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Objective: A novel efficient pH-sensitive targeted magnetic resonance imaging (MRI) contrast agent and innovative radio-sensitizing system were synthesized based on MnO2 NPs coated with biocompatible poly-dimethyl-amino-ethyl methacrylate-Co-itaconic acid, (DMAEMA-Co-IA) and targeted with methotrexate (MTX). Materials and methods: The as-established NPs were fully characterized and evaluated for MRI signal enhancement, relaxivity, in vitro cell targeting, cell toxicity, blood compatibility, and radiotherapy (RT) efficacy. Results: The targeted NPs MnO2@Poly(DMAEMA-Co-IA) and MTX-loaded NPs inhibited MCF-7 cell viability more effectively than free MTX after 24 and 48 h, respectively, with no noticeable toxicity. Additionally, the insignificant hemolytic activity demonstrated their proper hemo-compatibility. T1-weighted magnetic resonance imaging was used to distinguish the differential uptake of the produced MnO2@Poly(DMAEMA-Co-IA)-MTX NPs in malignant cells compared to normal ones in the presence of high and low MTX receptor cells (MCF-7 and MCF-10A, respectively). In MRI, the produced theranostic NPs displayed pH-responsive contrast enhancement. As shown by in vitro assays, treatment of cells with MnO2@Poly(DMAEMA-Co-IA)-MTX NPs prior to radiotherapy in hypoxic conditions significantly enhanced therapeutic efficacy. Conclusion: We draw the conclusion that using MnO2@Poly(DMAEMA-Co-IA)-MTX NPs in MR imaging and combination radiotherapy may be a successful method for imaging and radiation therapy of hypoxia cells. [ABSTRACT FROM AUTHOR]

Aim of the study: Our objective was to quantify the accuracy of dose calculation in the build-up region of the tangential field of the breast for a Ti- GRT treatment planning system (TPS). Material and methods: Thermoluminescent dosimeter (TLD) chips were arranged in a RANDO phantom for the dose measurement. TiGRT TPS was also used for the dose calculation. Finally, confidence limit values were obtained to quantify the accuracy of the dose calculation of the TPS at the build-up region. Results: In the open field, for gantry angles of 15°, 30°, and 60°, the confidence limit values were 17.68, 19.97, and 34.62 at a depth of 5 mm, and 24.01, 19.07, and 15.74 at a depth of 15 mm, respectively. In the wedge field, for gantry angles of 15°, 30°, and 60°, the confidence limit values were 21.64, 26.80, and 34.87 at a depth of 5 mm, and 27.92, 22.04, and 20.03 at a depth of 15 mm, respectively. Additionally, the findings showed that at a depth of 5 mm, the confidence limit values increased with increasing gantry angle while at a depth of 15 mm, the confidence limit values decreased with increasing gantry angle. Conclusions: Overall, TiGRT TPS overestimated doses compared to TLD measurements, and the confidence limit values were greater for the wedge field than for the open fields. Our findings suggest that the assessment of dose distributions in largedose gradient regions (i.e. build-up region) should not entirely rely on TPS calculations. [ABSTRACT FROM AUTHOR]

[Display omitted] 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 (Bi 2 O 3) 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 Bi 2 O 3 @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 Bi 2 O 3 @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 Bi 2 O 3 @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 results demonstrated that the targeted Bi 2 O 3 @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 Bi 2 O 3 @PCD-CUR-Glu NPs, integrated with CT imaging and chemo-radiotherapy, have great potential as a versatile theranostic system for clinical application. [ABSTRACT FROM AUTHOR]