A multifunctional vanillin-infused chitosan-PVA hydrogel reinforced by nanocellulose and CuO-Ag nanoparticles as antibacterial wound dressing

Wound healing is an intricate and ever-evolving phenomenon that involves a series of biological processes and multiple stages. Despite the growing utilization of nanoparticles to enhance wound healing, these approaches often overlook properties like mechanical stability, toxicity, and efficacy. Hence, a multifunctional wound dressing is fabricated using Chitosan-PVA membrane crosslinked with vanillin and reinforced with nano-cellulose and CuO-Ag nanoparticles in this study. FTIR, SEM, and XRD were employed to study the morphology and structural properties of the membrane. Biomedical tests including biodegradability, antimicrobial study, cytotoxicity, and animal models were conducted to evaluate the membrane's performance as a wound healing material. The membrane displayed impressive mechanical strength, measuring as high as 49.985 ± 2.31 MPa, and had a hydrophilic nature, with moisture retention values up to 98.84 % and swelling percentages as high as 191.67 %. It also demonstrated biodegradable properties and high cell viability of up to 92.30 %. Additionally, the fabricated membranes exhibited excellent antimicrobial activity against both gram-positive and gram-negative bacteria, with maximum zone of inhibition measuring 16.8 ± 0.7 mm and 9.2 ± 0.1 mm, respectively. Moreover, the membranes also demonstrated superior wound healing properties. These results suggested great potential of fabricated membranes as an effective wound dressing material.

Straw incorporation into microplastic-contaminated soil can reduce greenhouse gas emissions by enhancing soil enzyme activities and microbial community structure

Microplastic (MP) contamination poses a substantial threat to agroecosystems, disrupting soil properties, nutrient cycles, and microbial communities and ultimately affecting plant growth and ecosystem resilience. The effects of straw addition on the storage of soil organic carbon (SOC) and greenhouse gas emissions have been extensively explored, but these effects have not been examined in the context of MP contamination. To assess the impacts of legume straw and polyethylene microplastics on SOC fractions and carbon dioxide (CO2) and nitrous oxide (N2O) emissions, 7-month soil incubation experiments were performed. The results revealed that the inclusion of legume straw in soil considerably increased microbial SOC compared to the control. However, straw addition to MP-contaminated soil reduced microbial SOC compared to that in soil containing only straw. In contrast, the addition of straw to MP-contaminated soil elevated (+44%) the SOC mineral relative to the sole application of straw. Intriguingly, straw incorporation into MP-contaminated soil reduced microbial biomass carbon and nitrogen relative to soil containing only straw. Straw addition to MP-contaminated soil enhanced the nitrification activity and reduced the relative expression of AOBamoABC gene compared to sole straw-incorporated soil and the control. Greenhouse gas emissions were also modulated; for instance, straw incorporation into MP-contaminated soil reduced CO2 and N2O emissions by -11% and -46%, compared to straw incorporation alone. The urease and phosphatase activities were decreased (-58% and -12%) in the MP-polluted soil with straw incorporation compared with those in the soil in which only straw was applied. However, invertase and catalase activities were upregulated in the straw-incorporated soil contaminated with MPs. Straw addition in the MP-polluted soil considerably enhanced (+2%) the microbial community structure (indicated by PLFA) compared to the sole straw application. These results provide a comprehensive perspective on the role of legume straw incorporation in addressing MP pollution, showcasing its potential for sustainable agricultural practices in the face of evolving environmental challenges.

Development and testing of environment friendly nanohybrid coatings for sustainable agriculture technologies

Less than 50% of the applied urea fertilizer is taken up by plants due to poor nitrogen (N) use efficiency which affects overall agricultural productivity and leads to serious environmental and economic problems. Additionally, soils with high salinity might limit zinc (Zn) availability. Low Zn use efficiency (<30%) when applied as synthetic salts, e.g., zinc sulfate has therefore minimized their applicability. Within the past two decades, nanotechnology has gained a lot of interest in the development of effective nano fertilizers with high nutrient use efficiency (NUE). In this perspective, the approach of coating conventional fertilizers with nano materials especially, the ones which are essential nutrients has researched because of their high use efficiency and reduced losses. In this work, a novel and innovative formulation of hybrid nano fertilizer has been prepared for the sustainable release of nutrients. Zinc oxide nanoparticles (ZnO-NPs <50 nm) were incorporated into the biodegradable polymer (gelatin) and coated on urea using a fluidized bed coater. Among all the formulations, GZnSNPs (1.5% gelatin+0.5% elemental Zn as ZnO-NPs) showed a significant delay in urea release (<80 %) after 120 min). The sand column experiment showed sustainable Zn release for GZnSNPs i.e., 2.7 ppm vs. 3.5 ppm (GZnS) after the 6th day. Moreover, a substantial increase in wheat grain yield (6500 kg/ha), N uptake (46.5 kg/ha) and Zn uptake (21.64 g/ha) were observed for fields amended with GZnSNPs. The composition of GZnSNPs was valuable since this attracted the highest return relative to the other treatments. Gelatin supplied small N-containing molecules, resulting in extra value addition with ZnO-NPs thus increasing yield and fertilizer properties more relative to the same amount of elemental Zn given via bulk salt. Therefore, the findings of the current study recommend the use of ZnO-NPs in the agricultural sector without any negative effects on yield and NUE.

Graphene-grafted bimetallic MOF membranes for hazardous & toxic contaminants treatment

Development of membrane with improved carbon dioxide (CO2) gas separation capability is a significant challenge. However, the fabrication of membrane that efficiently separate and purification CO2-containing gases has been the focus of global attention. Cellulose Acetate (CA) has robust reinforcing characteristics when incorporated within a suitable polymer matrix. This work focus on the synthesis of novel mixed matrix membranes (MMMs) by introducing Graphene-grafted bimetallic MOFs in Cellulose Acetate polymer. The graphene-grafted bimetallic MOF (GG-BM MOFs) was prepared by a hydrothermal technique. Whereas, the solution casting approach used to fabricate membranes. The 1-5 wt% of GG-BM MOFs incorporated into the CA matrix. The mechanical, hydrophilicity and adsorption characteristics of fabricated MMMs were investigated. The crystallinity of MMM enhanced after the addition of GG-BM MOFs. In addition, the mechanical characteristics of MMMs were improved with the incorporation of GG-BM MOFs inside the polymer matrix. Maximum stress and strain was obtained for 2 wt% MMM (36.4 N/mm2 and 11% respectively). The CO2 adsorption performance was evaluated at 10 bar and 45 °C. The FTIR results represent insignificant bond shifting with the addition GG-BM MOFs at these conditions. The overall results showed that MMMs containing 2 wt% GG-BM MOFs have good adsorption properties for CO2 i.e 3.15 wt% of CO2. The MMMs have shown a decrease in the mechanical properties and CO2 adsorption at the higher GG-BM MOFs loading due to the presence of agglomeration which was confirmed through SEM. Thus, the addition of GG-BM MOFs in the CA matrix positively altered the physicochemical characteristics of the resulting MMMs, which could assist them in achieving remarkable CO2 adsorption at 2 wt%.

Mechanical milling processed highly luminescent Cs-Pb-Br perovskite emitters

We report well-dispersed highly emitting perovskite emitters synthesized via the surfactant-assisted ball-milling method. Both the emitting peaks and the colour purity of the synthesized perovskite emitters can be effectively tuned through additive functionalization and precursor engineering.

Development of ZnO-GO-NiO membrane for removal of lead and cadmium heavy metal ions from wastewater

The presence of heavy metal (HM) ions, such as lead, cadmium, and chromium in industrial wastewater discharge are major contaminants that pose a risk to human health. These HMs should separate from the wastewater to ensure the reuse of the discharged water in the process and mitigate their environmental impacts. The distinctive mechanical properties of 2D graphene oxide (GO), and the antifouling characteristics of metal oxides (ZnO/NiO) nanoparticles combined to produce composites supporting special features for wastewater treatment. This study employed solution casting and phase inversion methods to synthesize PSF-based GO, ZnO-GO, and ZnO-GO-NiO mixed matrix membranes and the effects of variation in composition on the removal of lead (Pb2+) and cadmium (Cd2+) ion was examined. Several characterization techniques including X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray, and Fourier transform infrared spectroscopy were applied to analyze the synthesized NPs and MMMs. The composite membranes were also analyzed in terms of their porosity, permeability, hydrophilicity, surface roughness, zeta potential, thermal stability, mechanical strength, and flux regeneration at various transmembrane pressures (2-3 kgcm-2), and pH value (5.5). The highest adsorption capacities were measured to be 308.16 mg g-1 and 354.80 mg g-1 for Pb (II) and Cd (II), respectively, for membrane (M4_A) having 0.3 wt% of ZnO-GO-NiO nanocomposite, at 200 mg L-1 of feed concentration and 1.60 mL min-1 of permeate flux. The Pb (II) and Cd (II) adsorption breakthrough curves were created, and the results of the experiment were compared with the data of the Thomas model.

Alleviation of cadmium toxicity in wheat by strigolactone: Regulating cadmium uptake, nitric oxide signaling, and genes encoding antioxidant defense system

Cadmium (Cd) in the food system poses a serious threat to human health. The evidence on strigolactones-mediated alleviation of abiotic stress signaling and eliciting physiological modifications in plants is scarce. Therefore, this experiment was conducted to explore the role of exogenous applied strigolactone (SL) in alleviating the toxic effects of Cd and to unravel its physiological, biochemical, and molecular mechanisms in wheat. Excessive accumulation of Cd drastically reduces growth attributes (-15%), nitric oxide signaling, and photosynthetic pigments by increasing oxidative stress biomarkers. Foliar applied SL (4 μM) decreased the Cd-induced growth inhibition (+10%), lessened plant Cd contents (-38% and -36%), shielded chlorophyll pigments (+25%), and considerably decreased Cd-induced oxidative stress in wheat. Moreover, SL applied on wheat foliage remarkably enhanced shoot and root nitric oxide content (+122% and +156%) and nitric oxide synthase activity (104% and 92%) in wheat, efficiently mitigating the Cd-induced suppression of superoxide dismutase and peroxidase, elevating the expression of genes encoding antioxidant defense system. The results of the current research exhibit that SL (GR24) could be a potential candidate for detoxification of Cd by reducing Cd contents, elevating the expression of genes encoding antioxidant defense system, and protecting wheat plants from oxidative stress by indirectly reducing oxidative stress biomarkers andsubsequently contributing to decreasing the possible risk of Cd contamination.

Algal-based wood as a green and sustainable alternative for environmentally friendly & flexible electronic devices membrane bioreactor

Electronic are usually constructed from non-renewable, non-biodegradable, and hazardous materials. Due to the frequent upgrading or discarding of electronic devices, which contributes significantly to environmental pollution, there is a high demand for electronics made from renewable and biodegradable materials with less harmful components. To this end, due to their flexibility, strong mechanical, and optical properties, wood-based electronics have become very appealing as substrates especially for flexible electronics and optoelectronics. However, incorporating numerous features including high conductivity and transparency, flexibility, and mechanical robustness into an environmentally friendly electronic device remains very challenging. Herein, authors have provided the techniques used to fabricate sustainable wood based flexible electronics coupled with their chemical, mechanical, optical, thermal, thermomechanical, and surface properties for various applications. Additionally, the synthesis of a conductive ink based on lignin and the development of translucent wood as a substrate are covered. Future developments and broader applications of wood-based flexible materials are discussed in the final section of the study, with an emphasis on their potential in fields including wearable electronics, renewable energy, and biomedical devices. This research improves upon prior efforts by demonstrating new ways to simultaneously attain better mechanical and optical qualities and environmental sustainability.

Development and testing of zinc sulfate and zinc oxide nanoparticle-coated urea fertilizer to improve N and Zn use efficiency

Nitrogen (N) losses from conventional fertilizers in agricultural systems are very high, which can lead to serious environmental pollution with economic loss. In this study, innovative slow-release fertilizers were prepared using zinc (Zn) [nanoparticles (NPs) or in bulk], using molasses as an environmentally friendly coating. Several treatments were prepared using Zn in different concentrations (i.e., 0.25%, 0.5%, and 4% elemental Zn). The zinc oxide nanoparticles (ZnO-NPs) were prepared from zinc sulfate heptahydrate (ZnSO₄·7H₂O), and were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Furthermore, the Zn-loaded urea samples were tested for urea N release rate, leaching of water from soil, and crushing strength to assess the impact of coating on the final finished product. Pot experiments were conducted simultaneously to check the agronomic effects of Zn-coated slow-release urea on the growth and development of wheat (Triticum aestivum L.). The laboratory and pot results confirmed that the ZnO-NP treatments boost wheat growth and yield as a result of reduced N and Zn release. UZnNPs2 (urea coated with 0.5% ZnO-NPs and 5% molasses) demonstrated the best results among all the treatments in terms of slow nutrient release, N and Zn uptake, and grain yield. The UZnNPs2 treatment increased plant yield by 34% (i.e., 4,515 vs. 3,345 kg ha^-1) relative to the uncoated prill-treated crop because of the slower release of Zn and N.

Polyvinyl alcohol and aminated cellulose nanocrystal membranes with improved interfacial compatibility for environmental applications

Biogas up-gradation is a useful method to control CO₂ emission and enhance the green process. The demand for renewable sources is increasing due to the depletion of fossil fuels. Thin-film nanocomposites functionalized with tunable molecular-sieving nanomaterials have been employed to tailor membranes with enhanced permeability and selectivity. In this work, the cellulose nanocrystals as a filler in the polyvinyl alcohol matrix are prepared to achieve high-performance facilitated transport membranes for CO₂ capture. Considering the mechanical stability, interfacial compatibility and high moisture uptake of the filler, the main objective of this work was to develop a novel aminated CNC (Am-CNC)/polyvinyl alcohol nanocomposite membrane for biogas upgrading. The hydroxyl groups (O-H) on the reducing end of the cellulose nanocrystals were replaced by amino groups (N-H₂). It was discovered through Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) that adding Am-CNCs in PVA membranes shows an increment in the CO₂ removal and effectively upgrades the biogas. The effect of change in concentration of Am-CNC and feed pressure was investigated. The results showed that with increasing Am-CNC concentration up to 1.5 wt%, the thickness of the selective membrane layer increased from 0.95 to 1.9 μm with a decrease in the moisture uptake from 85.04 to 58.84%. However, the best CO₂ permeance and selectivity were achieved at 0.306 m³/m².bar.h (STP) and 33.55, respectively. Furthermore, there was a more than two-fold decrease in CO₂ permeance and a 27% decrease in the CO₂/CH₄ selectivity when the feed pressure increased from 5 to 15 bar. It was revealed that PVA/Am-CNC membrane is high performing for the biogas upgradation.

Cellulose acetate based sustainable nanostructured membranes for environmental remediation

Membrane-based gas separation has a great potential for reducing environmentally hazardous carbon dioxide (CO₂) gas. The polymeric membranes developed for CO₂ capturing have some limitations in their selectivity and permeability. There is a need to overcome these issues and developed such membranes having high-performance CO₂ capture with cost-effectiveness. The present study aimed to synthesize mixed matrix membranes (MMMs) having improved properties CO₂ adsorption performance and stability than that of pure polymer. Further, the effect on CO₂ adsorption by increasing the filler concentration in MMMs was investigated. The MMMs were synthesized by incorporating (1-5 wt%) Cu-MOF-GO composites as filler into cellulose-acetate (CA) polymer matrix by adopting the solution casting method. The performance of MMMs was studied by changing the Cu-MOF-GO composite concentration (1-5 wt%) in the polymer matrix at 45 °C up to 15 bar. Morphological analysis by using SEM confirms that by increasing the concentration of Cu-MOF-GO more than 3% will result in their agglomeration in MMM. The successful incorporation of MOF within the polymer matrix of MMMs was confirmed through the presence of functional groups using FTIR and Raman spectroscopy. XRD analysis revealed that pure CA changes its semi-crystalline behaviour into crystalline by the addition of Cu-MOF-GO. The maximum tensile stress and strain rate of MMMs was 45.1 N/mm² and 12.8%. In addition, with an increase in (4-5 wt%) Cu-MOF-GO concentration the hydrophilicity of MMMs decreases. The maximum uptake rate of CO₂ was 1.79 mmol/g and 7.98 wt% at 15 bar. The adsorption results conclude that Cu-MOF-GO composite and CA-based MMM can be effective for CO₂ capture.

Facile coating of micronutrient zinc for slow release urea and its agronomic effects on field grown wheat (Triticum aestivum L.)

Slow release urea has been widely tested in recent past as an effective method to enhance the crop productivity with fewer environmental concerns. However, very few research studies have been performed using micronutrients as a source of slow release of urea nitrogen. A laboratory and field study were carried out to check the agronomic effects of zinc oxide nanoparticles and its bulk salt coatings on urea prills on wheat (Triticum aestivum L.). Different concentrations of zinc oxide nanoparticles (0.25, 0.5 and 4% elemental zinc) were coated on urea prills to slow down the release rate. Bulk zinc oxide salt (ZnO) with similar concentrations was also used in parallel to make a comparison between nano and bulk salt. The SEM of zinc oxide nanoparticles clearly depicted zinc oxide nanoparticles size within a range of 50-90 nm. The XRD and FTIR spectrums also showed its characteristics peak at designated positions. Field study revealed than 0.5% zinc oxide nanoparticles coated urea boosted the crop growth and yield in comparison to the bulk zinc oxide coated urea having similar zinc concentrations, i.e., 0.25%, 0.5% and 4% elemental zinc. The plant parameters like plant height, root length, root volume, grain yield and dry matter weight were significantly increased due to application of zinc oxide nanoparticles.

Functionalized organic filler based integrated membranes for environmental remediation

Mixed matrix membranes (MMMs) are synthesized for efficient CO₂ separation released from various anthropogenic sources, which are due to global environmental concerns. The synergetic effect of porous nitrogen-rich, CO₂-philic filler and polymer in mixed matrix-based membranes (MMMs) can separate CO₂ competent. The development of various loadings of porphyrin poly(N-isopropyl Acryl Amide) (P-NIPAM)as functionalized organic fillers (5-20%) in polysulfone (PSU) through solution casting is carried out followed by the various characterizations including field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), Fourier Transform Infrared Spectrometer(FT-IR) analysis and pure and mixed gas permeations ranging from 2 to 10 bar feed pressure. Due to both organic species interactions in the matrix, well-distributed fillers and homogenous surfaces, and cross-sectional structures were observed due to π-π interactions and Lewis's basic functionalities. The strong affinity of porous nitrogen-rich and CO₂-philic fillers through gas permeation analysis showed high CO₂/CH₄ and CO₂/N₂ gas performance that surpassed Robeson's upper bound limit. Comparatively, MMMs showed improved CO₂/CH₄ permeabilities from 87.5 ± 0.5 Barrer to 88.2 ± 0.9 Barrer than pure polymer matrix. For CO₂/N₂, CO₂ permeabilities improved to 75 ± 0.8 Barrer than pure polymer matrix. For both gas pairs (CO₂/CH₄, CO₂/N₂), respective pureselectivities (84%; 86%) and binary selectivities (85% and 85%)were improved. Various theoretical gas permeation models were used to predict CO₂ permeabilities for MMMs from which the modified Maxwell-Wagner-Sillar model showed the least AARE% of 0.87. The results showed promising results for efficient CO₂ separation due to exceptional functionalized P-PNIPAM affinitive properties. Finally, cost analysis reflected the inflated cost of membranes production for industrial setup using indigenous resources.

Moringa concanensis-Mediated Synthesis and Characterizations of Ciprofloxacin Encapsulated into Ag/TiO2/Fe2O3/CS Nanocomposite: A Therapeutic Solution against Multidrug Resistant E. coli Strains of Livestock Infectious Diseases

Background: Multidrug resistant MDR bacterial strains are causing fatal infections, such as mastitis. Thus, there is a need for the development of new target-oriented antimicrobials. Nanomaterials have many advantages over traditional antibiotics, including improved stability, controlled antibiotic release, targeted administration, enhanced bioavailability, and the use of antibiotic-loaded nanomaterials, such as the one herein reported for the first time, appear to be a promising strategy to combat antibiotic-resistant bacteria. The use of rationally designed metallic nanocomposites, rather than the use of single metallic nanoparticles (NPs), should further minimize the bacterial resistance. Aim: Green synthesis of a multimetallic/ternary nanocomposite formed of silver (Ag), titanium dioxide (TiO2), and iron(III) oxide (Fe2O3), conjugated to chitosan (CS), in which the large spectrum fluoroquinolone antibiotic ciprofloxacin (CIP) has been encapsulated. Methods: The metallic nanoparticles (NPs) Ag NPs, TiO2 NPs, and Fe2O3 NPs were synthesized by reduction of Moringa concanensis leaf aqueous extract. The ternary junction was obtained by wet chemical impregnation technique. CIP was encapsulated into the ternary nanocomposite Ag/TiO2/Fe2O3, followed by chitosan (CS) conjugation using the ionic gelation method. The resulting CS-based nanoparticulate drug delivery system (NDDS), i.e., CIP-Ag/TiO2/Fe2O3/CS, was characterized in vitro by gold standard physical techniques such as X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), Fourier-transform infrared (FTIR) spectroscopy. Pharmacological analyses (i.e., LC, EE, ex-vivo drug release behavior) were also assessed. Further, biological studies were carried out both ex vivo (i.e., by disk diffusion method (DDM), fluorescence-activated single cell sorting (FACS), MTT assay) and in vivo (i.e., antibacterial activity in a rabbit model, colony-forming unit (CFU) on blood agar, histopathological analysis using H&E staining). Results: The encapsulation efficiency (EE) and the loading capacity (LC) of the NDDS were as high as 94% ± 1.26 and 57% ± 3.5, respectively. XRD analysis confirmed the crystalline nature of the prepared formulation. FESEM revealed nanorods with an average diameter of 50−70 ± 12 nm. FTIR confirmed the Fe-O-Ti-CS linkages as well as the successful encapsulation of CIP into the NDDS. The zeta potential (ZP) of the NDDS was determined as 85.26 ± 0.12 mV. The antimicrobial potential of the NDDS was elicited by prominent ZIs against MDR E. coli (33 ± 1.40 mm) at the low MIC of 0.112 μg/mL. Morphological alterations (e.g., deformed shape and structural damages) of MDR pathogens were clearly visible overtime by FESEM after treatment with the NDDS at MIC value, which led to the cytolysis ultimately. FACS analysis confirmed late apoptotic of the MDR E. coli (80.85%) after 6 h incubation of the NDDS at MIC (p < 0.05 compared to untreated MDR E. coli used as negative control). The highest drug release (89% ± 0.57) was observed after 8 h using PBS medium at pH 7.4. The viability of bovine mammary gland epithelial cells (BMGE) treated with the NDDS remained superior to 90%, indicating a negligible cytotoxicity (p < 0.05). In the rabbit model, in which infection was caused by injecting MDR E. coli intraperitoneally (IP), no colonies were detected after 72 h of treatment. Importantly, the histopathological analysis showed no changes in the vital rabbit organs in the treated group compared to the untreated group. Conclusions: Taken together, the newly prepared CIP-Ag/TiO2/Fe2O3/CS nanoformulation appears safe, biocompatible, and therapeutically active to fight MDR E. coli strains-causing mastitis.

Challenges and recent trends with the development of hydrogel fiber for biomedical applications

Hydrogel is the most emblematic soft material which possesses significantly tunable and programmable characteristics. Polymer hydrogels possess significant advantages including, biocompatible, simple, reliable and low cost. Therefore, research on the development of hydrogel for biomedical applications has been grown intensely. However, hydrogel development is challenging and required significant effort before the application at an industrial scale. Therefore, the current work focused on evaluating recent trends and issues with hydrogel development for biomedical applications. In addition, the hydrogel's development methodology, physicochemical properties, and biomedical applications are evaluated and benchmarked against the reported literature. Later, biomedical applications of the nano-cellulose-based hydrogel are considered and critically discussed. Based on a detailed review, it has been found that the surface energy, intermolecular interactions, and interactions of hydrogel adhesion forces are major challenges that contribute to the development of hydrogel. In addition, compared to other hydrogels, nanocellulose hydrogels demonstrated higher potential for drug delivery, 3D cell culture, diagnostics, tissue engineering, tissue therapies and gene therapies. Overall, nanocellulose hydrogel has the potential for commercialization for different biomedical applications.

Synthesis and Characterization of Carbon Dots Coated CaCO3 Nanocarrier for Levofloxacin Against Multidrug Resistance Extended-Spectrum Beta-Lactamase Escherichia coli of Urinary Tract Infection Origin

The multidrug resistance (MDR) Escherichia coli having Extended-Spectrum Beta-Lactamase (ESBL) genes and the capacity to create a biofilm acts as a major reduction in the therapeutic effectiveness of antimicrobials. In search of a novel nanocarrier (NC) for targeted delivery of antibiotics, carbon dots (CDs) coated calcium carbonate nanocarriers (CCNC) from organic chicken eggshells conjugated with levofloxacin (Lvx) were synthesized. Our main objectives were to explore the antimicrobial, antibiofilm, and NC potential of CDs coated CaCO₃ Nanocarrier conjugated with levofloxacin (CD-CCNC-Lvx) to combat biofilm-producing MDR ESBL E. coli of urinary tract infection origin. The synthesized NC system was physiochemically characterized, validating the synthesis of CCNC and CD-CCNC-Lvx with a particle size of 56 and 14 nm, respectively. Scanning electron microscopy (SEM) showed rod shape morphology. X-ray diffraction results discovered crystalline and dispersed nanoparticles. In vitro release drug kinetics illustrated sustained release of Lvx. NC system exhibited strong antibacterial and antibiofilm potential against E. coli with a noticeable low minimal inhibitory concentration (MIC). MIC of CCNC was found to be 30 ± 0.1 μg/mL and CD-CCNC-Lvx was 20 ± 0.1 μg/mL for MDR ESBL-producing E. coli. The synergistic effect of NC upon conjugation with Lvx showed incredible activity with 30 mm zone of inhibition and 68% biofilm inhibition. Flow cytometry analysis revealed treated E. coli cells showed 58.69% reduction in cell viability. SEM images of treated bacterial cells showed morphological changes, which were also confirmed by our flow cytometry findings leading to cell membrane damage in E. coli. NC system also downregulated the bla_CTX-M gene in E. coli. The hemolytic analysis proved biocompatibility with human red blood cells (RBCs). It is concluded that CCNC has the potential to be used as NC for target delivery of antibiotics and may combat toxicity of antibiotics as the inhibition of E. coli was noticed at low MIC concentration.

Occurrence, influencing factors, toxicity, regulations, and abatement approaches for disinfection by-products in chlorinated drinking water: A comprehensive review

Disinfection is considered as a vital step to ensure the supply of clean and safe drinking water. Various approaches are adopted for this purpose; however, chlorination is highly preferred all over the world. This method is opted owing to its several advantages. However, it leads to the formation of certain by-products. These chlorination disinfection by-products (DBPs) are genotoxic, carcinogenic and mutagenic. Still chlorination is being practiced worldwide. Present review gives insights into the occurrence, toxicity and factors affecting the formation of regulated (THMs, HAAs) and emerging DBPs (N-DBPs, HKs, HAs and aromatic DBPs) found in drinking water. Furthermore, remediation techniques used to control DBPs have also been summarized here. Key findings are: (i) concentration of regulated DBPs surpassed the permissible limit in most of the regions, (ii) high chlorine dose, high NOM, more reaction time (up to 3 h) and high temperature (up to 30 °C) enhance the formation of THMs and HAAs, (iii) high pH favors the formation of THMs while low pH is suitable of the formation of HAAs, (iv) high NOM, low temperature, low chlorine dose and moderate pH favors the formation of unstable DBPs (N-DBPs, HKs and HAs), (v) DBPs are toxic not only for humans but for aquatic fauna as well, (vi) membrane technologies, enhanced coagulation and AOPs remove NOM, (vii) adsorption, air stripping and other physical and chemical methods are post-formation approaches (viii) step-wise chlorination is assumed to be an efficient method to reduce DBPs formation without any treatment. Toxicity data revealed that N-DBPs are found to be more toxic than C-DBPs and aromatic DBPs than aliphatic DBPs. In majority of the studies, merely THMs and HAAs have been studied and USEPA has regulated just these two groups. Future studies should focus on emerging DBPs and provide information regarding their regulation.

Biogenic copper nanoparticles produced by using the Klebsiella pneumoniae strain NST2 curtailed salt stress effects in maize by modulating the cellular oxidative repair mechanisms

The negative effects of salinity on plant growth and physiology are well-established, which is one of the major threats to food security in semi-arid and arid regions of the world. The current research focuses on biosynthesis of copper nanoparticles (CuNPs) from a bacterial strain NST2, which was genetically identified as Klebsiella pneumoniae based on taxonomic identity of 16S rRNA gene. The strain was selected for bioprospecting of CuNPs owing to its Cu tolerance potential. The biologically-synthesized CuNPs were confirmed in culture by using ultraviolet visible spectroscopy. The material characteristics of green CuNPs were further investigated by using Fourier transform infrared spectroscopy, X-ray diffractometer, scanning electron microscopy and transmission electron microscopy, where crystallite size was ranged from 22.44 nm to 44.26 nm and particles were stabilized by various functional groups, such as carbonyl and amine groups. When 100 mg kg^-1 of green CuNPs were mixed in saline soil in a pot experiment, the maize plants showed increased root and shoot length (43.52% and 44.06%, respectively), fresh weight (46.05% and 51.82%, respectively) and dry weight (47.69% and 30.63%, respectively) in comparison to control maize plants without CuNPs application. Moreover, green CuNPs at their highest treatment level (100 mg kg^-1 of soil) counteracted the lipid peroxidation and oxidative damage in maize plants by promoting the activities of antioxidants and demoting the cellular levels of reactive oxygen species and ionic contents of Na⁺ and Cl^-. Conclusively, biogenic CuNPs is an emerging and promising technique, which could replace traditional methods of salinity management in agricultural soils.

Cellulose acetate-polyvinyl alcohol blend hemodialysis membranes integrated with dialysis performance and high biocompatibility

Hemodialysis considered as therapy of end-stage renal disease (ESRD) for the separation of protein and uremic toxins based on their molecular weights using semi-permeable membranes. Cellulose Acetate (CA) hemodialysis membrane has been widely used in the biomedical field particularly for hemodialysis applications. The main issue of CA membrane is less selectivity and hemocompatibility. In this study, to enhance the filtration capability and biocompatibility of CA hemodialysis membrane modified by using Polyvinyl Alcohol (PVA) and Polyethylene Glycol (PEG) as additives. CA-PVA flat sheet membranes were cast by phase inversion method, and separation was done by dead-end filtration cell. The synthesized membranes were described in terms of chemical structure using Fourier Transform Infrared Spectroscopy (FTIR) and morphology by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), pure water flux, solute permeation, and protein retention. Biocompatibility of the membranes was tested by the platelet adherence, hemolysis ratio, thrombus formation, and plasma recalcification time. SEM images exposed that the CA-PVA membrane has a uniform porous structure. 42.484 L/m² h is the maximum pure water flux obtained. The CA-PVA rejected up to 95% of bovine serum albumin (BSA). A similar membrane separated 93% of urea and 89% of creatinine. Platelet adhesion and hemolysis ratio of casted membranes were less than the pure CA membrane. Increased clotting time and less thrombus formation on the membrane's surface showed that the fabricated membrane is biocompatible. CA-PVA hemodialysis membranes are more efficient than conventional reported hemodialysis membranes. It revealed that CA-PVA is high performing biocompatible hemodialysis membrane.

Bursting the Virulence Traits of MDR Strain of Candida albicans Using Sodium Alginate-based Microspheres Containing Nystatin-loaded MgO/CuO Nanocomposites

INTRODUCTION

Candida albicans is a major opportunistic pathogen that causes a wide range of human infections. Currently available therapeutic agents are limited for treating these fungal infections due to multidrug resistance as well as their nonbiodegradability, poor biocompatibility and toxicity. In order to battle these limitations, we have synthesized a polymeric system as microcarriers to deliver the antifungal drug. The objective of the present study was to immobilize MgO/CuO nanocomposite and nystatin-loaded MgO/CuO nanocomposites in nontoxic, nonimmunogenic, biodegradable and biocompatible sodium alginate microspheres for the first time.

MATERIALS AND METHODS

Nanoparticle-loaded sodium alginate microspheres were prepared by ionotropic gelation technique using calcium chloride as a cross-linker. Synthesized microspheres were characterized using standard characterization techniques and were evaluated for biological activity against MDR strain of C. albicans.

RESULTS

Characterization of microspheres by Fourier-transform infrared spectroscopy confirmed loading of Nys-MgO/CuO NPs, scanning electron microscopy (SEM) revealed rough spherical beads with a highly porous surface having an average size in the range of 8-10 µm. X-ray diffraction (XRD) analyzed its semicrystalline structure. Entrapment efficiency of Nys-MgO/CuO NPs was 80% and release kinetic study revealed sustained and prolonged release of drug in pH 5.5. Flow cytometry analysis showed yeast cell death caused by Nys-MgO/CuO MS exhibits late apoptotic features. In cytotoxicity assay 5-14 mg of microspheres did not cause hemolysis. Microspheres reduced virulence traits of C. albicans such as germ tube and biofilm formation were compromised at concentration of 5 mg/mL. Antimicrobial assessment results revealed a pronounced inhibitory effect against C. albicans.

CONCLUSION

The in vitro experiments have shown promising results based on good stability, Nys-MgO/CuO NP-encapsulated microspheres can be used as a prolonged controlled release system against MDR pathogenic C. albicans.

Green synthesis of silver nanoparticles transformed synthetic textile dye into less toxic intermediate molecules through LC-MS analysis and treated the actual wastewater

The illegal disposal of waste from textile industries having recalcitrant pollutants is a worldwide problem with more severity in developing nations. We used an ecofriendly method to synthesize silver nanoparticles (AgNPs) from a locally-isolated bacterial strain Bacillus marisflavi TEZ7 and employed them as photocatalysts to degrade not only synthetic azo dyes but also actual textile effluents followed by phytotoxicity evaluation and identification of degradation molecules. The strain TEZ7 was taxonomically identified through the 16S rRNA gene sequence analysis. Biogenic AgNPs were characterized for stabilizing molecules, crystal structure, size, shape and elemental composition by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The photocatalytic degradation efficiency of biogenic AgNPs for three azo dyes such as Direct Blue-1, Methyl Red, and Reactive Black-5 ranged between 54.14 and 96.92% after 5 h of sunlight exposure at a concentration of 100 mg/L. Moreover, the actual wastewater treatment analysis revealed that the 100 mg/L dose of AgNPs significantly decreased the concentration of various physico-chemical parameters of textile effluents such as pH, EC, chlorides, sulphates, hardness, BOD, COD, TSS and TDS. Furthermore, six intermediate molecules of methyl red degradation were identified by LC-MS and it was established by a pot study that these degradation molecules have no phytotoxic effects on rice plants. It was concluded that the AgNPs can be used as an efficient and low-cost strategy for the degradation of azo dyes containing textile wastewaters.

Dechlorane Plus as an emerging environmental pollutant in Asia: a review

Dechlorane Plus (DP) is an unregulated, highly chlorinated flame retardant. It has been manufactured from past 40 years but its presence in the environment was initially reported in 2006. Later, it has been found in various biotic and abiotic environmental matrices. However, little attention has been paid to monitor its presence in Asia. Many studies have reported the occurrence of DP in the environment of Asia, yet the data are scarce, and studies are limited to few regions. The objective of present review is to summarize the occurrence, distribution, and toxicity of this ubiquitous pollutant in various environmental matrices (biotic and abiotic). DP has also been reported in the areas with no emission sources, which proves its long-range transport. Moreover, urbanization and industrialization also affect the distribution of DP, i.e., high levels of DP have been found in urban areas relative to the rural. Tidal movement also incorporates in transport of DP across the aquatic system. Further, bioaccumulation trend of DP in various tissues is kidney > liver > muscle tissues, whereas, blood brain barrier resists its accumulation in brain tissues. Additionally, gender-based accumulation trends revealed high DP levels in females in comparison to males due to strong metabolism of males. Furthermore, methodological aspects and instrumental analysis used in previous studies have also been summarized here. However, data on biomagnification in aquatic ecosystem and bioaccumulation of DP in terrestrial food web are still scarce. Toxicity behavior of syn-DP and anti-DP is still unknown which might gain the interest for future studies.

Biodegradable Polymer Coated Granular Urea Slows Down N Release Kinetics and Improves Spinach Productivity

Low nitrogen (N) utilization efficiency due to environmental N losses from fertilizers results in high-cost on-farm production. Urea coating with biodegradable polymers can prevent these losses by controlling the N release of fertilizers. We calculated N release kinetics of coated granular with various biodegradable polymeric materials and its impact on spinach yield and N uptake. Different formulations were used, (i) G-1: 10% starch + 5% polyvinyl alcohol (PVA) + 5% molasses; (ii) G-2: 10% starch + 5% PVA + 5% paraffin wax (PW); (iii) G-3: 5% gelatin + 10% gum arabic + 5% PW; (iv) G-4: 5% molasses + 5% gelatin + 10% gum arabic, to coat urea using a fluidized bed coater. The morphological and X-ray diffraction (XRD) analyses indicated that a uniform coating layer with no new phase formation occurred. In the G-2 treatment, maximum crushing strength (72.9 N) was achieved with a slowed-down N release rate and increased efficiency of 31%. This resulted in increased spinach dry foliage yield (47%), N uptake (60%) and apparent N recovery (ANR: 130%) from G-2 compared to uncoated urea (G-0). Therefore, coating granular urea with biodegradable polymers is a good choice to slower down the N release rate and enhances the crop yield and N utilization efficiency from urea.

Biogenic copper nanoparticles synthesized by using a copper-resistant strain Shigella flexneri SNT22 reduced the translocation of cadmium from soil to wheat plants

The mechanistic role of green copper nanoparticles (CuNPs) in cadmium (Cd) toxicity alleviation in plants is poorly understood. Here, the CuNPs, synthesized by using a bacterium Shigella flexneri SNT22, were confirmed through UV-vis spectroscopy with a characteristic peak at 334.50 nm. Moreover, FT-IR, XRD, SEM, and TEM techniques revealed that the spherical shaped crystals of CuNPs with a size range of 17.24 nm to 38.03 nm were stabilized by coating proteins. Diff ;erent levels of CuNPs (e.g., 25, 50, and 100 mg kg^-1 of soil) were examined in pots having Cd-mixed soil to evaluate their effect on wheat plants in a growth chamber under optimal environmental conditions. Treatment of soil with 100 mg kg^-1 of CuNPs increased plant length by 44.4 %, shoot dry weight by 28.26 %, nitrogen contents by 41.60 %, and phosphorus contents by 58.79 %, whereas decreased the acropetal Cd translocation by 49.62 %. An increase in the N, P, K⁺, Ca²⁺, K⁺/Na⁺, and Ca²⁺/Na⁺ contents and decrease in the Na⁺ concentration in wheat plants treated with CuNPs was also recorded. Overall, the results are valuable to establish a green CuNPs-based approach for sustainable wheat growth in metal-contaminated soils.

Bioprospecting a native silver-resistant Bacillus safensis strain for green synthesis and subsequent antibacterial and anticancer activities of silver nanoparticles

Green nanomaterials have gained much attention due to their potential use as therapeutic agents. The present study investigated the production of silver nanoparticles (AgNPs) from a silver-resistant Bacillus safensis TEN12 strain, which was isolated from metal contaminated soil and taxonomically identified through 16S rRNA gene sequencing. The formation of AgNPs in bacterial culture was confirmed by using UV-vis spectroscopy with an absorption peak at 426.18 nm. Fourier transform infrared (FTIR) spectroscopy confirmed the involvement of capping proteins and alcohols for stabilization of AgNPs. Moreover, X-ray diffraction analysis (XRD), scanning and transmission electron microscopy (SEM and TEM) confirmed the crystalline nature and spherical shape of AgNPs with particle size ranging from 22.77 to 45.98 nm. The energy dispersive X-ray spectroscopy (EDX) revealed that 93.54% silver content is present in the nano-powder. AgNPs showed maximum antibacterial activity (20.35 mm and 19.69 mm inhibition zones) at 20 µg mL-1 concentration against Staphylococcus aureus and Escherichia coli, respectively and significantly reduced the pathogen density in broth culture. Furthermore, AgNPs demonstrated significant anticancer effects in the human liver cancer cell line (HepG2) in MTT assay, whereas, no cytotoxic effects were demonstrated by AgNPs on normal cell line (HEK293). The present study suggests that the biogenic AgNPs may substitute chemically synthesized drugs with wider applications as antibacterial and anticancer agents.

Silver Nanoparticles Synthesized by Using Bacillus cereus SZT1 Ameliorated the Damage of Bacterial Leaf Blight Pathogen in Rice

Amongst serious biotic factors deteriorating crop yield, the most destructive pathogen of rice is Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial leaf blight (BLB) disease. This study involved targeted use of biogenic silver nanoparticles (AgNPs) to control BLB in order to cope with the disadvantages of chemical disease control. AgNPs were biologically synthesized from natively isolated Bacillus cereus strain SZT1, which was identified through 16S rRNA gene sequence analysis. Synthesis of AgNPs in bacterial culture supernatant was confirmed through UV-VIS spectroscopy. Fourier transform infrared spectroscopy (FTIR) confirmed that the existence of AgNPs was stabilized with proteins and alcoholic groups. X-ray diffraction (XRD) data revealed the crystalline nature and imaging with scanning electron microscopy (SEM) and transmission electron microscopy (TEM), showing the spherical shape of AgNPs with particle sizes ranging from 18 to 39 nm. The silver presence in AgNPs was further confirmed by energy dispersive spectra. Biogenic AgNPs showed substantial antibacterial activity (24.21 ± 1.01 mm) for Xoo. In a pot experiment, AgNPs were found to be effective weapons for BLB by significantly increasing the plant biomass with a decreased cellular concentration of reactive oxygen species and increased concentration of antioxidant enzyme activity.

Use of biogenic copper nanoparticles synthesized from a native Escherichia sp. as photocatalysts for azo dye degradation and treatment of textile effluents

Textile wastewater contains a huge amount of azo dyes and heavy metals and catastrophically deteriorates the agricultural field by affecting its phyisco-chemical/biological and nutritional properties when directly drained to agricultural lands without any treatment. Recently, biogenic copper nanoparticles (CuNPs) have gained considerable attention for photocatalytic degradation of wastewater pollutants owing to their unique physico-chemical and biological properties, low cost and environmental sustainability. The current study reports the synthesis of CuNPs by a native copper-resistant bacterial strain Escherichia sp. SINT7 and evaluation of the photocatalytic activity of the biogenic CuNPs for azo dye degradation and treatment of textile effluents. Scanning electron microscopy and transmission electron microscopy revealed the spherical shape of biogenic CuNPs with particle size ranging from 22.33 to 39 nm. Moreover, X-ray diffraction data revealed that the CuNPs have spherical crystalline shapes with an average particle size of 28.55 nm. FTIR spectra showed the presence of coating proteins involved in the stabilization of nanomaterial. Azo dye degradation assays indicated that CuNPs decolorized congo red (97.07%), malachite green (90.55%), direct blue-1 (88.42%) and reactive black-5 (83.61%) at a dye concentration of 25 mg L^-1 after 5 h of sunlight exposure. However, at 100 mg L^-1 dye concentration, the degradation percentage was found to be 83.90%, 31.08%, 62.32% and 76.84% for congo red, malachite green, direct blue-1 and reactive black-5, respectively. Treatment of textile effluents with CuNPs resulted in a significant reduction in pH, electrical conductivity, turbidity, total suspended solids, total dissolved solids, hardness, chlorides and sulfates as compared to the non-treated samples. Thus, the promising dye detoxification and textile effluent recycling efficiency of biogenic CuNPs may lead to the development of eco-friendly and cost-efficient process for large-scale wastewater treatment.

In vitro antifungal activity of 9, 10-dihydrophenanthrene-2-carboxylic acid isolated from a marine bacterium: Pseudomonas putida

An antifungal compound 9, 10-dihydrophenanthrene - 2 - carboxylic acid was isolated from a marine derived bacterium Pseudomonas putida isolated from surface water samples of Karachi fish harbor coast line. The structure was explored using extensive 1D- and 2D-NMR spectroscopic techniques. The compound was found to be active against fungal strains obtained from clinical samples whereas strong activity was noted against Candida albicans with a MIC value of 20μg/ml, as the purified compound showed promising anticandidal activity a multidisciplinary approach is needed to explore further this compound as potential pharmacological lead compound against Candida spp and will add in the global hunt for clinically functional antifungal agents.

Effect of drying parameters on the physical, morphological and thermal properties of spray-dried inulin

This study focuses on the thermal, morphological and physical properties of spray-dried chicory root inulin using a thermogravimetric analyzer, environmental scanning electron microscopy, X-ray diffractogram and modulated differential scanning calorimetry. Different spray-drying conditions were investigated by varying inlet temperature, outlet temperature and aspirator speed. The starting material was semicrystalline. A feed temperature of 95°C was employed, which produced a completely transparent solution for spray drying. At that particular temperature, the powder samples obtained were entirely amorphous and morphology resembled each other except for higher solid content. The low glass transition temperature (T g) (106.83°C) was evident by treating low-molecular-weight samples, whereas high-molecular-weight samples exhibited high T g (125.81°C). The semicrystalline samples due to the high concentration and milky dispersion exhibited high decomposition temperature. The feed temperature, molecular weight and concentration of the samples tend to have a significant effect on the properties of spray-dried inulin.

The effect of large area graphene oxide (LAGO) nanosheets on the mechanical properties of polyvinyl alcohol

Large area graphene oxide sheets were synthesized, dispersed in water and used as nanofiller for mechanical improvement in terms of Young’s modulus and ultimate tensile strength (UTS) of polyvinyl alcohol (PVA) at low loading. The molecular level dispersion and interfacial interactions between the graphene oxides and polymeric matrix PVA were the real challenges. An excellent improvement in mechanical properties at 0.35 wt% loading was observed. Modulus improved from 1.58 GPa to 2.72 GPa (~71% improvement), UTS improved from 120 MPa to 197 MPa (~65% improvement), and in spite of these improvements, interestingly, there was no fall in elongation at break at this loading.