Manganese Dioxide Nanoparticles Research Articles

Enhancement in the optical and carbon dioxide gas sensing properties of polythiophene by dispersion of manganese dioxide nanoparticles

The present research article demonstrates the dispersion of manganese dioxide (MnO2) nanoparticles in polythiophene (PTh) to enhance the optical and gas sensing properties of PTh/MnO2 nanocomposites. The structural aspects of the as-synthesized nanocomposites were demonstrated by the techniques such as X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM). Furthermore, the optical characterization of the resulting composite was investigated using UV-Vis spectroscopy. UV-Vis analyses of obtained nanocomposite revealed a forbidden band of ∼ 3.7 eV. The prepared nanocomposites were exposed to CO2 gas to investigate the composites suitability for gas sensing application, which prove to be promising materials. The prominent exploit of the present work is that 0.8 Wt.% MnO2 loaded PTh composite material exhibits significant sensing response at low operating temperature including good stability and fast response and recovery time. The core objective of this work is the discussion of the enhancement in stability, response and recovery time as a consequence of the interaction between the CO2 gas and the as-synthesized nanocomposites.

Hollow Manganese Dioxide Nanoparticles for Drug Delivery and Imaging

Hollow Manganese Dioxide Nanoparticles for Drug Delivery and Imaging

Dual-targeted delivery of temozolomide by multi-responsive nanoplatform via tumor microenvironment modulation for overcoming drug resistance to treat glioblastoma.

Glioblastoma (GBM) is the most aggressive primary brain tumor with low survival rate. Currently, temozolomide (TMZ) is the first-line drug for GBM treatment of which efficacy is unfortunately hindered by short circulation time and drug resistance associated to hypoxia and redox tumor microenvironment. Herein, a dual-targeted and multi-responsive nanoplatform is developed by loading TMZ in hollow manganese dioxide nanoparticles functionalized by polydopamine and targeting ligands RAP12 for photothermal and receptor-mediated dual-targeted delivery, respectively. After accumulated in GBM tumor site, the nanoplatform could respond to tumor microenvironment and simultaneously release manganese ion (Mn2+), oxygen (O2) and TMZ. The hypoxia alleviation via O2 production, the redox balance disruption via glutathione consumption and the reactive oxygen species generation, together would down-regulate the expression of O6-methylguanine-DNA methyltransferase under TMZ medication, which is considered as the key to drug resistance. These strategies could synergistically alleviate hypoxia microenvironment and overcome TMZ resistance, further enhancing the anti-tumor effect of chemotherapy/chemodynamic therapy against GBM. Additionally, the released Mn2+ could also be utilized as a magnetic resonance imaging contrast agent for monitoring treatment efficiency. Our study demonstrated that this nanoplatform provides an alternative approach to the challenges including low delivery efficiency and drug resistance of chemotherapeutics, which eventually appears to be a potential avenue in GBM treatment.

Heavy metals immobilization and bioavailability in multi-metal contaminated soil under ryegrass cultivation as affected by ZnO and MnO2 nanoparticle-modified biochar

Pollution by heavy metals (HMs) has become a global problem for agriculture and the environment. In this study, the effects of pristine biochar and biochar modified with manganese dioxide (BC@MnO2) and zinc oxide (BC@ZnO) nanoparticles on the immobilization and bioavailability of Pb, Cd, Zn, and Ni in soil under ryegrass (Lolium perenne L.) cultivation were investigated. The results of SEM–EDX, FTIR, and XRD showed that ZnO and MnO2 nanoparticles were successfully loaded onto biochar. The results showed that BC, BC@MnO2 and BC@ZnO treatments significantly increased shoots and roots dry weight of ryegrass compared to the control. The maximum dry weight of root and shoot (1.365 g pot−1 and 4.163 g pot−1, respectively) was reached at 1% BC@MnO2. The HMs uptake by ryegrass roots and shoots decreased significantly after addition of amendments. The lowest Pb, Cd, Zn and Ni uptake in the plant shoot (13.176, 24.92, 32.407, and 53.88 µg pot−1, respectively) was obtained in the 1% BC@MnO2 treatment. Modified biochar was more successful in reducing HMs uptake by ryegrass and improving plant growth than pristine biochar and can therefore be used as an efficient and cost effective amendment for the remediation of HMs contaminated soils. The lowest HMs translocation (TF) and bioconcentration factors were related to the 1% BC@MnO2 treatment. Therefore, BC@MnO2 was the most successful treatment for HMs immobilization in soil. Also, a comparison of the TF values of plant showed that ryegrass had a good ability to accumulate all studied HMs in its roots, and it is a suitable plant for HMs phytostabilization.

Construction of lymph nodes-targeting tumor vaccines by using the principle of DNA base complementary pairing to enhance anti-tumor cellular immune response

Tumor vaccines, a crucial immunotherapy, have gained growing interest because of their unique capability to initiate precise anti-tumor immune responses and establish enduring immune memory. Injected tumor vaccines passively diffuse to the adjacent draining lymph nodes, where the residing antigen-presenting cells capture and present tumor antigens to T cells. This process represents the initial phase of the immune response to the tumor vaccines and constitutes a pivotal determinant of their effectiveness. Nevertheless, the granularity paradox, arising from the different requirements between the passive targeting delivery of tumor vaccines to lymph nodes and the uptake by antigen-presenting cells, diminishes the efficacy of lymph node-targeting tumor vaccines. This study addressed this challenge by employing a vaccine formulation with a tunable, controlled particle size. Manganese dioxide (MnO2) nanoparticles were synthesized, loaded with ovalbumin (OVA), and modified with A50 or T20 DNA single strands to obtain MnO2/OVA/A50 and MnO2/OVA/T20, respectively. Administering the vaccines sequentially, upon reaching the lymph nodes, the two vaccines converge and simultaneously aggregate into MnO2/OVA/A50-T20 particles through base pairing. This process enhances both vaccine uptake and antigen delivery. In vitro and in vivo studies demonstrated that, the combined vaccine, comprising MnO2/OVA/A50 and MnO2/OVA/T20, exhibited robust immunization effects and remarkable anti-tumor efficacy in the melanoma animal models. The strategy of controlling tumor vaccine size and consequently improving tumor antigen presentation efficiency and vaccine efficacy via the DNA base-pairing principle, provides novel concepts for the development of efficient tumor vaccines.Graphical

Characterization and application of targeted MnO2/CS@ALA-MTX nano-radiosensitizers for boosting X-ray radiotherapy of brain tumors

The current study aimed to investigate the potential of methotrexate (MTX) functionalized, 5-aminolevulinic acid (5-ALA)-modified, chitosan-coated manganese dioxide (MnO2/CS) nanoparticles (NPs) as a targeted radiosensitizer for cancer therapy. The novelty of the current study lies in the development of the MnO2/CS@5-ALA-MTX NPs as a novel formulation with high encapsulation capacity, site specificity, and biosafety for targeted drug delivery. The study also emphasizes comprehensive in-vitro tests to understand the cell death mechanisms after radiosensitization. The effects of MnO2/CS@5-ALA-MTX NPs on U87MG cell lines treated with radiation were examined in-vitro and in-vivo. Mitochondrial function and reactive oxygen species (ROS) production were evaluated under normoxia and hypoxia conditions. The combination of MTX and 5-ALA provided tumor-targeting ability, while the CS coating prolonged the circulation time of the nano-system. The synthesized MnO2/CS@5-ALA-MTX NPs had an average size of 70 ± 9 nm, a Zeta potential of −6 ± 2 mV, and a polydispersity of 0.240. The loading efficiency and release profile of the drug delivery system were assessed and demonstrated its capacity for drug delivery. The MTT assay on U87MG cells revealed that MnO2/CS@5-ALA-MTX NPs reduced cell viability compared to MTX alone. Both in-vitro and in-vivo studies demonstrated tumor-enhanced radiosensitization using MTX functionalized MnO2/CS NPs. The mice receiving MnO2/CS@5-ALA-MTX NPs and subsequent radiation exposure exhibited significant tumor inhibition and increased survival ratios. Notably, tumor-bearing mice treated with MnO2/CS@5-ALA-MTX NPs and X-ray irradiation demonstrated more effective tumor rejection compared to the groups treated with X-ray alone or NPs alone. In conclusion, the results highlight the potential of MnO2/CS@5-ALA-MTX NPs as a targeted radiosensitizer for cancer therapy. The NPs exhibited promising tumor-inhibiting effects and enhanced radiosensitization both in-vitro and in-vivo, suggesting their potential as a valuable approach for cancer treatment in the future.

Multi-Functional Nano-Doped Hollow Fiber from Microfluidics for Sensors and Micromotors.

Nano-doped hollow fiber is currently receiving extensive attention due to its multifunctionality and booming development. However, the microfluidic fabrication of nano-doped hollow fiber in a simple, smooth, stable, continuous, well-controlled manner without system blockage remains challenging. In this study, we employ a microfluidic method to fabricate nano-doped hollow fiber, which not only makes the preparation process continuous, controllable, and efficient, but also improves the dispersion uniformity of nanoparticles. Hydrogel hollow fiber doped with carbon nanotubes is fabricated and exhibits superior electrical conductivity (15.8 S m-1), strong flexibility (342.9%), and versatility as wearable sensors for monitoring human motions and collecting physiological electrical signals. Furthermore, we incorporate iron tetroxide nanoparticles into fibers to create magnetic-driven micromotors, which provide trajectory-controlled motion and the ability to move through narrow channels due to their small size. In addition, manganese dioxide nanoparticles are embedded into the fiber walls to create self-propelled micromotors. When placed in a hydrogen peroxide environment, the micromotors can reach a top speed of 615 μm s-1 and navigate hard-to-reach areas. Our nano-doped hollow fiber offers a broad range of applications in wearable electronics and self-propelled machines and creates promising opportunities for sensors and actuators.

Potential in-vitro antioxidant and anti-inflammatory activity of Martynia annua extract mediated Phytosynthesis of MnO2 nanoparticles

The present research work describes the phyto-synthesis of Manganese dioxide nanoparticles (MnO2NPs) from the reduction of potassium permanganate using Martynia annua (M.annua) plant extract. From the literature review, we clearly understood the M.annua plant has anti-inflammatory activity. Manganese dioxides are important materials due to their wide range of applications. Their increased surface area gives them distinct capabilities, as it increases their mechanical, magnetic, optical, and catalytic qualities, allowing them to be used in more pharmaceutical applications. A detailed review of literature highlighting the issues related to this present work and its knowledge gap that none of the inflammatory activities had been done by MnO2 NPs synthesized from M.annua plant extract. So we selected this study. The product MnO2 NPs showed the wavelength centre at 370 nm and was monitored by UV–Vis spectra. The wave number around 600 cm−1 has to the occurrence of O–Mn–O bonds of pure MnO2 confirmed by FTIR spectroscopy. Transmission electron microscopy images showed the morphology of MnO2 NPs as spherical-shaped particles with average sizes at 7.5 nm. The selected area electron diffraction analysis exhibits the crystalline nature of MnO2 NPs. The obtained MnO2 NPs showed potential antioxidant and anti-inflammatory activity was compared to the plant extract. The synthesized MnO2 NPs have a large number of potential applications in the field of pharmaceutical industries. In the future, we isolate the phytocompounds present in the M.annua plant extract and conduct a study against corona virus. MnO2 produces manganese (III) oxide and oxygen, which increases fire hazard. But further research is required to understand their environmental behaviour and safety.

Reactive Oxygen Species Scavenging Injectable Hydrogel Potentiates the Therapeutic Potential of Mesenchymal Stem Cells in Skin Flap Regeneration.

Cell-based therapies offer tremendous potential for skin flap regeneration. However, the hostile microenvironment of the injured tissue adversely affects the longevity and paracrine effects of the implanted cells, severely reducing their therapeutic effectiveness. Here, an injectable hydrogel (nGk) with reactive oxygen species (ROS) scavenging capability, which can amplify the cell viability and functions of encapsulated mesenchymal stem cells (MSCs), is employed to promote skin flap repair. nGk is formulated by dispersing manganese dioxide nanoparticles (MnO2 NPs) in a gelatin/κ-carrageenan hydrogel, which exhibits satisfactory injectable properties and undergoes a sol-gel phase transition at around 40 °C, leading to the formation of a solid gel at physiological temperature. MnO2 NPs enhance the mechanical properties of the hydrogel and give it the ability to scavenge ROS, thus providing a cell-protective system for MSCs. Cell culture studies show that nGk can mitigate the oxidative stress, improve cell viability, and boost stem cell paracrine function to promote angiogenesis. Furthermore, MSC-loaded nGk (nGk@MSCs) can improve the survival of skin flaps by promoting angiogenesis, reducing inflammatory reactions, and attenuating necrosis, providing an effective approach for tissue regeneration. Collectively, injectable nGk has substantial potential to enhance the therapeutic benefits of MSCs, making it a valuable delivery system for cell-based therapies.

Manganese dioxide nanoparticles provoke inflammatory damage in BV2 microglial cells via increasing reactive oxygen species to activate the p38 MAPK pathway.

With the widespread use of manganese dioxide nanoparticles (nano MnO2), health hazards have also emerged. The inflammatory damage of brain tissues could result from nano MnO2, in which the underlying mechanism is still unclear. During this study, we aimed to investigate the role of ROS-mediated p38 MAPK pathway in nano MnO2-induced inflammatory response in BV2 microglial cells. The inflammatory injury model was established by treating BV2 cells with 2.5, 5.0, and 10.0μg/mL nano MnO2 suspensions for 12 h. Then, the reactive oxygen species (ROS) scavenger (20nM N-acetylcysteine, NAC) and the p38 MAPK pathway inhibitor (10μM SB203580) were used to clarify the role of ROS and the p38 MAPK pathway in nano MnO2-induced inflammatory lesions in BV2 cells. The results indicated that nano MnO2 enhanced the expression of pro-inflammatory cytokines IL-1β and TNF-α, elevated intracellular ROS levels and activated the p38 MAPK pathway in BV2 cells. Controlling intracellular ROS levels with NAC inhibited p38 MAPK pathway activation and attenuated the inflammatory response induced by nano MnO2. Furthermore, inhibition of the p38 MAPK pathway with SB203580 led to a decrease in the production of inflammatory factors (IL-1β and TNF-α) in BV2 cells. In summary, nano MnO2 can induce inflammatory damage by increasing intracellular ROS levels and further activating the p38 MAPK pathway in BV2 microglial cells.

A Nucleobase‐Driven Self‐Gelled Hyaluronic Acid‐Based Injectable Adhesive Hydrogel Enhances Intervertebral Disc Repair

AbstractCell therapy strategies hold great promise for nucleus pulposus (NP) regeneration and intervertebral disc degeneration (IVDD) treatment. However, their therapeutic efficiency is compromised by the anoikis of administered cells and the harsh environment in degenerated intervertebral discs (IVD). Inspired by the ability of nucleobases to form multiple H‐bonds, a nucleobase‐driven self‐gelling strategy is proposed for the incorporation of nucleobases (e.g., thymine) into hyaluronic acid (HA) chains to trigger gel formation through enhanced intermolecular H‐bond interactions. An aqueous solution of a thymine‐modified HA (HAT) supramolecular polymer is shown to exhibit self‐gelation behavior, injectability, tissue adhesion, and hydration capacity (comparable to that observed in the NP tissue of a 25‐year‐old adult). These characteristics enable the injection and filling of the HAT hydrogel system in the IVD, integration of the separated NP tissues, restoration of the biomechanical functions of the degenerated IVD, and securing of the encapsulated cells in the NP site. Manganese dioxide (MnO2) nanoparticles incorporated into the HAT system (HATMn) regulate oxidative stress and the hypoxic microenvironment in degenerated IVD, ensuring the viability of the encapsulated cells. The 12‐week in vivo study results demonstrate that the administration of the MSCs‐laden HATMn system (HATMn‐MSCs) effectively restores the structure and function of degenerated IVD.

Biocompatibility assessment of bovine serum albumin conjugated manganese dioxide nanoparticle and their therapeutic role against microwave radiation induced haematological toxicity in male Wistar rats

Microwave (MW) radiations are widely used in communications, radar and medical treatment and thus human exposure to MW radiations have increased tremendously, raising health concerns as MW has been implicated in induction of oxidative stress condition in our body. Few metallic nanoparticles (NPs) have been shown to mimic the activity of antioxidant enzymes and hence can be applied for the modulation of adverse effects caused by MW. Present study aimed to assess the biocompatibility of Bovine serum albumin (BSA) conjugated manganese dioxide nanoparticles (MNP*) and to counteract the impact of MW on the haematological system of male Wistar rats. Experiments were conducted in two sets. Set I involved biodistribution and antioxidant activity evaluation of MNP* at different doses. Results showed a dose-dependent increase in antioxidant potential and significant biodistribution in the liver, spleen, kidney, and testis, with no organ damage, indicating its biocompatibility. Experiment set II constituted the study of separate and combined effects of MW and MNP* on haematological parameters, oxidative status, and genotoxic study in the blood of rats. MW exposure significantly altered red blood cell count, hemoglobin, packed cell volume percentage, monocyte percentage, aspartate aminotransferase, Alanine aminotransferase and uric acid. MW also induced significant DNA damage in the blood. A significant increase in lipid peroxidation and a decrease in antioxidant enzyme superoxide dismutase was also observed in MW exposed group. However, these alterations were reduced significantly when MNP* was administered. Thus, MNP* showed biocompatibility and modulatory effects against MW-induced alterations in the haematological system of rats.

Investigations on Chemically Synthesized Pure and Doped Manganese Dioxide Nanoparticles for Dye Removal and Photocatalytic Applications.

Pure and Mg2+, Ni2+, Cd2+ doped MnO2 nanoparticles were synthesized by chemical co-precipitation method. These samples were characterised by PXRD, SEM, EDX, FTIR, UV-Vis-NIR, PL, Antibacterial, Cyclic Voltammetry, Dye Degradation and Photocatalytic studies. From the powder XRD studies, the crystallite size of the particle was calculated using Scherer formula and found that the synthesized nanoparticles were in the range from 10 to 12nm. The morphology of all the synthesized samples was viewed from SEM micrograph. The composition and purity of the samples were identified from EDX studies. In FTIR spectra metal-oxygen stretching and bending modes of vibrations were observed. From the absorption spectra of UV-Vis optical analysis values of absorption coefficient, extinction coefficient, refractive index, real and imaginary part of optical dielectric constant and optical conductivity were compared. The band gap energy obtained from Tauc's plot varies from 1.21 to 1.51eV exhibits semiconducting behaviour of all the synthesized samples. Investigations on photoluminecsence spectrum reveals blue shift in wavelength for doped nanooxides compared to pure MnO2. Antimicrobial activity of synthesised samples against gram positive and gram negative bacteria was determined. The obtained results reveal very high bacterial resistance in Cd2+ doped MnO2 nanoparticles with higher activity towards bacterial resistance compared to standard drug. The specific capacitance values were determined from Cyclic Voltammetry studies. Using the batch method of dye removing technique the percentage of malachite green dye removal was calculated. Also the photocatalytic efficiency of all the synthesized MnO2 samples in removing malachite green dye was studied by exposing to sunlight for different dosage and contact time. Ni2+ doped MnO2 shows relatively higher % of dye degradation capacity about 93% for 0.1g of dosage of photocatalysts.

Optimizing Oxygen-Production Kinetics of Manganese Dioxide Nanoparticles Improves Hypoxia Reversal and Survival in Mice with Bone Metastases.

Persistent hypoxia in bone metastases induces an immunosuppressive environment, limiting the effectiveness of immunotherapies. To address chronic hypoxia, we have developed manganese dioxide (MnO2) nanoparticles with tunable oxygen production kinetics for sustained oxygenation in bone metastases lesions. Using polyethylene glycol (PEG)-stabilized MnO2 or poly(lactic[50]-co-glycolic[50] acid) (50:50 PLGA), poly(lactic[75]-co-glycolic[25] acid) (75:25 PLGA), and polylactic acid (PLA)-encapsulated MnO2 NPs, we demonstrate that polymer hydrophobicity attenuates burst oxygen production and enables tunable oxygen production kinetics. The PEG-MnO2 NPs resulted in rapid hypoxia reduction in spheroids, which was rapidly attenuated, while the PLA-MnO2 NPs exhibited delayed hypoxia control in cancer spheroids. The 50:50 PLGA-MnO2 NPs exhibited the best short- and long-term control of hypoxia in cancer spheroids, resulting in sustained regulation of the expression of HIF-1α and immunosuppressive genes. The sustained control of hypoxia by the 50:50 PLGA-MnO2 NPs enhanced the cytotoxicity of natural killer cells against cancer spheroids. In vivo, 50:50 PLGA-MnO2 showed greater accumulation in the long bones and pelvis, common sites for bone metastases. The NPs decreased hypoxia in bone metastases and decreased regulatory T cell levels, resulting in enhanced survival of mice with established bone metastases.

Mnox Nanoenzyme Armed CAR-NK Cells Enhance Solid Tumor Immunotherapy by Alleviating the Immunosuppressive Microenvironment.

Adoptively transferred cells usually suffer from exhaustion, limited expansion, and poor infiltration, partially attributing to the complicated immunosuppressive microenvironment of solid tumors. Therefore, it is necessary to explore more effective strategies to improve the poor tumor microenvironment (TME) to efficaciously deliver and support extrinsic effector cells in vivo. Herein, an intelligent biodegradable hollow manganese dioxide nanoparticle (MnOX) that possesses peroxidase activity to catalyze excess H2O2 in the TME to produce oxygen and relieve the hypoxia of solid tumors is developed. MnOX nanoenzymes modified with CD56 antibody could specifically bind CAR-NK (chimeric antigen receptor modified natural killer) cells. It is demonstrated that CAR-NK cells incorporated with MnOX nanoenzymes effectively infiltrate into tumor tissues with an improved TME, which results in superior antitumor activity in solid tumor-bearing mice. The antibody connection between MnOX nanoenzymes and CAR-NK endows the lowest efficient dosage of MnOX. This study features a smart synergistic immunotherapy approach for solid tumors using MnOX nanoenzyme-armed CAR-NK cells, which would provide a valuable tool for immunocyte therapy in solid tumors.

Green synthesis of manganese dioxide (MnO2) nanoparticles produced with acerola (Malpighia emarginata) leaf extract

In this work, green synthesis of manganese dioxide nanoparticles was carried out using aqueous extract from acerola leaves (Malpighia emarginata), evaluating the effect of pH and concentration of the plant extract. The materials were characterized by XRD, nitrogen adsorption-desorption (BET), FTIR, TG/DTG, SEM and EDX, showing that the synthesis parameters had a statistically significant effect on the yield and particle diameter. The crystal phase was identified as α-MnO2, in addition to observations of high thermal stability and mesoporous structure with surface areas from 34.074 to 40.298 m2 g−1. The experimental design showed that the effect of pH on the particle size depended on the level of extract concentration used, as for 30 g L−1 an increase in pH decreased the diameter while with 60 g L−1 an opposite effect was observed.

Biosafe Polydopamine-Decorated MnO2 Nanoparticles with Hemostasis and Antioxidative Properties for Postoperative Adhesion Prevention.

Surgical bleeding and cumulative oxidative stress are significant factors in the development of postoperative adhesions, which are always associated with adverse patient outcomes. However, effective strategies for adhesion prevention are currently lacking in clinical practice. In this study, we propose a solution using polydopamine-decorated manganese dioxide nanoparticles (MnO2@PDA) with rapid hemostasis and remarkable antioxidant properties to prevent postsurgical adhesion. The PDA modification provides MnO2@PDA with enhanced tissue adhesiveness and hemocompatibility with negligible hemolysis. Furthermore, MnO2@PDA exhibits impressive antioxidant and free radical scavenging properties, protecting cells from the negative effects of oxidative stress. The hemostatic activity of MnO2@PDA is evaluated in a mouse truncated tail model and a liver injury model, with results demonstrating reduced bleeding time and volume. The in vivo test on a mouse cecal abrasion model shows that MnO2@PDA exhibits excellent antiadhesion properties coupled with alleviated inflammation around the damaged tissue. Therefore, MnO2@PDA, which exhibits high biosafety, rapid hemostasis, and beneficial antioxidant capacity, displays exceptional antiadhesion performance, holding great potential for clinical applications to prevent postoperative adhesion.

Eco-friendly Synthesized Manganese Dioxide Nanoparticles Using Tridax procumbens as Potent Antimicrobial and Dye Degrading Agent

Manganese dioxide nanoparticles (MnO2 NPs) were synthesized via a typical green synthesis method involving Tridax procumbens (TP) leaf extract extraction and utilization. The as-prepared material was further characterized using various physio-chemical methods to comprehend its structural, morphological, and optical properties. Powder X-ray diffraction (PXRD) reveals a tetragonal system with a space group of I 41/a m d, clearly indicating the presence of phytochemicals (impurity peaks at 25.46° and 54.92° diffraction angles). The calculated crystalline size of the sample was found to be 43 nm. Field Emission Scanning Electron Microscope (FESEM) results confirm the precursors of the as-prepared sample, also revealing the agglomerated structure. Furthermore, deeper morphology and crystallinity of the as-prepared MnO2 NPs have been studied through High-Resolution Transmission Electron Microscope (HR-TEM) images, which affirms the information about calculated d-spacing value (0.328 nm) and confirming crystallinity through Selected Area Electron Diffraction (SAED) image. Absorption studies were conducted on as-prepared samples, which show a characteristic band at 257 nm, affirming the formation of MnO2 NPs. The same was utilized to evaluate the band gap energy (4.46 eV) through the Kubelka-Munk function. To further confirm the calculated particle size and stability of the as-prepared MnO2 NPs, Dynamic Light Scattering (DLS) analysis was conducted, and the results revealed that the particles’ size was 58.72 nm. The prepared samples were subjected to study antimicrobial studies against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacterial species. The inhibition zone of the antibacterial disc soaked with as-prepared MnO2 NPs showed a significant increase compared to the TP leaf extract and commercially available MnO2 NPs. Also, the degradation of the Titan Yellow dye solution was conducted employing UV irradiation, and it was found that the maximum degradation percentage was attained after 120 minutes of irradiation. Furthermore, the pH effect on %degradation and reusability test were also conducted. The obtained results showed a pinnacle pH point of 4 where the degradation was maximum and found a decent decrement in %degradation after 4th usage. All the acquired results were utilized to study the degradation reaction kinetics, which was found that the present degradation holds good for both 0th and 1st order kinetic equations. Henceforth, the acquired results suggest that the green synthesized MnO2 NPs are potent candidates for antimicrobial and degrading activities.

Traceable Lactate-Fueled Self-Acting Photodynamic Therapy against Triple-Negative Breast Cancer

The depth of light penetration and tumor hypoxia restrict the efficacy of photodynamic therapy (PDT) in triple-negative breast cancer (TNBC), while the overproduction of lactate (LA) facilitates the development, aggressiveness, and therapy resistance of TNBC. To address these issues, a self-acting PDT nanosystem (HL@hMnO 2 -LOx@HA) is fabricated by loading 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-alpha (HPPH), luminol, and LA oxidase (LOx) in a hyaluronic acid (HA)-coated hollow manganese dioxide (hMnO 2 ) nanoparticle. LOx catalyzes the oxidation of LA into pyruvate and hydrogen peroxide (H 2 O 2 ), thus depleting the overproduced intratumoral LA. In the acidic tumor microenvironment, H 2 O 2 reacts with luminol and hMnO 2 to yield blue luminescence as well as O 2 and Mn 2+ , respectively. Mn 2+ could further enhance this chemiluminescence. HPPH is then excited by the chemiluminescence through chemiluminescence resonance energy transfer for self-illuminated PDT. The generated O 2 alleviates the hypoxia state of the TNBC tumor to produce sufficient 1 O 2 for self-oxygenation PDT. The Mn 2+ performs T 1 magnetic resonance imaging to trace the self-acting PDT process. This work provides a biocompatible strategy to conquer the limits of light penetration and tumor hypoxia on PDT against TNBC as well as LA overproduction.

Reduction of Recombination Processes in PVC Photocatalytic Membranes Modified with Green Prepared Nanoparticles

The enhanced photocatalytic membranes were prepared by green synthesized Tin dioxide (SnO2) and manganese dioxide (MnO2) nanoparticles (NPs) blended with polyvinyl chloride (PVC) polymeric solution to produce a photocatalytic flat sheet membrane that was used in wastewater treatment. The surface and morphological structure of the produced membranes were studied using atomic force microscopy (AFM), and field emission scanning electron microscopy (FESEM). The elemental compositions and chemical bonding of the membranes were examined using Raman and Fourier transform infrared spectroscopy (FTIR). A sessile-drop approach was used to look at the membrane surface's hydrophilicity. Images of FESEM, AFM, Raman spectra, and FTIR analysis proved the existence of NPs on membrane surfaces. The modified membrane's hydrophilicity was significantly improved after NPs addition. Furthermore, Humic acid removal under darkness was enhanced for the modified membrane than the blank PVC. At the same time, it enhanced from 81% to 92, 100, and 99% for SnO2, MnO2, and SnO2/MnO2 respectively. The photocatalytic ability of the Photocatalytic membranes was examined in sunlight where it was found to be enhanced when exposed to sunlight as compared to when kept in the dark. The prepared membranes exhibited an enhancement removal performance. Both the water flux and the rejection were enhanced in sunlight. The SnO2/MnO2 photocatalytic membrane exhibited a better removal ability and good water flux. The potential utility of our research lies in its application within the water treatment industry, specifically as an effective technique for modifying PVC membranes.