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Skin is a major administration route for drugs, and all transdermal formulations must be tested for their capability to overcome the cutaneous barrier. Therefore, developing highly reliable skin models is crucial for preclinical studies. The current in vitro models are unable to replicate the living skin in all its complexity; thus, to date, excised human skin is considered the gold standard for in vitro permeation studies. However, skin explants have a limited life span. In an attempt to overcome this problem, we used an innovative bioreactor that allowed us to achieve good structural and functional preservation in vitro of explanted human skin for up to 72 h. This device was then used to set up an in vitro inflammatory model by applying two distinct agents mimicking either exogenous or endogenous stimuli: i.e., dithranol, inducing the contact dermatitis phenotype, and the substance P, mimicking neurogenic inflammation. Our in vitro system proved to reproduce inflammatory events observed in vivo, such as vasodilation, increased number of macrophages and mast cells, and increased cytokine secretion. This bioreactor-based system may therefore be suitably and reliably used to simulate in vitro human skin inflammation and may be foreseen as a promising tool to test the efficacy of drugs and cosmetics.

The investigation of the absorption of drug delivery systems, designed for the transport of therapeutic molecules inside the body, could be relatively simplified by the fluorophore association and tracking by means of bio-imaging techniques (i.e., optical in vivo imaging or confocal and multiphoton microscopy). However, when a fluorescence signal comes out from the skin, its specific detection can be problematic. Skin high autofluorescence can hinder the observation of administered exogenous fluorophores conjugated to drug delivery systems, making it more challenging to detect their biodistribution. In the present study, we have developed a method based on the spectrofluorometric analysis of skin samples to discriminate the fluorescent signal coming from administered fluorescent molecules from the background. Moreover, we gave a semi-quantitative evaluation of the signal intensity. Thus, we distinguished two gel formulations loading the fluorophore rhodamine B (called GEL RHO and GEL SLN-RHO). The two formulations of gels, one of which containing solid lipid nanoparticles (GEL RHO-SLN), were administered on skin explants incubated in a bioreactor, and the penetration was evaluated at different time points (2 and 6 hours). Cryostatic sections of skin samples were observed with confocal laser scanning microscopy, and a spectrofluorometric analysis was performed. Significantly higher signal intensity in the samples administered with SLN-RHO GEL, with a preferential accumulation in the hair bulbs, was found. Reaching also the deeper layers of the hair shaft after 6 hours, the solid lipid nanoparticles thickened with polymer represent a suitable drug delivery system for transcutaneous administration.

This research was funded by the FUR (Fondo Unico della Ricerca—University of Verona) of M. Perduca. C.J.-L. acknowledges funding from projects CGL2016-76723 from the Ministerio de Economía y Competitividad from Spain and Fondo Europeo de Desarrollo Regional (FEDER) and Programa Operativo FEDER 2014–2020 (A-BIO-376-UGR18) Junta de Andalucia. M.P.C.-J. acknowledges funding from projects PID2019-109294RB-100 from the Ministerio de Ciencia e Innovación from Spain., We are grateful to the “Centro Piattaforme Tecnologiche” of the University of Verona for giving access to DLS equipment. CJL acknowledges. the Unidad Cientıfica de Excelencia UCE PP 2016.05 (U. Granada) and Instituto de Biotecnología. Y.J. wants to acknowledge a FPU2016 grant (ref. FPU16_04580) from the Ministerio de Educación, Ciencia y Deporte y Competitividad (Spain). AS-L is funded by the Spanish Ministry of Science, Innovation and Universities: Formación de Doctores 2018 (ref. PRE2018-0854409). Thanks go to the Scientific Instrumentation Center (CIC) personnel of the University of Granada for technical assistance with the TEM.We also thank Salvatore Calogero Gaglio for his help in preparing Figure S4., Magnetococcus marinus magnetosome-associated protein MamC, expressed as recombinant, has been proven to mediate the formation of novel biomimetic magnetic nanoparticles (BMNPs) that are successful drug nanocarriers for targeted chemotherapy and hyperthermia agents. These BMNPs present several advantages over inorganic magnetic nanoparticles, such as larger sizes that allow the former to have larger magnetic moment per particle, and an isoelectric point at acidic pH values, which allows both the stable functionalization of BMNPs at physiological pH value and the molecule release at acidic (tumor) environments, simply based on electrostatic interactions. However, difficulties for BMNPs cell internalization still hold back the efficiency of these nanoparticles as drug nanocarriers and hyperthermia agents. In the present study we explore the enhanced BMNPs internalization following upon their encapsulation by poly (lactic-co-glycolic) acid (PLGA), a Food and Drug Administration (FDA) approved molecule. Internalization is further optimized by the functionalization of the nanoformulation with the cell-penetrating TAT peptide (TATp). Our results evidence that cells treated with the nanoformulation [TAT-PLGA(BMNPs)] show up to 80% more iron internalized (after 72 h) compared to that of cells treated with BMNPs (40%), without any significant decrease in cell viability. This nanoformulation showing optimal internalization is further characterized. In particular, the present manuscript demonstrates that neither its magnetic properties nor its performance as a hyperthermia agent are significantly altered due to the encapsulation. In vitro experiments demonstrate that, following upon the application of an alternating magnetic field on U87MG cells treated with BMNPs and TAT-PLGA(BMNPs), the cytotoxic effect of BMNPs was not affected by the TAT-PLGA enveloping. Based on that, difficulties shown in previous studies related to poor cell uptake of BMNPs can be overcome by the novel nanoassembly described here., FUR (Fondo Unico della Ricerca-University of Verona), Ministerio de Economia y Competitividad from Spain CGL2016-76723, European Commission CGL2016-76723, Junta de Andalucia A-BIO-376-UGR18, Spanish Government PID2019-109294RB-100

Autohemotherapy is the most used method to administer O2-O3 systemically. It consists in exposing a limited amount of blood to a gaseous O2-O3 and reinfusing it, thus activating a cascade of biochemical pathways involving plasma and blood cells that gives rise to antioxidant and anti-inflammatory responses. The therapeutic effects strictly depend on the O3 dose, it is therefore necessary to understand the relationship between the O3 concentration and the effects on blood cells involved in antioxidant and immune response. Here we performed a basic study on the effects of the low O3 concentrations used for autohemotherapy on the structural and functional features of the human T-lymphocyte-derived Jurkat cells. Ultrastructural, biomolecular, and bioanalytic techniques were used. Our findings showed that 10, 20, and 30 µg O3 concentrations were able to trigger Nrf2-induced antioxidant response and increase IL-2 secretion. However, viability and proliferation tests as well as ultrastructural observations revealed stress signs after treatment with 20 and 30 µg O3, thus designating 10 µg O3 as the optimal concentration in combining cell safety and efficient antioxidant and immune response in our in vitro system. These data offer novel evidence of the fine regulatory role played by the oxidative stress level in the hormetic response of T lymphocytes to O2-O3 administration.

The in vitro models are receiving growing attention in studies on skin permeation, penetration, and irritancy, especially for the preclinical development of new transcutaneous drugs. However, synthetic membranes or cell cultures are unable to effectively mimic the permeability and absorption features of the cutaneous barrier. The use of explanted skin samples maintained in a fluid dynamic environment would make it possible for an in vitro experimentation closer to in vivo physiological conditions. To this aim, in the present study, we have modified a bioreactor designed for cell culture to host explanted skin samples. The preservation of the skin was evaluated by combining light, transmission, and scanning electron microscopy, for the histo/cytological characterization, with nuclear magnetic resonance spectroscopy, for the identification in the culture medium of metabolites indicative of the functional state of the explants. Our morphological and metabolomics results demonstrated that fluid dynamic conditions ameliorate significantly the structural and functional preservation of skin explants in comparison with conventional culture conditions. Our in vitro system is, therefore, reliable to test novel therapeutic agents intended for transdermal administration in skin samples from biopsies or surgical materials, providing predictive information suitable for focused in vivo research and reducing animal experimentation.

Colloidally stable nanoparticles-based magnetic agents endowed with very high relaxivity and specific absorption rate are extremely desirable for efficient magnetic resonance imaging and magnetic hyperthermia, respectively. Here, we report a water dispersible magnetic agent consisting of zinc-doped superparamagnetic iron oxide nanoparticles (i.e., Zn-SPIONs) of 15 nm size with high saturation magnetization coated with an amphiphilic polymer for effective magnetic resonance imaging and magnetic hyperthermia of glioblastoma cells. These biocompatible polymer-coated Zn-SPIONs had 24 nm hydrodynamic diameter and exhibited high colloidal stability in various aqueous media, very high transverse relaxivity of 471 mM−1 s−1, and specific absorption rate up to 743.8 W g−1, which perform better than most iron oxide nanoparticles reported in the literature, including commercially available agents. Therefore, using these polymer-coated Zn-SPIONs even at low concentrations, T2-weighted magnetic resonance imaging and moderate magnetic hyperthermia of glioblastoma cells under clinically relevant magnetic field were successfully implemented. In addition, the results of this in vitro study suggest the superior potential of Zn-SPIONs as a theranostic nanosystem for brain cancer treatment, simultaneously acting as a contrast agent for magnetic resonance imaging and a heat mediator for localized magnetic hyperthermia.

A small number of fluorinated 7-phenyl-pyrroloquinolinone (7-PPyQ) derivatives was synthesized in an attempt to improve the metabolic stability of 3N-ethyl-7-PPyQ and 3N-benzoyl-7-PPyQ. The possible impacts of the fluorine-hydrogen isosterism on both biological activity and metabolic stability were evaluated. Introduction of a fluorine atom in the 2 or 3 position of the 7-phenyl ring yielded the 7-PPyQ derivatives 12, 13 and 15, which showed potent cytotoxicity (low micromolar and sub-nanomolar GI50s) both in human leukemic and solid tumor cell lines. None of them induced significant cell death in quiescent and proliferating human lymphocytes. Moreover, 12, 13 and 15 exhibited remarkable cytotoxic activity in the multidrug-resistant cell line CEMVbl100, suggesting that they are not substrates for P-glycoprotein. All compounds inhibited tubulin assembly and the binding of [3H]colchicine to tubulin, with the best activity occurring with compound 15. Mechanistic studies carried out on compound 12 indicated that it caused (a) a strong G2/M arrest; (b) apoptosis in a time- and concentration-dependent manner; (c) a significant production of ROS (in good agreement with the observed mitochondrial depolarization); (d) caspase-3 and poly (ADP-ribose) polymerase activation; and (e) a decrease in the expression of anti-apoptotic proteins. In vivo experiments in a murine syngeneic tumor model demonstrated that compounds 12 and 15 significantly reduced tumor mass at doses four times lower than that required for the reference compound combretastatin A-4 phosphate. Neither monofluorination of the 7-phenyl ring of 3N-ethyl-7-PPyQ nor replacement of the benzoyl function of 3N-benzoyl-7-PPyQ with a 2-fluorobenzoyl moiety led to any improvement in the metabolic stability.

During last years, evidence has been provided on the involvement of overweight and obesity in the pathogenesis and aggravation of several life-threatening diseases. Here, we demonstrate that, under appropriate administration conditions, polyhedral iron oxide nanoparticles are efficiently and safely taken up by 3T3 cell line-derived adipocytes (3T3 adipocytes) in vitro. Since these nanoparticles proved to effectively produce heat when subjected to alternating magnetic field, 3T3 adipocytes were submitted to superparamagnetic iron oxide nanoparticles-mediated hyperthermia treatment (SMHT), with the aim of modulating their lipid content. Notably, the treatment resulted in a significant delipidation persisting for at least 24 h, and in the absence of cell death, damage or dedifferentiation. Interestingly, transcript expression of adipose triglyceride lipase (ATGL), a key gene involved in canonical lipolysis, was not modulated upon SMHT, suggesting the involvement of a novel/alternative mechanism in the effective lipolysis observed. By applying the same experimental conditions successfully used for 3T3 adipocytes, SMHT was able to induce delipidation also in primary cultures of human adipose-derived adult stem cells. The success of this pioneering approach in vitro opens promising perspectives for the application of SMHT in vivo as an innovative safe and physiologically mild strategy against obesity, potentially useful in association with balanced diet and healthy lifestyle.

The thiol or sulfhydryl group, as part of low molecular weight non-peptide biomolecules, as well as part of the cysteine residues in peptides and proteins, is known to play extremely important roles in several aspects of cellular function. Glutathione (γ-Glu-Cys-Gly; GSH) is the most abundant thiol-containing peptide in mammals, being present intracellularly in the low millimolar concentration range, but only in the low micromolar concentration range in the majority of extracellular fluids. Notably, intracellular levels of GSH have been found to be significantly upregulated in a number of human cancers, a phenomenon thought to contribute, in concert with overexpression of some GSHassociated enzymes, to the development of tumor cell chemo- and radioresistance. On the other hand, various natural and synthetic chemical entities of different sizes show significant cytotoxic activity only upon interaction with a thiol, and can therefore exploit the GSH-rich intracellular environment of tumors. This review article attempts to summarize the current structural and pharmacological knowledge in the field of thiol-activated anticancer agents, with a focus on the mechanism(s) of their activation. Even though a great part of the available thiol-activated anticancer compounds is still in the preclinical phase of testing, some of them are undergoing trials in cancer patients.

Explanted organs and tissues represent suitable experimental systems mimicking the functional and structural complexity of the living organism, with positive ethical and economic impact on research activities. However, their preservation in culture is generally limited, thus hindering their application as experimental models for biomedical research. In the present study, we investigated the potential of an innovative fluid dynamic culture system to improve the structural preservation in vitro of explanted mouse skeletal muscles (soleus). We used light and transmission electron microscopy to compare the morphological features of muscles maintained either in multiwell plates under conventional conditions or in a bioreactor mimicking the flow of physiological fluids. Our results demonstrate that fluid dynamic conditions markedly slowed the progressive structural deterioration of the muscle tissue occurring during the permanence in the culture medium, prolonging the preservation of some organelles such as mitochondria up to 48 h.

Background Systemic Sclerosis (SSc) is an autoimmune disorder frequently affected by an interstitial lung involvement (ILD) that significantly deteriorates long term outcomes. In previous experiments we proved that specifically engineered gold-nanoparticles (GNP) loaded with imatinib and targeted with an anti CD44 Ab (GNP-HCim) significantly inhibited proliferation and induced apoptosis of fibroblast-like cells derived from ILD-SSc patients [1]. In vitro, GNP-HCim showed higher efficacy compared to the drug alone. Objectives To demonstrate in vivo the efficacy of GNP-HCim in ameliorating bleomycin-induced lung fibrosis Methods Eight-week-old C57BL6 male mice (n=8/group) were assigned to either: (1) controls receiving intratracheal aereosolization of saline solution and unloaded functionalised GNP (GNP-HC); (2) mice treated with intratracheal instillation of bleomycin (50 uL) on day 0 and GNP-HC; (3) mice treated with bleomycin on day 0 plus GNP-HCim; (4) mice treated with bleomycin plus intraperitoneal (i.p.) Imatinib (50 mg/kg, once daily). GNP-HC or GNP-HCim were administered by intratracheal instillation on day 10–15–20–25 and 3 h before culling. All mice were sacrificed on day 28. Lung specimens were analysed by electron microscopy, immunohistochemistry and immunofluorescence (IF). Data were evaluated by 2 blind observers and analysed with GraphPrism software for statistics. Results The administration of imatinib i.p or via GNP-HC reduced pathologic changes of the lungs as evaluated by the Lung Injury score and the Ashcroft score (p Conclusions In the experimental model of bleomycin-induced lung fibrosis imatinib delivered to lungs through inhalation of anti CD44 targeted GNP was as effective as imatinib administered by i.p. route. These data favour the use of GNP in the development of new therapeutic approaches to SSc-ILD, which might be associated to a lower toxicity and side effects of systemic treatment. References Cova E, Ann rheum Dis 2016, 75(Suppl2): 61. Disclosure of Interest None declared

A small library of 7-pyrrolo[3,2-f]quinolinones was obtained by introducing benzoyl, sulfonyl and carbamoyl side chains at the 3-N position, and their cytotoxicity against a panel of leukemic and solid tumor cell lines was evaluated. Most of them showed high antiproliferative activity with GI50s ranging from micro-to sub-nanomolar values, and these values correlated well with the inhibitory activities of the compounds against tubulin polymerization. Based on a recently proposed colchicine bind site inhibitors (CBSIs) pharmacophore, the interactions of the novel 7-PPyQs at the colchicine domain were rationalized. The most active compounds (4a and 4b) did not induce significant cell death in normal human lymphocytes, suggesting that the compounds may be selective against cancer cells. In particular, 4a was a potent inducer of apoptosis in both the HeLa and Jurkat cell lines. On the other hand, the sulfonyl derivative 4b exhibited a lower potency in comparison with 4a. With both compounds, induction of apoptosis was associated with dissipation of the mitochondrial transmembrane potential and production of reactive oxygen species, suggesting that cells treated with the compounds followed the intrinsic pathway of apoptosis.

Structural and functional MRI was used in conjunction with computerized electron microscopy morphometry to study changes 2 h, 24 h and 3 days after 4-aminopyridine-induced seizures lasting 2 h in rats. T2 (relaxation time) values showed changes throughout the cerebral cortex, hippocampus, amygdala and medial thalamus, with a different temporal progression, showing a complete recovery only after 3 days. Two hours after seizures, the apparent diffusion coefficient was decreased throughout the brain compared to control animals, and a further decrease was evident 24 h after seizures. This was followed by a complete recovery at 3 days post-seizures. Functional MRI was performed using regional cerebral blood volume (rCBV) maps. The rCBV was increased shortly after convulsions (2 h) in all structures investigated, with a significant return to baseline values in the parietal cortex and hippocampus, but not in the medial thalamic nuclei, 24 h after seizure onset. No rCBV alterations were detected 3 days after seizures. Electron microscopy of tissue samples of parietal neocortex and hippocampus revealed prominent astrocytic swelling 2 h post-convulsions which decreased thereafter gradually. In conclusion, this experiment reports for the first time structural and functional brain alterations, lasting several hours, in 4-aminopyridine-treated rats after seizure onset. MRI approach combined with histological and ultrastructural analysis provided a clarification of the mechanisms involved in the brain acute response to ictal activity.

Biocompatible highly bright silica nanoparticles were designed, prepared and tested in small living organisms for both in vivo and ex vivo imaging. The results that we report here demonstrate that they are suitable for optical imaging applications as a possible alternative to commercially available fluorescent materials including quantum dots. Moreover, the tunability of their photophysical properties, which was enhanced by the use of different dyes as doping agents, constitutes a very important added value in the field of medical diagnostics.

Spontaneous light emission from living animals can overcome the investigated light signals in small animal luminescence imaging. Despite autofluorescence emission is well studied the spontaneous luminescence background is less known and its importance is growing due to the new born imaging techniques like Cerenkov Luminescence Imaging and Radionuclide Luminescence Imaging in which faint sources are often involved. In order to investigate the spontaneous emission we studied the background luminescence in vivo from health Nu/Nu mice in optical imaging acquisitions and we related it with the optical properties of the diet of the animals. In particular luminescence images of mice feed with normal diet used in animal facilities were acquired using a commercial optical imager. The intensity and the spectral features of the luminescence emission from the animal surface after sunshine exposition and after normal lighting laboratory conditions were measured. The same was done with the pellets of food used to feed the animals. We found a background emission from the entire animal surface and localized light sources in the abdominal/lumbar region. Their intensity can be modulated by the light exposition of the animals before the imaging session and decreases along the time when they are put in darkness. The comparison of the luminescence time decay of animals and pellets suggests that the light sources are related to the persistent luminescence of the molecules contained in the food. So ambient exposure before imaging is important for luminescence imaging in order to keep down the background. The optical properties of food are also important and it necessary to check them before to feed the animals not only in fluorescence imaging but also in luminescence imaging.

Object The work is aimed to develop a murine model of rectal cancer, which could be used to monitor lymph node metastasis development by magnetic resonance imaging (MRI) and optical imaging (OI) techniques. Subjects and methods Ht-29 cancer cells were directly injected into the submucosal layer of the rectum of athymic nude mice using trans-anal rectal cancer cell injection (TARCI). Thirty-six mice were inoculated with 10 × 105 cells and five mice were treated with sterile phosphate buffer solution. One to 4 weeks after cell injection, tumor growth was evaluated in vivo using T2-weighted MRI at 4.7T. A further group of animal (n = 6) treated with ht-29_luc cells, with the same protocol, was monitored by optical imaging. In both groups, the presence of the primary tumor and of lymph nodes metastasis was confirmed by histology. Results In all animals, primary tumors were detectable by MRI, 1 week from TARCI. After 4 weeks primary tumors showed a mean longitudinal diameter of about 2 cm. All animals developed regional lymph node metastases. Others organs (e.g. lung or liver) were not affected. In fat-suppressed, T2-weighted MRI, lymph nodes appeared as small areas characterized by hyper-intense signal compared to muscle. OI permitted evaluation of the primary tumor growth in perineal region. Conclusions TARCI of ht-29 cells into the rectum of nude mice is a feasible way to obtain a easily reproducible model of regional lymph node metastases could be monitored by magnetic resonance and optical imaging techniques.

The main purpose of this work was to investigate both in vitro and in vivo Cherenkov radiation (CR) emission coming from 18F and 32P. The main difference between 18F and 32P is mainly the number of the emitted light photons, more precisely the same activity of 32P emits more CR photons with respect to 18F. In vitro results obtained by comparing beta counter measurements with photons average radiance showed that Cherenkov luminescence imaging (CLI) allows quantitative tracer activity measurements. In order to investigate in vivo the CLI approach, we studied an experimental xenograft tumor model of mammary carcinoma (BB1 tumor cells). Cherenkov in vivo dynamic whole body images of tumor bearing mice were acquired and the tumor tissue time activity curves reflected the well-known physiological accumulation of 18F-FDG in malignant tissues with respect to normal tissues. The results presented here show that it is possible to use conventional optical imaging devices for in vitro or in vivo study of beta emitters.

In this reply, we address the criticisms by Drs Mitchell, Gill and Cherry (Mitchell et al 2010 Phys. Med. Biol. 55 L43–4) regarding our paper recently published in Physics Medicine and Biology (Spinelli et al 2010 Phys. Med. Biol. 55 483–95). In our paper we showed that it is possible to acquire Cerenkov radiation images of mice injected with 18F-FDG using an optical imaging device. We also showed two different approaches that can be used in order to estimate the depth of the Cerenkov radiation source inside the mouse. More precisely, we will discuss the criticisms regarding the proposed model of the Cerenkov radiation spectrum for positron emitters and the estimation methods of the radiation source depth by providing further experimental results.

In vivo optical imaging instruments are generally devoted to the acquisition of light coming from fluorescence or bioluminescence processes. Recently, an instrument was conceived with radioisotopic detection capabilities (Kodak in Vivo Multispectral System F) based on the conversion of x-rays from the phosphorus screen. The goal of this work is to demonstrate that an optical imager (IVIS 200, Xenogen Corp., Alameda, USA), designed for in vivo acquisitions of small animals in bioluminescent and fluorescent modalities, can even be employed to detect signals due to radioactive tracers. Our system is based on scintillator crystals for the conversion of high-energy rays and a collimator. No hardware modifications are required. Crystals alone permit the acquisition of photons coming from an in vivo 20 g nude mouse injected with a solution of methyl diphosphonate technetium 99 metastable (Tc99m-MDP). With scintillator crystals and collimators, a set of measurements aimed to fully characterize the system resolution was carried out. More precisely, system point spread function and modulation transfer function were measured at different source depths. Results show that system resolution is always better than 1.3 mm when the source depth is less than 10 mm. The resolution of the images obtained with radioactive tracers is comparable with the resolution achievable with dedicated techniques. Moreover, it is possible to detect both optical and nuclear tracers or bi-modal tracers with only one instrument.

Mesenchymal stem cells (MSCs) represent a promising therapeutic approach for neurological autoimmune diseases; previous studies have shown that treatment with bone marrow-derived MSCs induces immune modulation and reduces disease severity in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Here we show that intravenous administration of adipose-derived MSCs (ASCs) before disease onset significantly reduces the severity of EAE by immune modulation and decreases spinal cord inflammation and demyelination. ASCs preferentially home into lymphoid organs but also migrates inside the central nervous system (CNS). Most importantly, administration of ASCs in chronic established EAE significantly ameliorates the disease course and reduces both demyelination and axonal loss, and induces a Th2-type cytokine shift in T cells. Interestingly, a relevant subset of ASCs expresses activated α4 integrins and adheres to inflamed brain venules in intravital microscopy experiments. Bioluminescence imaging shows that α4 integrins control ASC accumulation in inflamed CNS. Importantly, we found that ASC cultures produce basic fibroblast growth factor, brain-derived growth factor, and platelet-derived growth factor-AB. Moreover, ASC infiltration within demyelinated areas is accompanied by increased number of endogenous oligodendrocyte progenitors. In conclusion, we show that ASCs have clear therapeutic potential by a bimodal mechanism, by suppressing the autoimmune response in early phases of disease as well as by inducing local neuroregeneration by endogenous progenitors in animals with established disease. Overall, our data suggest that ASCs represent a valuable tool for stem cell–based therapy in chronic inflammatory diseases of the CNS.

Objective: We studied ob/ob and wild-type (WT) mice to characterize the adipose tissues depots and other visceral organs and to establish an experimental paradigm for in vivo phenotyping. Research Methods and Procedures: An in vivo evaluation was conducted using magnetic resonance imaging and 1H-magnetic resonance spectroscopy (1H-MRS). We used T1-weighted images and three-dimensional spin echo T1-weighted images for the morphological analysis and 1H-MRS spectra on all body mass, as well as 1H-MRS spectra focalized on specific lipid depots [triglyceride (TG) depots] for a molecular analysis. Results: In ob/ob mice, three-dimensional evaluation of the trunk revealed that ∼64% of the volume consists of white adipose tissue, which is 72% subcutaneous and 28% visceral. In vivo 1H-MRS showed that 20.00 ± 6.92% in the WT group and 58.67 ± 6.65% in the ob/ob group of the total proton content is composed of TG protons. In in vivo-localized spectra of ob/ob mice, we found a polyunsaturation degree of 0.5247 in subcutaneous depots. In the liver, we observed that 48.7% of the proton signal is due to water, whereas in the WT group, the water signal amounted to 82.8% of the total proton signal. With the sequences used, the TG amount was not detectable in the brain or kidneys. Discussion: The present study shows that several parameters can be obtained by in vivo examination of ob/ob mice by magnetic resonance imaging and 1H-MRS and that the accumulated white adipose tissue displays low polyunsaturation degree and low hydrolipidic ratio. Relevant anatomical alterations observed in urinary and digestive apparatuses should be considered when ob/ob mice are used in experimental paradigms.

This preliminary study describes magnetic resonance imaging (MRI) data on the effects of sub-chronic nicotine administration in rats. Nicotine 0.4 mg/kg s.c. free base was given once a day for 4 days to Wistar adult male rats. On day 5, anaesthetized subjects were observed using an MRI tomography system. Regional cerebral blood volume (rCBV) and transversal relaxation time (T2) MRI parameters were measured. Nicotine treatment increased T2 values, with a significant effect in the cingulate cortex. A trend to increase was also observed in the prefrontal cortex and nucleus accumbens. Similarly, the effect of nicotine on rCBV was a significant increase in values compared to saline treatment. Post hoc analysis showed a significant effect of nicotine in the prefrontal cortex, cingulate cortex, mediodorsal thalamus and lateral posterior thalamus. This study showed for the first time that sub-chronic nicotine administration can induce changes in MRI pattern which are (i) similar to human MRI studies, and (ii) common to those described for markers of neuronal metabolic activation in corticolimbic brain regions known to be involved in nicotine dependence.

Contrast-enhanced ultrasound (CEUS) is an advanced approach to in vivo assessment of tumor vascularity and is being increasingly adopted in clinical oncology. It is based on 1- to 10 μm-sized gas microbubbles, which can cross the capillary beds of the lungs and are effective echo enhancers. It is known that high cell density, high transendothelial fluid exchange, and poorly functioning lymphatic circulation all provoke solid stress, which compresses vessels and drastically reduces tumor blood flow. Given their size, we supposed that the perfusion of microbubbles is affected by anatomic features of tumor vessels more than are contrast agents traditionally used in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Here, we compared dynamic information obtained from CEUS and DCE-MRI on two experimental tumor models exhibiting notable differences in vessel anatomy. We found that tumors with small, flattened vessels show a much higher resistance to microbubble perfusion than to MRI contrast agents, and appear scarcely vascularized at CEUS examination, despite vessel volume adequate for normal function. Thus, whereas CEUS alone could induce incorrect diagnosis when tumors have small or collapsed vessels, integrated analysis using CEUS and DCE-MRI allows in vivo identification of tumors with a vascular profile frequently associated with malignant phenotypes.