Synthesis of Mn3O4 nanoparticles by thermal decomposition of a [bis(salicylidiminato)manganese(II)] complex

Mitochondrial-targeting Mn3O4/UIO-TPP nanozyme scavenge ROS to restore mitochondrial function for osteoarthritis therapy

Excessive reactive oxygen species (ROS)-induced mitochondrial damage has impact on osteoarthritis (OA). Nanozyme mimics as natural enzyme alternatives to scavenge excessive ROS has offered a promising strategy for OA therapy. Herein, we reported a novel mitochondrial-targeting Mn3O4/UIO-TPP nanozyme using metal-organic frameworks with loaded Mn3O4 as the enzyme-like active core combining mitochondria-targeting triphenylphosphine (TPP) groups to serve as ROS scavengers for therapy of OA. With sequential catalysis of superoxide dismutase-like, catalase (CAT)-like, and hydroxyl radical (·OH) scavenging potentials, the nanozyme can target mitochondria by crossing subcellular barriers to effectively eliminate ROS to restore mitochondrial function and inhibit inflammation and chondrocyte apoptosis. It also has favorable biocompatibility and biosafety. Based on anterior cruciate ligament transection-induced OA joint models, this mitochondrial-targeting nanozyme effectively mitigated the inflammatory response with the Pelletier score reduction of 49.9% after 8-week therapy. This study offers a prospective approach to the design of nanomedicines for ROS-related diseases.

Research progress in green synthesis of manganese and manganese oxide nanoparticles in biomedical and environmental applications - A review

Nanomaterials and nanotechnology have this unassailable position for environmental remediation and medicine. Currently, global environmental pollution and public health problems are increasing and need to be urgently addressed. Manganese (Mn) is one of the essential metal elements for plants and animals, it is necessary to integrate with nanotechnology. Mn and Mn oxide (MnO) nanoparticles (NPs) have applications in dye degradation, biomedicine, electrochemical sensors, plant and animal growth, and catalysis. However, the current research is limited, especially in terms of optimal synthesis of Mn and MnO NPs, separation, purification conditions, and the development of potential application areas is too basic and do not support by in-depth studies. Hence, this review comprehensively discusses the classification, green synthesis methods, and applications of Mn and MnO NPs in biomedical, environmental, and other fields and gives a perspective for the future.

Low-energy production of a monolithic catalyst with MnCu-synergetic enhancement for catalytic oxidation of volatile organic compounds

Producing a low-cost catalyst by a low-cost method is one of the hottest topics in the field of catalytic oxidization of volatile organic compounds (VOCs). In this work, a catalyst formula with a low-energy requirement was optimized in the powdered state, and verified in the monolithic state. An effective MnCu catalyst was synthesized at a temperature as low as 200 °C. Removals were all bigger than 88% for toluene, ethyl acetate, hexane, formaldehyde, and cyclohexanone at a low temperature of 240 °C. The MnCu catalyst was then loaded on a honeycomb cordierite, which was also effective for toluene removal at 240 °C. After characterizations, active phases were Mn₃O₄/CuMn₂O₄ in both the powdered and monolithic catalysts. The enhanced activity was attributed to balanced distributions of low-valence Mn and Cu, as well as abundant surface oxygen vacancies. The obtained catalyst is produced by low energy and effective at low temperature, which suggests a perspective application.

Metal Oxides Nanoparticles: General Structural Description, Chemical, Physical, and Biological Synthesis Methods, Role in Pesticides and Heavy Metal Removal through Wastewater Treatment

Nanotechnology (NT) is now firmly established in both the private home and commercial markets. Due to its unique properties, NT has been fully applied within multiple sectors like pharmacy and medicine, as well as industries like chemical, electrical, food manufacturing, and military, besides other economic sectors. With the growing demand for environmental resources from an ever-growing world population, NT application is a very advanced new area in the environmental sector and offers several advantages. A novel template synthesis approach is being used for the promising metal oxide nanostructures preparation. Synthesis of template-assisted nanomaterials promotes a greener and more promising protocol compared to traditional synthesis methods such as sol-gel and hydrothermal synthesis, and endows products with desirable properties and applications. It provides a comprehensive general view of current developments in the areas of drinking water treatment, wastewater treatment, agriculture, and remediation. In the field of wastewater treatment, we focus on the adsorption of heavy metals and persistent substances and the improved photocatalytic decomposition of the most common wastewater pollutants. The drinking water treatment section covers enhanced pathogen disinfection and heavy metal removal, point-of-use treatment, and organic removal applications, including the latest advances in pesticide removal.

Precursor Engineering for the Synthesis of Mixed Anionic Metal (Cu, Mn) Chalcogenide Nanomaterials via Solvent-Less Synthesis

Metal-organic ligands with mixed chalcogenides are potential compounds for the preparation of mixed anionic metal chalcogenide alloys. However, only a few of such ligands are known, and their complexes are not well explored. We have prepared homo- and hetero-dichalcogenoimidodiphosphinate [(EE'PⁱPr₂NH)] (E, E' = Se, Se; S, S; S, Se) complexes of manganese and copper through metathetical reactions. The X-ray single crystal structure of [Mn{(SePⁱPr₂)₂N}₂] 1 revealed a triclinic crystal system, with a MnSe₄ core unit, whereas the crystal structure determination of [Mn{(SPⁱPr₂)(SePⁱPr₂)N}₂] 2 indicated a triclinic crystal system with a Mn(S/Se)₂ unit. Both metal centers are tetrahedral, with two deprotonated bidentate ligands forming the coordination sphere. The free ligand was found to exhibit a gauche configuration in the solid state. The energies of the various rotamers of dithio-analogue were studied by DFT calculations. The decomposition behavior of complexes with homo- and heterochalcogenides was investigated, and the complexes were employed as single-source precursors to generate manganese and copper chalcogenides through solvent-less melt reactions between 500 and 550 °C. The deposited powders were characterized by powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), transmission electron microscopy (TEM), and elemental mapping. MnS, MnSe₂, and MnSSe phases were obtained from the decomposition of respective manganese complexes. In contrast, the decomposition of copper-based complexes yielded Cu_2-xSe and the sulfur-doped Cu₃Se₂ phase from seleno- and mixed thio/seleno-complexes of Cu, respectively. The morphology ranged from random sheet-like structures to agglomerated platelets, while the selected area electron diffraction (SAED) revealed the crystalline nature of the materials. Depending on the nature of the complex and the temperature, different amounts of phosphorus were present as an impurity in the synthesized products.

Carbon Nanostructures As Antibacterials and Active Food-Packaging Materials: A Review

In this article, we discuss carbon nanoparticles for application as antibacterials and food-packaging materials. The use of petroleum-derived products, synthetic materials, ceramics, wax, etc. in the food-packaging industry emits polluted gas and wastewater, which leads to environmental pollution. To overcome the problems faced by the industry to preserve and package food, carbon nanomaterials may be good alternatives to enhance the shelf life of food without affecting the nutrients. Carbon atoms bond with each other in diverse ways to form many allotropes, resulting in a variety of carbon nanomaterials (CNMs). CNMs include zero-dimensional carbon dots, graphene quantum dots, 1-dimensional carbon nanotubes, 2-dimensional pristine graphene, graphene oxide, reduced graphene oxide, and other derivatives of graphene. Most of the carbon-based nanomaterials are synthesized through a green process that is widely used in the field of food science and technology, and they are used mostly as antibacterial agents and as a biofiller in the development of active food-packaging materials. Carbon nanomaterials (CNMs), viz., carbon dots, graphene, activated carbon-based nanocomposites, carbon nanotubes, etc., are found to be environmentally benign and better materials for food packaging. With antibacterial efficiency, they support food preservation and other applications as well. Thus, carbon nanostructures are found to be applicable as superior materials for food preservation and packaging in modern industry.

Comparison Between L-312 Hydrophobic-Hydrophilic Acrylate and US-860 UV Hydrophilic Acrylate IOL Opacification Characteristic

Objective

To compare opacity characteristics of US-860 UV and L-312 IOL, and report the phenomenon of glistenings in hydrophobic-hydrophilic acrylic IOLs.

Setting

Qingdao Eye Hospital.

Design

Experimental study.

Methods

Four medical records (4 eyes) of patients with L-312 or US-860 UV IOL opacification reporting decreased or lost vision who underwent IOL explanation between 2019 and 2021 were reviewed. Explanted IOLs were analyzed by slit-lamp examination, confocal microscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) at Qingdao Eye Hospital and Qingdao university of science and technology.

Results

The 4 explanted IOLs were represented by 2 hydrophilic acrylic designs. The preoperative mean corrected distance visual acuity changed from 1.84 ± 1.09 logarithm of the minimum angle of resolution (log MAR) to 0.20 ± 0.03 log MAR postoperatively except case 3. The mean interval of the L-312 IOL was 56.67 ± 14.19 months (range 44 to 72 months), and the interval of the US-860 UV IOL was 27 months. Morphological findings were surface, subsurface calcifications of the US-860 UV IOL material, and the optical region of L-312 IOLs are teeming with a great number of vacuoles by light microscope, scanning electron microscope and Energy Dispersive X-ray Spectral.

Conclusion

The cause of US-860 UV opacification was primary calcification, and vacuoles resulted in L-312 IOL opacification.

Novel Biogenic Synthesis of a Ag@Biochar Nanocomposite as an Antimicrobial Agent and Photocatalyst for Methylene Blue Degradation

The conventional synthesis of nanomaterials employing physical and chemical methods usually requires high cost and toxic chemicals. Thus, a facile, ecofriendly, cost-effective, novel, and sustainable route for the synthesis of a silver-loaded biochar nanocomposite (Ag@biochar) using Chenopodium ambrosioides leaf extract and biomass is reported for the first time in this study to advocate many of the principles of green chemistry such as safer solvents and auxiliaries. UV spectroscopic analysis at 420 nm indicated the formation of silver nanoparticles (AgNPs). The band gap energy of Ag@biochar was 1.9 eV, confirming its potential use as a photocatalyst. Ag@biochar was found to be photoluminescent at 425 nm. AgNPs on the surface of biochar were predominantly spherical with a size range of 25-35 nm and a surface area of 47.61 m²/g. A zeta potential of -5.87 mV designated the stability of Ag@biochar. Testing the photocatalytic potential of Ag@biochar to remove methylene blue from wastewater demonstrated its high removal efficiency that reached 88.4% due to its high efficiency of electron transfer confirmed via electrochemical impedance spectroscopy analysis and retained 70.65% after six cycles of reuse. Ag@biochar was shown to be a powerful broad-spectrum antimicrobial agent as it completely prevented the growth of Escherichia coli and also inhibited the growth of Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus subtilis, and Candida albicans with the inhibition zones of 19, 18, 22, and 16 mm, respectively.

Pharmaceuticals and personal care products in water and wastewater: a review of treatment processes and use of photocatalyst immobilized on functionalized carbon in AOP degradation

The presence of emerging contaminants such as pharmaceutical and personal care products in many aqueous matrices have been reported. One of such matrix is streams of wastewater, including wastewater treatment plants inflows and outflows and wastewater flow by-passing wastewater treatment plants. Their persistence arises from their resistant to breakdown, hence they may remain in the environment over long time, with a potential to cause adverse effects including endocrine disruption, gene toxicity, the imposition of sex organs, antibiotic resistance and many others in some aquatic organisms exposed to arrays of residues of pharmaceutical and personal care products. Among the treatment techniques, advanced oxidation processes have been reported to be a better technique through which these PPCPs can be degraded in the WWTPs. Heterogeneous photocatalysis using various photocatalyst immobilized on solid support such as activated carbon, graphene and carbon nanotubes in AOPs have been shown to be a viable and efficient method of PPCPs degradation. This is because, the performance of most WWTPs is limited since they were not designed to degrade toxic and recalcitrant PPCPs. This review highlight the occurrence, concentration of PPCPs in wastewater and the removal efficiency of heterogeneous photocatalysis of TiO2 immobilized on solid supports.

Ultrasound-accelerated synthesis of uniform SrMnO3 nanoparticles as water-oxidizing catalysts for water splitting systems

One of the major issue in the 21st century is the humans request to green energy. The best form of green, sustainable and safe energy is hydrogen source due to its ecological and economical aspects. Herein, In order to obtain a highly water-oxidizing catalysts for water splitting systems, the sonochemical procedure applied for fabrication of practical SrMnO₃ nanoparticles. Also, the influence of various green capping agents (fruit juices and vegetable wastes) was studied on the formation of uniform particles. In the present work ultrasonic probe with 60 W/cm² intensity and 18 kHz frequency was used for sample synthesis. Further, catalytic behavior of these nanomaterials investigated in water splitting reaction for O₂ evolution by modifying the operational variables. The best catalytic behavior observed by those nanoparticles that indicated the smallest size and the most uniform morphology (Max amount of TON = 7.556). By utilizing the ultrasonic irradiation, the catalytic behavior of SrMnO₃ nanoparticles improved (TON (ultrasonic bath) = 8.430, TON (ultrasonic probe) = 11.315). Therefore, nano-SrMnO₃ was introduced as an efficient and novel nanocatalyst for O₂ evolution reaction.

Manganese oxide synthesized from spent Zn-C battery for supercapacitor electrode application

Manganese oxide (Mn₃O₄) nanomaterials have promising potential to be used as supercapacitor electrode materials due to its high energy storage performance and environmental compatibility. Besides, every year huge volume of waste batteries including Zn-C battery ends up in landfill, which aggravates the burden of waste disposal in landfill and creates environmental and health threat. Thus, transformation of waste battery back into energy application, is of great significance for sustainable strategies. Compared with complex chemical routes which mostly apply toxic acids to recover materials from Zn-C battery, this study establishes the recovery of Mn₃O₄ particles via thermal route within 900 °C under controlled atmosphere. Synthesized Mn₃O₄ were confirmed by XRD, EDS, FTIR, XPS and Raman analysis and FESEM micrographs confirmed the coexistence of spherical and cubic Mn₃O₄ particles. Mn₃O₄ electrode derived from waste Zn-C battery demonstrate compatible electrochemical performance with standard materials and conventional synthesis techniques. Mn₃O₄ electrode exhibited highest capacitance value of 125 Fg⁻¹ at 5 mVs⁻¹ scan rate. The stability of the electrode showed good retention in discharge and charge capacity by about 80% after 2100 cycles. This study demonstrates that waste Zn-C battery can be further utilized for energy storage application, providing sustainable and economic benefits.

Metal Nanoparticles: Thermal Decomposition, Biomedicinal Applications to Cancer Treatment, and Future Perspectives

Monodispersed forms of metal nanoparticles are significant to overcome frightening threat of cancer. This review examined pragmatically thermal decomposition as one of the best ways to synthesize monodispersed metal nanoparticles which are stable and of small particle sizes. Controlled morphology for delivery of anticancer agent to specific cells can also be obtained with thermal decomposition. In addition to thermal decomposition, the study also looked into processes of characterization techniques, biological evaluation, toxicity of nanoparticles, and future perspectives.

Sonochemical synthesis of SrMnO3 nanoparticles as an efficient and new catalyst for O2 evolution from water splitting reaction

The principal focus of this investigation is to prepare the SrMnO₃ nanostructures by different chemical methods such as ultrasonic, co-precipitation, microwave, and hydrothermal methods. The influence of calcination temperature, and ultrasound irradiation power, and the presence of surfactant investigated on morphology and size of SrMnO₃ nanostructures. As-prepared nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray energy dispersive spectroscopy (EDS) and ultraviolet-visible (UV-Vis) spectroscopy. The results indicated that by changing in method and reaction condition, product appeared in different size, morphology, and uniformity. The morphology and size of nanostructures have been influenced on the properties of nano-SrMnO₃. For investigation of properties, the SrMnO₃ was used in catalytic water splitting for O₂ evolution in presence of (NH₄)₂Ce(NO₃)_6. The effect of nano-catalysts and the concentration of (NH₄)₂Ce(NO₃)₆ have been studied on O₂ evolution reaction. Results show that the efficiency of water splitting increased by enhancement in the size and uniformity of catalysts and introduced the SrMnO₃ as a new and efficient catalyst for O₂ evolution reaction.

Effect of ligand on particle size and morphology of nanostructures synthesized by thermal decomposition of coordination compounds

Thermal decomposition of organometallic and various coordination compounds are known as general method to synthesize a wide range of nanostructures including metals, metal oxides and sulfides. Herein, in order to coordinate metals and prepare suitable precursor - due to the efficient role of precursor on the particle size and morphology of products - appropriate ligands will be introduced.

A systematic investigation on the interaction of l-cysteine functionalised Mn3O4 nanoparticles with lysozyme

Interactions of cysteine capped Mn₃O₄ nanoparticles with HEWL.

Influence of the protocol of fibroin extraction on the antibiotic activities of the constructed composites

The effect of the solvents for silk fibroin (SF) extraction on its antimicrobial activity was studied. Extraction protocols were performed using LiBr (SF_L) and Ajisawa’s reagent (CaCl₂:ethanol:H₂O) (SF_C). The morphological and structural characteristics of the extracted SF and their composites were assessed. Corresponding bactericidal activities against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922) and Pseudomonas aeroginosa (ATCC 27853) were performed. The resulting solutions were either casted into films or individually incorporated into composites of silver nanoparticles (NS) embedded into chitosan fragments (Cs) through γ-irradiation. Films of SF, obtained by using the two solvents, as well as the final prepared composites of SF, NS and Cs were analyzed using XRD, FTIR, SEM, TEM and zeta potential at several pH values. The band gap values were calculated. The results proved that, although SF_C consumed shorter gelation time, yet SF_L exerted higher antibiotic activity against the tested microorganisms. Moreover, the final composites had the ability to significantly reduce the growth of these medically relevant bacteria and are, therefore, recommended as a novel natural antibacterial biomaterial for several biomedical applications.

A very simple and high-yield method to synthesize nanolayered Mn oxide

Nanolayered Mn oxides have been prepared by a very simple, low-cost and high-yield method using soap, KOH, MnCl2 and H2O2. Scanning electron microscopy, transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray diffraction spectrometry have been used to characterize the phase and the morphology of the nanolayered Mn oxide. The nanolayered Mn oxide shows good catalytic activity toward water oxidation in the presence of cerium(iv) ammonium nitrate.

Mn3O4 Nanoparticles: Synthesis, Characterization, and Dielectric Properties

Mn3O4 nanoparticles were prepared by a simple chemical route using cetyltetramethylammonium bromide (CTAB) as a template agent. Mn3O4 nanocrystals present an octahedral shape, and their crystallite size varies between 20 and 80 nm. They were characterized by XRD, SEM, DTA/TG, and IR spectroscopy. XRD studies confirm the presence of a highly crystalline Mn3O4 phase. The Rietveld refinement of the X-ray diffraction data confirms that Mn3O4 nanoparticles crystallize in the tetragonal system with space group I41/amd. DTA/TG and XRD measurements demonstrate the phase transition toward a spinel structure between 25 and 700∘C. The electrical conductivity increases between 80 and 300∘C, suggesting a semiconducting behaviour of Mn3O4. Both dielectric dispersion (ε′) and dielectric loss (ε′′) were investigated from 80 and 300∘C in the frequency range of 10 Hz–13 MHz. The dielectric properties showed typical dielectric dispersion based on the Maxwell-Wagner model.