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Despite the tremendous advancements made in cell tracking, in vivo imaging and volumetric analysis, it remains difficult to accurately quantify the number of infused cells following stem cell therapy, especially at the single cell level, mainly due to the sensitivity of cells. In this study, we demonstrate the utility of both liquid scintillator counter (LSC) and accelerator mass spectrometry (AMS) in investigating the distribution and quantification of radioisotope labeled adipocyte derived mesenchymal stem cells (AD-MSCs) at the single cell level after intravenous (IV) transplantation. We first show the incorporation of 14 C-thymidine (5 nCi/ml, 24.2 ng/ml) into AD-MSCs without affecting key biological characteristics. These cells were then utilized to track and quantify the distribution of AD-MSCs delivered through the tail vein by AMS, revealing the number of AD-MSCs existing within different organs per mg and per organ at different time points. Notably, the results show that this highly sensitive approach can quantify one cell per mg which effectively means that AD-MSCs can be detected in various tissues at the single cell level. While the significance of these cells is yet to be elucidated, we show that it is possible to accurately depict the pattern of distribution and quantify AD-MSCs in living tissue. This approach can serve to incrementally build profiles of biodistribution for stem cells such as MSCs which is essential for both research and therapeutic purposes.

Precise targeting with minimal side effects is of particular interest for personalized medicine, although it remains a challenge. Herein, we demonstrate precision photodynamic therapy (PDT) utilizing human mesenchymal stem cells (MSCs) as cellular vehicles to deliver a new activatable photosensitizer (PcS). In vivo real-time optical imaging tests indicated that PcS-loaded MSCs possess excellent tumor-homing properties. More importantly, dye transfer assays confirm that MSCs precisely transfer PcS into human colon cancer cells (HCT116) via the "bystander effect." Upon localized light irradiation, the growth of intraperitoneal xenograft tumors was significantly inhibited by the photodynamic effect. These findings represent a promising strategy for precise oncotherapy., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Risk of teratoma formation during human pluripotent stem cell (hPSC)-based cell therapy is one of the technical hurdles that must be resolved before their wider clinical application. To this end, selective ablation of undifferentiated hPSCs has been achieved using small molecules whose application should be safe for differentiated cells derived from the hPSCs., Objective: However, the functional safety of such small molecules in the cells differentiated from hPSCs has not yet been extensively validated., Method: We used the survivin inhibitor YM155, which induced highly selective cell death of hPSCs for ablating undifferentiated hESCs after differentiation to human mesenchymal stem cells (hMSCs) and examined whether hMSCs remained fully functional after being exposed by YM155., Results: We demonstrated that human mesenchymal stem cells (hMSCs) derived from human embryonic stem cells (hESCs) remained fully functional in vitro and in vivo, while hESCs were selectively ablated., Conclusion: These results suggest that a single treatment with YM155 after differentiation of hMSCs would be a valid approach for teratoma-free cell therapy., (Copyright © 2017. Published by Elsevier B.V.)

Background: Rotator cuff tears (RCTs) induce chronic muscle weakness and shoulder pain. Treatment of RCT using surgery or drugs causes lipid infiltration and fibrosis, which hampers tissue regeneration and complete recovery. The pluripotent stem cell-derived multipotent mesenchymal stem cells (M-MSCs) represent potential candidate next-generation therapies for RCT. Methods: The difference between M-MSCs and adult-MSCs was compared and analyzed using next-generation sequencing (NGS). In addition, using a rat model of RCT, the muscle recovery ability of M-MSCs and adult-MSCs was evaluated by conducting a histological analysis and monitoring the cytokine expression level. Results: Using NGS, it was confirmed that M-MSC was suitable for transplantation because of its excellent ability to regulate inflammation that promotes tissue repair and reduced apoptosis and rejection during transplantation. In addition, while M-MSCs persisted for up to 8 weeks in vivo, they significantly reduced inflammation and adipogenesis-related cytokine levels in rat muscle. Significant differences were also confirmed in histopathological remission. Conclusions: M-MSCs remain in the body longer to modulate immune responses in RCTs and have a greater potential to improve muscle recovery by alleviating acute inflammatory responses. This indicates that M-MSCs could be used in potential next-generation RCT therapies. [ABSTRACT FROM AUTHOR]

Despite the tremendous advancements made in cell tracking, in vivo imaging and volumetric analysis, it remains difficult to accurately quantify the number of infused cells following stem cell therapy, especially at the single cell level, mainly due to the sensitivity of cells. In this study, we demonstrate the utility of both liquid scintillator counter (LSC) and accelerator mass spectrometry (AMS) in investigating the distribution and quantification of radioisotope labeled adipocyte derived mesenchymal stem cells (AD-MSCs) at the single cell level after intravenous (IV) transplantation. We first show the incorporation of 14C-thymidine (5 nCi/ml, 24.2 ng/ml) into AD-MSCs without affecting key biological characteristics. These cells were then utilized to track and quantify the distribution of AD-MSCs delivered through the tail vein by AMS, revealing the number of AD-MSCs existing within different organs per mg and per organ at different time points. Notably, the results show that this highly sensitive approach can quantify one cell per mg which effectively means that AD-MSCs can be detected in various tissues at the single cell level. While the significance of these cells is yet to be elucidated, we show that it is possible to accurately depict the pattern of distribution and quantify AD-MSCs in living tissue. This approach can serve to incrementally build profiles of biodistribution for stem cells such as MSCs which is essential for both research and therapeutic purposes. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is an inflammatory skin disease caused by an imbalance between Th1 and Th2 cells. AD patients suffer from pruritus, excessive dryness, red or inflamed skin, and complications such as sleep disturbances and depression. Although there are currently many AD treatments available there are insufficient data on their long-term stability and comparative effects. Moreover, they have limitations due to various side effects. Multipotent mesenchymal stem cells (M-MSCs) might have potential for next-generation AD therapies. MSCs are capable of immune function regulation and local inflammatory response inhibition. M-MSCs, derived from human embryonic stem cells (hESC), additionally have a stable supply. In L507 antibody array, M-MSCs generally showed similar tendencies to bone marrow-derived mesenchymal stem cells (BM-MSCs), although the immunoregulatory function of M-MSCs seemed to be superior to BM-MSCs. Based on the characteristics of M-MSCs on immunoregulatory functions, we tested a M-MSC conditioned media concentrate (MCMC) in mice with AD lesions on their dorsal skin. MCMC significantly decreased RNA expression levels of inflammatory cytokines in the mouse dorsal skin. It also suppressed serum IgE levels. In addition, significant histopathologic alleviation was identified. In conclusion, secretions of M-MSCs have the potential to effectively improve AD-related inflammatory lesions. M-MSCs showed potential for use in next-generation AD treatment. [ABSTRACT FROM AUTHOR]

Background: Vitrification is the most promising technology for successful cryopreservation of living organisms without ice crystal formation. However, high concentrations (up to ~ 6–8 M) of cryoprotective agents (CPAs) used in stem cell induce osmotic and metabolic injuries. Moreover, the application of conventional slow-freezing methods to cultures of 3-D organoids of stem cells in various studies, is limited by their size. Results: In this study, we evaluated the effect of high concentrations of CPAs including cytotoxicity and characterized human mesenchymal stem cell (MSC) at single cell level. The cell viability, cellular damage, and apoptotic mechanisms as well as the proliferation capacity and multipotency of cells subjected to vitrification were similar to those in the slow-freezing group. Furthermore, we identified the possibility of vitrification of size-controlled 3-D spheroids for cryopreservation of organoid with high survivability. Conclusions: Our results demonstrate successful vitrification of both single cell and spheroid using high concentration of CPAs in vitro without cytotoxicity. [ABSTRACT FROM AUTHOR]

Adipose-derived mesenchymal stem cells (AD-MSCs) have been studied as desirable cell sources for regenerative medicine and therapeutic application. However, it has still remained a challenge to obtain enough adequate and healthy cells in large quantities. To overcome this limitation, various biomaterials have been used to promote expansion of MSCs in vitro. Recently, hexanoyl glycol chitosan (HGC) was introduced as a new biomaterial for various biomedical applications, in particular 3D cell culture, because of its biodegradability, biocompatibility, and other promising biofunctional properties. In this study, the effect of HGC on the proliferation of AD-MSCs was examined in vitro, and its synergistic effect with basic fibroblast growth factor (bFGF), which has been widely used to promote proliferation of cells, was evaluated. We found that the presence of HGC increased the proliferative capacity of AD-MSCs during long-term culture, even at low concentrations of bFGF. Furthermore, it suppressed the expression of senescence-related genes and improved the mitochondrial functionality. Taken all together, these findings suggest that the HGC demonstrate a potential for sustained growth of AD-MSCs in vitro. [ABSTRACT FROM AUTHOR]