Lattice variation as a function of concentration and grain size in MgO-NiO solid solution system

The study aimed to understand how changes in crystal's size affect the lattice parameters and crystal structure of Mg1-xNixO solid solution for six X values ranging from x = 0 to x = 1. Mg1-xNixO was synthesized via two different wet-chemical techniques: the sol-gel and the microwave hydrothermal method, both followed by calcination at different temperatures of 673, 873, 1073, 1273 and 1473 K. As annealing caused grain growth, the varied temperature range allowed to examine a wide range of grain sizes. The lattice parameters and x values were determined from XRD (X-ray diffraction) peak positions and intensities respectively. The grain size was evaluated by XRD line profile analysis and supported by SEM (scanning electron microscope) observations. At the temperatures of 673 and 873 K grain size was in the nanometric range and from 1073 K and above grain size was in the micrometric range. A non-monotonic lattice variation versus grain size was found for each concentration. When grain size decreased there was a slight contraction, however for grain size in the nanometric range there was a severe lattice expansion. Both lattice parameter changes were explained by two effects acting together: contraction due to surface stress and expansion due to weakening of the ionic bonding at nanocrystalline particles. In this current research study, the lattice parameter was mapped in two dimensions: concentration and grain size. The findings of this study provided valuable insights into the lattice variation in the MgO-NiO solid solution system.

Plant-Assisted Green Synthesis of MgO Nanoparticles as a Sustainable Material for Bone Regeneration: Spectroscopic Properties

This work is devoted to magnesium oxide (MgO) nanoparticles (NPs) for their use as additives for bone implants. Extracts from four different widely used plants, including Aloe vera, Echeveria elegans, Sansevieria trifasciata, and Sedum morganianum, were evaluated for their ability to facilitate the "green synthesis" of MgO nanoparticles. The thermal stability and decomposition behavior of the MgONPs were analyzed by thermogravimetric analysis (TGA). Structure characterization was performed by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), and Raman scattering spectroscopy (RS). Morphology was studied by scanning electron microscopy (SEM). The photocatalytic activity of MgO nanoparticles was investigated based on the degradation of methyl orange (MeO) using UV-Vis spectroscopy. Surface-enhanced Raman scattering spectroscopy (SERS) was used to monitor the adsorption of L-phenylalanine (L-Phe) on the surface of MgONPs. The calculated enhancement factor (EF) is up to 102 orders of magnitude for MgO. This is the first work showing the SERS spectra of a chemical compound immobilized on the surface of MgO nanoparticles.

Adjuvant Novel Nanocarrier-Based Targeted Therapy for Lung Cancer

Lung cancer has the lowest survival rate due to its late-stage diagnosis, poor prognosis, and intra-tumoral heterogeneity. These factors decrease the effectiveness of treatment. They release chemokines and cytokines from the tumor microenvironment (TME). To improve the effectiveness of treatment, researchers emphasize personalized adjuvant therapies along with conventional ones. Targeted chemotherapeutic drug delivery systems and specific pathway-blocking agents using nanocarriers are a few of them. This study explored the nanocarrier roles and strategies to improve the treatment profile's effectiveness by striving for TME. A biofunctionalized nanocarrier stimulates biosystem interaction, cellular uptake, immune system escape, and vascular changes for penetration into the TME. Inorganic metal compounds scavenge reactive oxygen species (ROS) through their photothermal effect. Stroma, hypoxia, pH, and immunity-modulating agents conjugated or modified nanocarriers co-administered with pathway-blocking or condition-modulating agents can regulate extracellular matrix (ECM), Cancer-associated fibroblasts (CAF),Tyro3, Axl, and Mertk receptors (TAM) regulation, regulatory T-cell (Treg) inhibition, and myeloid-derived suppressor cells (MDSC) inhibition. Again, biomimetic conjugation or the surface modification of nanocarriers using ligands can enhance active targeting efficacy by bypassing the TME. A carrier system with biofunctionalized inorganic metal compounds and organic compound complex-loaded drugs is convenient for NSCLC-targeted therapy.

MgO Nanoparticles Obtained from an Innovative and Sustainable Route and Their Applications in Cancer Therapy

This paper aimed to evaluate the biological damages towards diseased cells caused by the use of MgO nanoparticles (NPs). The NPs are produced by a calcination process of a precursor, which is an aqueous suspension of nanostructured Mg(OH)2, in turn synthesized following our original, time-energy saving and scalable method able to guarantee short times, high yield of production (up to almost 10 kg/week of NPs), low environmental impact and low energy demand. The MgO NPs, in the form of dry powders, are organized as a network of intercrystallite channels, in turn constituted by monodispersed and roughly spherical NPs < 10 nm, preserving the original pseudo hexagonal-platelet morphology of the precursor. The produced MgO powders are diluted in a PBS solution to obtain different MgO suspension concentrations that are subsequently put in contact, for 3 days, with melanoma and healthy cells. The viable count, made at 24, 48 and 72 h from the beginning of the test, reveals a good cytotoxic activity of the NPs, already at low MgO concentrations. This is particularly marked after 72 h, showing a clear reduction in cellular proliferation in a MgO-concentration-dependent manner. Finally, the results obtained on human skin fibroblasts revealed that the use MgO NPs did not alter at all both the vitality and proliferation of healthy cells.

Nanofibrous Dressing with Nanocomposite Monoporous Microspheres for Chemodynamic Antibacterial Therapy and Wound Healing

The excessive use of antibiotics and consequent bacterial resistance have emerged as crucial public safety challenges for humanity. As a promising antibacterial treatment, using reactive oxygen species (ROS) can effectively address this problem and has the advantages of being highly efficient and having low toxicity. Herein, electrospinning and electrospraying were employed to fabricate magnesium oxide (MgO)-based nanoparticle composited polycaprolactone (PCL) nanofibrous dressings for the chemodynamic treatment of bacteria-infected wounds. By utilizing electrospraying, erythrocyte-like monoporous PCL microspheres incorporating silver (Ag)- and copper (Cu)-doped MgO nanoparticles were generated, and the unique microsphere-filament structure enabled efficient anchoring on nanofibers. The composite dressings produced high levels of ROS, as confirmed by the 2,7-dichloriflurescin fluorescent probe. The sustained generation of ROS resulted in efficient glutathione oxidation and a remarkable bacterial killing rate of approximately 99% against Staphylococcus aureus (S. aureus). These dressings were found to be effective at treating externally infected wounds. The unique properties of these composite nanofibrous dressings suggest great potential for their use in the medical treatment of bacteria-infected injuries.

Cytotoxic effects of dose dependent inorganic magnesium oxide nanoparticles on the reproductive organs of rats

INTRODUCTION

Magnesium oxide nanoparticles (MgO NPs) have a variety of applications that have contributed to their elevated popularity, however, the safety and toxic effects on humans are also of concern with these increased applications. There is insufficient data regarding the effect of MgO NPs on reproductive organs, which are crucial aspects to the body's vital physiological functions. The present study was undertaken in male and female rats to assess the reproductive toxicological potential of two doses (low versus high) of MgO NPs on testicular and ovarian tissues. The toxicity was evaluated using histological, hormonal, and oxidative parameters.

MATERIAL AND METHODS

In this work, magnesium oxide nanoparticles (MgO NPs) were synthesized by the sol-gel route and were characterized by X ray diffraction analysis (XRD) and Fourier transform infra-red spectroscopy (FTIR). Forty-eight adult Wister albino rats were used in this experiment which were divided into groups of male and female, and then further into control, low dose MgO NPs, and high dose MgO NPs. The low dose used was 131.5 mg/kg b.w. (1/10 LD50) while the high dose used was 263 mg/kg b.w. (1/5 LD50). All doses were given orally by gastric tube. After 4 weeks, blood samples were collected to investigate the level of sex hormones and both ovarian and testicular tissues were examined for variable oxidative parameters and histopathological changes by light microscopy.

RESULTS

The obtained findings showed that high dose of MgO NPs produced considerable changes in sex hormones and stress parameters in both male and female rats in comparison to the low dose and control groups. Histomorphometric analysis demonstrated the presence of histopathological alterations in the testicular and ovarian tissues.

CONCLUSION

The results of this study showed dose-dependent adverse effects of MgO NPs on the testis and ovary both functionally and histopathologically as compared to the control rats.

Raman spectroscopy investigation of magnesium oxide nanoparticles

We investigate Raman spectra (100 cm-1 to 3900 cm-1) of magnesium oxide nanoparticles with nominal sizes of 10 nm, 20 nm, 40 nm, 50 nm, and 300 nm. The crystal structure of MgO prohibits first-order modes and yet, there are numerous reports of relatively intense peaks throughout the literature. Raman signals at approximately 278 cm-1 and 445 cm-1 that were attributed to MgO nanoparticles by previous authors are shown to belong to layers of Mg(OH)2 formed on the surface of MgO nanoparticles. Through an annealing process at 400 °C in an O2 atmosphere, we observe that modes in the 3700 cm-1 spectral region, which are a signature of OH groups, disappear together with modes at 278 cm-1 and 445 cm-1, thus establishing a necessary criterion to associate all of these peaks to the presence of OH groups on the surface.

Radiation attenuation properties of chemically prepared MgO nanoparticles/HDPE composites

Sheets of high-density polyethylene (HDPE) loaded with magnesium oxide in micro and nano were synthesized with different weight percentages of micro-MgO (0,5,10,20 and 30% by weight) and nano-MgO (5 and 30%) and shaped in form of disc and dog bone shape. The morphological, mechanical, and attenuation characteristics of each concentration were determined. The linear attenuation coefficients (LAC) of the prepared discs were calculated using a well-calibrated scintillation detector and five standard gamma-ray point sources (²⁴¹Am, ¹³³Ba, ¹³⁷Cs, ⁶⁰Co and ¹⁵²Eu). The LAC was theoretically calculated for HDPE/micro-MgO composites using XCOM software. A good agreement between the theoretical and experimental results was observed. The comparison between micro and nano-MgO as a filler in HDPE was evaluated. The results proved that the loaded nano-MgO in different proportions of HDPE produced greater attenuation coefficients than its micro counterpart. The addition of nano MgO with different weight percentage led to a significant improvement in the mechanical properties of HDPE, the ultimate force and ultimate stress increased as the concentration of nano MgO increased, and the young modulus of HDPE also increased with increasing concentration of micro and nano MgO.

Facile synthesis of MgO nanoparticles for effective degradation of organic dyes

In the present study, we have synthesized magnesium oxide (MgO) nanoparticles by a facile and cost-effective chemical co-precipitation method with annealing at three different temperatures (350°C, 450°C, and 550°C) for the removal of various organic dyes. X-ray diffraction studies revealed that the prepared samples are having sizes below 20 nm and with pure phase. Phase transformation of hexagonal Mg(OH)₂ nanoparticles to discretely cubical structured MgO nanoparticles has been observed with increasing the annealing temperatures which is also supported by the TGA/DSC analysis. Mg-O stretching vibration peaks in the range of 400-800 cm^-1 obtained by FTIR spectroscopy support the formation of MgO nanoparticles. The observed Raman active bands for the annealed sample at 550°C confirm the formation of the nanocrystalline phase since these bands are typically absent in the bulk MgO as well as in Mg(OH)₂. The surface morphology of the as-prepared Mg(OH)₂ are aggregated nano-petals which changed into spherical shape for MgO annealed at 550°C as studied by field emission scanning electron microscopy (FESEM). The specific surface area of MgO nanoparticles annealed at 550°C using BET isotherms is found to be 37.487 m²g^-1. The optical bandgaps of the prepared samples are found to be in the range of 4.4 to 5.1 eV using the Tauc plot. Adsorption studies with a variation of initial brilliant green dye concentration and contact time are carried out along with the studies of adsorption kinetic and isotherm models. Langmuir isotherm model is the most suitable model on the basis of correlation constant with maximum BG dye adsorption capacity onto MgO@550°C which is found to be 63.9 mg/g. The adsorption kinetics followed the pseudo-second-order model. Also prepared pristine MgO nanoparticles showed significant photocatalytic performance for the degradation of various dyes; brilliant green (BG: 88.91%), methylene blue (MB: 79.05%), crystal violet (CV: 76.49%), methyl orange (MO: 68.62%), and brilliant blue (BB: 40.44%) under visible irradiation. MgO nanoparticles could be a promising adsorbent and photocatalyst that may be employed in the treatment of effluents from industries.

Comparative Evaluation of Bioefficiency and Photocatalytic Activity of Green Synthesized Bismuth Oxide Nanoparticles Using Three Different Leaf Extracts

Nanotechnology has emerged as a promising method for wastewater recycling. In this line, the current study emphasizes the leaf-extract-mediated biosynthesis of bismuth oxide nanostructures (BiONPs) using three different plants, namely Coldenia procumbens Linn (Creeping Coldenia), Citrus limon (Lemon), and Murraya koenigii (Curry) through a greener approach and evaluates their biological properties as well as photocatalytic performance for the first time. As-synthesized BiONPs were physiochemically characterized using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray analysis (EDAX). Using the well diffusion method, research on the antibacterial efficiency of BiONPs against human pathogenic Gram-positive bacteria, such as Staphylococcus aureus and Enterococcus faecalis, and Gram-negative bacteria, including Escherichia coli and Klebsiella pneumonia, revealed that Gram-negative bacteria exhibited relatively strong activity. The larvicidal activity assessed against Aedes aegypti and Aedes albopictus mosquito larvae reveals promising larvicidal activity with a minimal dosage of BiONPs with LC₅₀ values of 5.53 and 19.24 ppm, respectively, after 24 h of exposure. The excellent photocatalytic activity of as-synthesized BiONPs was demonstrated through the photodegradation of malachite green (MG) and methylene blue (MB) dyes with respective degradation performance parameters of 70 and 90%. The biogenic synthetic approach reported here enables the scalable commercial synthesis of bismuth nanostructures for their widespread use in catalysis for wastewater treatment and environmental cleanup.

Magnetic, Optical and Phonon Properties of Ion-Doped MgO Nanoparticles. Application for Magnetic Hyperthermia

The influence of size and doping effects on the magnetization M, phonon ω and band gap energy Eg of MgO nanoparticles is studied using a microscopic model. The room-temperature ferromagnetism is due to surface or/and doping effects in MgO nanoparticles (NPs). The influence of the spin-phonon interaction is discussed. M increases with decreasing NP size. M and Eg can increase or decrease by different ion doping (Co, Al, La, Fe) due to the different strain that appears. It changes the lattice parameters and the exchange interaction constants. We found that MgO NP with size of 20 nm and Fe- or Co-doping concentration x = 0.1 and x = 0.2, respectively, have a Curie temperature TC = 315 K, i.e., they are appropriate for application in magnetic hyperthermia, they satisfy the conditions for that. The energy of the phonon mode ω = 448 cm-1 increases with decreasing NP size. It increases with increasing Co and Fe, or decreases with Sr ion doping.

Synthesis and Spectral Characterisation of Fabricated Cerium-Doped Magnesium Oxide Nanoparticles: Evaluation of the Antimicrobial Potential and Its Membranolytic Activity through Large Unilamellar Vesicles

Considerable attention has been given to Magnesium oxide nanoparticles lately due to their antimicrobial potential, low toxicity to humans, high thermal stability, biocompatibility, and low cost of production. However, their successful transformation into sustainable drugs is limited due to their low membrane permeability, which reduces their bioavailability in target cells. Herein we propose Cerium-doped magnesium oxide nanoparticles (MgOCeNPs) as a powerful solution to above mentioned limitations and are compared with MgO NPs for their membrane permeability and antimicrobial activity. Both pure and Ce-doped were characterized by various spectroscopic and microscopic techniques, in which an X-ray diffraction (XRD) examination reveals the lattice patterns for doped nanoparticles. Furthermore, Atomic Force Microscopy (AFM) revealed the three-dimensional (3D) structure and height of the nanoparticle. The crystal structure (FCC) of MgO did not change with Ce doping. However, microstructural properties like lattice parameter, crystallite size and biological activity of MgO significantly changed with Ce doping. In order to evaluate the antimicrobial potential of MgOCeNPs in comparison to MgO NPs and to understand the underlying mechanisms, the antibacterial activity was investigated against human pathogenic bacteria E. coli and P. aeruginosa, and antifungal activity against THY-1, a fungal strain. MgOCeNPs were studied by several methods, which resulted in a strong antibacterial and antifungal activity in the form of an elevated zone of inhibition, reduced growth curve, lower minimum inhibitory concentration (MIC₈₀) and enhanced cytotoxicity in both bacterial and fungal strain as compared to MgO nanoparticles. The study of the growth curve showed early and prolonged stationary phase and early decline log phase. Both bacterial and fungal strains showed dose-dependent cytotoxicity with enhancement in intracellular reactive oxygen species (ROS) generation and formation of pores in the membrane when interacting with egg-phosphatidylcholine model Large Unilamellar Vesicles (LUVs). The proposed mechanism of MgOCeNPs toxicity evidently is membranolytic activity and induction of ROS production, which may cause oxidative stress-mediated cytotoxicity. These results confirmed that MgOCeNPs are a novel and very potent antimicrobial agent with a great promise of controlling and treating other microbes.

Magnesium Oxide Nanoparticles: Effective Antilarvicidal and Antibacterial Agents

People are vulnerable to mosquito-borne infections in tropical and subtropical climate countries. Due to resistive issues, vector control is an immediate concern in today's environment. The current study describes the synthesis of magnesium oxide by four different approaches including green, microwave, sol-gel, and hydrothermal methods. The synthesized magnesium oxide (MgO) nanoparticles were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM), and energy-dispersive X-ray analysis (EDAX) techniques. The FT-IR studies reveal the presence of functional groups in the synthesized nanoparticles. The structural and morphological studies were investigated using XRD and HRSEM. EDAX reveals the presence of Mg and O in the prepared samples. The synthesized MgO NPs were screened for antibacterial studies against Gram-positive strains, Enterococcus faecalis and Staphylococcus aureus, two Gram-negative cultures, Escherichia coli and Klebsiella pneumoniae, using different concentrations. The results indicated excellent antibacterial activity against both Gram-positive and Gram-negative bacteria at 50 mg/mL hydrothermally produced MgO nanoparticles, with a maximal zone of inhibition (ZOI) of 5 mm for S. aureus, 7 mm for E. faecalis, and 6 mm for K. pneumoniae. The ZOI of E. coli was found to be the greatest at 9 mm when 50 mg/mL sol-gel-produced MgO nanoparticles were used. The synthesized MgO nanostructures were tested against fourth-instar larvae of Aedes aegypti and Aedes albopictus, and the hydrothermally synthesized MgO nanostructures exhibited better results when compared with other methods of synthesis. The reports show that A. aegypti and A. albopictus mortality rates were reported to be the lowest with green-manufactured MgO nanoparticles (7.5 g mL-1) and the highest with hydrothermally synthesized MgO nanoparticles (120 g mL-1). The research indicates that MgO nanostructures are promising drugs for antibacterial and mosquitocidal larvae control properties.

In vitro and in vivo study on antiprotozoal activity of calcium oxide (CaO) and magnesium oxide (MgO) nanoparticles on promastigote and amastigote forms of Leishmania major

BACKGROUND

Currently, anti-leishmanial drugs have been developed. However, the available compounds have several side effects such as drug resistance and toxicity that cause some limitation for use. The development of nanoparticles (NPs) use in biological research and the proven effectiveness of CaONPs and MgONPs on bacteria and fungi, along with the lack of information about its antileishmanial effects, have motivated this study. CaO and MgONPs possess considerable antibacterial effects because of their alkalinity and active oxygen species. This study has taken into account the impacts of these two NPs on the L. major in vitro and in vivo.

METHODS

To evaluate the antileishmanial activity of NPs, the cytotoxic effect of CaONPs, MgONPs, and MgOCaONPs against L. major amastigotes, promastigotes, as well as macrophages, was evaluated using counting or MTT assay. The possible apoptosis of L. major by CaONPs, MgONPs, and MgOCaONPs was evaluated via flow cytometry assay. For in vivo study, BALB/c mice were allocated to five groups and the lesions of infected mice with L. major promastigotes were treated with a 200 μg/mL concentration CaONPs, MgONPs, and MgOCaONPs, then the mice underwent a 4-week follow-up to examine the wound diameter and survival rates.

RESULTS

The XRD-pattern related to CaONPs and MgONPs indicating the cubic phase and Rocksalt cubic structures. According the effects of nanoparticle on promastigotes the IC₅₀ values of CaONPs, MgONPs, and MgOCaONPs within 72 h were 7.9 ug/mL, 10.3 ug/mL, and 8.0 ug/mL respectively. CaONPs, MgONPs, and MgOCaONPs induced apoptosis in about 7.8%, 53.57%, and 12.8% of promastigotes. All mice presented lesions. MgONPs was the most effective in reducing the size of the lesions.

CONCLUSION

According to the results of the present research, MgONPs and CaONPs showed good in vitro and in vivo effects on L. major promastigotes and intracellular amastigotes especially MgONPs, and also it seems that MgONPs are applicable in Leishmania infection treatment due to their potential antileishmanial effects.

The mechanistic effects of human digestion on magnesium oxide nanoparticles: implications for probiotics Lacticaseibacillus rhamnosus GG and Bifidobacterium bifidum VPI 1124

The effects of nanoparticles (NPs) on the human gut microbiota are of high interest due to the link between the gut homeostasis and overall human health. The human intake of metal oxide NPs has increased due to its use in the food industry as food additives. Specifically, magnesium oxide nanoparticles (MgO-NPs) have been described as antimicrobial and antibiofilm. Therefore, in this work we investigated the effects of the food additive MgO-NPs, on the probiotic and commensal Gram-positive Lactobacillus rhamnosus GG and Bifidobacterium bifidum VPI 1124. The physicochemical characterization showed that food additive MgO is formed by nanoparticles (MgO-NPs) and after a simulated digestion, MgO-NPs partially dissociate into Mg2+. Moreover, nanoparticulate structures containing magnesium were found embedded in organic material. Exposures to MgO-NPs for 4 and 24 hours increased the bacterial viability of both L. rhamnosus and B. bifidum when in biofilms but not when as planktonic cells. High doses of MgO-NPs significantly stimulated the biofilm development of L. rhamnosus, but not B. bifidum. It is likely that the effects are primarily due to the presence of ionic Mg2+. Evidence from the NPs characterization indicate that interactions bacteria/NPs are unfavorable as both structures are negatively charged, which would create repulsive forces.

A Study on the Effect of Nanoscale MgO and Hydrogen Bonding in Nanofiber Mats for the Controlled Drug Release along with In Vitro Breast Cancer Cell Line and Antimicrobial Studies

Nanosized metal oxide-incorporated drug carriers have received significant attention due to their biocompatibility, mechanical strength, controlled drug release, and biodegradability. Herein, an attempt was made to fabricate polycaprolactone-based electrospun nanofiber mats involving the 5-fluorouracil (5Fu) drug, MgO nanoparticle, methyl cellulose, and polyethylene glycol. The chemical interactions, surface wettability, mechanical properties, structural and morphological changes, and thermal stability were studied by the respective analyses. The ionic interaction between 5Fu, MgO, and polymers were found to be responsible for the controlled drug release. Zero-order kinetic and model data also revealed that a controlled drug release pattern was observed in a period of 16 days. Furthermore, the nanofiber mats were subjected to cytotoxicity studies against MDA-MB-231 cancer cell line and the results showed higher cytotoxicity in a short time of 24 h and less toxicity to normal L929 fibroblast cell line. The apoptosis in cancer cell lines was also tested by AO/PI staining assay and confirmed by fluorescence microscopy. In addition, the growth inhibition of several bacterial and fungal strains was tested for the mats and the results exhibited good inhibition activity. Hence, the reported nanofiber drug carrier was found to be an efficient implant for the controlled release of anticancer drug along with other significant properties.

Microenvironmental Behaviour of Nanotheranostic Systems for Controlled Oxidative Stress and Cancer Treatment

The development of smart, efficient and multifunctional material systems for diseases treatment are imperative to meet current and future health challenges. Nanomaterials with theranostic properties have offered a cost effective and efficient solution for disease treatment, particularly, metal/oxide based nanotheranostic systems already offering therapeutic and imaging capabilities for cancer treatment. Nanoparticles can selectively generate/scavenge ROS through intrinsic or external stimuli to augment/diminish oxidative stress. An efficient treatment requires higher oxidative stress/toxicity in malignant disease, with a minimal level in surrounding normal cells. The size, shape and surface properties of nanoparticles are critical parameters for achieving a theranostic function in the microenvironment. In the last decade, different strategies for the synthesis of biocompatible theranostic nanostructures have been introduced. The exhibition of therapeutics properties such as selective reactive oxygen species (ROS) scavenging, hyperthermia, antibacterial, antiviral, and imaging capabilities such as MRI, CT and fluorescence activity have been reported in a variety of developed nanosystems to combat cancer, neurodegenerative and emerging infectious diseases. In this review article, theranostic in vitro behaviour in relation to the size, shape and synthesis methods of widely researched and developed nanosystems (Au, Ag, MnO_x, iron oxide, maghemite quantum flakes, La₂O_3−x, TaO_x, cerium nanodots, ITO, MgO_1−x) are presented. In particular, ROS-based properties of the nanostructures in the microenvironment for cancer therapy are discussed. The provided overview of the biological behaviour of reported metal-based nanostructures will help to conceptualise novel designs and synthesis strategies for the development of advanced nanotheranostic systems.

Radiodynamic therapy with CsI(na)@MgO nanoparticles and 5-aminolevulinic acid

Background

Radiodynamic therapy (RDT) holds the potential to overcome the shallow tissue penetration issue associated with conventional photodynamic therapy (PDT). To this end, complex and sometimes toxic scintillator–photosensitizer nanoconjugates are often used, posing barriers for large-scale manufacturing and regulatory approval.

Methods

Herein, we report a streamlined RDT strategy based on CsI(Na)@MgO nanoparticles and 5-aminolevulinic acid (5-ALA). 5-ALA is a clinically approved photosensitizer, converted to protoporphyrin IX (PpIX) in cancer cells’ mitochondria. CsI(Na)@MgO nanoparticles produce strong ~ 410 nm X-ray luminescence, which matches the Soret band of PpIX. We hypothesize that the CsI(Na)@MgO-and-5-ALA combination can mediate RDT wherein mitochondria-targeted PDT synergizes with DNA-targeted irradiation for efficient cancer cell killing. Because scintillator nanoparticles and photosensitizer are administered separately, the approach forgoes issues such as self-quenching or uncontrolled release of photosensitizers.

Results

When tested in vitro with 4T1 cells, the CsI(Na)@MgO and 5-ALA combination elevated radiation-induced reactive oxygen species (ROS), enhancing damages to mitochondria, DNA, and lipids, eventually reducing cell proliferation and clonogenicity. When tested in vivo in 4T1 models, RDT with the CsI(Na)@MgO and 5-ALA combination significantly improved tumor suppression and animal survival relative to radiation therapy (RT) alone. After treatment, the scintillator nanoparticles, made of low-toxic alkali and halide elements, were efficiently excreted, causing no detectable harm to the hosts.

Conclusions

Our studies show that separately administering CsI(Na)@MgO nanoparticles and 5-ALA represents a safe and streamlined RDT approach with potential in clinical translation.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01537-z.

Structure, optical properties and antimicrobial activities of MgO-Bi2-xCrxO3 nanocomposites prepared via solvent-deficient method

MgO–Bi_2−xCr_xO₃ nanocomposites for x = 0 and 0.07 were fabricated using the solvent-deficient route. X-ray diffraction method, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA) and UV–Vis spectroscopy were employed to study the properties. The samples were also evaluated for the antibacterial activity. The x = 0 sample showed a dominant monoclinic crystalline structure of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha\text{-}{\text{Bi}}_{2}{\text{O}}_{3}$$\end{document}α-Bi2O3 phase. No peaks attributed to MgO were observed. Cr-doped \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text{MgO}{-}{\text{Bi}}_{2}{\text{O}}_{3}$$\end{document}MgO-Bi2O3 in which Bi was substituted showed that \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{the tetragonal BiCrO}}_{3}$$\end{document}the tetragonal BiCrO3 phase was also present in the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text{MgO}{-}{\text{Bi}}_{2}{\text{O}}_{3}$$\end{document}MgO-Bi2O3 composite. The Scherrer formula was employed to determine the crystallite size of the samples. The Cr-doped sample showed a decrease in the crystallite size. The microstructures of the non-doped MgO–Bi₂O₃ and MgO–Bi_1.93Cr_0.07O₃ composites consisted of micrometer sized grains and were uniformly distributed. Direct transition energy gap, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${E}_{\text{g}}$$\end{document}Eg decreased from 3.14 to 2.77 eV with Cr-doping as determined from UV–Vis spectroscopy. The Cr-doped \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text{MgO}{-}{\text{Bi}}_{2}{\text{O}}_{3}$$\end{document}MgO-Bi2O3 nanocomposites exhibited two energy gaps at 2.36 and 2.76 eV. The antibacterial activity was determined against gram-negative bacteria (Salmonella typhimurium and Pseudomonas aeruginosa) and gram-positive bacteria (Staphylococcus aureus) by disc diffusion method. Cr-doping led to a decrease in inhibitory activity of MgO–Bi_2−xCr_xO₃ nanocomposite against the various types of bacteria.

Subchronic toxicity of magnesium oxide nanoparticles to Bombyx mori silkworm

Despite many research efforts devoted to the study of the effects of magnesium oxide nanoparticles (MgO NPs) on cells or animals in recent years, data related to the potential long-term effects of this nanomaterial are still scarce. The aim of this study is to explore the subchronic effects of MgO NPs on Bombyx mori silkworm, a complete metamorphosis insect with four development stages (egg, larva, pupa, month). With this end in view, silkworm larvae were exposed to MgO NPs at different mass concentrations (1%, 2%, 3% and 4%) throughout their fifth instar larva. Their development, survival rate, cell morphology, gene expressions, and especially silk properties were compared with a control. The results demonstrate that MgO NPs have no significant negative impact on the growth or tissues. The cocooning rate and silk quality also display normal results. However, a total of 806 genes are differentially expressed in the silk gland (a vital organ for producing silk). GO (Gene Ontology) results show that the expression of many genes related to transporter activity are significantly changed, revealing that active transport is the main mechanism for the penetration of MgO NPs, which also proves that MgO NPs are adsorbed by cells. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis demonstrates that the longevity regulating pathway-worm, peroxisome and MAPK signaling pathway are closely involved in the biological effects of MgO NPs. Overall, subchronic exposure to MgO NPs induced no apparent negative impact on silkworm growth or silks but changed the expressions of some genes.

Cytotoxicity Assessment of Surface-Modified Magnesium Hydroxide Nanoparticles

Magnesium-based nanoparticles have shown promise in regenerative therapies in orthopedics and the cardiovascular system. Here, we set out to assess the influence of differently functionalized Mg nanoparticles on the cellular players of wound healing, the first step in the process of tissue regeneration. First, we thoroughly addressed the physicochemical characteristics of magnesium hydroxide nanoparticles, which exhibited low colloidal stability and strong aggregation in cell culture media. To address this matter, magnesium hydroxide nanoparticles underwent surface functionalization by 3-aminopropyltriethoxysilane (APTES), resulting in excellent dispersible properties in ethanol and improved colloidal stability in physiological media. The latter was determined as a concentration- and time-dependent phenomenon. There were no significant effects on THP-1 macrophage viability up to 1.500 μg/mL APTES-coated magnesium hydroxide nanoparticles. Accordingly, increased media pH and Mg²⁺ concentration, the nanoparticles dissociation products, had no adverse effects on their viability and morphology. HDF, ASCs, and PK84 exhibited the highest, and HUVECs, HPMECs, and THP-1 cells the lowest resistance toward nanoparticle toxic effects. In conclusion, the indicated high magnesium hydroxide nanoparticles biocompatibility suggests them a potential drug delivery vehicle for treating diseases like fibrosis or cancer. If delivered in a targeted manner, cytotoxic nanoparticles could be considered a potential localized and specific prevention strategy for treating highly prevalent diseases like fibrosis or cancer. Looking toward the possible clinical applications, accurate interpretation of in vitro cellular responses is the keystone for the relevant prediction of subsequent in vivo biological effects.

Genotoxic assessment of cerium and magnesium nanoparticles and their ionic forms in Eisenia hortensis coelomocytes by alkaline comet assay

The present study aimed to evaluate the genotoxic potential of cerium oxide (CeO₂ ), magnesium oxide (MgO) nanoparticles and their ionic forms by alkaline comet assay. Eisenia hortensis were exposed to different series of concentrations (25, 50, 100, 200, and 400 μg/ml) of chemicals for 48 h to find LC₅₀ . The LC₅₀ for MgO and CeO₂ NPs were 70 and 80 μg/ml. Whereas, the LC₅₀ for their ionic forms were 50 and 70 μg/ml. To assess the potential DNA damage caused by the chosen chemicals, E. hortensis was further exposed for 48 h to the following concentrations, based on their respective LC_50s : LC_50/2 , LC⁵⁰ , and 2xLC₅₀ . Comet scores demonstrated the significant increase (p < 0.05) in DNA damage at all concentrations, both for NPs and ionic forms in a concentration-dependent manner. Findings of the present study revealed the genotoxic effects of CeO₂ NPs, MgO NPs and their ionic forms on E. hortensis.

Evaluation of Mechanical Properties and Antibacterial Activity of Nano Titania-Enriched Alkasite Restorative Material: An In Vitro Study

Background:

A biocompatible additive with the ability to establish antibacterial action for restorative materials without sacrificing their physical properties is always in demand. Nano titania (TiO2 nanoparticles) was shown to have antimicrobial action against a wide range of microorganisms. Alkasite is a modern esthetic restorative material that has outstanding properties; however, it is deficient in antibacterial activity.

Objective:

TiO2 nanoparticles (NPs) were included in alkasite, and both mechanical properties and antibacterial activity of the new formulations were assessed.

Materials and Methods:

Nano titania powder was coupled to alkasite powder in proportions of 3 and 5% (w/w). There were 105 specimens made in total. Evaluation parameters were compressive strength, surface microhardness, surface roughness, water sorption and solubility, and antibacterial activity. One and two-way ANOVA were used for the statistical analysis, followed by Tukey′s test (p<0.05).

Results:

Both ratios of nano titania, 3 and 5% (w/w), significantly increased compressive strength, antibacterial activity against different pathogens, and decreased water solubility of alkasite (p<0.05). Only 5% (w/w) nano titania-modified alkasite exhibited significant decrease in water sorption (p<0.05). Conversely, an insignificant increase in microhardness and surface roughness was observed with both ratios, 3 and 5% (w/w) of nano titania (p˃0.05).

Conclusion:

Nano titania seems to be a very promising complementary additive to the alkasite restorative material, capable of generating considerable antibacterial effectiveness while also enhancing certain mechanical properties.

Enhanced antibacterial activity of acid treated MgO nanoparticles on Escherichia coli

Acid treatment is one of the effective methods that directly modifies surface physical and chemical properties of inorganic materials, which improves the materials' application potential. In this work, the surface modified MgO nanoparticles (NPs) were prepared through a facile acid-treatment method at room temperature. Compared with the untreated sample, the surviving Escherichia coli (E. coli, ATCC 25922) colonies of the modified MgO NPs decreased from 120 to 54 (10² CFU mL^-1). The enhanced antibacterial activity may be due to the improvement of oxygen vacancies and absorbed oxygen (O_A) content (from 41.6% to 63.1%) as confirmed by electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS). These findings revealed that the acid treatment method could directly modify the surface of MgO NPs to expose more oxygen vacancies, which would promote reactive oxygen species (ROS) generation. The membrane tube and single ROS scavenging results further indicated that the increased antibacterial ability originated from the synergetic effect of ROS damage (especially ˙O₂ ^-) and direct contact between H-MgO NPs and E. coli.

A Tagetes minuta based eco-benign synthesis of multifunctional Au/MgO nanocomposite with enhanced photocatalytic, antibacterial and DPPH scavenging activities

In this research work, facile, economical and eco-benign experimental procedure were adopted to synthesize Au/MgO nanocomposite with the help of Tagetes minuta leaves extract. Phytochemicals present in the leaves of Tagetes minuta were acting as reducing and stabilizing agents to avoid aggregation of nanomaterials during the preparation of Au/MgO nanocomposite. The biologically synthesized nanocomposite were systematically characterized by UV-vis spectroscopy, Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared microscopy (FTIR), High resolution transmission electron microscopy (HRTEM), Thermogravimetric analysis (TGA), dynamic light scattering (DLS) and elemental mapping. UV-visible spectrum confirmed the presence of MgO and Au due to the presence of two SPR peaks at 315 nm and 528 nm, respectively. Moreover, the Au/MgO nanocomposite exhibited superior photocatalytic, antibacterial, hemolytic, and antioxidant activities. Photocatalytic performance tests of Au/MgO nanocomposite were- appraised by the rapid degradation of the methylene blue (MB) under UV light illumination. More importantly, after four successive cycles of MB degradation, the photocatalytic efficacy remained unchanged, which ensures the stability of the Au/MgO nanocomposite. Furthermore, the antibacterial tests showed that the advanced nanocomposite inhibited the growth of Escherichia coli, Bacillus subtilis, and Staphylococcus aureus with zones of inhibition 18 (±0.3), 21 (±0.5), and 19 (±0.4) mm, respectively. The cytotoxicity study revealed that Au/MgO nanocomposite is nontoxic to ordinary healthy RBCs. Interestingly, the Au/MgO nanocomposite also possesses an excellent antioxidant activity, whereby effectively scavenging 82% stable and harmful DPPH. Overall, the present study concludes that eco-benign Au/MgO nanocomposite has excellent potential for the remediation of bacterial pathogens and degradation of MB.

Graphene Oxide-Doped MgO Nanostructures for Highly Efficient Dye Degradation and Bactericidal Action

Various concentrations (0.01, 0.03 and 0.05 wt ratios) of graphene oxide (GO) nanosheets were doped into magnesium oxide (MgO) nanostructures using chemical precipitation technique. The objective was to study the effect of GO dopant concentrations on the catalytic and antibacterial behavior of fixed amount of MgO. XRD technique revealed cubic phase of MgO, while its crystalline nature was confirmed through SAED profiles. Functional groups presence and Mg-O (443 cm-1) in fingerprint region was evident with FTIR spectroscopy. Optical properties were recorded via UV-visible spectroscopy with redshift pointing to a decrease in band gap energy from 5.0 to 4.8 eV upon doping. Electron-hole recombination behavior was examined through photoluminescence (PL) spectroscopy. Raman spectra exhibited D band (1338 cm-1) and G band (1598 cm-1) evident to GO doping. Formation of nanostructure with cubic and hexagon morphology was confirmed with TEM, whereas interlayer average d-spacing of 0.23 nm was assessed using HR-TEM. Dopants existence and evaluation of elemental constitution Mg, O were corroborated using EDS technique. Catalytic activity against methyl blue ciprofloxacin (MBCF) was significantly reduced (45%) for higher GO dopant concentration (0.05), whereas bactericidal activity of MgO against E. coli was improved significantly (4.85 mm inhibition zone) upon doping with higher concentration (0.05) of GO, owing to the formation of nanorods.

Silk Fibroin Coated Magnesium Oxide Nanospheres: A Biocompatible and Biodegradable Tool for Noninvasive Bioimaging Applications

Fluorescent nanoparticles (NPs) have been increasingly studied as contrast agents for better understanding of biological processes at the cellular and molecular level. However, their use as bioimaging tools is strongly dependent on their optical emission as well as their biocompatibility. This work reports the fabrication and characterization of silk fibroin (SF) coated magnesium oxide (MgO) nanospheres, containing oxygen, Cr³⁺ and V²⁺ related optical defects, as a nontoxic and biodegradable hybrid platform for bioimaging applications. The MgO-SF spheres demonstrated enhanced emission efficiency compared to noncoated MgO NPs. Furthermore, SF sphere coating was found to overcome agglomeration limitations of the MgO NPs. The hybrid nanospheres were investigated as an in vitro bioimaging tool by recording their cellular uptake, trajectories, and mobility in human skin keratinocytes cells (HaCaT), human glioma cells (U87MG) and breast cancer cells (MCF7). Enhanced cellular uptake and improved intracellular mobilities of MgO-SF spheres compared to MgO NPs was demonstrated in three different cell lines. Validated infrared and bright emission of MgO-SF NP indicate their prospects for in vivo imaging. The results identify the potential of the hybrid MgO-SF nanospheres for bioimaging. This study may also open new avenues to optimize drug delivery through biodegradable silk and provide noninvasive functional imaging feedback on the therapeutic processes through fluorescent MgO.

Two-Step Triethylamine-Based Synthesis of MgO Nanoparticles and Their Antibacterial Effect against Pathogenic Bacteria

Magnesium oxide nanoparticles (MgO NPs) were obtained by the calcination of precursor microparticles (PM) synthesized by a novel triethylamine-based precipitation method. Scanning electron microscopy (SEM) revealed a mean size of 120 nm for the MgO NPs. The results of the characterizations for MgO NPs support the suggestion that our material has the capacity to attack, and have an antibacterial effect against, Gram-negative and Gram-positive bacteria strains. The ability of the MgO NPs to produce reactive oxygen species (ROS), such as superoxide anion radicals (O2•-) or hydrogen peroxide (H2O2), was demonstrated by the corresponding quantitative assays. The MgO antibacterial activity was evaluated against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, with minimum inhibitory concentrations (MICs) of 250 and 500 ppm on the microdilution assays, respectively. Structural changes in the bacteria, such as membrane collapse; surface changes, such as vesicular formation; and changes in the longitudinal and horizontal sizes, as well as the circumference, were observed using atomic force microscopy (AFM). The lipidic peroxidation of the bacterial membranes was quantified, and finally, a bactericidal mechanism for the MgO NPs was also proposed.

Enhanced anti-Escherichia coli properties of Fe-doping in MgO nanoparticles

Hetero-elements doping is an effective way to modify the composition and nanostructure of metal oxides. These modifications could lead to changes in physical and chemical properties correspondingly. In this study, Fe-doped MgO nanoparticles (NPs) were synthesized by simple calcination method in air. The antibacterial activity of MgO NPs against Escherichia coli (E. coli, ATCC 25922) was significantly improved as shown by the bactericidal efficacy test results. According to X-ray diffraction (XRD) results, Fe was successfully doped into MgO lattice and mainly adopted interstitial doping. The Fe-doping led to increased oxygen vacancies and OA content (from 13.5% to 41.3%) on MgO surface, which may have facilitated the reactive oxygen species (ROS) generation and bacteria death. The wrinkled and sunken E. coli surface after contact with Fe-doped MgO NPs also confirmed the existence of adsorption damage mechanism. Thus, the antibacterial activity enhancement against E. coli was originated from the synergistic effect of increased ROS concentration and the interaction with Fe-doped MgO NPs.

Synthesis of ppy–MgO–CNT nanocomposites for multifunctional applications

Cotton is one of the most important raw materials for textile and clothing production. The main drawbacks of cotton fibers are their poor mechanical properties and high flammability. Compared with some synthetic polymer fibers, cotton fabrics treated with modern flame-retardant and reinforcement finishes often cannot meet rigid military specifications. Polypyrrole–magnesium oxide (ppy–MgO) and polypyrrole–magnesium oxide–carbon nanotube (ppy–MgO–CNT) composites were prepared with various weight ratios by in situ chemical polymerization method. 1,2,3,4-Butane tetracarboxylic acid (BTCA) was used as a cross-linking agent in the presence of sodium hypophosphite (SHP). The composite sol was coated on cotton fabric using the pad-dry-cure technique. The coated cotton fabrics were characterized by SEM, EDAX, XRD, UV-DRS and FT-IR analysis, and tested for flame retardant and UPF application. The flame-retardant study showed a maximum char length of 0.3 cm and the char yield was about 49% for the ppy–MgO–CNT composite. For that UPF application, a 30 UPF value was shown for the ppy–MgO–CNT composite. In the case of the antibacterial study, the zone of inhibition was observed for all of the test samples against MRSA and PAO1 bacteria. The zone of inhibition showed as 4.0, 3.0 mm for the ppy–MgO–CNT composite. Hence, the ppy–MgO–CNT composite was found to be efficient.

Cotton is one of the most important raw materials for textile and clothing production.

The antibacterial and angiogenic effect of magnesium oxide in a hydroxyapatite bone substitute

Bone graft infections are serious complications in orthopaedics and the growing resistance to antibiotics is increasing the need for antibacterial strategies. The use of magnesium oxide (MgO) is an interesting alternative since it possesses broad-spectrum antibacterial activity. Additionally, magnesium ions also play a role in bone regeneration, which makes MgO more appealing than other metal oxides. Therefore, a bone substitute composed of hydroxyapatite and MgO (HAp/MgO) spherical granules was developed using different sintering heat-treatment cycles to optimize its features. Depending on the sintering temperature, HAp/MgO spherical granules exhibited distinct surface topographies, mechanical strength and degradation profiles, that influenced the in vitro antibacterial activity and cytocompatibility. A proper balance between antibacterial activity and cytocompatibility was achieved with HAp/MgO spherical granules sintered at 1100 ºC. The presence of MgO in these granules was able to significantly reduce bacterial proliferation and simultaneously provide a suitable environment for osteoblasts growth. The angiogenic and inflammation potentials were also assessed using the in vivo chicken embryo chorioallantoic membrane (CAM) model and the spherical granules containing MgO stimulated angiogenesis without increasing inflammation. The outcomes of this study evidence a dual effect of MgO for bone regenerative applications making this material a promising antibacterial bone substitute.

Cytotoxicity and insulin resistance reversal ability of biofunctional phytosynthesized MgO nanoparticles

The present study investigates the cytotoxicity of hexagonal MgO nanoparticles synthesized via Amaranthus tricolor leaf extract and spherical MgO nanoparticles synthesized via Amaranthus blitum and Andrographis paniculata leaf extracts. In vitro cytotoxicity analysis showed that the hexagonal MgO nanoparticles synthesized from A. tricolor extract demonstrated the least toxicity to both diabetic and non-diabetic cells at 600 μl/ml dosage. The viability of the diabetic cells (3T3-L1) after incubation with varying dosages of MgO nanoparticles was observed to be 55.3%. The viability of normal VERO cells was 86.6% and this stabilized to about 75% even after exposure to MgO nanoparticles dosage of up to 1000 μl/ml. Colorimetric glucose assay revealed that the A. tricolor extract synthesized MgO nanoparticles resulted in ~ 28% insulin resistance reversal. A reduction in the expression of GLUT4 protein at 54 KDa after MgO nanopaSrticles incubation with diabetic cells was observed via western blot analysis to confirm insulin reversal ability. Fluorescence microscopic analysis with propidium iodide and acridine orange dyes showed the release of reactive oxygen species as a possible mechanism of the cytotoxic effect of MgO nanoparticles. It was inferred that the synergistic effect of the phytochemicals and MgO nanoparticles played a significant role in delivering enhanced insulin resistance reversal capability in adipose cells.

Glioma cells eradication by photoexcitation of bioengineered molybdenum trioxide nanoparticles synthesized by wet chemical and microwave route: Dose dependent photosensitizer bioactivity

Here, we surveyed the usage of MoO₃ nanostructure in role of a photosensitizer to eradicate glioma cells. This is the first endeavor upon survey of usage of nanostructured MoO₃ to treat glioma in vitro. Here, we offer a simple way for preparation of bioactive MoO₃ nanostructure via two different routes; wet chemical and microwave. The influence of diverse experimental factors like various alcoholic solvents and presence of capping agent was investigated on the final properties of synthesized products. Dimension and morphology of inorganic molybdenum trioxide nanostructures checked with TEM, HRTEM and also SEM images. Moreover, the cytotoxicity effect of optimized MoO₃ nanoparticles was investigated on T98 and A172 cell lines. Both T98 and A172 cell lines indicated dose-dependent manner in the presence of increasing concentration of MoO₃ nanostructures, but T98 cells were less sensitive to MoO₃ in comparison with A172. Anti-glioma role of MoO₃ nanostructures excited with the aid of UVC illumination studied in vitro as well. By studying the UV exposure lonely, it is evident that UV effects on cell viability about 50% in both cell lines after 24 h. Interestingly, by combining nanostructured MoO₃ with UVC illumination, decrement in the proliferation value could be remarkably occurred in comparison with controls. The outcomes denote that the photodynamic therapy with the help of nanostructured MoO₃ may be beneficial to treat glioma.

Exchange Reactions at Mineral Interfaces

Exchange reactions are a family of chemical reactions that appear when mineral surfaces come into contact with protic solvents. Exchange reactions can also be understood as a unique interaction at mineral interfaces. Particularly significant interactions occurring at mineral surfaces are those with water and CO₂. The rather complex process occurring when minerals such as calcium silicate hydrate (C-S-H) phases come into contact with aqueous environments is referred to as a metal-proton exchange reaction (MPER). This process leads to the leaching of calcium ions from the near-surface region, the first step in the corrosion of cement-bound materials. Among the various corrosion reactions of C-S-H phases, the MPER appears to be the most important one. A promising approach to bridging certain problems caused by MPER and carbonation is the passivation of C-S-H surfaces. Today, such passivation is reached, for instance, by the functionalization of C-S-H surfaces with water-repelling organic films. Unfortunately, these organic films are weak against temperature and especially weak against abrasion. Exchange reactions at mineral interfaces allow the preparation of intrinsic, hydrophobic surfaces of C-S-H phases just at room temperature via a metal-metal exchange reaction.

Preventing fungal growth on heritage paper with antifungal and cellulase inhibiting magnesium oxide nanoparticles

Microorganisms such as bacteria, fungi, algae and moulds are highly proficient at colonizing artistic and architectural heritage. The irreparable damage they cause to unique artefacts results in immeasurable cultural and societal losses to our shared cultural heritage, which represent an important social and economic resource for Europe. With the overall aim of preventing fungal deterioration of paper artefacts, we report the use of magnesium oxide nanoparticles (MgO NPs) of average diameter 12 nm as potent antifungal agents against fungi commonly found colonising paper heritage: A. niger, C. cladosporioides and T. reesei. Dispersions of MgO NPs on original 18th century paper samples from the Archives of the Spanish Royal Botanic Garden were effective at preventing fungal colonisation without altering the appearance of the paper artefacts. Importantly, MgO NPs also inhibit cellulase activity in the filamentous fungi T. resei and A. niger, two of the principle biodeteriogens of cellulosic materials. In addition, our report provides three simple new procedures for studying the fungal colonisation prevention properties of nanomaterials on paper samples. Overall this opens the door to the use of colourless, low-cost, and scalable nanomaterials for preventing biodeterioration in cellulose-based artefacts.

Approaches to synthesize MgO nanostructures for diverse applications

Magnesium oxide remained interesting from long time for several important phenomena like; defect induced magnetism, spin electron reflectivity, broad laser emission etc. Moreover, nanostructures of this material exhibited suitability for different kinds of applications ranging from wastewater treatment to spintronics depending upon their shape and size. In this way, researchers had grown nanostructures in the form of nanoparticles, thin films, nanotubes, nanowalls, nanobelts. Though nanoparticles and thin films are well known form of nanostructures and wide variety of synthesis approaches are available, however, limited methodology for other nanostructures are available. In order to grow these nanostructures in an optimized way an understanding of these methods is essential. Thus, this review article depicts an overview of various approaches for design of different kinds of nanostructures.