Structural, morphological, mechanical, and electronic properties of nickel substituted manganese oxide (NixMn1-xO, x= 0.0, 0.2, 0.4) for electronic applications.

The structural, morphological, mechanical, and electronic properties of nickel-substituted manganese oxide (NixMn1-xO, where x = 0.0, 0.2, and 0.4) were studied using experimental techniques. The compounds were synthesized using a hydrothermal method. The face-centered cubic structures of the examined compounds were confirmed by XRD. Scanning electron microscopy (SEM) images revealed that the particles were well-shaped, while elemental mapping with energy dispersive spectroscopy (EDS) confirmed that the examined compounds had the appropriate proportions of Ni, Mn, and O. The FT-IR spectroscopy results indicated the respective functional groups. Raman spectroscopy results disclosed the vibration modes of the respective materials. The Tauc plot reveals the semiconducting nature of the compounds. The UV-Vis bandgap study revealed the semiconductor natures of compounds. This demonstrates that these nanoparticles can be used in atom lasers, photovoltaics, and other electronic applications.

Green Synthesis of CeO2 Nanoparticles from the Abelmoschus esculentus Extract: Evaluation of Antioxidant, Anticancer, Antibacterial, and Wound-Healing Activities.

Metal oxide nanoparticles synthesized by the biological method represent the most recent research in nanotechnology. This study reports the rapid and ecofriendly approach for the synthesis of CeO2 nanoparticles mediated using the Abelmoschus esculentus extract. The medicinal plant extract acts as both a reducing and stabilizing agent. The characterization of CeO2 NPs was performed by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), and Fourier transform infrared spectroscopy (FTIR). The in vitro cytotoxicity of green synthesized CeO2 was assessed against cervical cancerous cells (HeLa). The exposure of CeO2 to HeLa cells at 10-125 µg/mL caused a loss in cellular viability against cervical cancerous cells in a dose-dependent manner. The antibacterial activity of the CeO2 was assessed against S. aureus and K. pneumonia. A significant improvement in wound-healing progression was observed when cerium oxide nanoparticles were incorporated into the chitosan hydrogel membrane as a wound dressing.

Manganese-Doped Cerium Oxide Nanocomposite Induced Photodynamic Therapy in MCF-7 Cancer Cells and Antibacterial Activity.

In this experimental approach, we explored the structures, morphologies, phototoxicities, and antibacterial activities of undoped and Mn-doped ceria nanocomposite materials, Mn x Ce1-x O2. The Mn x Ce1-x O2 nanocomposites were synthesized by employing a soft chemical route. Our prime focus was on the influence of different factors, both physical and chemical, i.e., the concentration of manganese in the product, size of the nanocomposite, drug dose, and incubation time, on the bacterial strains. Different bacterial strains were selected as experimental biological models of the antibacterial activity of the manganese-doped cerium oxide nanocomposite. In addition to the photodynamic response, the adenocarcinoma cell line (MCF-7) was also studied. Based on cell viability losses and bacterial inhibition analyses, the precise mechanisms of apoptosis or necrosis of 5-ALA/PpIX-exposed MCF-7 cells under 630 nm red lights and under dark conditions were elucidated. It was observed that the undoped nanocomposites had lower cytotoxicities and inhibitions compared with those of the doped nanocomposites towards pathogens. The antibacterial activity and effectiveness for photodynamic therapy were enhanced in the presence of the manganese-doped ceria nanocomposite, which could be attributed to the correlation of the maximum reactive oxygen species generation for targeted toxicity and maximum antioxidant property in bacteria growth inhibition. The optimized cell viability dose and doping concentration will be beneficial for treating cancer and bacterial infections in the future.

In Vitro Cytotoxicity and Morphological Assessments of GO-ZnO against the MCF-7 Cells: Determination of Singlet Oxygen by Chemical Trapping.

Graphene-based materials have attracted considerable interest owing to their distinctive characteristics, such as their biocompatibility in terms of both their physical and intrinsic chemical properties. The use of nanomaterials with graphene as a biocompatible agent has increased due to an uptick in dedication from biomedical investigators. Here, GO-ZnO was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-Vis) spectroscopy, energy dispersive X-ray analysis (EDAX), and Raman spectroscopy for structural, morphological, and elemental analysis. The toxic extent of GO-ZnO was noted by a methyl-thiazole-tetrazolium (MTT), while cellular morphology was observed towards the MCF-7 cells using an inverted microscope at magnification 40×. The cytotoxic effect of GO-ZnO investigated the cell viability reduction in a dose-dependent manner, as well as prompted the cell demise/destruction in an apoptotic way. Moreover, statistical analysis was performed on the experimental outcomes, with p-values < 0.05 kept as significant to elucidate the results. The generation of reactive oxygen species (ROS) demonstrated the potential applicability of graphene in tumor treatment. These key results attest to the efficacy of GO-ZnO nanocomposites as a substantial candidate for breast malignancy treatment.

Second cancer risk after 3D-CRT, IMRT and VMAT for breast cancer.

PURPOSE: Second cancer risk after breast conserving therapy is becoming more important due to improved long term survival rates. In this study, we estimate the risks for developing a solid second cancer after radiotherapy of breast cancer using the concept of organ equivalent dose (OED). MATERIALS AND METHODS: Computer-tomography scans of 10 representative breast cancer patients were selected for this study. Three-dimensional conformal radiotherapy (3D-CRT), tangential intensity modulated radiotherapy (t-IMRT), multibeam intensity modulated radiotherapy (m-IMRT), and volumetric modulated arc therapy (VMAT) were planned to deliver a total dose of 50 Gy in 2 Gy fractions. Differential dose volume histograms (dDVHs) were created and the OEDs calculated. Second cancer risks of ipsilateral, contralateral lung and contralateral breast cancer were estimated using linear, linear-exponential and plateau models for second cancer risk. RESULTS: Compared to 3D-CRT, cumulative excess absolute risks (EAR) for t-IMRT, m-IMRT and VMAT were increased by 2 ± 15%, 131 ± 85%, 123 ± 66% for the linear-exponential risk model, 9 ± 22%, 82 ± 96%, 71 ± 82% for the linear and 3 ± 14%, 123 ± 78%, 113 ± 61% for the plateau model, respectively. CONCLUSION: Second cancer risk after 3D-CRT or t-IMRT is lower than for m-IMRT or VMAT by about 34% for the linear model and 50% for the linear-exponential and plateau models, respectively.

Can the risk of secondary cancer induction after breast conserving therapy be reduced using intraoperative radiotherapy (IORT) with low-energy x-rays?

BACKGROUND: Radiation induced secondary cancers are a rare but severe late effect after breast conserving therapy. Intraoperative radiotherapy (IORT) is increasingly used during breast conserving surgery. The purpose of this analysis was to estimate secondary cancer risks after IORT compared to other modalities of breast radiotherapy (APBI - accelerated partial breast irradiation, EBRT - external beam radiotherapy). METHODS: Computer-tomography scans of an anthropomorphic phantom were acquired with an INTRABEAM IORT applicator (diameter 4 cm) in the outer quadrant of the breast and transferred via DICOM to the treatment planning system. Ipsilateral breast, contralateral breast, ipsilateral lung, contralateral lung, spine and heart were contoured. An INTRABEAM source (50 kV) was defined with the tip of the drift tube at the center of the spherical applicator. A dose of 20 Gy at 0 mm depth from the applicator surface was prescribed for IORT and 34 Gy (5 days × 2 × 3.4 Gy) at 10 mm depth for APBI. For EBRT a total dose of 50 Gy in 2 Gy fractions was planned using two tangential fields with wedges. The mean and maximal doses, DVHs and volumes receiving more than 0.1 Gy and 4 Gy of organs at risk (OAR) were calculated and compared. The life time risk for secondary cancers was estimated according to NCRP report 116. RESULTS: IORT delivered the lowest maximal doses to contralateral breast (< 0.3 Gy), ipsilateral (1.8 Gy) and contralateral lung (< 0.3 Gy), heart (1 Gy) and spine (< 0.3 Gy). In comparison, maximal doses for APBI were 2-5 times higher. EBRT delivered a maximal dose of 10.4 Gy to the contralateral breast and 53 Gy to the ipsilateral lung. OAR volumes receiving more than 4 Gy were 0% for IORT, < 2% for APBI and up to 10% for EBRT (ipsilateral lung). The estimated risk for secondary cancer in the respective OAR is considerably lower after IORT and/or APBI as compared to EBRT. CONCLUSIONS: The calculations for maximal doses and volumes of OAR suggest that the risk of secondary cancer induction after IORT is lower than compared to APBI and EBRT.