Considerable progress has been made on the development of adipose-derived stem/stromal cells (ASCs) as pro-angiogenic therapeutic tools. However, variable clinical results highlight the need for devising strategies to enhance their therapeutic efficacy. Since ASCs proliferate and stabilize newly formed vessels during the angiogenic phase of adipose tissue formation, we hypothesized that mimicking an angiogenic milieu during culture of ASCs would enhance their capacity to support endothelial cell survival and angiogenesis. To test this, we compared the effect of an endothelial growth medium (EGM-2) and conventional media (αMEM) on the progenitor and angiogenic properties of ASCs. ASCs cultured in EGM-2 (ASC-EGM) displayed the highest clonogenic efficiency, proliferative potential and multilineage potential. After co-culture under growth factor starvation, only ASC-EGM attenuated luciferase-expressing human umbilical vein endothelial cells (HUVEC) apoptosis and supported the formation of endothelial cords in a dose-dependent manner. These effects were recapitulated by the conditioned medium of ASC-EGM, which displayed a 100-fold higher expression of hepatocyte growth factor in comparison with ASC-αMEM. Next, HUVEC and ASCs were co-transplanted subcutaneously into immunodeficient mice, and the survival of HUVEC was monitored by bioluminescent imaging. After 60 days, the survival of HUVEC transplanted alone was equivalent to that of HUVEC co-transplanted with ASC-αMEM (15.0 ± 0.7 vs. 13.0 ± 0.5%). Strikingly, co-transplantation with ASC-EGM increased HUVEC survival to 105.0 ± 3.5%, and the resulting organoids displayed functional vasculature with the highest human-derived vascular area. These findings demonstrate that pre-conditioning of ASCs in endothelial growth medium augment their pro-angiogenic properties and could enhance their therapeutic efficacy against ischemic diseases.

Magnetic hyperthermia (MHT) has been shown as a promising alternative therapy for glioblastoma (GBM) treatment. This study consists of three parts: The first part evaluates the heating potential of aminosilane-coated superparamagnetic iron oxide nanoparticles (SPIONa). The second and third parts comprise the evaluation of MHT multiple applications in GBM model, either in vitro or in vivo. The obtained heating curves of SPIONa (100 nm, +20 mV) and their specific absorption rates (SAR) stablished the best therapeutic conditions for frequencies (309 kHz and 557 kHz) and magnetic field (300 Gauss), which were stablished based on three in vitro MHT application in C6 GBM cell line. The bioluminescence (BLI) signal decayed in all applications and parameters tested and 309 kHz with 300 Gauss have shown to provide the best therapeutic effect. These parameters were also established for three MHT applications in vivo, in which the decay of BLI signal correlates with reduced tumor and also with decreased tumor glucose uptake assessed by positron emission tomography (PET) images. The behavior assessment showed a slight improvement after each MHT therapy, but after three applications the motor function displayed a relevant and progressive improvement until the latest evaluation. Thus, MHT multiple applications allowed an almost total regression of the GBM tumor in vivo. However, futher evaluations after the therapy acute phase are necessary to follow the evolution or tumor total regression. BLI, positron emission tomography (PET), and spontaneous locomotion evaluation techniques were effective in longitudinally monitoring the therapeutic effects of the MHT technique.

BACKGROUND Mesenchymal stem cells (MSCs) have been widely tested for their therapeutic efficacy in the ischemic brain and have been shown to provide several benefits. A major obstacle to the clinical translation of these therapies has been the inability to noninvasively monitor the best route, cell doses, and collateral effects while ensuring the survival and effective biological functioning of the transplanted stem cells. Technological advances in multimodal imaging have allowed in vivo monitoring of the biodistribution and viability of transplanted stem cells due to a combination of imaging technologies associated with multimodal nanoparticles (MNPs) using new labels and covers to achieve low toxicity and longtime residence in cells. AIM To evaluate the sensitivity of triple-modal imaging of stem cells labeled with MNPs and applied in a stroke model. METHODS After the isolation and immunophenotypic characterization of human bone marrow MSCs (hBM-MSCs), our team carried out lentiviral transduction of these cells for the evaluation of bioluminescent images (BLIs) in vitro and in vivo . In addition, MNPs that were previously characterized (regarding hydrodynamic size, zeta potential, and optical properties), and were used to label these cells, analyze cell viability via the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay and BLI analysis, and quantify the internalization process and iron load in different concentrations of MNPs via magnetic resonance imaging (MRI), near-infrared fluorescence (NIRF), and inductively coupled plasma-mass spectrometry (ICP-MS). In in vivo analyses, the same labeled cells were implanted in a sham group and a stroke group at different times and under different MNP concentrations (after 4 h or 6 d of cell implantation) to evaluate the sensitivity of triple-modal images. RESULTS hBM-MSC collection and isolation after immunophenotypic characterization were demonstrated to be adequate in hBM samples. After transduction of these cells with luciferase (hBM-MSC Luc ), we detected a maximum BLI intensity of 2.0 x 10 8 photons/s in samples of 10 6 hBM-MSCs. Analysis of the physicochemical characteristics of the MNPs showed an average hydrodynamic diameter of 38.2 ± 0.5 nm, zeta potential of 29.2 ± 1.9 mV and adequate colloidal stability without agglomeration over 18 h. The signal of iron load internalization in hBM-MSC Luc showed a close relationship with the corresponding MNP-labeling concentrations based on MRI, ICP-MS and NIRF. Under the highest MNP concentration, cellular viability showed a reduction of less than 10% compared to the control. Correlation analysis of the MNP load internalized into hBM-MSC ...

The primary objective of this study is to monitor tumor growth by using image techniques and behavioral testing through general and specific motor activities (spontaneous movements and gait). Our sample includes male Wistar rats, 2 months old and weighing 250–300 g, that is categorized into three groups: control, sham, and experimental. The experimental group was anesthetized; the C6 cells with luciferase expression that were suspended in a culture medium were implanted into the right frontoparietal cortex of the rats. The sham group received implant only with culture medium without cells. Images and behavioral tests were evaluated at base time and at 7, 14, 21, and 28 days after induced tumor growth analysis. The tumor volume measured by magnetic resonance imaging (MRI) and quantitative bioluminescence imaging (BLI) signal showed a correlation coefficient of r = 0.96. The MRI showed that the mean tumor volume increased by approximately 10, 26, and 49 times according to a comparison of tumor volume on the seventh day with 14, 21, and 28 days, respectively. The quantification of the BLI signal was (4.12 ± 2.01) x 108, (8.33 ± 3.12) x 108, (28.43 ± 6.32) x 108, and (63.02 ± 10.53) x 108 photons/s at the seventh, fourteenth, twenty-first, and twenty-eighth day, respectively. After 14 days of tumor induction, both behavioral tests showed significant differences between tumor and sham or control groups. Our study showed a high correlation between MRI and BLI for tumor growth monitoring with complement aspects analysis in tumor volume. In addition, functional behavioral analysis displayed sensitivity to monitor tumor growth, as well as to detect early significant changes between groups, primarily in the tumor group. The results of gait analysis were more sensitive than general motor analysis.