Potential antibacterial, antibiofilm, and photocatalytic performance of gamma-irradiated novel nanocomposite for enhanced disinfection applications with an investigated reaction mechanism

BACKGROUND

Water scarcity is now a global challenge due to the population growth and the limited amount of available potable water. In addition, modern industrialization, and microbial pathogenesis is resulting in water pollution on a large scale.

METHODS

In the present study, reusable Co0.5Ni0.5Fe2O4/SiO2/TiO2 composite matrix was incorporated with CdS NPs to develop an efficient photocatalyst, and antimicrobial agents for wastewater treatment, and disinfection purpose. The antibacterial performance of the gamma-irradiated samples was evaluated against various types of Gram-positive bacteria using ZOI, MIC, antibiofilm, and effect of UV-exposure. Antibacterial reaction mechanism was assessed by bacterial membrane leakage assay, and SEM imaging. In addition, their photocatalytic efficiency was tested against MB cationic dye as a typical water organic pollutant.

RESULTS

Our results showed that, the formed CdS NPs were uniformly distributed onto the surface of the nanocomposite matrix. While, the resulted CdS-based nanocomposite possessed an average particle size of nearly 90.6 nm. The antibacterial performance of the prepared nanocomposite was significantly increased after activation with gamma and UV irradiations. The improved antibacterial performance was mainly due to the synergistic effect of both TiO2 and CdS NPs; whereas, the highest photocatalytic efficiency of MB removal was exhibited in alkaline media due to the electrostatic attraction between the cationic MB and the negatively-charged samples. In addition, the constructed heterojunction enabled better charge separation and increased the lifetime of the photogenerated charge carriers.

CONCLUSION

Our results can pave the way towards the development of efficient photocatalysts for wastewater treatment and promising antibacterial agents for disinfection applications.

Recent advances in modification of novel carbon-based composites: Synthesis, properties, and biotechnological/ biomedical applications

Nowadays, carbon-based materials owing to great interest in biomedical science/biotechnology and applied for effective diagnosis and treatment of disease. To enhance the effectiveness of carbon nanotubes (CNTs)/graphene-based materials for bio-medical science/technology applications, different kinds of surface modification/functionalization were developed for the attachment of metal oxides nanostructures, biomolecules and polymers. The attachment of pharmaceutical agents with CNTs/graphene, make it a favorable candidate in research field of bio-medical science/technology applications. Surface modified/functionalized CNTs and graphene derivatives materials integrated with pharmaceutical agents has been developed for the purpose of cancer therapy, antibacterial action, pathogens bio detection, drug and gene delivery. Surface modification or functionalization of CNT/graphene materials provides good platform for pharmaceutical agents attachment with improved surface Raman scattering, fluorescence and its quenching capability. Graphene-based biosensing and bioimaging technologies are widely applied to identify numerous trace level analytes. These fluorescent and electrochemical sensors are utilized primarily for detecting organic, inorganic, and biomolecules. In this article, we highlights and summarized overview of the current research progress concerned on the CNTs/graphene-based materials as a new generation materials for detection and treatment of diseases.

Cocatalyst loaded Al-SrTiO3 cubes for Congo red dye photo-degradation under wide range of light

The continued pollution, waste, and unequal distribution of the limited amount of fresh water on earth are pushing the world into water scarcity crisis. Consequently, development of revolutionary, cost-effective, and efficient techniques for water purification is essential. Herein, molten flux method was used for the preparation of micro-sized Al-doped SrTiO₃ photocatalyst loaded with RhCr₂O₃ and CoOOH cocatalysts via simple impregnation method for the photo-assisted degradation of Congo red dye under UV and visible irradiation compared with P25 standard photocatalyst. In addition, photoelectrochemical analysis was conducted to reveal the separation and transfer efficiency of the photogenerated e^-/h⁺ pairs playing the key role in photocatalysis. SEM and TEM analyses revealed that both P25 and the pristine SrTiO₃ have spherical shapes, while Al-doped SrTiO₃ and the sample loaded with cocatalysts have cubic shapes with a relatively higher particle size reaching 145 nm. In addition, the lowest bandgap is due to Al⁺³ ion doping and excessive surface oxygen vacancies, as confirmed by both UV-Vis diffuse-reflectance and XPS analyses. The loading of the cocatalysts resulted in a change in the bandgap from n-type (pristine SrTiO₃ and Al-SrTiO₃) into p-type (cocatalyst loaded sample) as exhibited by Mott-Schottky plots. Besides, the cocatalyst-loaded sample exhibited good performance stability after 5 cycles of the photocatalytic removal of Congo red dye. OH^· radical was the primary species responsible for CR degradation as confirmed by experiments with radical scavengers. The observed performance of the prepared samples under both UV and visible light could foster the ongoing efforts towards more efficient photocatalysts for water purification.

Medical applications of biopolymer nanofibers

A wide array of biomedical applications, extending from the fabrication of implant materials to targeted drug delivery, can be attributed to polymers. The utilization of chemical monomers to form polymers, such as polypropylene, polystyrene, and polyethylene, can provide high mechanical stability to them and they can be utilized for diverse electronic or thermal applications. However, certain chemical-based synthetic polymers are toxic to humans, animals, plants, and microbial cells. Thus, biopolymers have been introduced as an alternative to make them utilizable for biomedical applications. Even though biopolymers possess beneficial biomedical applications, they are not stable in biological fluids and exhibit toxicity in certain cases. Recent advances in nanotechnology have expanded its applicational significance in various domains, especially in the evolution of biopolymers to transform them into nanoparticles for numerous biomedical applications. In particular, biopolymers are fabricated as nanofibers to enhance their biological properties and to be utilized for exclusive biomedical applications. The aim of this review is to present an overview of various biopolymer nanofibers and their distinct synthesis approaches. In addition, the medical applications of biopolymer nanofibers, including antimicrobial agents, drug delivery systems, biosensor production, tissue engineering, and implant fabrication, are also discussed.

Enhanced photocatalytic and antimicrobial performance of a multifunctional Cu-loaded nanocomposite under UV light: theoretical and experimental study

Due to modern industrialization and population growth, access to clean water has become a global challenge. In this study, a metal-semiconductor heterojunction was constructed between Cu NPs and the Co_0.5Ni_0.5Fe₂O₄/SiO₂/TiO₂ composite matrix for the photodegradation of potassium permanganate, hexavalent chromium Cr(VI) and p-nitroaniline (pNA) under UV light. In addition, the electronic and adsorption properties after Cu loading were evaluated using density functional theory (DFT) calculations. Moreover, the antimicrobial properties of the prepared samples toward pathogenic bacteria and unicellular fungi were investigated. Photocatalytic measurements show the outstanding efficiency of the Cu-loaded nanocomposite compared to that of bare Cu NPs and the composite matrix. Degradation efficiencies of 44% after 80 min, 100% after 60 min, and 65% after 90 min were obtained against potassium permanganate, Cr(VI), and pNA, respectively. Similarly, the antimicrobial evaluation showed high ZOI, lower MIC, higher protein leakage amount, and cell lysis of nearly all microbes treated with the Cu-loaded nanocomposite.

Engineered magnetic oxides nanoparticles as efficient sorbents for wastewater remediation: a review

The rapid urbanization and industrialization is causing worldwide water pollution, calling for advanced cleaning methods. For instance, pollutant adsorption on magnetic oxides is efficient and very practical due to the easy separation from solutions by an magnetic field. Here we review the synthesis and performance of magnetic oxides such as iron oxides, spinel ferrites, and perovskite oxides for water remediation. We present structural, optical, and magnetic properties. Magnetic oxides are also promising photocatalysts for the degradation of organic pollutants. Antimicrobial activities and adsorption of heavy metals and radionucleides are also discussed.

Hepatocellular carcinoma cell line-microenvironment induced cancer-associated phenotype, genotype and functionality in mesenchymal stem cells

Mesenchymal stromal cells (MSCs) have shown promise in liver cancer treatment. However, when MSCs are recruited to hepatic site of injury, they acquire cancerous promoting phenotype.

AIMS

To assess the influence of Hepatocellular carcinoma (HCC) microenvironment on human adipose MSCs (hA-MSCs) and predict hA-MSCs intracellular miRNAs role.

MATERIALS AND METHODS

After indirect co-culturing with Huh-7 cells, hA-MSCs were characterized via cell cycle profile, proliferation and migration potentials by MTT and scratch assays respectively. Functional enrichment analysis of deregulated proteins and miRNA targets was also analyzed.

KEY FINDINGS

Co-cultured hA-MSCs could acquire a cancer-associated phenotype as shown by upregulation of CAF, cancer markers, and downregulation of differentiation markers. Migration of these cancer-associated cells was increased concomitantly with upregulation of adhesion molecules, but not epithelial to mesenchymal transition markers. Co-cultured cells showed increased proliferation confirmed by downregulation in cell percentage in G0/G1, G2/M and upregulation in S phases of cell cycle. Upregulation of miR-17-5p and 615-5p in co-cultured hA-MSCs was also observed. Functional enrichment analysis of dysregulated proteins in co-cultured hA-MSCs, including our selected miRNAs targets, showed their involvement in development of cancer-associated characteristics.

SIGNIFICANCE

This study suggests an interaction between tumor cells and surrounding stromal components to generate cancer associated phenotype of some CAF-like characteristics, known to favor cancer progression. This sheds the light on the use of hA-MSCs in HCC therapy. hA-MSCs modulation may be partially achieved via dysregulation of intracellular miR17-5P and 615-5p expression, suggesting an important role for miRNAs in HCC pathogenesis, and as a possible therapeutic candidate.

Recent advances in dye and metal ion removal using efficient adsorbents and novel nano-based materials: an overview

Excessive levels of dyes and heavy metals in water sources have long been a source of concern, posing significant environmental and public health threats. However, adsorption is a feasible technique for removing dye contaminants and heavy metals from water due to its high efficiency, cost-effectiveness, and easy operation. Numerous researchers in batch studies extensively evaluated various adsorbents such as natural materials, and agriculture-derived and industrial wastes; however, large-scale application is still missing. Nanotechnology is a novel approach that has arisen as one of the most versatile and cost-effective ways for dye and heavy metal removal. Its promotion on large-scale applications to investigate technological, fiscal, and environmental aspects for wastewater decontamination is particularly important. This review critically reviews wastewater treatment techniques, emphasizing the adsorption process and highlighting the most effective parameters: solution pH, adsorbent dosage, adsorbent particle size, initial concentration, contact time, and temperature. In addition, a comprehensive, up-to-date list of potentially effective low-cost adsorbents and nano-sorbents for the removal of dyes and heavy metals has been compiled. Finally, the challenges towards the practical application of the adsorption process based on various adsorbents have been drawn from the literature reviewed, and our suggested future perspectives are proposed.

Influence of Ce3+ Substitution on Antimicrobial and Antibiofilm Properties of ZnCexFe2-xO4 Nanoparticles (X = 0.0, 0.02, 0.04, 0.06, and 0.08) Conjugated with Ebselen and Its Role Subsidised with γ-Radiation in Mitigating Human TNBC and Colorectal Adenocarcinoma Proliferation In Vitro

Cancers are a major challenge to health worldwide. Spinel ferrites have attracted attention due to their broad theranostic applications. This study aimed at investigating the antimicrobial, antibiofilm, and anticancer activities of ebselen (Eb) and cerium-nanoparticles (Ce-NPs) in the form of ZnCexFe2-XO4 on human breast and colon cancer cell lines. Bioassays of the cytotoxic concentrations of Eb and ZnCexFe2-XO4, oxidative stress and inflammatory milieu, autophagy, apoptosis, related signalling effectors, the distribution of cells through the cell-cycle phases, and the percentage of cells with apoptosis were evaluated in cancer cell lines. Additionally, the antimicrobial and antibiofilm potential have been investigated against different pathogenic microbes. The ZOI, and MIC results indicated that ZnCexFe2-XO4; X = 0.06 specimen reduced the activity of a wide range of bacteria and unicellular fungi at low concentration including P. aeruginosa (9.5 mm; 6.250 µg/mL), S. aureus (13.2 mm; 0.390 µg/mL), and Candida albicans (13.5 mm; 0.195 µg/mL). Reaction mechanism determination indicated that after ZnCexFe2-xO4; X = 0.06 treatment, morphological differences in S.aureus were apparent with complete lysis of bacterial cells, a concomitant decrease in the viable number, and the growth of biofilm was inhibited. The combination of Eb with ZFO or ZnCexFe2-XO4 with γ-radiation exposure showed marked anti-proliferative efficacy in both cell lines, through modulating the oxidant/antioxidant machinery imbalance, restoring the fine-tuning of redox status, and promoting an anti-inflammatory milieu to prevent cancer progression, which may be a valuable therapeutic approach to cancer therapy and as a promising antimicrobial agent to reduce the pathogenic potential of the invading microbes.

Nanomaterial-based drug delivery systems as promising carriers for patients with COVID-19

Once the World Health Organization (WHO) declared the COVID-19 outbreak to be pandemic, massive efforts have been launched by researchers around the globe to combat this emerging infectious disease. Here we review the most recent data on the novel SARS-CoV-2 pathogen. We analyzed its etiology, pathogenesis, diagnosis, prevention, and current medications. After that, we summarized the promising drug delivery application of nanomaterial-based systems. Their preparation routes, unique advantages over the traditional drug delivery routes and their toxicity though risk analysis were also covered. We also discussed in detail the mechanism of action for one example of drug-loaded nanomaterial drug delivery systems (Avigan-contained nano-emulsions). This review provides insights about employing nanomaterial-based drug delivery systems for the treatment of COVID-19 to increase the bioavailability of current drugs, reducing their toxicity, and to increase their efficiency.

Nanocomposite matrix conjugated with carbon nanomaterials for photocatalytic wastewater treatment

The problem of hazardous wastewater remediation is a complicated issue and a global challenge. Herein, a layered Co_0.5Ni_0.5Fe₂O₄/SiO₂/TiO₂ composite matrix was prepared and incorporated with three carbon nanomaterials having different dimensionalities, carbon dots (C-dots, 0D), single-walled carbon nanotubes (1D), and reduced graphene oxide (2D), in an effort to create effective photocatalytic nanocomposites for chloramine-T removal from water. Microstructural analyses confirmed the formation of nanocomposites and revealed their chemistry and structure. Elemental mapping revealed a uniform distribution of elements throughout the nanocomposite matrix that was free of impurities. The spherical shape of the matrix particles (average diameter ~90 nm) and their conjugation with the carbon nanomaterials were confirmed. Nitrogen adsorption-desorption isotherms revealed that the nanocomposites were mesoporous but also contained macropores. The surface chemical compositions of the nanocomposites were investigated and showed a range of available binding energies. The kinetics of photocatalysis by the system were studied, and the effects of different parameters (such as photocatalyst dose and charge-carrier scavengers) on the efficiency of chloramine-T degradation were also investigated. The nanocomposite loaded with 10% C-dots exhibited high UV-assisted photocatalytic activity for chloramine-T degradation (65% removal efficiency).

Chitosan and EDTA conjugated graphene oxide antinematodes in Eggplant: Toward improving plant immune response

A new strategy regarding the fabrication of chitosan (CS) or ethylene diamine tetraacetic acid (EDTA) on graphene oxide (GO) was performed. The nematocidal potential against Meloidogyne incognita causing root-knot infection in eggplant was tested. The plant immune response was investigated through measuring the photosynthetic pigments, phenols and proline contents, oxidative stress, and antioxidant enzymes activity. Results indicating that, the treatment by pure GO recorded the most mortality percentages of M. incognita 2^nd juveniles followed by GO-CS then GO-EDTA. In vivo greenhouse experiments reveals that, the most potent treatment in reducing nematodes was GO-CS which recorded 85.42%, 75.3%, 55.5%, 87.81%, and 81.32% in numbers of 2^nd juveniles, galls, females, egg masses and the developmental stage, respectively. The highest chlorophyll a (104%), chlorophyll b (46%), total phenols (137.5%), and free proline (145.2%) were recorded in GO-CS. The highest malondialdehyde (MDA) value was achieved by GO-EDTA (7.22%), and hydrogen peroxide (H₂O₂) content by 47.51% after the treatment with pure GO. Treatment with GO-CS increased the activities of catalase (CAT) by 98.3%, peroxidase (POD) by 97.52%, polyphenol oxidase (PPO) by 113.8%, and superoxide dismutase (SOD) by 42.43%. The synthesized nanocomposites increases not only the nematocidal activity but also the plant systematic immune response.

Advanced materials and technologies for supercapacitors used in energy conversion and storage: a review

Supercapacitors are increasingly used for energy conversion and storage systems in sustainable nanotechnologies. Graphite is a conventional electrode utilized in Li-ion-based batteries, yet its specific capacitance of 372 mA h g−1 is not adequate for supercapacitor applications. Interest in supercapacitors is due to their high-energy capacity, storage for a shorter period and longer lifetime. This review compares the following materials used to fabricate supercapacitors: spinel ferrites, e.g., MFe2O4, MMoO4 and MCo2O4 where M denotes a transition metal ion; perovskite oxides; transition metals sulfides; carbon materials; and conducting polymers. The application window of perovskite can be controlled by cations in sublattice sites. Cations increase the specific capacitance because cations possess large orbital valence electrons which grow the oxygen vacancies. Electrodes made of transition metal sulfides, e.g., ZnCo2S4, display a high specific capacitance of 1269 F g−1, which is four times higher than those of transition metals oxides, e.g., Zn–Co ferrite, of 296 F g−1. This is explained by the low charge-transfer resistance and the high ion diffusion rate of transition metals sulfides. Composites made of magnetic oxides or transition metal sulfides with conducting polymers or carbon materials have the highest capacitance activity and cyclic stability. This is attributed to oxygen and sulfur active sites which foster electrolyte penetration during cycling, and, in turn, create new active sites.

Carbon dots conjugated nanocomposite for the enhanced electrochemical performance of supercapacitor electrodes

Naturally, a combination of metal oxides and carbon materials enhances the electrochemical performance of supercapacitor (SC) electrodes. We report on two different materials with highly conductive carbon dots (CDs) and a Co_0.5Ni_0.5Fe₂O₄/SiO₂/TiO₂ nanocomposite with a high power density, a high specific surface area, and a nanoporous structure to improve power and energy density in energy storage devices. A simple and low-cost process for synthesizing the hybrid SC electrode material Co_0.5Ni_0.5Fe₂O₄/SiO₂/TiO₂/CDs, known as CDs-nanocomposite, was performed via a layer-by-layer method; then, the CDs-nanocomposite was loaded on a nickel foam substrate for SC electrochemical measurements. A comparative study of the surface and morphology of CDs, the Co_0.5Ni_0.5Fe₂O₄/SiO₂/TiO₂ nanocomposite and CDs-nanocomposite was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), BET surface area, and Raman spectroscopy. The synthesized CDs-nanocomposite electrode material displayed enhanced electrochemical performance, having a high specific capacitance of 913.7 F g⁻¹ at a scan rate of 5 mV s⁻¹ and capacitance retention of 72.2%, as well as remarkable long-life cyclic stability over 3000 cycles in the three-electrode setup and 1 M KOH electrolyte. It also demonstrated a superior energy density of 130.7 W h kg⁻¹. The improved electrochemical behavior of the CDs-nanocomposite for SC electrodes, together with its fast and simple synthesis method, provides a suitable point of reference. Other kinds of metal oxide nanocomposites can be synthesized for use in energy storage devices.

Schematic diagram for the detailed steps of loading CDs-nanocomposite on nickel foam (NF) substrate to enhance the electrochemical performance of supercapacitor (SC) electrodes.

Nanostructured Mg substituted Mn-Zn ferrites: A magnetic recyclable catalyst for outstanding photocatalytic and antimicrobial potentials

With recently increasing the environmental problems and expected energy crisis, it is necessary to synthesis a low-cost, efficient, and UV-light responsive photocatalyst for contaminants' degradation. The nanostructured spinel ferrite Mn_0.5Zn_0.5-xMg_xFe₂O₄ NPs (x = 0.0, 0.125, 0.25, 0.375 and 0.50) were synthesized via the sol-gel method. The crystallite size was lied in nano regime ranging from 21.8 to 36.5 nm. The surface chemical composition of the Mn_0.5Zn_0.5-xMg_xFe₂O₄ NPs was investigated via XPS analysis. Mossbauer spectra showed that the peaks were shifted to higher values of the maximum magnetic field as the Mg content increased, indicating that the crystallinity is enhanced while the crystal size is decreased. Also, various parameters such as the photocatalyst dose, dyes concentration, pH, point of zero charge, and the metals leaching were studied. The point of zero charge (PZC) has found at pH = 2.38. The Mn_0.5Zn_0.125Mg_0.375Fe₂O₄ NPs showed an excellent UV-assisted photocatalytic activity against Chloramine T (90 % removal efficiency) and Rhodamine B (95 % removal efficiency) after 80 min as compared to pure Mn_0.5Zn_0.5Fe₂O₄ ferrite NPs. Besides, it a recyclable catalyst at least four times with a negligible reduction of photocatalytic activity with slight elements leaching. Furthermore, the Mn_0.5Zn_0.25Mg_0.25Fe₂O₄ NPs showed a high antimicrobial activity towards pathogenic bacteria and yeats.

Gum Arabic polymer-stabilized and Gamma rays-assisted synthesis of bimetallic silver-gold nanoparticles: Powerful antimicrobial and antibiofilm activities against pathogenic microbes isolated from diabetic foot patients

In this research, irradiation by gamma rays was employed as an eco-friendly route for the construction of bimetallic silver-gold nanoparticles (Ag-Au NPs), while Gum Arabic polymer was used as a capping agent. Ag-Au NPs were characterized through UV-Vis., XRD, EDX, HR-TEM, FTIR, SEM/mapping and EDX analysis. Antibiofilm and antimicrobial activities were examined against some bacteria and Candida sp. isolates from diabetic foot patients. Our results revealed that the synthesis of Ag-Au NPs depended on the concentrations of tetra-chloroauric acid and silver nitrate. HR-TEM analysis confirmed the spherical nature and an average diameter of 18.58 nm. FTIR results assured many functional groups in Gum Arabic which assisted in increasing the susceptibility of incorporation with Ag-Au NPs. Our results showed that, Ag-Au NPs exhibited the highest antimicrobial performance against B. subtilis (14.30 mm ZOI) followed by E. coli (12.50 mm ZOI) and C. tropicalis (11.90 mm ZOI). In addition, Ag-Au NPs were able to inhibit the biofilm formation by 99.64%, 94.15%, and 90.79% against B. subtilis, E. coli, and C. tropicalis, respectively. Consequently, based on the promising properties, they showed superior antimicrobial potential at low concentration and continued-phase durability, they can be extensively-used in many pharmaceutical and biomedical applications.

Carbon-dot-loaded CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2 nanocomposite with enhanced photocatalytic and antimicrobial potential: An engineered nanocomposite for wastewater treatment

Water scarcity is now a serious global issue resulting from population growth, water decrease, and pollution. Traditional wastewater treatment plants are insufficient and cannot meet the basic standards of water quality at reasonable cost or processing time. In this paper we report the preparation, characterization and multiple applications of an efficient photocatalytic nanocomposite (CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2/C-dots) synthesized by a layer-by-layer method. Then, the photocatalytic capabilities of the synthesized nanocomposite were extensively-studied against aqueous solutions of chloramine-T trihydrate. In addition, reaction kinetics, degradation mechanism and various parameters affecting the photocatalytic efficiency (nanocomposite dose, chloramine-T initial concentration, and reaction pH) were analyzed in detail. Further, the antimicrobial activities of the prepared nanocomposite were tested and the effect of UV-activation on the antimicrobial abilities of the prepared nanocomposite was analyzed. Finally, a comparison between the antimicrobial abilities of the current nanocomposite and our previously-reported nanocomposite (CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2) had been carried out. Our results revealed that the prepared nanocomposite possessed a high degree of crystallinity, confirmed by XRD, while UV-Vis. recorded an absorption peak at 299 nm. In addition, the prepared nanocomposite possessed BET-surface area of (28.29 ± 0.19 m2/g) with narrow pore size distribution. Moreover, it had semi-spherical morphology, high-purity and an average particle size of (19.0 nm). The photocatalytic degradation efficiency was inversely-proportional to chloramine-T initial concentration and directly proportional to the photocatalyst dose. In addition, basic medium (pH 9) was the best suited for chloramine-T degradation. Moreover, UV-irradiation improved the antimicrobial abilities of the prepared nanocomposite against E. coli, B. cereus, and C. tropicalis after 60 min. The observed antimicrobial abilities (high ZOI, low MIC and more efficient antibiofilm capabilities) were unique compared to our previously-reported nanocomposite. Our work offers significant insights into more efficient water treatment and fosters the ongoing efforts looking at how pollutants degrade the water supply and the disinfection of water-borne pathogenic microorganisms.

Fabrication of Ultra-Pure Anisotropic Zinc Oxide Nanoparticles via Simple and Cost-Effective Route: Implications for UTI and EAC Medications

The purposes of this work are to evaluate the antimicrobial, antibiofilm, anticancer, and antioxidant abilities of anisotropic zinc oxide nanoparticles (ZnO NPs) synthesized by a cost-effective and eco-friendly sol-gel method. The synthesized ZnO NPs were entirely characterized by UV-Vis, XRD, FTIR, HRTEM, zeta potential, SEM mapping, BET surface analyzer, and EDX elemental analysis. Antimicrobial and antibiofilm activities of ZnO NPs were investigated against multidrug-resistant (MDR) bacteria and yeast causing serious diseases like urinary tract infection (UTI). The anticancer activity was performed against Ehrlich ascites carcinoma (EAC). Additionally, antioxidant scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was observed. The synthesized ZnO NPs exhibited an absorption peak at 385.0 nm characteristic to the surface plasmon resonance (SPR). Data obtained from HRTEM, SEM, and XRD confirmed the anisotropic crystalline nature of the prepared ZnO NPs with an average particle size of 68.2 nm. The calculated surface area of the prepared ZnO NPs was 10.62 m²/g and the porosity was 13.16%, while pore volume was calculated to be 0.013 cm³/g and the average pore size was about 3.10 nm. The prepared ZnO NPs showed promising antimicrobial activity against all tested UTI-causing pathogens. It showed a prominent antimicrobial capability against Candida tropicalis with a zone of inhibition (ZOI) reaching 22.4 mm, 13 mm ZOI for Bacillus subtilis, and 12.5 mm ZOI for Pseudomonas aeruginosa. Additionally, the prepared ZnO NPs showed enhanced biofilm repression of about 79.33%, 72.94%, and 33.68% against B. subtilis, C. tropicalis, and P. aeruginosa, respectively. Moreover, the prepared ZnO NPs had a powerful antioxidant property with 33.0% scavenging ability after applied DPPH assay. Surprisingly, upon ZnO NPs treatment, cancer cell viability reduced from 100 to 58.5% after only 24 h due to their unique antitumor activity. Therefore, according to these outstanding properties, this study could give insights for solving serious industrial, pharmaceutical, and medical challenges, particularly in the EAC and UTI medications.

Microbial acetylcholinesterase inhibitors for Alzheimer's therapy: recent trends on extraction, detection, irradiation-assisted production improvement and nano-structured drug delivery

Abstract

Neurodegenerative disorders especially Alzheimer’s disease (AD) are significantly threatening the public health. Acetylcholinesterase (AChE) inhibitors are compounds of great interest which can be used as effective agents for the symptomatic treatment of AD. Although plants are considered the largest source for these types of inhibitors, the microbial production of AChE inhibitors represents an efficient, easily manipulated, eco-friendly, cost-effective, and alternative approach. This review highlights the recent advances on the microbial production of AChE inhibitors and summarizes all the previously reported successful studies on isolation, screening, extraction, and detecting methodologies of AChE inhibitors from the microbial fermentation, from the earliest trials to the most promising anti-AD drug, huperzine A (HupA). In addition, improvement strategies for maximizing the industrial production of AChE inhibitors by microbes will be discussed. Finally, the promising applications of nano-material-based drug delivery systems for natural AChE inhibitor (HupA) will also be summarized.

Key Points

• AChE inhibitors are potential therapies for Alzheimer’s disease.

• Microorganisms as alternate sources for prospective production of such inhibitors.

• Research advances on extraction, detection, and strategies for production improvement.

• Nanotechnology-based approaches for an effective drug delivery for Alzheimer’s disease.

Merits of photocatalytic and antimicrobial applications of gamma-irradiated CoxNi1−xFe2O4/SiO2/TiO2;x= 0.9 nanocomposite for pyridine removal and pathogenic bacteria/fungi disinfection: implication for wastewater treatment

In this paper, we report a layer-by-layer approach for the preparation of a concentric recyclable composite (Co_xNi_1−xFe₂O₄/SiO₂/TiO₂; x = 0.9) designed for wastewater treatment. The prepared composite was investigated by X-ray diffraction spectroscopy, high-resolution transmission electron microscopy and scanning electron microscopy (SEM) supported with energy dispersive X-ray (EDX) spectroscopy to analyze crystallinity, average particle size, morphology and elemental composition, respectively. The antimicrobial activities of the prepared composite have been investigated against multi-drug-resistant bacteria and pathogenic fungi using a variety of experiments, such as zone of inhibition, minimum inhibitory concentration, biofilm formation and SEM with EDX analysis of the treated bacterial cells. In addition, the effects of gamma irradiation (with different doses) and UV irradiation on the antibacterial abilities of the prepared composite have been evaluated. Moreover, the effect of gamma irradiation on the crystallite size of the prepared composite has been studied under varying doses of radiation (25 kGy, 50 kGy and 100 kGy). Finally, the photocatalytic efficiency of the prepared composite was tested for halogen-lamp-assisted removal of pyridine (artificial wastewater). Various parameters affecting the efficiency of the photocatalytic degradation, such as photocatalyst dose, pyridine concentration, pH, point of zero charge and the presence of hydrogen peroxide, have been studied. Our results show that the synthesized composite has a well-crystallized semi-spherical morphology with an average particle size of 125.84 nm. In addition, it possesses a high degree of purity, as revealed by EDX elemental analysis. Interestingly, the prepared composite showed promising antibacterial abilities against almost all the tested pathogenic bacteria and unicellular fungi, and this was further improved after gamma and UV irradiation. Finally, the prepared composite was very efficient in the light-assisted degradation of pyridine and its degradation efficiency can be tuned based on various experimental parameters. This work provides a revolutionary nanomaterial-based solution for the global water shortage and water contamination by offering a new wastewater treatment technique that is recyclable, cost effective and has an acceptable time and quality of water.

In this paper, we report a layer-by-layer approach for the preparation of a concentric recyclable composite (Co_xNi_1−xFe₂O₄/SiO₂/TiO₂; x = 0.9) designed for wastewater treatment.

Dysregulated MicroRNA Fingerprints and Methylation Patterns in Hepatocellular Carcinoma, Cancer Stem Cells, and Mesenchymal Stem Cells

Hepatocellular carcinoma (HCC) is one of the top causes of cancer mortality worldwide. Although HCC has been researched extensively, there is still a need for novel and effective therapeutic interventions. There is substantial evidence that initiation of carcinogenesis in liver cirrhosis, a leading cause of HCC, is mediated by cancer stem cells (CSCs). CSCs were also shown to be responsible for relapse and chemoresistance in several cancers, including HCC. MicroRNAs (miRNAs) constitute important epigenetic markers that regulate carcinogenesis by acting post-transcriptionally on mRNAs, contributing to the progression of HCC. We have previously shown that co-culture of cancer cells with mesenchymal stem cells (MSCs) could induce the reprogramming of MSCs into CSC-like cells. In this review, we evaluate the available data concerning the epigenetic regulation of miRNAs through methylation and the possible role of this regulation in stem cell and somatic reprogramming in HCC.

Comparison of different uncoated and starch-coated superparamagnetic iron oxide nanoparticles: Implications for stem cell tracking

However, labelling of stem cells using nanoparticles (NPs) for tracking purpose has been intensively investigated, the biosafety of these materials needs more clarification. Herein, different forms of iron oxide Fe₂O₃, Fe₃O₄, and Co_xNi_1-x Fe₂O₄ NPs either uncoated or starch-coated (ST-coated) were prepared. We successfully labelled adipose-derived stem cells (ASCs) using these NPs with the aid of lipofectamine as a transfection agent (TA). We then evaluated the effect of these NPs on stem cell proliferation, viability, migration and angiogenesis. Results showed that ASCs labelled with Fe₂O₃, Fe₃O₄, ST-Fe₂O₃ and ST-Fe₃O₄ did not show any significant difference in proliferation compared to that of TA-treated cells. Moreover, they have shown a protective effect against apoptosis. Conversely, Co_xNi_1-x Fe₂O₄ NPs caused a significant decrease in cell proliferation. Compared to that of the TA-treated cells, the migration capacity of cells labelled with Fe₂O₃, Fe₃O₄ and Co_xNi_1-xFe₂O₄ was significantly compromised. Interestingly, the ST-coated composites reversed this effect. Among the groups treated with different NPs, the angiogenic potential of the ASCs was most robust in the ST-Fe₂O₃-treated group. In conclusion, labelling ASCs with ST-Fe₂O₃ NPs enhanced cell migration and angiogenic potential and conferred higher resistance to apoptosis than labelling the cells with the other tested NPs.

C-dots dispersed macro-mesoporous TiO2 phtocatalyst for effective waste water treatment

Synthesis of macro-mesoporous Titania (Titanium dioxide-TiO2) nanospheres was successfully achieved using a modified template-free methodology to incorporate macroporous channels into a mesoporous TiO2 framework to form mixed macro-mesoporous TiO2 spheres (MMPT), which were doped with carbon dots (C-dots) to form improved nanocomposites (C-dots@MMPT). Elemental composition, surface bonding and optical properties of these nanocomposites were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and ultraviolet-visible absorption spectroscopy (UV-VIS). Evaluation of photocatalytic activity for each (C-Dots@MMPT) sample was performed via degrading the Methylene Blue (MB) dye compared with bare samples (MMPT) under visible light irradiation using 300 Watt halogen lamp.