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Mesenchymal stem cells are an attractive cell type for cytotherapy in wound healing. The authors recently developed a novel, adipose-tissue-derived, injectable extracellular matrix/stromal vascular fraction gel (ECM/SVF-gel) for stem cell therapy. This study was designed to assess the therapeutic effects of ECM/SVF-gel on wound healing and potential mechanisms. ECM/SVF-gel was prepared for use in nude mouse excisional wound healing model. An SVF cell suspension and phosphate-buffered saline injection served as the control. The expression levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and monocyte chemotactic protein-1 (MCP-1) in ECM/SVF-gel were analyzed at different time points. Angiogenesis (tube formation) assays of ECM/SVF-gel extracts were evaluated, and vessels density in skin was determined. The ECM/SVF-gel extract promoted tube formation in vitro and increased the expression of the angiogenic factors VEGF and bFGF compared with those in the control. The expression of the inflammatory chemoattractant MCP-1 was high in ECM/SVF-gel at the early stage and decreased sharply during the late stage of wound healing. The potent angiogenic effects exerted by ECM/SVF-gel may contribute to the improvement of wound healing, and these effects could be related to the enhanced inflammatory response in ECM/SVF-gel during the early stage of wound healing.

An adipose tissue engineering chamber model of spontaneous adipose tissue generation from an existing fat flap has been described. However, the chamber does not completely fill with adipose tissue in this model. Here, the effect of adipose tissue extract (ATE) on adipose tissue regeneration was investigated. In vitro, the adipogenic and angiogenic capacities of ATE were evaluated using Oil Red O and tube formation assays on adipose-derived stem cells (ASCs) and rat aortic endothelial cells (RAECs), respectively. In vivo, saline or ATE was injected into the adipose tissue engineering chamber 1 week after its implantation. At different time points post-injection, the contents were morphometrically, histologically, and immunohistochemically evaluated, and the expression of growth factors and adipogenic genes was analyzed by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR. With the exception of the baseline control group, in which fat flaps were not inserted into a chamber, the total volume of fat flap tissue increased significantly in all groups, especially in the ATE group. Better morphology and structure, a thinner capsule, and more vessels were observed in the ATE group than in the control group. Expression of angiogenic growth factors and adipogenic markers were significantly higher in the ATE group. ATE therefore significantly promoted adipose tissue regeneration and reduced capsule formation in an adipose tissue engineering chamber model. These data suggest that ATE provides a more angiogenic and adipogenic microenvironment for adipose tissue formation by releasing various cytokines and growth factors that also inhibit capsule formation.

Liposuction aspirates separate into fatty and fluid portions. Cells isolated from the fatty portion are termed processed lipoaspirate (PLA) cells and isolated from the fluid portion termed liposuction aspirate fluid (LAF) cells, both of which contain adipose-derived stromal cells (ASCs). Here, we examined the biological differences between PLA and LAF cells and then tested the differentiation capacity of LAF cells in vivo. The cell surface marker and the multiple differentiation ability of fresh isolated PLA and LAF cells and which from passaged 3-5 were examined in vitro. LAF cells were then incubated in adipogenic medium, stained with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (DiI), mixed with fibrin glue then injected to nude mice; fibrin glue without cells was as a control. Three months later, the transplants were subjected to macroscopic observation and histological analysis. PLA and LAF cells were similar in growth kinetics, morphology, capacity for differentiation, and surface marker profiles. After plating, both PLA and LAF cells showed increased expression of CD29, CD44, CD133 and HLA DR and decreased expression of CD34. In vivo differentiation assay showed the mixture of LAF cells and fibrin glue formed adipose tissue which contained red fluorescent DiI-positive adipocytes. LAF cells can be harvested more easily than PLA cells. The in vivo adipogenic capacity suggested LAF cells would be useful and valuable for cell-based therapies and soft tissue reconstruction., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Autologous fat tissue has been used as a potential filler for soft-tissue defects, despite unpredictable clinical outcomes and low graft survival. Co-transplantation of adipose-derived stem cells (ASCs) is an alternative therapeutic approach to effectively enhance the survival and quality of transplanted fat tissue by increasing neovascularization. Nevertheless, the mechanisms by which ASCs exerted their angiogenic effects remain obscure. ASCs can secrete several angiogenic growth factors, for example vascular endothelial growth factor, hepatocyte growth factor and basic fibroblast growth factor. Hypoxic conditions may promote the proliferation of ASCs and their secretion. However, the differentiation of ASCs into endothelial cells (ECs), pericytes and smooth muscular cells in vivo has not been confirmed. The role of ASCs early after aspirated fat transplantation may be to induce new vessels from the recipient region to grow around and into the graft by releasing significant amounts of angiogenic growth factors rather than to differentiate into ECs, pericytes or smooth muscular cells forming new vessels, an effect that might be enhanced by hypoxia., (© 2013 International Federation for Cell Biology.)

Objective: To review the mechanism of improved revascularization of free fat grafting with adipose-derived stem cells (ADSCs)., Methods: The literature related to the basic researches of ADSCs in free fat grafting and angiogenesis was reviewed., Results: Angiogenesis is a sequence process in time and space which is regulated by various factors. ADSCs possess the capability of secreting many angiogenic growth factors and differentiating into various lineages., Conclusion: ADSCs affect every process of angiogenesis with clear improved angiogenic effects, however, the mechanisms of angiogenic effects need the further researches.

Objective: To explore the optimal dosage, timing and cytotoxicity of bromodeoxyuridine (BrdU) labelling for rabbit adipose-derived stromal stem cells (ADSCs) in vitro so as to confirm its feasibility for stem cells labelling and tracer means., Methods: Six rabbits were used in this experiment, aged 8-12 weeks, weighing 1.5-2.0 kg and neglecting their gender. 1-2 mL fat was removed, the ADSCs were isolated and cultured using the adherence method in vitro. The 3rd passage of ADSCs was incubated withBrdU at 5, 10, 15 and 20 microg/mL (groups A, B, C and D) for 12, 24, 48 and 72 hours to identify the optimal BrdU concentration and incubating time for cell labelling. Immunohistochemistry and trypanblau strain were performed respectively to calculate the labelling index (positive rate) and the cells' activity for different time after BrdU labelling. The ADSCs without BrdU labelling were used as control (Group E)., Results: The main appearance of primary ADSCs was short fusiform shape, and of the 3rd passage ADSCs long fusiform shape. The 3rd passage of ADSCs could differentiate into osteoblasts and adipocytes under corresponding inductive medium. The ADSCs' nucleus show green fluor under fluorescence microscope after labeled by the BrdU. The labelling ratio increased in groups A, B, C and D after incubating 12 hours, the mean labelling ratio were 30.6% +/- 2.3%, 32.4% +/- 1.9%, 45.8% +/- 1.8%, 50.8% +/- 3.1%, respectively, and the labelling ratio of Group E was 0. There were significant differences between groups C, D and Group A (P < 0.01). The labelling ratio of groups A, B, C and D were 45.9% +/- 2.0%, 87.9% +/- 3.3%, 90.6% +/- 2.9%, 91.7%+/- 3.2%, respectively after 24 hours and the labelling ratio of Group E was 0. There were significant differences between groups B, C, D and Group A (P < 0.01). The results of all groups after incubating 48 hours and 72 hours were similar to that after incubating 24 hours. The cell counting of groups A, B, C and D were better than that of Group E, but showing no siginificant differences (P > 0.05)., Conclusion: The most appropriate time for BrdU labelling ADSCs is 48 hours, the most appropriate concentration is 10 microg/mL. The labelling rate is high and cytotoxicity is little.

Adipose-derived stem cells (ASCs) are a critical adult stem cell subpopulation and are widely utilized in the fields of regenerative medicine and stem cell research due to their abundance, ease of harvest, and low immunogenicity. ASCs, which are homologous with skin by nature, can treat immune-related skin diseases by promoting skin regeneration and conferring immunosuppressive effects, with the latter being the most important therapeutic mechanism. ASCs regulate the immune response by direct cell–cell communication with immune cells, such as T cells, macrophages, and B cells. In addition to cell–cell interactions, ASCs modulate the immune response indirectly by secreting cytokines, interleukins, growth factors, and extracellular vesicles. The immunomodulatory effects of ASCs have been exploited to treat many immune-related skin diseases with good therapeutic outcomes. This article reviews the mechanisms underlying the immunomodulatory effects of ASCs, as well as progress in research on immune-related skin diseases. [ABSTRACT FROM AUTHOR]