Assessment of ovarian cancer tumors treated with intraperitoneal cisplatin therapy by nanoscopic X-ray fluorescence imaging

Ovarian cancer is amongst the most common types of cancer in women, with a relatively low overall cure rate of approximately 30%. This is therefore an important incentive to urge for further research in order to maximize the chances of survival for these patients. Intraperitoneal chemotherapy with Cisplatin is an effective treatement for ovarian cancer; however, many questions still remain concerning the ideal treatment protocol and tumor resistance towards the drug, which should be resolved for optimal application of this therapy. For the first time in-vivo grown tumors treated with both hyper- and normothermic intraperitoneal chemotherapy have been studied using nano-XRF spectroscopy to examine the platinum (Pt) distribution within the analyzed tissues. These measurements prove Pt resides predominantly outsides the cancer cells in the stroma of the tissue. These findings indicate the resistance mechanism of the cancer cells prevents Cisplatin from diffusing through their cell membranes. This is an important addition to the existing knowledge on the resistance mechanism providing insights which might help to overcome this effect. In our aim to find the optimal treatment protocol, no significant differences were found between the two examined procedures. A more extensive data set will be needed to draw definite conclusions

Novel tetrakis lanthanide β-diketonate complexes : structural study, luminescent properties and temperature sensing

Lanthanide β-diketonate complexes have been extensively investigated in the past, as they are cheap, easy to synthesize and they tend to form highly stable complexes with lanthanide ions. Lanthanide β-diketonate complexes have been used as NMR shift reagents, also they are good precursors for further synthesis in some more complex matrixes (such as sol-gels, polymers…), used as OLEDs and as temperature probes because of their distinct luminescence properties.1 Optical thermometry based on luminescence is an expanding field of research because non-contact temperature sensing can have different applications, such as in bioimaging, anti-counterfeiting or in industry where it is necessary to have good sensing properties in precisely defined temperature ranges.2 Here, we report novel structures of different homonuclear (Ln3+ = Eu, Tb, Sm, Dy, Pr, Nd, Er, and Yb) complexes and four heteronuclear complexes: two Eu-Tb and two Tb-Sm complexes with different ratios of the two ions. The trifluoro-acetylacetone (TFAC) ligand has been chosen for the synthesis because it is well known and widely used in complexation chemistry. Up till now, there have not been any reported structures of tetrakis TFAC complexes with lanthanides. The complexes crystallize in the orthorhombic system with Pna2 space group with four molecules per unit cell. The structure consists of a [Ln(TFAC)4]- salt with a sodium cation, where the Ln ion is coordinated with eight O atoms from the TFAC ligand. The homonuclear complexes show luminescent properties in both the visible and NIR region. The Dy complex shows temperature-dependent luminescence in the 280-380 K region, with a maximum value of Sr = 3.45% K-1 at 280 K. The heteronuclear complexes of Tb-Sm with different ion ratios also show good temperature-dependent luminescent properties in this region with maximum Sr = 2.30 % K-1 at 360 K. For the Eu-Tb complexes, it was also observed that the different ions ratios influence the temperature-dependent luminescence in the way that they can be sensitive in the different temperature regions. For a complex with a higher Tb3+ contents temperature sensing properties were observed in the 10-335 K range, with a maximum Sr value of 1.65 K-1 at 285 K. When more Eu3+ ions are present in the heteronuclear complex, it shows temperature sensing abilities in the physiological region, from 273-373 K, with a maximum Sr value of 2.70 K-1 at 353 K. References 1 K. Binnemmans, Rare-earth beta-diketonates, Handbook of the Physics and Chemistry of Rare Earths, 2005, Chapter 35, pp. 107-272. 2 C. D. S. Brites, A. Millan, L. D. Carlos, Lanthanides in Luminescent Thermometry, Handbook of the Physics and Chemistry of Rare Earths, 2016, Chapter 49, pp. 339-427

Three-dimensional reconstruction of the tissue-specific multielemental distribution within Ceriodaphnia dubia via multimodal registration using laser ablation ICP-mass spectrometry and X-ray spectroscopic techniques

In this work, the three-dimensional elemental, distribution profile within the freshwater crustacean Ceriodaphnia dubia was constructed at a spatial resolution down to S mu m via a data, fusion approach employing state-of-the-art laser ablation inductively coupled plasma-time-of-flight mass spectrometry (LAICP-TOFMS) and laboratory-based absorption microcomputed tomography (mu-CT). C. dubia was exposed to elevated Cu, Ni, and Zn concentrations, chemically fixed, dehydrated, stained, and embedded, prior to mu-CT analysis. Subsequently, the sample was cut into 5 pm thin sections that were subjected to LA-ICPTOFMS imaging. Multimodal image registration was performed to spatially align the 2D LA-ICP-TOFMS images relative to the Corresponding slices of the 3D mu-CT reconstruction. Mass channels corresponding to the isotopes of a single element were merged to improve the signal-to-noise ratios within the elemental images. In order to aid the visual interpretation of the data, LA-ICP-TOEMS data wete projected onto the mu-CT voxels representing tissue. Additionally, the image resolution and elemental sensitivity were compared to those obtained with synchrotron radiation based 3D confocal mu-X-ray fluorescence imaging upon a chemically fixed and air-dried C. dubia specimen

Three-dimensional reconstruction of the distribution of elemental tags in single cells using laser ablation ICP-mass spectrometry via registration approaches

This paper describes a workflow towards the reconstruction of the three-dimensional elemental distribution profile within human cervical carcinoma cells (HeLa), at a spatial resolution down to 1 μm, employing state-of-the-art laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) instrumentation. The suspended cells underwent a series of fixation/embedding protocols and were stained with uranyl acetate and an Ir-based DNA intercalator. A priori, laboratory-based absorption micro-computed tomography (μ-CT) was applied to acquire a reference frame of the morphology of the cells and their spatial distribution before sectioning. After CT analysis, a trimmed 300 × 300 × 300 μm^3 block was sectioned into a sequential series of 132 sections with a thickness of 2 μm, which were subjected to LA-ICP-MS imaging. A pixel acquisition rate of 250 pixels s^−1 was achieved, through a bidirectional scanning strategy. After acquisition, the two-dimensional elemental images were reconstructed using the timestamps in the laser log file. The synchronization of the data required an improved optimization algorithm, which forces the pixels of scans in different ablation directions to be spatially coherent in the direction orthogonal to the scan direction. The volume was reconstructed using multiple registration approaches. Registration using the section outline itself as a fiducial marker resulted into a volume which was in good agreement with the morphology visualized in the μ-CT volume. The 3D μ-CT volume could be registered to the LA-ICP-MS volume, consisting of 2.9 × 10^7 voxels, and the nucleus dimensions in 3D space could be derived

Responses of an abyssal meiobenthic community to short-term burial with crushed nodule particles in the south-east Pacific

Increasing industrial metal demands due to rapid technological developments may drive the prospection and exploitation of deep-sea mineral resources such as polymetallic nodules. To date, the potential environmental consequences of mining operations in the remote deep sea are poorly known. Experimental studies are scarce, especially with regard to the effect of sediment and nodule debris depositions as a consequence of seabed mining. To elucidate the potential effects of the deposition of crushed polymetallic nodule particles on abyssal meiobenthos communities, a short (11 d) in situ experiment at the seafloor of the Peru Basin in the south-east Pacific Ocean was conducted in 2015. We covered abyssal, soft sediment with approx. 2 cm of crushed nodule particles and sampled the sediment after 11 d of incubation at 4200 m water depth. Short-term ecological effects on the meiobenthos community were studied including changes in their composition and vertical distribution in the sediment as well as nematode genus composition. Additionally, copper burden in a few similar-sized but randomly selected nematodes was measured by means of micro X-ray fluorescence (µXRF). At the end of the experiment, 46±1 % of the total meiobenthos occurred in the added crushed nodule layer, while abundances decreased in the underlying 2 cm compared to the same depth interval in undisturbed sediments. Densities and community composition in the deeper 2–5 cm layers remained similar in covered and uncovered sediments. The migratory response into the added nodule material was particularly seen in polychaetes (73±14 %, relative abundance across all depth layers) copepods (71±6 %), nauplii (61±9 %) and nematodes (43±1 %). While the dominant nematode genera in the added nodule material did not differ from those in underlying layers or the undisturbed sediments, feeding type proportions in this layer were altered, with a 9 % decrease of non-selective deposit feeders and an 8 % increase in epistrate feeders. Nematode tissue copper burden did not show elevated copper toxicity resulting from burial with crushed nodule particles. Our results indicate that burial with a 2 cm layer of crushed nodule particles induces changes in the vertical structure of meiobenthos inside the sediment and an alteration of nematode feeding type proportions within a short time frame of 11 d, while nematode tissue copper burden remains unchanged. These findings considerably contribute to the understanding of the short-term responses of meiobenthos to physical disturbances in the deep sea