring the Total Volatile Basic Nitrogen of Fish

An intelligent indicator was developed by immobilizing bromocresol green (BCG) within the polyacrylamide (PAAm) hydrogel matrix to monitor the total volatile basic nitrogen (TVB-N) content of fish. The FTIR analysis indicated that BCG was effectively incorporated into the PAAm through the formation of intermolecular hydrogen bonds. A thermogravimetric analysis (TGA) showed that the PAAm/BCG indicator had a mere 0.0074% acrylamide monomer residue, meanwhile, the addition of BCG improved the thermal stability of the indicator. In vapor tests with various concentrations of trimethylamine, the indicator performed similarly at both 4 °C and 25 °C. The total color difference values (ΔE) exhibited a significant linear response to TVB-N levels ranging from 4.29 to 30.80 mg/100 g at 4 °C (R2 = 0.98). Therefore, the PAAm/BCG indicator demonstrated stable and sensitive color changes based on pH variations and could be employed in smart packaging for real-time assessment of fish freshness.

Isolation, characterization, development and evaluation of phytoconstituent based formulation for diabetic neuropathy

Background

Morus alba Linn, referred to as white mulberry, is a potential traditional medicine for diabetes and neuroprotection.

Aim

Isolation, characterization, development and evaluation of phytoconstituent based formulation for diabetic neuropathy.

Material and methods

The stem Bark of M. alba was peeled and subjected to extraction. A phytoconstituent was then isolated by column chromatography and characterized using Mass spectroscopy, FTIR, and NMR. The isolated phytoconstituent was used to formulate a nanoemulsion. Nanoemulsion was also characterized for viscosity, surface tension, refractive index, pH, and particle size. Selected nanoemulsion formulations were then tested for acute oral toxicity and diabetic neuropathy, including behavioral, hematological, histopathological, and biomarker examinations.

Results

The spectral analysis affirmed that the isolated compound was found to be chrysin. A nanoemulsion formulation was made using the chrysin and was characterized and found to be stable during the stability testing and fulfilled all other testing parameters. Then acute oral toxicity study of the formulations was found to be safe. Formulations were found to possess significant results against diabetic neuropathy in rats. Biomarkers were analyzed for their mechanistic involvement in reducing neuropathy in rats, and it was found that the oxidative pathway was considerably restored, suggesting that chrysin causes these effects via this pathway.

Conclusions

Results suggests that isolated phytoconstituent (chrysin) from the bark of Morus alba derived nanoemulsion has protective and beneficial effects by diminishing the oxidative damage against alloxan-induced diabetic neuropathy in rats.

Biogenic Synthesis of Copper Nanoparticles: A Systematic Review of Their Features and Main Applications

Nanotechnology is an innovative field of study that has made significant progress due to its potential versatility and wide range of applications, precisely because of the development of metal nanoparticles such as copper. Nanoparticles are bodies composed of a nanometric cluster of atoms (1-100 nm). Biogenic alternatives have replaced their chemical synthesis due to their environmental friendliness, dependability, sustainability, and low energy demand. This ecofriendly option has medical, pharmaceutical, food, and agricultural applications. When compared to their chemical counterparts, using biological agents, such as micro-organisms and plant extracts, as reducing and stabilizing agents has shown viability and acceptance. Therefore, it is a feasible alternative for rapid synthesis and scaling-up processes. Several research articles on the biogenic synthesis of copper nanoparticles have been published over the past decade. Still, none provided an organized, comprehensive overview of their properties and potential applications. Thus, this systematic review aims to assess research articles published over the past decade regarding the antioxidant, antitumor, antimicrobial, dye removal, and catalytic activities of biogenically synthesized copper nanoparticles using the scientific methodology of big data analytics. Plant extract and micro-organisms (bacteria and fungi) are addressed as biological agents. We intend to assist the scientific community in comprehending and locating helpful information for future research or application development.

Transition metal-based nanoparticles as potential antimicrobial agents: recent advancements, mechanistic, challenges, and future prospects

Bacterial transmission is considered one of the potential risks for communicable diseases, requiring promising antibiotics. Traditional drugs possess a limited spectrum of effectiveness, and their frequent administration reduces effectiveness and develops resistivity. In such a situation, we are left with the option of developing novel antibiotics with higher efficiency. In this regard, nanoparticles (NPs) may play a pivotal role in managing such medical situations due to their distinct physiochemical characteristics and impressive biocompatibility. Metallic NPs are found to possess extraordinary antibacterial effects that are useful in vitro as well as in vivo as self-modified therapeutic agents. Due to their wide range of antibacterial efficacy, they have potential therapeutic applications via diverse antibacterial routes. NPs not only restrict the development of bacterial resistance, but they also broaden the scope of antibacterial action without binding the bacterial cell directly to a particular receptor with promising effectiveness against both Gram-positive and Gram-negative microbes. This review aimed at exploring the most relevant types of metal NPs employed as antimicrobial agents, particularly those based on Mn, Fe, Co, Cu, and Zn metals, and their antimicrobial mechanisms. Further, the challenges and future prospects of NPs in biological applications are also discussed.

A review on the green synthesis of nanoparticles, their biological applications, and photocatalytic efficiency against environmental toxins

Green synthesis of nanoparticles (NPs) using plant materials and microorganisms has evolved as a sustainable alternative to conventional techniques that rely on toxic chemicals. Recently, green-synthesized eco-friendly NPs have attracted interest for their potential use in various biological applications. Several studies have demonstrated that green-synthesized NPs are beneficial in multiple medicinal applications, including cancer treatment, targeted drug delivery, and wound healing. Additionally, due to their photodegradation activity, green-synthesized NPs are a promising tool in environmental remediation. Photodegradation is a process that uses light and a photocatalyst to turn a pollutant into a harmless product. Green NPs have been found efficient in degrading pollutants such as dyes, herbicides, and heavy metals. The use of microbes and flora in green synthesis technology for nanoparticle synthesis is biologically safe, cost-effective, and eco-friendly. Plants and microbes can now use and accumulate inorganic metallic ions in the environment. Various NPs have been synthesized via the bio-reduction of biological entities or their extracts. There are several biological and environmental uses for biologically synthesized metallic NPs, such as photocatalysis, adsorption, and water purification. Since the last decade, the green synthesis of NPs has gained significant interest in the scientific community. Therefore, there is a need for a review that serves as a one-stop resource that points to relevant and recent studies on the green synthesis of NPs and their biological and photocatalytic efficiency. This review focuses on the green fabrication of NPs utilizing diverse biological systems and their applications in biological and photodegradation processes.

Recent Advances and Perspectives of Nanomaterials in Agricultural Management and Associated Environmental Risk: A Review

The advancement in nanotechnology has enabled a significant expansion in agricultural production. Agri-nanotechnology is an emerging discipline where nanotechnological methods provide diverse nanomaterials (NMs) such as nanopesticides, nanoherbicides, nanofertilizers and different nanoforms of agrochemicals for agricultural management. Applications of nanofabricated products can potentially improve the shelf life, stability, bioavailability, safety and environmental sustainability of active ingredients for sustained release. Nanoscale modification of bulk or surface properties bears tremendous potential for effective enhancement of agricultural productivity. As NMs improve the tolerance mechanisms of the plants under stressful conditions, they are considered as effective and promising tools to overcome the constraints in sustainable agricultural production. For their exceptional qualities and usages, nano-enabled products are developed and enforced, along with agriculture, in diverse sectors. The rampant usage of NMs increases their release into the environment. Once incorporated into the environment, NMs may threaten the stability and function of biological systems. Nanotechnology is a newly emerging technology, so the evaluation of the associated environmental risk is pivotal. This review emphasizes the current approach to NMs synthesis, their application in agriculture, interaction with plant-soil microbes and environmental challenges to address future applications in maintaining a sustainable environment.

Chitosan/Starch-Based Active Packaging Film with N, P-Doped Carbon Dots for Meat Packaging

Nitrogen, phosphorus-doped green-tea-derived carbon dots (NP-CDs) incorporated chitosan/starch (Chi/St) based multifunctional nanocomposite films were prepared. FE-SEM images verified a homogeneous distribution of CDs with minimum aggregation in the fabricated films. Incorporating NP-CDs led to enhanced UV-light blocking (93.1% of UV-A and ∼99.7% of UV-B) without significantly affecting the films' water transparency and water vapor permeability. Besides, incorporating NP-CDs into the Chi/St films enhanced antioxidant activity (98.0% for ABTS and 71.4% for DPPH) and displayed strong antibacterial activity against L. monocytogenes, E. coli, and S. aureus. Wrapping the meat in the prepared film and storing it at 20 °C has been shown to reduce bacterial growth (less than 2.5 Log CFU/g after 48 h) without significantly altering the actual color of the wrapped meat. The Chi/St film loaded with NP-CD has high potential as an active packaging material to ensure safety and extend the shelf life of meat products.

GO-Enabled Bacterial Cellulose Membranes by Multistep, In Situ Loading: Effect of Bacterial Strain and Loading Pattern on Nanocomposite Properties

This paper presents the results of research on the preparation and properties of GO/BC nanocomposite from bacterial cellulose (BC) modified with graphene oxide (GO) using the in situ method. Two bacterial strains were used for the biosynthesis of the BC: Komagataeibacter intermedius LMG 18909 and Komagataeibacter sucrofermentans LMG 18788. A simple biosynthesis method was developed, where GO water dispersion was added to reinforced acetic acid-ethanol (RAE) medium at concentrations of 10 ppm, 25 ppm, and 50 ppm at 24 h and 48 h intervals. As a result, a GO/BC nanocomposite membrane was obtained, characterized by tensile strength greater by 150% as compared with the pure BC (̴ 50 MPa) and lower volume resistivity of ~4 ∙ 10⁹ Ω × cm. Moreover, GO addition increases membrane thickness up to ~10% and affects higher mass production, especially with low GO concentration. All of this may indicate the possibility of using GO/BC membranes in fuel cell applications.

Recent insights into metallic nanoparticles in shelf-life extension of agrifoods: Properties, green synthesis, and major applications

Nanotechnology emerged as a revolutionary technology in various fields of applied sciences, such as biomedical engineering and food technology. The pivotal roles of nanocompounds have been explored in various fields, such as food protection, preservation, and enhancement of shelf life. In this sequence, metallic nanoparticles (MNPs) are proven to be useful in developing products with antimicrobial activity and subsequently improve the shelf life of agrifoods. The major application of MNPs has been observed in the packaging industry due to the combining ability of biopolymers with MNPs. In recent years, various metal nanoparticles have been explored to formulate various active food packaging materials. However, the method of production and the need for risk evaluation are still a topic of discussion among researchers around the world. In general, MNPs are synthesized by various chemical and physical means, which may pose variable health risks. To overcome such issues, the green synthesis of MNPs using microbial and plant extracts has been proposed by various researchers. In this review, we aimed at exploring the green synthesis of MNPs, their properties and characterization, various ways of utilizing MNPs to extend their shelf life, and, most importantly, the risk associated with these along with their quality and safety considerations.

Mulberry plant as a source of functional food with therapeutic and nutritional applications: A review

Medicinal plants from the family Moraceae have diverse applications in agriculture, cosmetics, food, and the pharmaceutical industry. Their extensive spectrum of pharmacological activity for treating numerous inflammatory illnesses, cancer, cardiovascular diseases, and gastrointestinal problems reflects their biological and therapeutic value. This article summarizes the molecular mechanisms related to the biological implications of mulberry extracts, fractions, and isolated bioactive compounds from different parts in various health-related ailments. Additionally, the food industry and animal nutrition applications are summarized. Phytochemicals such as steroids, saponins, alkaloids, glycosides, polysaccharides, and phenolic compounds including terpenoids, flavonoids, anthocyanins, and tannins are found in this medicinal plant. The aqueous, ethanolic, and methanolic extracts, as well as bioactive compounds, have anti-oxidative, hypoglycemic, nephroprotective, antimicrobial, neuroprotective, anti-mutagenic, hepatoprotective, anthelmintic, immune-modulatory, cardioprotective, and skin protecting activities. Mulberry supplementation in food products improves the stability of phenolics, sensory properties, antioxidant activity, and antimicrobial properties. Mulberry leaves in animal feed increase the nutrient digestibility, growth parameters, antimicrobial, and antioxidant properties. PRACTICAL APPLICATIONS: This review summarized the in vivo and in vitro biological activities of the mulberry and isolated constituents in various health conditions. In addition, the food uses such as antioxidant potential, antimicrobial, and physicochemical properties were discussed. Furthermore, in vivo studies revealed mulberry as a significant protein source and its flavonoids as potential animal foliage.

Phytochemical characterization of Morus nigra fruit ultrasound-assisted ethanolic extract for its cardioprotective potential

The current work investigated the phytochemical profile of ultrasound-assisted ethanolic extract of Morus nigra (M. nigra) fruit. FTIR analysis of M. nigra fruit extract revealed the presence of alcohols (O-H), alkanes (C-H stretch), alkenes (C=C), and alkynes (C≡C). The HPLC analysis quantified the quercetin, gallic acid, vanillic acid, chlorogenic acid, syringic acid, cinnamic acid, sinapic acid, and kaempferol. Furthermore, the cardioprotective activity of ethanolic extract of M. nigra fruit was investigated. Cholesterol supplementation (2%) in the daily diet and exposure to cigarette smoke (2 cigarettes twice a day) were to induce hypertension in rats. The experimental animals were categorized into four groups: G0 (negative control), G1 (positive control), G2 (standard drug), and G3 (M. nigra fruit). The fruit extract administration at 300 mg/kg BW/day orally for 2 months significantly (p < .001) enhanced the activities of serum and cardiac tissue antioxidants in hypertensive rats. Meanwhile, the fruit extract reduced the elevated serum lipid profile while significantly increasing the high-density lipoproteins in G3 than G1 and G2. The increase in blood pressure, liver transaminases, and serum lactate dehydrogenase also reduced significantly in M. nigra fruit extract-treated rats. Histopathological findings revealed mild normalization of cardiac myocytes with central nuclei, branching, and cross-striations. Consequently, the M. nigra fruit extract exerted the cardioprotective potential via increasing the antioxidant enzymes and reducing the lipids, lactate dehydrogenase, liver transaminases, and blood pressure. The therapeutic potential of M. nigra fruit can be due to flavonols and phenolic acids. PRACTICAL APPLICATIONS: The present work quantified the Morus nigra fruit phytochemicals and its significant role in reducing lipid markers and blood pressure and improving antioxidant status in rats fed a hypercholesterolemic diet and exposed to cigarette smoke. Conclusively, the inclusion of M. nigra fruit in daily diet could improve the cardiac health of the individuals. Furthermore, the therapeutic potential of M. nigra fruit and its isolated constituents in modulating the gene expression against cardiac problems can explore after clinical trials and standardization in higher animals.

Pectin/carbon quantum dots fluorescent film with ultraviolet blocking property through light conversion

Carbon quantum dots (CQDs) were synthesized using glucose as a carbon source through a hydrothermal method. CQDs showed negligible cytotoxicity to L929 cells even after prolonged exposure of 72 h. The addition of CQD did not affect the pectin film's mechanical properties, water contact angle, and thermal stability. However, the CQD-added composite film generates reactive oxygen species (ROS), providing high antibacterial activity against pathogenic bacteria (L. monocytogenes and E. coli) and antifungal activity against mold (Aspergillus flavus), where a 100% eradication of bacteria and fungi population was observed. Also, the addition of CQD strengthens the antioxidant activity of the composite films by 95%. Further, the CQD-added pectin film converted ultraviolet rays into blue light, which improved the film's UV protection properties. Therefore, the pectin/CQD film has a high potential for a light conversion active packaging film that may prevent the deterioration of high-fat foods.

Design and Preparation of a Biobased Colorimetric pH Indicator from Cellulose and Pigments of Bacterial Origin, for Potential Application as Smart Food Packaging

Nowadays, worldwide challenges such as global warming, pollution, unsustainable consumption patterns, and scarcity of natural resources are key drivers toward future-oriented bioeconomy strategies, which rely on renewable biobased resources, such as bacterial pigments and bacterial cellulose (BC), for materials production. Therefore, the purpose of this study was to functionalize bacterial cellulose with violacein, flexirubin-type pigment, and prodigiosin and test their suitability as pH indicators, due to the pigments’ sensitivity to pH alterations. The screening of the most suitable conditions to obtain the BC-pigment indicators was achieved using a full factorial design, for a more sustainable functionalization process. Then, the pH response of functionalized BC to buffer solutions was assessed, with color changes at acidic pH (BC-violacein indicator) and at alkaline pH (BC-violacein, BC-prodigiosin, and BC-flexirubin-type pigment indicators). Moreover, the indicators also revealed sensitivity to acid and base vapors. Furthermore, leaching evaluation of the produced indicators showed higher suitability for aqueous foods. Additionally, color stability of the functionalized BC indicators was carried out, after light exposure and storage at 4 °C, to evaluate the indicators’ capacity to maintain color/sensitivity. Thus, BC membranes functionalized with bacterial pigments have the potential to be further developed and used as pH indicators.

Green Chemistry Based Gold Nanoparticles Synthesis Using the Marine Bacterium Lysinibacillus odysseyi PBCW2 and Their Multitudinous Activities

Green chemistry has paved an 'avant-garde avenue' in the production and fabrication of eco-friendly stable nanoparticles employing the utilization of biological agents. In the present study we present the first report on the potential of the marine bacterium Lysinibacillus odysseyi PBCW2 for the extracellular production of gold nanoparticles (AuNPs). Utilizing a variety of methods, AuNPs in the cell-free supernatant of L. odysseyi (CFS-LBOE) were identified and their antioxidant, antibacterial, and dye-degrading properties were examined. The visual coloring of the reaction mixture to a ruby red hue showed the production of LBOE-AuNPs; validated by means of XRD, TEM, SEM, XRD, DLS, TGA, and FT-IR analysis. Additionally, the 2,2-diphenyl-1-picrylhydrazyl technique and the well diffusion assay were used to examine their dose-dependent antioxidant and antibacterial activity. These biogenic LBOE-AuNPs showed 91% dye degradation efficiency during catalytic reduction activity on BTB dye, demonstrating their versatility as options for heterogeneous catalysis.

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.

Ixiolirion tataricum anthocyanins-loaded biocellulose label: Characterization and application for food freshness monitoring

A new intelligent pH-sensitive colorimetric label was fabricated by immobilizing Ixiolirion tataricum anthocyanins (ITA) into biocellulose (bacterial nanocellulose; BNC) film and was then studied to determine how it can be used as a label for monitoring freshness/spoilage of shrimp during storage at 4 °C. The formation of new interactions between ITA and BNC film and disruption of crystalline structure of BNC after anthocyanins immobilization were approved by FT-IR and XRD analyses, respectively. According to FE-SEM observations, the porosity of the BNC network decreased after ITA incorporation. The fabricated BNC-ITA label showed a distinct color change from violet to green over the pH range of 4-12. The pH, total volatile basic nitrogen (TVB-N), total psychrophiles count (TPC), and the quantity of biogenic amines (histamine, cadaverine, putrescine, and tyramine) in the shrimp samples and their correlation with color changes on the label were measured over a 4-day storage period. Consistent with changes in levels of TVB-N, TPC, pH, and biogenic amines, a visually distinguishable color change occurred on the BNC-ITA label as blue (fresh), dark green (medium fresh), and kelly green (spoiled). This research showed that ITA as a novel pH-sensitive dye is a promising candidate for developing pH labels for seafood intelligent packaging.

Preparation and characterization of intelligent packaging film for visual inspection of tilapia fillets freshness using cyanidin and bacterial cellulose

An intelligent pH-sensitive film was developed by incorporating cyanidin-3-glucoside (C3G) into bacterial cellulose (BC), and its application as a freshness indicator for tilapia fillets was investigated. The physical properties of the film were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results demonstrated the mechanical properties of the film were significantly changed due to higher crystallinity induced by C3G. XRD and FTIR analysis showed the increased crystallinity and transmittance intensity of the BC-C3G film. Moreover, this film exhibited distinctive color changes from red to green when exposed to buffers with a pH of 3 to 10. In accordance with changes in total volatile basic nitrogen (TVB-N) and total viable count (TVC) of tilapia fillets, the indicator demonstrated visualized color changes as rose-red (fresh), purple (still suitable), and lavender (spoiled) during storage at both 25 °C and 4 °C. The results suggest that this film has great potential to be used as an intelligent indicator to monitor the freshness of fish.

Application of carbon dots in food preservation: a critical review for packaging enhancers and food preservatives

Carbon dots (CDs) have two unique advantages: one is ease of synthesis at low price, the other is desirable physical and chemical properties, such as ultra-small size, abundant surface functional groups, nontoxic/low-toxicity, good biocompatibility, excellent antibacterial and antioxidant activities etc. These advantages provide opportunities for the development of new food packaging enhancers and food preservatives. This paper systematically reviews the studies of CDs used to strengthen the physical properties of food packaging, including strengthen mechanical strength, ultraviolet (UV) barrier properties and water barrier properties. It also reviews the researches of CDs used to fabricate active packaging with antioxidant and/or antibacterial properties and intelligent packaging with the capacity of sensing the freshness of food. In addition, it analyzes the antioxidant and antibacterial properties of CDs as preservatives, and discusses the effect of CDs applied as coating agents and nano-level food additives for extension the shelf life of food samples. It also provides a brief review on the security and the release behavior of CDs.

Carbon dots synthesized from microorganisms and food by-products: active and smart food packaging applications

Nanotechnology is rapidly becoming a commercial reality for application in food packaging. In particular, the incorporation of nanoparticles into packaging materials is being used to increase the shelf life and safety of foods. Carbon dots (C-dots) have a diverse range of potential applications in food packaging. They can be synthesized from environmentally friendly sources such as microorganisms, food by-products, and waste streams, or they may be generated in foods during normal processing operations, such as cooking. These processes often produce nitrogen- and sulfur-rich heteroatom-doped C-dots, which are beneficial for certain applications. The incorporation of C-dots into food packaging materials can improve their mechanical, barrier, and preservative properties. Indeed, C-dots have been used as antioxidant, antimicrobial, photoluminescent, and UV-light blocker additives in food packaging materials to reduce the chemical deterioration and inhibit the growth of pathogenic and spoilage microorganisms in foods. This article reviews recent progress on the synthesis of C-dots from microorganisms and food by-products of animal origin. It then highlights their potential application for the development of active and intelligent food packaging materials. Finally, a discussion of current challenges and future trends is given.

Covalent immobilization of bromocresol purple on cellulose nanocrystals for use in pH-responsive indicator films

This study developed pH-indicator films by combining esterified cellulose nanocrystals (e-CNCs) with activated bromocresol purple (a-BCP) via covalent bonding for pH-sensitive color-changing applications. The e-CNC/a-BCP particles were incorporated into cellulose acetate polymer to prepare pH-sensitive color changing films. Binding of a-BCP to e-CNCs was proven by attenuated total reflection infrared (ATR-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Colorimetric analysis showed that films containing 10% or 15% e-CNC/a-BCP particles had critical color changes either at pH 4-5, or pH 7-8. The films with 10% e-CNC/a-BCP particles also revealed excellent leaching resistance under acidic conditions. Color changes were reversible between pH 2 and 10. These pH-indicator films had visible color changes in response to pH variations, color reversibility, leaching resistance, and sufficient rigidity even though mechanical properties decreased as the e-CNC/a-BCP content increased from 0% to 15%.

Bioactive Phytochemicals from Mulberry: Potential Anti-Inflammatory Effects in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

The fruits of the mulberry tree (Morus alba L.), known as white mulberry, have been consumed in various forms, including tea, beverages, and desserts, worldwide. As part of an ongoing study to discover bioactive compounds from M. alba fruits, the anti-inflammatory effect of compounds from M. alba were evaluated in lipopolysaccharide (LPS)-stimulated mouse RAW 264.7 macrophages. Phytochemical analysis of the ethanol extract of the M. alba fruits led to the isolation of 22 compounds. Among the isolated compounds, to the best of our knowledge, compounds 1, 3, 5, 7, 11, 12, and 14-22 were identified from M. alba fruits for the first time in this study. Inhibitory effects of 22 compounds on the production of the nitric oxide (NO) known as a proinflammatory mediator in LPS-stimulated RAW 264.7 macrophages were evaluated using NO assays. Western blot analysis was performed to evaluate the anti-inflammatory effects of cyclo(L-Pro-L-Val) (5). We evaluated whether the anti-inflammatory effects of cyclo(L-Pro-L-Val) (5) following LPS stimulation in RAW 264.7 macrophages occurred because of phosphorylation of IκB kinase alpha (IKKα), IκB kinase beta (IKKβ), inhibitor of kappa B alpha (IκBα), nuclear factor kappa B (NF-κB) and activations of inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Cyclo(L-Pro-L-Val) (5) significantly suppressed phosphorylations of IKKα, IKKβ, IκBα, and NF-κB and activations of iNOS and COX-2 in a concentration-dependent manner. Taken together, these results indicate that cyclo(L-Pro-L-Val) (5) can be considered a potential therapeutic agent for the treatment of inflammation-associated disorders.

Green Synthesis of Metallic Nanoparticles: Applications and Limitations

The past decade has witnessed a phenomenal rise in nanotechnology research due to its broad range of applications in diverse fields including food safety, transportation, sustainable energy, environmental science, catalysis, and medicine. The distinctive properties of nanomaterials (nano-sized particles in the range of 1 to 100 nm) make them uniquely suitable for such wide range of functions. The nanoparticles when manufactured using green synthesis methods are especially desirable being devoid of harsh operating conditions (high temperature and pressure), hazardous chemicals, or addition of external stabilizing or capping agents. Numerous plants and microorganisms are being experimented upon for an eco–friendly, cost–effective, and biologically safe process optimization. This review provides a comprehensive overview on the green synthesis of metallic NPs using plants and microorganisms, factors affecting the synthesis, and characterization of synthesized NPs. The potential applications of metal NPs in various sectors have also been highlighted along with the major challenges involved with respect to toxicity and translational research.

Optimization and characterization of eco-friendly antimicrobial nanocellulose sheet prepared using carbon dots of white mulberry (Morus alba L.)

BACKGROUND

Carbon dots (C-dots) with antimicrobial activity were synthesized from the white mulberry extract with the aim of fabricating anti-listeria nanopaper using bacterial nanocellulose (BNC). Highly dispersed synthesized C-dots with a size smaller than 10 nm (approximately 4.9 nm) were impregnated into BNC by an ex situ coating method and then mechanical, morphological, UV-protectant and antibacterial activity were assessed. Randomized response surface methodology using a central composite design was applied to investigate the optimized concentration of C-dots in the BNC membrane.

RESULTS

An optimized nanopaper including C-dots at a concentration of 530 g L^-1 and an impregnation time of 14 h at 30 °C with significant antimicrobial activity on Listeria monocytogenes was designed. The addition of C-dots into BNC significantly increased ultimate tensile strength and decreased strain with respect to breaking BNC. A BNC sheet with high-efficient UV-blocking property was prepared using C-dots.

CONCLUSION

Based on the results, the designed nanopaper shows a substantial capacity with respect to the fabrication of antimicrobial/UV-blocking sheets for food active packaging. © 2020 Society of Chemical Industry.

Versatile nanocellulose-based nanohybrids: A promising-new class for active packaging applications

The food packaging industry is rapidly growing as a consequence of the development of nanotechnology and changing consumers' preferences for food quality and safety. In today's globalization of markets, active packaging has achieved many advantages with the capability to absorb or release substances for prolonging the food shelf life over the traditional one. Therefore, it is critical to developing multifunctional active packaging materials from biodegradable polymers with active agents to decrease environmental challenges. This review article addresses the recent advances in nanocelluloses (NCs)- baseds nanohybrids with new function features in packaging, focusing on the various synthesis methods of NCs-based nanohybrids, and their reinforcing effects as active agents on food packaging properties. The applications of NCs-based nanohybrids as antioxidants, antimicrobial agents, and UV blocker absorbers for prolonging food shelf-life are also reviewed. Overall, these advantages make the CNs-based nanohybrids with versatile properties promising in food and packaging industries, which will impact more readership with concern for future research.

The role of genetic manipulation and in situ modifications on production of bacterial nanocellulose: A review

Natural polysaccharides are well-known biomaterials because of their availability and low-cost, with applications in diverse fields. Cellulose, a renowned polysaccharide, can be obtained from different sources including plants, algae, and bacteria, but recently much attention has been paid to the microorganisms due to their potential of producing renewable compounds. In this regard, bacterial nanocellulose (BNC) is a novel type of nanocellulose material that is commercially synthesized mainly by Komagataeibacter spp. Characteristics such as purity, porosity, and remarkable mechanical properties made BNC a superior green biopolymer with applications in pharmacology, biomedicine, bioprocessing, and food. Genetic manipulation of BNC-producing strains and in situ modifications of the culturing conditions can lead to BNC with enhanced yield/productivity and properties. This review mainly highlights the role of genetic engineering of Komagataeibacter strains and co-culturing of bacterial strains with additives such as microorganisms and nanomaterials to synthesize BNC with improved functionality and productivity rate.

Protective effects of green and chemical zinc oxide nanoparticles on testis histology, sperm parameters, oxidative stress markers and androgen production in rats treated with cisplatin

Cancer treatment with cisplatin (CP) is associated with adverse side effects on male reproductive tissues. Although beneficial effects of zinc oxide nanoparticles (ZnO NPs) in cancer therapy have received considerable attention, data related to the protective effects of green ZnO NPs against CP-induced male reproductive dysfunctions are limited. Forty-five rats were divided into 9 groups including G1 (control), G2 (sham), G3 (ZnO bulk), G4 (green ZnO NPs), G5 (chemical ZnO NPs), G6 (CP), G7 (CP + ZnO bulk), G8 (CP + green ZnO NPs), and G9 (CP + chemical ZnO NPs). CP was administrated (5 mg/kg/week) for 4 weeks, and animals were simultaneously treated with different forms of ZnO (5 mg/kg/day). Testis histology, sperm parameters, oxidative stress markers, testosterone concentration, and expression of genes related in steroidogenesis were analyzed in different experimental groups. Testis tissue damage and epididymal sperm disorders induced by CP attenuated when animals were treated with different forms of ZnO, especially green ZnO NPs. Decreased testosterone concentration and increased MDA level in CP-treated rats were reversed following administration different forms of ZnO, especially green and chemical ZnO NPs. Co-administration of ZnO NPs to CP-treated rats restored the suppressive effects of CP on activities of antioxidant enzymes (SOD, GPX, CAT) and the transcription of the STAR gene. None of the ZnO forms had a significant regulatory effect on the expression of CYP11A1 in CP-treated rats. The results showed that in most of the evaluated factors, green ZnO NPs showed a greater protective effect than other forms of ZnO.

Green Synthesis of Metallic Nanoparticles and Their Prospective Biotechnological Applications: an Overview

The green synthesis of nanoparticles (NPs) using living cells is a promising and novelty tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs; however, biological methods are preferred due to its eco-friendly, clean, safe, cost-effective, easy, and effective sources for high productivity and purity. High pressure or temperature is not required for the green synthesis of NPs, and the use of toxic and hazardous substances and the addition of external reducing, stabilizing, or capping agents are avoided. Intra- or extracellular biosynthesis of NPs can be achieved by numerous biological entities including bacteria, fungi, yeast, algae, actinomycetes, and plant extracts. Recently, numerous methods are used to increase the productivity of nanoparticles with variable size, shape, and stability. The different mechanical, optical, magnetic, and chemical properties of NPs have been related to their shape, size, surface charge, and surface area. Detection and characterization of biosynthesized NPs are conducted using different techniques such as UV-vis spectroscopy, FT-IR, TEM, SEM, AFM, DLS, XRD, zeta potential analyses, etc. NPs synthesized by the green approach can be incorporated into different biotechnological fields as antimicrobial, antitumor, and antioxidant agents; as a control for phytopathogens; and as bioremediative factors, and they are also used in the food and textile industries, in smart agriculture, and in wastewater treatment. This review will address biological entities that can be used for the green synthesis of NPs and their prospects for biotechnological applications.

Preparation of antimicrobial/ultraviolet protective bacterial nanocellulose film with carbon dots synthesized from lactic acid bacteria

Microbial biomass, as an environmentally friendly resource, has drawn a lot of attention as green biomaterials for production of unique and functionalized carbon dots (CDs). However, the hydrophilicity and high porosity drive bacterial nanocellulose as a suitable matrix for CDs with antimicrobial, photoluminescent and ultraviolet blocking features. For the first time, antimicrobial CDs were synthesized by hydrothermal method from cell-free supernatant of Lactobacillus acidophilus and characterized. Antimicrobial performance of CDs was examined on Escherichia coli (Gram-negative) and Listeria monocytogenes (Gram-positive). Additionally, the as-prepared CDs embedded by ex-situ method into nanocellulose in order to fabricate antimicrobial/ultraviolet protective nanopaper. The photoluminescent CDs with an average size of 2.8 nm and high-hydroxylated groups were synthesized. The CDs at 500 mg mL^-1 concentration had antibacterial activity towards both bacteria. Moreover, nanopaper displayed a fluorescence appearance under ultraviolet. Nanocellulose with CDs loading capacity of 71.74 ± 4.13 mg cm^-2 represented an appropriate stretchability and flexibility in comparison to nanocellulose. The CDs incorporated nanopaper also depicted greater ultraviolet-blocking specifications and inhibitory activity on Gram-positive bacterium than Gram-negative one. CDs can be used as a novel fluorescence antimicrobial/ultraviolet protective material in the nanocellulose film in order to develop an antimicrobial and forgery-proof packaging due to their fluorescence appearance.

Phytosynthesized Metallic Nanoparticles-between Nanomedicine and Toxicology. A Brief Review of 2019's Findings

Phytosynthesized nanoparticles represent a continuously increasing field of research, with numerous studies published each year. However, with the emerging interest in this area, the quality of the published works is also continuously increasing, switching from routine antioxidant or antimicrobial studies on trivial microbial lines to antibiotic-resistant strains or antitumoral studies. However, this increasing interest has not been not reflected in the studies regarding the toxicological effects of nanoparticles (NPs); this should be a subject of greatest interest, as the increasing administration of NPs in general (and phytosynthesized NPs in particular) could lead to their accumulation in the environment (soil, water and living organisms). The present review aims to present the most recent findings in the application of phytosynthesized NPs as antimicrobial and antitumoral agents, as well as the results regarding their toxicological potential.