Deficiency of miR-155 in leukemic B-cells results in cell cycle arrest and deregulation of MIR155HG/TP53INP1/CDKN1A/CCND1 network.

Background: Cell cycle progression and leukemia development are tightly regulated processes in which even a small imbalance in the expression of cell cycle regulatory molecules and microRNAs (miRNAs) can lead to an increased risk of cancer/leukemia development. Here, we focus on the study of a ubiquitous, multifunctional, and oncogenic miRNA-hsa-miR-155-5p (miR-155, MIR155HG), which is overexpressed in malignancies including chronic lymphocytic leukemia (CLL). Nonetheless, the precise mechanism of how miR-155 regulates the cell cycle in leukemic cells remains the subject of extensive research.

Digital Light Processing of F MRI-Traceable Gelatin-Based Biomaterial Inks towards Bone Tissue Regeneration.

Gelatin-based photo-crosslinkable hydrogels are promising scaffold materials to serve regenerative medicine. They are widely applicable in additive manufacturing, which allows for the production of various scaffold microarchitectures in line with the anatomical requirements of the organ to be replaced or tissue defect to be treated. Upon their in vivo utilization, the main bottleneck is to monitor cell colonization along with their degradation (rate).

Toxicity of Large and Small Surface-Engineered Upconverting Nanoparticles for In Vitro and In Vivo Bioapplications.

In this study, spherical or hexagonal NaYF:Yb,Er nanoparticles (UCNPs) with sizes of 25 nm (S-UCNPs) and 120 nm (L-UCNPs) were synthesized by high-temperature coprecipitation and subsequently modified with three kinds of polymers. These included poly(ethylene glycol) (PEG) and poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide) [P(DMA-AEA)] terminated with an alendronate anchoring group, and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). The internalization of nanoparticles by rat mesenchymal stem cells (rMSCs) and C6 cancer cells (rat glial tumor cell line) was visualized by electron microscopy and the cytotoxicity of the UCNPs and their leaches was measured by the real-time proliferation assay.

Experimental model of primary intraocular lymphoma based on BALB/CaNn strain and A20 cells is optimal for investigational research.

Aim: The purpose of this project was to compare the characteristics of two experimental murine models of primary intraocular lymphoma (PIOL) and determine which experimental model is most suitable for further investigational research to elucidate the pathophysiology of PIOL and to find new therapeutical strategies.

Methods: In both experimental models PIOL was induced in immunocompetent mice with intravitreal injection of syngeneic B-cell lymphoma cell lines. Murine strain C3H/HeN and cell line 38C13 were used in the first model and BALB/CaNn mice and cell line A20 in the second model.

Nanocomposite based on GdO nanoparticles and drug 5-fluorouracil as potential theranostic nano-cargo system.

We have prepared silica matrix with hexagonal symmetry of pores (SBA-15) and loaded it with anticancer drug 5-Fluorouracil (5-FU) to promote it as a drug delivery system. GdO nanoparticles were incorporated into the matrix to enhance nanosystems applicability as contrast agent for MRI, thus enabled this nanocomposite to be used as multifunctional nano-based therapeutic agent. Drug release profile was obtained by UV-VIS spectroscopy, and it indicates the prolongated release of 5-FU during the first hours and the total release after 5 h.

Hydrophilic Copolymers with Hydroxamic Acid Groups as a Protective Biocompatible Coating of Maghemite Nanoparticles: Synthesis, Physico-Chemical Characterization and MRI Biodistribution Study.

Superparamagnetic iron oxide nanoparticles (SPION) with a "non-fouling" surface represent a versatile group of biocompatible nanomaterials valuable for medical diagnostics, including oncology. In our study we present a synthesis of novel maghemite (γ-FeO) nanoparticles with positive and negative overall surface charge and their coating by copolymer P(HPMA--HAO) prepared by RAFT (reversible addition-fragmentation chain-transfer) copolymerization of N-(2-hydroxypropyl)methacrylamide (HPMA) with N-[2-(hydroxyamino)-2-oxo-ethyl]-2-methyl-prop-2-enamide (HAO). Coating was realized via hydroxamic acid groups of the HAO comonomer units with a strong affinity to maghemite.

Chemical and Colloidal Stability of Polymer-Coated NaYF:Yb,Er Nanoparticles in Aqueous Media and Viability of Cells: The Effect of a Protective Coating.

Upconverting nanoparticles (UCNPs) are of particular interest in nanomedicine for in vivo deep-tissue optical cancer bioimaging due to their efficient cellular uptake dependent on polymer coating. In this study, particles, 25 nm in diameter, were prepared by a high-temperature coprecipitation of lanthanide chlorides. To ensure optimal dispersion of UCNPs in aqueous milieu, they were coated with three different polymers containing reactive groups, i.

Magnetic resonance tractography of the brachial plexus: step-by-step.

Background: Magnetic resonance (MR) tractography of the brachial plexus (BP) is challenging due to different factors such as motion artifacts, pulsation artifacts, signal-to-noise ratio, spatial resolution; eddy currents induced geometric distortions, sequence parameters and choice of used coils. Notably challenging is the separation of the peripheral nerve bundles and skeletal muscles as both structures have similar fractional anisotropy values. We proposed an algorithm for robust visualization and assessment of BP root bundles using the segmentation of the spinal cord (SSC, C4-T1) as seed points for the initial starting area for the fibre tracking algorithm.

Multimodal Contrast Agent Enabling pH Sensing Based on Organically Functionalized Gold Nanoshells with Mn-Zn Ferrite Cores.

Highly complex nanoparticles combining multimodal imaging with the sensing of physical properties in biological systems can considerably enhance biomedical research, but reports demonstrating the performance of a single nanosized probe in several imaging modalities and its sensing potential at the same time are rather scarce. Gold nanoshells with magnetic cores and complex organic functionalization may offer an efficient multimodal platform for magnetic resonance imaging (MRI), photoacoustic imaging (PAI), and fluorescence techniques combined with pH sensing by means of surface-enhanced Raman spectroscopy (SERS). In the present study, the synthesis of gold nanoshells with Mn-Zn ferrite cores is described, and their structure, composition, and fundamental properties are analyzed by powder X-ray diffraction, X-ray fluorescence spectroscopy, transmission electron microscopy, magnetic measurements, and UV-Vis spectroscopy.

Photoacoustic Properties of Polypyrrole Nanoparticles.

Photoacoustic imaging, an emerging modality, provides supplemental information to ultrasound imaging. We investigated the properties of polypyrrole nanoparticles, which considerably enhance contrast in photoacoustic images, in relation to the synthesis procedure and to their size. We prepared polypyrrole nanoparticles by water-based redox precipitation polymerization in the presence of ammonium persulphate (ratio Py:Oxi 1:0.

In vitro cellular activity of maghemite/cerium oxide magnetic nanoparticles with antioxidant properties.

Magnetic γ-FeO/CeO nanoparticles were obtained by precipitation of Ce(NO) with ammonia in the presence of γ-FeO seeds. The formation of CeO nanoparticles on the seeds was confirmed by transmission electron microscopy linked with selected area electron diffraction, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy, and dynamic light scattering. The γ-FeO/CeO particle surface was functionalized with PEG-neridronate to improve the colloidal stability in PBS and biocompatibility.

Condensed Clustered Iron Oxides for Ultrahigh Photothermal Conversion and Multimodal Imaging.

Magnetic iron oxide nanocrystals (MIONs) are established as potent theranostic nanoplatforms due to their biocompatibility and the multifunctionality of their spin-active atomic framework. Recent insights have also unveiled their attractive near-infrared photothermal properties, which are, however, limited by their low near-infrared absorbance, resulting in noncompetitive photothermal conversion efficiencies (PCEs). Herein, we report on the dramatically improved photothermal conversion of condensed clustered MIONs, reaching an ultrahigh PCE of 71% at 808 nm, surpassing the so-far MION-based photothermal agents and even benchmark near-infrared photothermal nanomaterials.

Understanding the Biological Basis of Glioblastoma Patient-derived Spheroids.

Background/aim: Resistance to glioblastoma (GB) therapy is attributed to the presence of glioblastoma stem cells (GSC). Here, we defined the behavior of GSC as it pertains to proliferation, migration, and angiogenesis.

Materials And Methods: Human-derived GSC were isolated and cultured from GB patient tumors.

Selective vulnerability of the hippocampus to the cytotoxic edema; magnetic resonance imaging and fluorescence microscopy studies in the rats.

Objectives: Changes in the hippocampus induced by water intoxication were studied using fluorescence microscopy (FM) and magnetic resonance imaging (MRI).

Methods: In three animals (rats), intracellular/extracellular distribution of Evans blue (EB) in cerebral cortex and hippocampus of both hemispheres was revealed by injection of EB into the internal carotid artery (ICA) in hyperhydrated rats (water intoxication, WI). A total of 8 experimental rats were used for the MRI study.

Magnetic resonance tractography of the lumbosacral plexus: Step-by-step.

MR tractography of the lumbosacral plexus (LSP) is challenging due to the difficulty of acquiring high quality data and accurately estimating the neuronal tracts. We proposed an algorithm for an accurate visualization and assessment of the major LSP bundles using the segmentation of the cauda equina as seed points for the initial starting area for the fiber tracking algorithm.Twenty-six healthy volunteers underwent MRI examinations on a 3T MR scanner using the phased array coils with optimized measurement protocols for diffusion-weighted images and coronal T2 weighted 3D short-term inversion recovery sampling perfection with application optimized contrast using varying flip angle evaluation sequences used for LSP fiber reconstruction and MR neurography (MRN).

Colloidally Stable P(DMA-AGME)-Ale-Coated Gd(Tb)F:Tb(Gd),Yb,Nd Nanoparticles as a Multimodal Contrast Agent for Down- and Upconversion Luminescence, Magnetic Resonance Imaging, and Computed Tomography.

Multimodal imaging, integrating several modalities including down- and up-conversion luminescence, - and ( *)-weighted MRI, and CT contrasting in one system, is very promising for improved diagnosis of severe medical disorders. To reach the goal, it is necessary to develop suitable nanoparticles that are highly colloidally stable in biologically relevant media. Here, hydrophilic poly(,-dimethylacrylamide--acryloylglycine methyl ester)-alendronate-[P(DMA-AGME)-Ale]-coated Gd(Tb)F:Tb(Gd),Yb,Nd nanoparticles were synthesized by a coprecipitation method in ethylene glycol (EG) followed by coating with the polymer.

Magnetic nanoparticles of Ga-substituted ε-Fe O for biomedical applications: Magnetic properties, transverse relaxivity, and effects of silica-coated particles on cytoskeletal networks.

Magnetic nanoparticles of ε-Fe Ga O with the volume-weighted mean size of 17 nm were prepared by thermal treatment of a mesoporous silica template impregnated with metal nitrates and were coated with silica shell of four different thicknesses in the range 6-24 nm. The bare particles exhibited higher magnetization than the undoped compound, 22.4 Am kg at 300 K, and were characterized by blocked state with the coercivity of 1.

Multiparametric Quantitative Brain MRI in Neurological and Hepatic Forms of Wilson's Disease.

Background: In Wilson's disease (WD), demyelination, rarefaction, gliosis, and iron accumulation in the deep gray matter cause opposing effects on T -weighted MR signal. However, the degree and interplay of these changes in chronically treated WD patients has not been quantitatively studied.

Purpose: To compare differences in brain multiparametric mapping between controls and chronically treated WD patients with neurological (neuro-WD) and hepatic (hep-WD) forms to infer the nature of residual WD neuropathology.

Manganese-Zinc Ferrites: Safe and Efficient Nanolabels for Cell Imaging and Tracking In Vivo.

Manganese-zinc ferrite nanoparticles were synthesized by using a hydrothermal treatment, coated with silica, and then tested as efficient cellular labels for cell tracking, using magnetic resonance imaging (MRI) in vivo. A toxicity study was performed on rat mesenchymal stem cells and C6 glioblastoma cells. Adverse effects on viability and cell proliferation were observed at the highest concentration (0.

Low-molecular-weight paramagnetic F contrast agents for fluorine magnetic resonance imaging.

Objective: F MRI requires biocompatible and non-toxic soluble contrast agents with high fluorine content and with suitable F relaxation times. Probes based on a DOTP chelate with 12 magnetically equivalent fluorine atoms (DOTP-tfe) and a lanthanide(III) ion shortening the relaxation times were prepared and tested.

Methods: Complexes of DOTP-tfe with trivalent paramagnetic Ce, Dy, Ho, Tm, and Yb ions were synthetized and characterized.

31P-MR spectroscopy in patients with mild and serious lower limb ischemia.

Background: 31P-MR spectroscopy is a technique for undertaking a comprehensive evaluation of muscle metabolism. The goal of this study was to compare patients with mild and severe lower limb ischemia measured by 31P-MR spectroscopy at rest and during exercise.

Methods: Sixteen non-diabetic mild peripheral arterial occlusive disease (PAOD) patients, 23 diabetic PAOD patients with severe ischemia and 19 healthy controls were examined by rest and dynamic 31P-MR spectroscopy with a 3T MR system equipped with an MR-compatible home-made pedal ergometer.

The Optimal Timing for Pancreatic Islet Transplantation into Subcutaneous Scaffolds Assessed by Multimodal Imaging.

Subcutaneously implanted polymeric scaffolds represent an alternative transplantation site for pancreatic islets (PIs) with the option of vascularisation enhancement by mesenchymal stem cells (MSC). Nevertheless, a proper timing of the transplantation steps is crucial. In this study, scaffolds supplemented with plastic rods were implanted into diabetic rats and two timing schemes for subsequent transplantation of bioluminescent PIs (4 or 7 days after rod removal) were examined by multimodal imaging.

Paramagnetic F Relaxation Enhancement in Nickel(II) Complexes of N-Trifluoroethyl Cyclam Derivatives and Cell Labeling for F MRI.

1,8-Bis(2,2,2-trifluoroethyl)cyclam (te2f) derivatives with two coordinating pendant arms involving methylenecarboxylic acid (Hte2f2a), methylenephosphonic acid (Hte2f2p), (2-pyridyl)methyl (te2f2py), and 2-aminoethyl arms (te2f2ae) in 4,11-positions were prepared, and their nickel(II) complexes were investigated as possible F MR tracers. The solid-state structures of several synthetic intermediates, ligands, and all complexes were confirmed by X-ray diffraction analysis. The average Ni···F distances were determined to be about 5.

The effects of grafted mesenchymal stem cells labeled with iron oxide or cobalt-zinc-iron nanoparticles on the biological macromolecules of rat brain tissue extracts.

Introduction: Rat mesenchymal stem cells (rMSCs) labeled with 1) poly-l-lysine-coated superparamagnetic iron oxide nanoparticles or 2) silica-coated cobalt-zinc-iron nanoparticles were implanted into the left brain hemisphere of rats, to assess their effects on the levels of oxidative damage to biological macromolecules in brain tissue.

Methods: Controls were implanted with unlabeled rMSCs. Animals were sacrificed 24 hours or 4 weeks after the treatment, and the implantation site along with the surrounding tissue was isolated from the brain.