Is the intravascular administration of mesenchymal stem cells safe? Mesenchymal stem cells and intravital microscopy.
ABSTRACT We investigated the kinetics of human mesenchymal stem cells (MSCs) after intravascular administration into SCID mouse cremaster vasculature by intravital microscopy. MSCs were injected into abdominal aorta through left femoral artery at two different concentrations (1 x 10(6) or 0.2 x 10(6) cell). Arterial blood velocity decrease by 60 and 18% 1 min after high/low dose MSCs injection respectively. The blood microcirculation was interrupted after 174+/-71 and 485+/-81 s. Intravital microscopy observation and histopathologic analysis of cremaster muscles indicated MSCs were entrapped in capillaries in both groups. 40 and 25% animals died of pulmonary embolism respectively in both high and low MSCs dose groups, which was detected by histopathologic analysis of the lungs. Intraarterial MSCs administration may lead to occlusion in the distal vasculature due to their relatively large cell size. Pulmonary sequestration may cause death in small laboratory animals. MSCs should be used cautiously for intravascular transplantation.
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ABSTRACT: Bioreactors have been widely acknowledged as valuable tools to provide a growth environment for engineering tissues and to investigate the effect of physical forces on cells and cell-scaffold constructs. However, evaluation of the bioreactor environment during culture is critical to defining outcomes. In this study, the performance of a hydrostatic force bioreactor was examined by experimental measurements of changes in dissolved oxygen (O2), carbon dioxide (CO2), and pH after mechanical stimulation and the determination of physical forces (pressure and stress) in the bioreactor through mathematical modeling and numerical simulation. To determine the effect of hydrostatic pressure on bone formation, chick femur skeletal cell-seeded hydrogels were subjected to cyclic hydrostatic pressure at 0-270 kPa and 1 Hz for 1 h daily (5 days per week) over a period of 14 days. At the start of mechanical stimulation, dissolved O2 and CO2 in the medium increased and the pH of the medium decreased, but remained within human physiological ranges. Changes in physiological parameters (O2, CO2, and pH) were reversible when medium samples were placed in a standard cell culture incubator. In addition, computational modeling showed that the distribution and magnitude of physical forces depends on the shape and position of the cell-hydrogel constructs in the tissue culture format. Finally, hydrostatic pressure was seen to enhance mineralization of chick femur skeletal cell-seeded hydrogels.Tissue Engineering Part C Methods 06/2014; · 4.64 Impact Factor
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ABSTRACT: Extracellular vesicle or EV is a term that encompasses all classes of secreted lipid membrane vesicles. Despite being scientific novelties, EVs are gaining importance as a mediator of important physiological and pathological intercellular activities possibly through the transfer of their cargo of protein and RNA between cells. In particular, exosomes, the currently best characterized EVs have been notable for their in vitro and in vivo immunomodulatory activities. Exosomes are nanometer-sized endosome-derived vesicles secreted by many cell types and their immunomodulatory potential is independent of their cell source. Besides immune cells such as dendritic cells, macrophages, and T cells, cancer and stem cells also secrete immunologically active exosomes that could influence both physiological and pathological processes. The immunological activities of exosomes affect both innate and adaptive immunity and include antigen presentation, T cell activation, T cell polarization to regulatory T cells, immune suppression, and anti-inflammation. As such, exosomes carry much immunotherapeutic potential as a therapeutic agent and a therapeutic target.Frontiers in Immunology 01/2014; 5:518.
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ABSTRACT: Hyposalivation is an intractable side‑effect of radiotherapy for head and neck cancer. It is caused by the irreversible loss of acinar cells and decreased saliva secretion. However, this situation severely compromises the quality of life of affected patients. Currently, there is no effective treatment for this condition. In the present study, we developed a novel approach to regenerate the function of the irradiation‑damaged salivary glands using human adipose tissue‑derived stem cell (hADSC) intraglandular transplantation. ZsGreen‑labeled hADSCs were adoptively transferred into Sprague‑Dawley (SD) rat submandibular glands immediately following exposure to 18 Gy irradiation. A higher salivary flow rate (SFR) was observed in the hADSC‑treated group. Tissue improvement, including angiogenesis, anti‑apoptosis and anti‑fibrosis, was detected in the hADSC‑treated glands as compared to the untreated glands. Quantitative reverse transcription PCR (RT-qPCR) revealed a significantly higher expression of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), cyclooxygenase‑2 (COX‑2) and matrix metalloproteinase‑2 (MMP‑2) in the hADSC‑treated rats. Furthermore, immunohistochemical analysis indicated that the hADSCs had differentiated into acinar and ductal cells in the rat submandibular glands. Thus, our results suggest that hADSCs are able to regenerate irradiation‑damaged salivary glands through glandular transplantation.International Journal of Molecular Medicine 07/2014; · 1.96 Impact Factor