Manganese Oxide Nanoparticles Research Articles

Anomalous Temperature-Induced Particle Size Reduction in Manganese Oxide Nanoparticles.

The intricate role of temperature in the structure-property relationship of manganese oxide nanoparticles (Mn3O4 NPs) remains an open question. In this study, we successfully synthesized Mn3O4 NPs using the hydrothermal method with two differing temperatures, namely, 90 and 150 °C. Interestingly, a smaller average particle size is found when Mn3O4 NPs are synthesized at 150 °C compared to 90 °C, corresponding to 46.54 and 63.37 nm, respectively. This was confirmed by the time variation of temperature setting of 150 °C where the size evolution was insignificant, indicating a competing effect of nucleation and growth particles. Under varying NaOH concentrations (2-6 M) at 150 °C, a reduction in the particle size is found at the highest NaOH concentration (6 M). The particle grows slightly, indicating that the growth state is dominant compared to the nucleation state at low concentrations of NaOH. This finding implies that the high nucleation rate originates from the excessive monomer supply in the high-temperature reaction. In terms of crystallinity order, the structural arrangement of Mn3O4 NPs (150 °C) is largely decreased; this is likely due to a facile redox shift to the higher oxidation state of manganese. In addition, the higher ratio of adsorbed oxygen and lattice oxygen in Mn3O4 NPs at 150 °C is indirectly due to the higher oxygen vacancy occupancies, which supported the crystallinity decrease. Our findings provide a new perspective on manganese oxide formation in hydrothermal systems.

A facile approach for the bio-fabrication of monometallic manganese oxide nano-catalyst for enhanced photocatalytic degradation of dyes and drug

The present work describes a green method based on the utilization of egg white for the preparation of manganese oxide (MnO) nanoparticles. The egg white liquid acts as a reducing and stabilizing agent. Morphological, physical, and optical properties were evaluated by UV–visible spectroscopy, SEM, EDX, and XRD. MnO Nanoparticles have a particle size of 29 nm. Morphological studies show that synthesized nanoparticles exhibit a spherical shape. EDX spectrum shows the presence of distinct peaks of Mn and O atoms with the elemental composition of 50.43 % and 33.83 % respectively. The crystalline construction of nanoparticles was investigated using XRD analysis. To test the potential of these nanoparticles as photocatalysts for the breakdown of drugs and colors in industrial effluent, photocatalysis of the dyes Methylene Blue, Bromophenol Blue, and the antibiotic Moxifloxacin HCl was carried out under sunshine. Maximum degradation efficiency achieved was 92.75 %, 84.60 %, and 73.92 % respectively.

Deciphering MnOx nanoparticles: A comprehensive analysis reveals Mn2O3 as the most cytotoxic variant in cellular systems

Manganese oxides (MnOx) nanoparticles have gained significant attention in various applications, including catalysis, energy storage, and biomedicine. However, concerns regarding their potential cytotoxicity have raised questions about their safe use in biological systems. In this study, we present a comparative investigation of the cytotoxic effect of three different MnOx nanoparticles, namely Mn3O4, Mn5O8, and Mn2O3, to evaluate their potential impact on cellular health. The structure and morphology of the synthesized nanoparticles were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) techniques. The cytotoxicity potential was assessed using PC12 cell as a model system in terms of cell viability assay, lactose dehydrogenase (LDH) release assay, and glutathione (GSH) release assay. Significant variations in cytotoxicity were observed among the different MnOx nanoparticles. Mn2O3 nanoparticles exhibited the highest cytotoxicity, followed by Mn3O4 and Mn5O8 nanoparticles, respectively. These results underscore the importance of considering nanoparticle composition in assessing their safety for potential biological applications.

The protective impact of curcumin, vitamin D and E along with manganese oxide and Iron (III) oxide nanoparticles in rats with scrotal hyperthermia: Role of apoptotic genes, miRNA and circRNA

BackgroundInfertility is one of the major factors affecting most people around the world. Short-term exposure to high temperatures can cause hyperthermia, which is one of the causes of male infertility. The aim of this study was to investigate the protective effect of curcumin, vitamins D and E along with Iron (III) oxide nanoparticles (Fe2O3-NPs) and manganese oxide nanoparticles (MnO2-NPs) on semen parameters and its effect on miRNA21 and circRNA0001518 expression. Material and methodsIn this study, the lower part of the rat was exposed to 43 °C for 5 weeks every other day for 5 weeks. Then the animals were killed. Tissue samples were collected for sperm parameters analysis, and tissue samples were taken for evaluation of apoptosis levels in germ cells, and RNA extraction in order to examine the expression of Bax, Bcl-2, miRNA, and CircRNA genes. ResultsThe results of this study showed that administration of curcumin, vitamin D, and vitamin E with Fe2O3-NPs and MnO2-NPs can improve the parameters of semen, Bax gene expression, Bcl-2 as well as miRNA and CircRNA in rats with testicular hyperthermia. In addition, curcumin by reducing the toxicity of Fe2O3 nanoparticles was able to reduce its negative effects and also reduce apoptosis in germ cells. This decrease in apoptosis was attributed to decreased Bcl-2 gene expression and increased expression of Bax, miRNA-21, and circRNA0001518. ConclusionAll the results of this study confirmed that Fe2O3-NPs and Mno2-NPs containing antioxidants or vitamins are useful in improving fertility in rats due to scrotal hyperthermia. Although Fe2O3-NPs and Mno2-NPs containing both antioxidants and vitamins had a greater effect on improving fertility and reducing the toxic effects of nanoparticles.

Room-Temperature Synthesis of Biogenic δ-MnO2 NPs for the Dehydrogenative Coupling of Diamines with Alcohols for Benzimidazole and Quinoxaline Synthesis: An Efficient Catalyst for Electrochemical Applications.

An efficient, unique, and eco-friendly biogenic synthesis of single-crystalline δ-phase manganese oxide nanoparticles (MnO2 NPs) using Gliricidia sepium leaves (GSL) extract at room temperature has been revealed for the first time. The active chemicals present in the GSL extract were found to serve as both reducing and stabilizing agents. The catalyst shows an excellent surface area of 301.13 m2 g-1, a mean pore diameter of 4.01 nm, and 39.97% w/w of active metal content. The reactivity of the synthesized catalyst was demonstrated by achieving a one-pot synthesis of benzimidazoles and quinoxalines via an acceptorless dehydrogenative coupling strategy utilizing biorenewable alcohols. The release of hydrogen gas was observed as the only side product and proven by its successful utilization for alkene reduction which supports the mechanistic elucidation. The release of hydrogen gas as a useful byproduct highlights the scientific importance of the present methodology. Additionally, gram-scale synthesis and catalyst recyclability studies are deliberated. Importantly, the δ-MnO2 NP catalyst exhibited superior catalytic activity and high durability toward hydrogen evolution reaction in alkaline media, highlighting the dual use of the catalyst. The δ-MnO2 NPs attain the current density of 10 mA/cm2 at an overpotential of 154 mV with a Tafel slope of 119 mV/dec.

Robust iron-doped manganese oxide nanoparticles from facile fabrication to photo-catalytic degradation application of binary dyes mixture

The manganese oxide (MnO2 and iron-doped manganese oxide (Fe–MnO2) nanoparticles (NPs) with reduced band gap (Eg) were fabricated through the co-precipitation process. They used to degrade Indigo Carmine (IC) and Rhodamine B (RB) binary mixture in an aqueous medium under solar light irradiation. From FT-IR, the twisting modes of the Mn–O bond and the stretching vibrations of the Fe–Mn–O2 bond were confirmed from the peaks observed at 480 cm−1,584 cm−1,675 cm−1, and 900 cm−1, 1150 cm−1, and 1200 cm−1 respectively. The MnO2 has an optical band gap of 3.2 eV, which was decreased to 3 eV in Fe–MnO2. The zero charge (PZC) point was 8 for Fe–MnO2 and 7 for MnO2. The BET surface area for Fe–MnO2 was 398 m2/g, relatively higher than MnO2 particles, having a surface area of 384 m2/g. The average crystallite sizes calculated from Scherer formulae were 37 nm for MnO2 and 31 nm for Fe–MnO2 NPs. SEM confirmed the irregular morphology of the prepared particles. It was analyzed that agglomeration occurs in MnO2 than the Fe–MnO2. The maximum degradation of IC dye was 99%, and that of RB was 98% at the optimum conditions. The data were best fitted to second-order kinetics.

Response surface methodology-artificial neural network application for bisphenol A treatment using carbon nanotubes manganese oxide composite

Bisphenol A (BPA) is an emerging pollutant that easily escapes conventional treatment techniques. It requires application of novel composite materials along with mathematical modelling for optimisation and evaluation of the treatment process. In the present study, manganese (IV) oxide (MnO2) nanoparticles were doped onto the surface of multi-walled carbon nanotubes to develop an adsorptive–oxidative composite. The composite was characterised using transmission electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and surface area analysis to confirm composite formation and study its properties. Conventional optimisation of pH (4–10), initial BPA concentration (10–50 mg/l) and contact time (0–60 min) was carried out and found to fit well with the Freundlich isotherm model (R 2 > 0.99) and followed a pseudo-second-order kinetic reaction. A central composite design model was applied using response surface methodology (RSM) to study individual parameters and their interaction effects to enhance process efficiency. Further, the experimental data sets and their responses from RSM were analysed using an artificial neural network. From random experimental sets (80%) of which (10%) each to train, validate and test were selected to analyse the variance of models for higher efficiency using Levenberg–Marquardt back-propagation (LM-BP) algorithm. Additionally, BPA-spiked simulated pharmaceutical waste water was treated with the composite to explore its treatment potential. This systematic experimental and computational approach aided in optimising treatment efficiency for real-time application.

Comprehensive insight into synergistic enhancement of nickel and iron doped lanthanum manganese oxide for biohydrogen production via anaerobic fermentation

Anaerobic fermentation offers an effective strategy to produce H2 from organic wastes, which facilitates waste utilization and the development of sustainable energy. However, the low hydrogen yield and instability of fermentation systems block the further industrial and commercial application. In this work, nickel and iron doped lanthanum manganese oxide nanoparticles (NPs) are successfully fabricated for researching their effects on H2 production and process stability. The advantages of lanthanum manganese oxides doped by nickel and iron in terms of bacterial activity and microbial community structures are studied in a fermentation system. The physicochemical properties of LaMn0.7Fe0.3O3 NPs and LaMn0.7Ni0.3O3 NPs are summarized and analyzed. The results show that the moderate addition of nanoparticles can both effectively increase the final H2 yield and stabilize the fermentation process simultaneously. The highest H2 yield of 223.08 mL/g and 246.10 mL/g correspond to 100 mg/L supplementation of LaMn0.7Fe0.3O3 NPs and LaMn0.7Ni0.3O3 NPs, respectively, which confirms that the LaMn0.7Ni0.3O3 NPs exhibit a more positive impact on anaerobic fermentation, while excess dosage nanoparticles (over 100 mg/L) may hamper the H2 production and inhibit the electron transfer to microbe. The underlying mechanism analysis reveals that Fe3+ and Ni2+ significantly improve the microbial transmembrane transportation and conversion rate of glucose into acetate, butyrate and H2 through stimulating the activity of related enzymes, leading to an enhanced H2 productivity. Meanwhile, Ni2+ and Fe3+ are helpful to the synthesis of ferredoxin and hydrogenase, which increase the activity of critical enzymes. The microbial community discloses that LaMn0.7Fe0.3O3 NPs and LaMn0.7Ni0.3O3 NPs separately make a 7.71%, 9.65% increase of Clostridium_sensu_stricto_1 compared to the control group, which is deeply involved in the sustainable H2 generation. Based on comprehensive evaluation, LaMn0.7Ni0.3O3 NPs will have a huge potential market for H2 production enhancement in anaerobic fermentation system.

Biological synthesis of manganese oxide nanoparticles from aerial parts of Prunus dulcis and their in vitro investigation of medical properties

The field of functional nanohybrid material is an emerging research area in material science due to its vast range of applications. The use of novel technology and innovative therapeutics has led to potent applications, including controlling the size of nanoparticles (NPs). This has resulted in a novel report on the synthesis of manganese oxide NPs using aerial parts of queen of roses Prunus dulcis (almond) leaves, seed, and seed oil (using Clevenger apparatus), which functions as a reducing agent. Manganese sulfate was used as a precursor in the synthesis process. The synthesized nanohybrid Mn3O4 NPs were studied using different characteristics techniques such as X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy‐dispersive X‐ray spectroscopy (EDX). The photoluminescence spectra display the blue emission ranging from 483.2 to 486.5 nm. The biosynthesized Mn3O4 NPs were tested for bactericidal activity and showed tremendous inhibition against gram‐positive and gram‐negative bacteria. The antioxidant activity of Mn3O4 NPs was enhanced using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assay, which revealed the higher activity of Mn3O4 NPs from P. dulcis leaf extract. In vitro cytotoxicity of hybrid Mn3O4 NPs was examined using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay against cervical cancer (HeLa cell line) with different concentrations. The results showed an IC50 value of 61.97 μg mL−1 for Mn3O4 NPs from P. dulcis leaf extract. In general, the phytosynthetic route with synergistic effect of nanohybrid demonstrated an interaction with cancer cells, highlighting a pioneering optimum approach in synthesis of Mn3O4 NPs from aerial parts of P. dulcis.

Unveiling the electrochemical advantages of a scalable and novel aniline-derived polybenzoxazole-reduced graphene oxide composite decorated with manganese oxide nanoparticles for supercapacitor applications

In the quest for better supercapacitor performance, materials with high energy storage, rapid charge transfer and excellent charge-discharge capabilities are crucial. However, improving energy density and optimizing electrode materials for supercapacitors remains a challenge. Within this perspective, we developed a novel aniline-derived polybenzoxazole-reduced graphene oxide composite (Mn3O4-pBOA-rGO) for supercapacitor applications. An electrode for supercapacitor applications was then fabricated using the synthesized composite. Various characterization techniques, such as X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy, were employed to analyze the structure of the material and cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge tests were performed to evaluate the supercapacitive performance. Remarkably, the Mn3O4-pBOA-rGO ternary nanocomposite-based electrode exhibited enhanced electrochemical performance achieving an energy density of 116 Wh kg−1 in a 1 M aqueous Na2SO4 electrolyte at a current density of 1 A g−1. In comparison, the Mn3O4-pBOA binary nanocomposite recorded an energy density of 25 Wh kg−1, while bare Mn3O4 yielded 10 Wh kg−1. The significantly improved electrochemical properties of the Mn3O4-pBOA-rGO composite present a promising and viable solution for supercapacitor applications.

In vitro anti-cancer and antimicrobial effects of manganese oxide nanoparticles synthesized using the Glycyrrhiza uralensis leaf extract on breast cancer cell lines

Abstract In this study, we evaluated the antiproliferative and apoptotic properties of Pluronic-F127-containing manganese oxide nanoparticles (PF-127-coated Mn2O3 NPs) derived from the leaf extract of Glycyrrhiza uralensis (GU) on breast adenocarcinoma, MCF7, and MDA-MB-231 cell lines. The leaf extract of GU contains bioactive molecules that act as a reducing or capping agent to form Mn2O3 NPs. Various analytical techniques were used to characterize the physiochemical properties of PF-127-coated Mn2O3 NPs, including spectroscopy (ultralight-Vis, Fourier transform infrared, photoluminescence), electron microscopy (field emission scanning electron microscopy and transmission electron microscopy), X-ray diffraction (XRD), electron diffracted X-ray spectroscopy (EDAX), and dynamic light scattering. The average crystallite size of Mn2O3 NPs was estimated to be 80 nm, and the NPs had a cubic crystalline structure. PF127-encapsulated Mn2O3 NPs significantly reduce MDA-MB-231 and MCF-7 cell proliferation, while increasing endogenous ROS and lowering mitochondrial matrix protein levels. DAPI, EtBr/AO dual staining, and Annexin-V-FITC-based flow cytometry analysis revealed that PF127-coated Mn2O3 NP-treated breast cancer cells exhibit nuclear damage and apoptotic cell death, resulting in cell cycle arrest in the S phase. Furthermore, PF127-encapsulated Mn2O3 NPs show strong antimicrobial efficacy against various strains. As a result, we can conclude that PF127-coated Mn2O3 NPs may be effective as future anticancer agents and treatment options for breast cancer.

Comparative Analysis of Own Experimental Data on Changes in Rat Behavioral Responses Following Subchronic Exposure to Various Nanoparticles

Introduction: Air pollution with nanoparticles (NPs) of different chemical composition is registered almost everywhere and, along with the growing use of nanotechnology products, poses serious human health risks related to NP exposure, included those for the nervous system. Objective: To compare changes in functioning of the central nervous system in rats following subchronic intraperitoneal exposure to nickel, manganese, copper, zinc, lead, silicon, and titanium oxide nanoparticles based on the results of behavioral tests. Materials and methods: We compared findings of our own subchronic toxicity studies of Ni, Mn, Cu, Zn, Pb, Si, and Ti oxide nanoparticles with a focus on behavioural responses. Results: The comparison showed differences in severity of rat behavioral responses observed after subchronic intraperitoneal instillation of metal oxide nanoparticles at a single dose of 2.5 mg/kg of body weight. We observed a decrease in exploratory activity of rats that was statistically significant in the group of rodents exposed to Mn3O4, NiO, and PbO NPs, and a change in the summation threshold index that increased statistically in the CuO and ZnO nanoparticle exposure groups. Conclusion: Our findings contribute to understanding of neurotoxic effects of nanoparticles and facilitate a more profound and trustworthy assessment of human health risks.

P17-18: Doping manganese oxide nanoparticles with 1% zinc oxide ameliorates their toxicity in the Raw 264.7 cells

P17-18: Doping manganese oxide nanoparticles with 1% zinc oxide ameliorates their toxicity in the Raw 264.7 cells

Synthesis and characterization of highly efficient Te-doped Mn3O4 and s-g-C3N4 /Te- Mn3O4 nanocomposites as an excellent antimicrobial and photocatalytic agent

This work aims to synthesize manganese oxide nanoparticles (Mn3O4NPs) using a co-precipitation method and analyzed them through XRD, SEM and FT-IR. The XRD analysis confirmed the tetragonal hausmanite structure of the Mn3O4 NPs, while SEM revealed an average particle size of 9–20 nm. Kinetic studies demonstrated the efficient photooxidation of methylene blue with first-order kinetics under UV or visible light. Degradation efficiencies varied between 82% and 93% depending on the light source. Furthermore, we used the zone inhibition approach to assess the antibacterial potency of various Mn3O4 NP contents alongside human pathogenic bacteria, namely Escherichia coli and Staphylococcus aureus. The results of the qualitative antibacterial tests revealed that E. coli, a Gram-negative bacterium, is more sensitive to Mn3O4 NPs than are Gram-positive bacteria, with a maximum zone diameter of 28 mm (S. aureus). Alternatively, it was determined that S-g-C3N4/Te-Mn2O3 had the maximum antifungal activity against Alternaria solani at 28.9 mm and against. Colletotrichum gloeosporioides at 47.3 mm.

Incorporation of thermally induced shaped and phases of manganese oxide nanoparticles into zein/PVA fiber blends

Incorporation of nanomaterials into polymers and their blend provide additional advantages to their use and structural support. Metals such as Ag, Cu, Ti, and Fe are often reported in their metallic or their oxide forms for applications in microbiological, water treatment, and biomedical fields. The integration of metal oxide nanoparticles into polymer fiber blends overcomes the mechanical instability and compatibility challenges of nanomaterials. Manganese-based oxides provide good stability and optical properties in their nanoscale useful in polymeric composite or fiber materials enhancement. MnO2 and Mn2O3 nanoparticles were synthesized at different calcination temperatures using the co-precipitation method and characterized a microscopic technique TEM, and TGA. TEM images and the XRD patterns confirmed that the manganese oxide nanoparticle were spheres and rod-shaped with corresponding cryptomelane and orthorhombic crystalline phases. Mn2O3 nanoparticles were successfully integrated into zein/PVA (80/20) fiber blends. SEM images confirmed that the inclusion of the nanoparticles into zein/PVA solutions increased the conductivity of the solutions which led to an improved morphology and increased surface area to volume ratio. XRD patterns and TGA showed that the incorporated nanoparticles were below the detection limit, therefore there was no significant change observed. Therefore, all characterization techniques illustrated that the effect of concentration significantly enhanced the morphology of the fiber blends.

Bioinspired palladium-doped manganese oxide nanocorns: a remarkable antimicrobial agent targeting phyto/animal pathogens

Microbial pathogens are known for causing great environmental stress, owing to which emerging challenges like lack of eco-friendly remediation measures, development of drug-resistant and mutational microbial strains, etc., warrants novel and green routes as a stepping stone to serve such concerns sustainably. In the present study, palladium (Pd) doped manganese (II, III) oxide (Mn3O4) nanoparticles (NPs) were synthesized using an aqueous Syzygium aromaticum bud (ASAB) extract. Preliminary phytochemical analysis of ASAB extract indicates the presence of polyphenolics such as phenols, alkaloids, and flavonoids that can act as potential capping agents in NPs synthesis, which was later confirmed in FTIR analysis of pure and Pd-doped Mn3O4 NPs. XRD, Raman, and XPS analyses confirmed the Pd doping in Mn3O4 NPs. FESEM and HRTEM study reveals the mixed morphologies dominated by nanocorns appearance. Zeta potential investigation reveals high stability of the synthesized NPs in colloidal solutions. The developed Pd-doped Mn3O4 NPs were tested against two fungal phytopathogens, i.e., Sclerotinia sclerotiorum and Colletotrichum gloeosporioides, known for causing great economic losses in yield and quality of different plant species. The antifungal activity of synthesized Pd‐doped Mn3O4 NPs displayed a dose‐dependent response with a maximum of ~92%, and ~72% inhibition was recorded against S. sclerotiorum and C. gloeosporioides, respectively, at 1000 ppm concentration. However, C. gloeosporioides demonstrated higher sensitivity to Pd‐doped Mn3O4 NPs upto 500 ppm) treatment than S. sclerotiorum. The prepared NPs also showed significant antibacterial activity against Enterococcus faecalis. The Pd-doped Mn3O4 NPs were effective even at low treatment doses, i.e., 50–100 ppm, with the highest Zone of inhibition obtained at 1000 ppm concentration. Our findings provide a novel, eco-benign, and cost-effective approach for formulating a nanomaterial composition offering multifaceted utilities as an effective antimicrobial agent.

Performance of IC Engines Using Chicken Waste as Biofuel, CNT and MnO Nano-Biofuels and Diesel Fuel: A Comparation Study

Biofuel production and its properties improvisation are the wide areas of research in internal combustion (IC) engines. This research derived biofuel from industrial chicken waste. Nanofuels were produced in this study by adding 40 nm-sized nanoparticles of carbon nanotube (CNT) and manganese oxide (MnO) with a variation of 100 to 200 ppm to the derived oil. Four fuel blends (biofuel (B), B with CNT, B with MnO, and B with CNT+MnO) were compared to the performance of diesel fuel in a 3.5 kW CI engine. The combustion process (peak pressure and heat release), brake thermal efficiency (BTE), and exhaust emissions (CO, HC, NOx, and CO2) were used as parameters to evaluate the fuel’s performance. The result revealed that nanofuel outperformed both diesel fuel and biofuel. The addition of 200 ppm CNT in biofuel enhanced the fuel properties, resulting in higher BTE by 28% and 9.7% compared to diesel fuel and biofuel. The CNT-biofuel also generated fewer emissions compared to diesel fuel by 26%, 9.4%, and 25% for NOx, HC, and CO gases respectively.

Biosynthesis and characterization of MnO2 and Zn/Mn2O4 NPs using Ziziphus spina-Christi aqueous leaves extract: Effect of decoration on photodegradation activity against various organic dyes

An aqueous leaf extract of Ziziphus spina-Christi is used to synthesize manganese oxide nanoparticles (MnO2 NPs) and zinc-coated manganese oxide nanoparticles (Zn/Mn2O4 NC). The study aims to investigate the photocatalytic degradation efficiency of MnO2 NPs and Zn/Mn2O4 NC in relation to the azo dyes methylene blue (MB), m-Toluidine (mT), and P-Toluidine (pT). X-ray diffraction analysis (XRD) confirmed the crystalline nature of the biosynthesized MnO2 NPs and Zn/Mn2O4, revealing their respective crystallite sizes to be approximately 14.65 nm and 22.97 nm. The scanning electron microscope (SEM) images demonstrated that the MnO2 NPs exhibit a tetragonal and spherical shape, while the Zn/Mn2O4 particles possess a spherical shape. UV–vis spectroscopy measurements indicated that the MnO2 NPs and Zn/Mn2O4 exhibit indirect bandgaps with energy values of 1.46 eV and 1.14 eV, respectively. Fourier transform infrared (FTIR) analysis revealed the presence of organic compounds containing CO and OH groups, such as carbohydrates, phenolic acids, tannins, and flavonoids derived from Ziziphus spina-Christi, suggesting a high likelihood of stability for the biosynthetic MnO2 and Zn/Mn2O4 materials. Interestingly, the photocatalytic degradation of the biosynthetic MnO2 and Zn/Mn2O4 provided good efficacy against the Methylene Blue (MB), m-Toluidine (mT), and P-Toluidine (pT) where the Zn/Mn2O4 exhibit an excellent degradation were 99.2, 99.8 and 98.4 % after 75 min. The biosynthetic MnO2 NPs and Zn/Mn2O4 NCs resulting from using aqueous ZSCLE were cost-effective and eco-friendly, and the decoration of MnO2 NPs by Zn improved their effectiveness.

Biosynthesized manganese oxide nanoparticles maintain firmness of tomato fruit by modulating soluble solids and reducing sugars under biotic stress

Nanoparticles have been reported to mitigate biotic and abiotic stresses in different fruits and vegetables. In this study, tomato fruit with black rot symptoms were collected and diagnosed. To control this disease, manganese oxide nanoparticles (MnO NPs) were synthesized in bacterial broth-culture. Based on microscopic, morphological, and genetic analyses, the pathogen causing black rot disease was identified as Aspergillus niger. MnO NPs were successfully synthesized in broth-culture of Bacillus subtilis, following the process of calcination and characterized. Fourier transform infrared (FTIR) spectrum revealed the existence of stabilizing and reducing agents (carboxylic acid, alkenes, and alkyl halides) on the surface of MnO NPs. X-Ray diffraction (XRD) analysis revealed the size (39 nm) and crystal-like nature of synthesized MnO NPs. Energy-dispersive X-ray spectroscopy (EDX) described the mass percentage of manganese (26.4%) and oxygen (23.3%). Scanning electron microscopy (SEM) displayed nearly spherical shape of MnO NPs and confirmed their nano-size. These MnO NPs exhibited significant mycelial growth inhibition of A. niger and notable control of tomato black rot disease of tomato. Though, all concentrations exhibited considerable effects, medium concentration of MnO NPs (2.5 mg/mL) performed best in both in vitro and in vivo analyses. At this concentration, tomato fruit maintained higher percentage of soluble solids, total sugars, reducing sugars and fruit firmness. These results proved very effective application of bacteria supplemented MnO NPs for the control of black rot disease of tomato. To our knowledge, this is the first study of tomato black rot, caused by A. niger in Pakistan.

PH-sensitive tumor-tropism hybrid membrane-coated nanoparticles for reprogramming the tumor microenvironment and boosting the antitumor immunity.

Metabolic dysregulation contributes not only to cancer development but also to a tumor immune microenvironment (TIME), which poses great challenges to chemo- and immunotherapy. Targeting metabolic reprogramming has recently emerged as a promising strategy for cancer treatment, but the lethality against solid tumors appears to be fairly restricted, partially due to the poor solubility of small molecule drugs. Herein, we construct a versatile biomimetic nanoplatform (referred to as HM-BPT) employing pH-sensitive tumor-tropism hybrid membrane-coated Manganese oxide (MnO2) nanoparticles for the delivery of BPTES, a glutamine metabolism inhibitor. Basically, hybrid membranes consisting of mesenchymal stem cell membranes (MSCm) and pH-sensitive liposomes (pSL) enable the biomimetic nanoplatform to target TME and escape from endo/lysosomes after endocytosis. The results reveal that HM-BPT treatment leads to remarkable tumor inhibition, cytotoxic T lymphocyte (CTL) infiltration, as well as M1 phenotype repolarization and stimulator of IFN genes (STING) pathway activation in macrophages in a 4T1 xenograft model. Furthermore, glutathione (GSH) depletion and oxygen (O2) supply synergistically ameliorate the immunosuppressive status of the TME, boosting potent antitumor immune responses. Overall, our study explores an integrated therapeutic platform for TME reprogramming and immune activation, offering tremendous promise for cancer combination therapy. STATEMENT OF SIGNIFICANCE: Metabolic abnormalities and the tumor immune microenvironment (TIME) lead to hyporesponsiveness to conventional therapies, ultimately resulting in refractory malignancies. In the current work, a biomimetic nanoplatform (HM-BPT) was developed for TME metabolic reprogramming in favor of immunotherapy. Particularly, hybrid membrane camouflage endowed the nanoplatform with TME targeting, endo/lysosomal escape, and sensitive release properties. The impact of hybrid membrane fusion ratio on cellular uptake and cell viability was explored, yielding beneficial references for the future development of bioactive nanomaterials. Intravenous administration of HM-BPT substantially relieved tumor burden and restored innate and acquired immune activation in 4T1 xenograft models. In conclusion, the created HM-BPT system has the potential to be a promising nanoplatform for combining cancer therapies.