High toxicity of Bi(OH)3 and α-Bi2O3 nanoparticles towards malignant 9L and MCF-7 cells

Characterization of multifunctional β-cyclodextrin-coated Bi2O3 nanoparticles conjugated with curcumin for CT imaging-guided synergetic chemo-radiotherapy in breast cancer

Nanotechnology-based diagnostic, and therapeutic approaches revolutionized the field of cancer detection, and treatment, offering tremendous potential for cost-effective interventions in the early stages of disease. This research synthesized bismuth oxide (Bi2O3) nanoparticles (NPs) that were modified with polycyclodextrin (PCD), and functionalized with glucose (Glu) to load curcumin (CUR) for CT imaging and chemo-radiotherapy applications in Breast Cancer. The prepared Bi2O3@PCD-CUR-Glu NPs underwent comprehensive characterization, encompassing various aspects, including cell migration, cytotoxicity, cellular uptake, blood compatibility, reactive oxygen species (ROS) generation ability, real-time PCR analysis, in-vivo safety assessment, in-vivo anti-tumor efficacy, as well as in-vitro CT contrast and X-ray RT enhancement evaluation. CT scan was conducted before and after (1 and 3 h) intravenous injection of Bi2O3@PCD-CUR-Glu NPs. Through the use of coupled plasma optical emission spectrometry (ICP-OES) analysis, the final prepared nanoparticle distribution in the Bab/c mice was assessed. The spherical NPs that were ultimately synthesized and had a diameter of around 80 nm demonstrated exceptional toxicity towards the SKBr-3 breast cancer cell line. The cell viability was at its lowest level after 48 h of exposure to a radiation dose of 2 Gy at a concentration of 100 µg/mL. The combined treatment involving using Bi2O3@PCD-CUR-Glu NPs along with X-ray radiation showed a substantial increase in the generation of ROS, specifically a remarkable 420 % growth. Gene expression analysis indicated that the expression levels of P53, and BAX pro-apoptotic genes were significantly increased. The in-vitro CT imaging analysis conducted unequivocally demonstrated the notable superiority of NPs over Omnipaque in terms of X-ray absorption capacity, a staggering 1.52-fold increase at 80 kVp. The resultsdemonstrated that the targeted Bi2O3@PCD-CUR-Glu NPs could enhance the visibility of a small mice tumor that is detectable by computed tomography and made visible through X-ray attenuation. Results suggested that Bi2O3@PCD-CUR-Glu NPs, integrated with CT imaging and chemo-radiotherapy, have great potential as a versatile theranostic system for clinical application.

Bismuth-Based Electrocatalysts for Identical Value-Added Formic Acid Through Coupling CO2 Reduction and Methanol Oxidation

It is an effective way to reduce atmospheric CO2 via electrochemical CO2 reduction reaction (CO2RR), while the slow oxygen evolution reaction (OER) occurs at the anode with huge energy consumption. Herein, methanol oxidation reaction (MOR) is used to replace OER, coupling CO2RR to achieve co-production of formate. Through enhancing OCHO* adsorption by oxygen vacancies engineering and synergistic effect by heteroatom doping, Bi/Bi2O3 and Ni─Bi(OH)3 are synthesized for efficient production of formate via simultaneous CO2RR and methanol oxidation reaction (MOR), achieving that the coupling of CO2RR//MOR only required 7.26 kWh gformate -1 power input, much lower than that of CO2RR//OER (13.67 kWh gformate -1). Bi/Bi2O3 exhibits excellent electrocatalytic CO2RR performance, achieving FEformate >80% in a wide potential range from -0.7 to -1.2 V (vs RHE). For MOR, Ni─Bi(OH)3 exhibits efficient MOR catalytic performance with the FEformate >98% in the potential range of 1.35-1.6 V (vs RHE). Not only demonstrates the two-electrode systems exceptional stability, working continuously for over 250 h under a cell voltage of 3.0 V, but the cathode and anode can maintain a FE of over 80%. DFT calculation results reveal that the oxygen vacancies of Bi/Bi2O3 enhance the adsorption of OCHO* intermediate, and Ni─Bi(OH)3 reduce the energy barrier for the rate determining step, leading to high catalytic activity.

Multifunctional bismuth oxide (Bi2 O3 ) particles: Evidence for selective melanoma therapy

The current study investigates the therapeutic and optical properties of bismuth oxide (Bi2 O3 ) particles for selective melanoma therapy and prevention. The Bi2 O3 particles were prepared using a standard precipitation method. The Bi2 O3 particles induced apoptosis in human A375 melanoma cells but not human HaCaT keratinocytes or CCD-1090Sk fibroblast cells. This selective apoptosis appears to be associated with a combination of factors: increased particle internalization (2.29 ± 0.41, 1.16 ± 0.08 and 1.66 ± 0.22-fold of control) and enhanced production of reactive oxygen species (ROS) (3.4 ± 0.1, 1.1 ± 0.1 and 2.05 ± 0.17-fold of control) in A375 cells compared to HaCaT and CCD-1090SK cells, respectively. As a high-Z element, bismuth is also an excellent contrast agent for computer tomography, which renders Bi2 O3 a theranostic material. Moreover, Bi2 O3 displays high UV absorption and low photocatalytic activity compared to other semiconducting metal oxides, which opens further potential fields of application as a pigment or as an active ingredient in sunscreens. Overall, this study demonstrates the multifunctional properties of Bi2 O3 particles surrounding the treatment and prevention of melanoma.

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, MnOx, iron oxide, maghemite quantum flakes, La2O3-x, TaOx, cerium nanodots, ITO, MgO1-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.

Metallic nanoparticle contamination from environmental atmospheric particulate matter in the last slab of the trophic chain: Nanocrystallography, subcellular localization and toxicity effects

Atmospheric particulate material (PM) from mining and steel industries comprises several metallic contaminants. PM₁₀ samples collected in a Brazilian region with a recognized influence of the steel and iron pelletizing industries were used to investigate metallic nanoparticle incorporation into human fibroblast cells (MRC-5). MRC-5 cells were exposed to 0 (control, ultrapure water), 2.5, 5, 10, 20 and 40 μg PM₁₀ mL^-1, for 24 h. Cytotoxic and genotoxic dose-response effects were observed on lysosome and DNA structure, and concentrations high as 20 and 40 μg PM₁₀ mL^-1 induced elevated cell death. Ultrastructure analyses showed aluminosilicate, iron, and the emerging metallic contaminants titanium, bismuth, and cerium nanoparticles were incorporated into lung cells, in which the nanocrystallography analysis indicated the bismuth as Bi₂O₃. All internalized metallic nanoparticles were free and unbound in the cytoplasm and nucleus thereby indicating bioavailability and potential interaction to biological processes and cellular structures. Pearson's correlation analysis showed Fe, Ni, Al, Cr, Pb and Hg as the main cytotoxic elements which are associated with the stainless steel production. The presence of internalized nanoparticles in human lung cells exposed to environmental atmospheric matter highlights the need for a greater effort by regulatory agencies to understand their potential damage and hence the need for future regulation, especially of emerging metallic contaminants.

Oxygen-vacancy abundant alpha bismuth oxide with enhanced cycle stability for high-energy hybrid supercapacitor electrodes

Bi₂O₃ is an outstanding electrode material due to its high theoretical specific capacity. Hence, the synthesis of δ-Bi₂O₃ materials with high oxygen-vacancy contents could improve their electrochemical performances but causes easy conversion to α-Bi₂O₃ with low oxygen-vacancy contents, leading to poor cycling stability and limited practical applications. To overcome these problems, an effective strategy for constructing high oxygen vacancies α-Bi₂O₃ on activated carbon fiber paper (ACFP) is developed in this study. To this end, ACFP/Bi(OH)₃ is first synthesized by the solvothermal method and then converted to ACFP/α-Bi₂O₃ by in situ electrochemical activation. The proposed innovative electrochemical method quickly and easily introduces oxygen vacancies while preserving the three-dimensional structure, thereby promoting the charge transfer and ions diffusion in ACFP/α-Bi₂O₃. Consequently, the specific capacity of ACFP/α-Bi₂O₃ reaches 906C g^-1 at 1 A g^-1, and the capacity retention remains above 70% after 3000 cycles, a value higher than that of δ-Bi₂O₃ (45%). Furthermore, the hybrid supercapacitor device assembled by ACFP/α-Bi₂O₃ delivers a maximum energy density of 114.9 Wh kg^-1 at 900 W kg^-1 and outstanding cycle stability with 73.56 % retention after 5500 cycles. In sum, the proposed ACFP/α-Bi₂O₃ with high performance and good stability looks promising for use as bismuth-based anode materials in supercapacitors and aqueous batteries.

Facile Synthesis of Zn-Doped Bi2O3 Nanoparticles and Their Selective Cytotoxicity toward Cancer Cells

Bismuth (III) oxide nanoparticles (Bi2O3 NPs) have shown great potential for biomedical applications because of their tunable physicochemical properties. In this work, pure and Zn-doped (1 and 3 mol %) Bi2O3 NPs were synthesized by a facile chemical route and their cytotoxicity was examined in cancer cells and normal cells. The X-ray diffraction results show that the tetragonal phase of β-Bi2O3 remains unchanged after Zn-doping. Transmission electron microscopy and scanning electron microscopy images depicted that prepared particles were spherical with smooth surfaces and the homogeneous distribution of Zn in Bi2O3 with high-quality lattice fringes without distortion. Photoluminescence spectra revealed that intensity of Bi2O3 NPs decreases with increasing level of Zn-doping. Biological data showed that Zn-doped Bi2O3 NPs induce higher cytotoxicity to human lung (A549) and liver (HepG2) cancer cells as compared to pure Bi2O3 NPs, and cytotoxic intensity increases with increasing concentration of Zn-doping. Mechanistic data indicated that Zn-doped Bi2O3 NPs induce cytotoxicity in both types of cancer cells through the generation of reactive oxygen species and caspase-3 activation. On the other hand, biocompatibility of Zn-doped Bi2O3 NPs in normal cells (primary rat hepatocytes) was greater than that of pure Bi2O3 NPs and biocompatibility improves with increasing level of Zn-doping. Altogether, this is the first report highlighting the role of Zn-doping in the anticancer activity of Bi2O3 NPs. This study warrants further research on the antitumor activity of Zn-doped Bi2O3 NPs in suitable in vivo models.

First extensive study of silver-doped lanthanum manganite nanoparticles for inducing selective chemotherapy and radio-toxicity enhancement

Nanoparticles have a great potential to increase the therapeutic efficiency of several cancer therapies. This research examines the potential for silver-doped lanthanum manganite nanoparticles to enhance radiation therapy to target radioresistant brain cancer cells, and their potential in combinational therapy with magnetic hyperthermia. Magnetic and structural characterisation found all dopings of nanoparticles (NPs) to be pure and single phase with an average crystallite size of approximately 15 nm for undoped NPs and 20 nm for silver doped NPs. Additionally, neutron diffraction reveals that La_0.9Ag_0.1MnO₃ (10%-LAGMO) NPs exhibit residual ferromagnetism at 300 K that is not present in lower doped NPs studied in this work, indicating that the Curie temperature may be manipulated according to silver doping. This radiobiological study reveals a completely cancer-cell selective treatment for LaMnO₃, La_0.975Ag_0.025MnO₃ and La_0.95Ag_0.05MnO₃ (0, 2.5 and 5%-LAGMO) and also uncovers a potent combination of undoped lanthanum manganite with orthovoltage radiation. Cell viability assays and real time imaging results indicated that a concentration of 50 μg/mL of the aforementioned nanoparticles do not affect the growth of Madin-Darby Canine Kidney (MDCK) non-cancerous cells over time, but stimulate its metabolism for overgrowth, while being highly toxic to 9L gliosarcoma (9LGS). This is not the case for 10%-LAGMO nanoparticles, which were toxic to both non-cancerous and cancer cell lines. The nanoparticles also exhibited a level of toxicity that was regulated by the overproduction of free radicals, such as reactive oxygen species, amplified when silver ions are involved. With the aid of fluorescent imaging, the drastic effects of these reactive oxygen species were visualised, where nucleus cleavage (an apoptotic indicator) was identified as a major consequence. The genotoxic response of this effect for 9LGS and MDCK due to 10%-LAGMO NPs indicates that it is also causing DNA double strand breaks within the cell nucleus. Using 125 kVp orthovoltage radiation, in combination with an appropriate amount of NP-induced cell death, identified undoped lanthanum manganite as the most ideal treatment. Real-time imaging following the combination treatment of undoped lanthanum manganite nanoparticles and radiation, highlighted a hinderance of growth for 9LGS, while MDCK growth was boosted. The clonogenic assay following incubation with undoped lanthanum manganite nanoparticles combined with a relatively low dose of radiation (2 Gy) decreased the surviving fraction to an exceptionally low (0.6 ± 6.7)%. To our knowledge, these results present the first biological in-depth analysis on silver-doped lanthanum manganite as a brain cancer selective chemotherapeutic and radiation dose enhancer and as a result will propel its first in vivo investigation.

Oxi-Redox Selective Breast Cancer Treatment: An In Vitro Study of Theranostic In-Based Oxide Nanoparticles for Controlled Generation or Prevention of Oxidative Stress

In this article, we demonstrate that specifically engineered oxide nanoparticles (NPs) have the potential to act as theranostic materials that are able to generate or prevent oxidative stress through their oxi-redox activity in various types of malignant and nonmalignant cells. The oxi-redox activity is related to the type and presence of surface defects, which is modified with appropriate synthesis conditions. In the present work, we used MDA-MB-231 and MCF-7 human breast cancer cells and nonmalignant MCF-10A human breast cells to demonstrate how controlled oxidative stress mediated by specifically nanoengineered indium tin oxide (ITO) NPs can selectively induce cell death in the cancer cells while reducing the oxidative stress in the normal cells and supporting their proliferation. The ITO NPs are also promising nanotheranostic materials for cancer therapy and contrast agents because of their multimodal imaging capabilities. We demonstrate that the synthesized ITO NPs can selectively increase the generation of reactive oxygen species (ROS) in both breast tumor cell lines, resulting in activation of apoptosis, and can also greatly suppress the cellular proliferation in both types of tumor cells. In contrast, the ITO NPs exhibit ROS scavenging-like behavior, significantly decreasing the ROS levels in MCF-10A cells exposed to the additional ROS, hydrogen peroxide (H₂O₂), so that they protect the proliferation of nonmalignant MCF-10A cells from ROS damage. In addition, fluorescent microscopy images revealed that the ITO NPs emit strong fluorescence that could be used to reveal their location. Moreover, computed tomography imaging demonstrated that the ITO NPs exhibited a comparable capability toward anatomical contrast enhancement. These results suggest that the synthesized ITO NPs have the potential to be a novel selective therapeutic agent with a multimodal imaging property for anticancer treatment.

Electrochemical synthesis of a new Bi(iii) complex by anodic oxidation of Bi in an aqueous solution of 4-toluenesulfonic acid

A new complex with a composition [Bi₆O₄(OH)₄](C₇H₇SO₃)₆ is formed on a bismuth plate via electrochemical synthesis at 1.0 V anodic polarization in 0.5 M p-toluenesulfonic acid.

Mathematical modeling of cytotoxicity of metal oxide nanoparticles using the index of ideality correlation criteria

Several types of metal oxide nanoparticles (MO-NPs) are often utilized as one of the novel class of materials in the pharmaceutical industry and human health. The wide use of MO-NPs forces an enhanced understanding of their potential impact on human health and the environment. The research aims to investigate and develop a nano-QFAR (nano-quantitative feature activity relationship) model applying the quasi-SMILES such as cell line, assay, time exposition, concentration, nanoparticles size and metal oxide type for prediction of cell viability (%) of MO-NPs. The total set of 83 quasi-SMILES of MO-NPs divided into training, validation and test sets randomly three times. The statistical model results based on the balance of correlation target function (TF₁) and index of ideality correlation target function (TF₂) and the Monte Carlo optimization were compared. The comparison of two target function results indicated that TF₂ improves the predictability of models. The significance of various eclectic features of both increase and decrease of cell viability (%) is provided. Mechanistic interpretation of significant factors for the model are proposed as well. The sufficient statistical quality of three nano-QFAR models based on TF₂ reveals that the developed models can be efficiency for predictions of the cell viability (%) of MO-NPs.