Supplementation of fat grafts with adipose-derived regenerative cells improves long-term graft retention.

Current practice of autologous fat transfer for soft tissue augmentation is limited by poor long-term graft retention. Adipose-derived regenerative cells (ADRCs) contain several types of stem and regenerative cells, which may help improve graft retention through multiple mechanisms. Using a murine fat transplantation model, ADRCs were added to transplanted fat to test whether ADRCs could improve the long-term retention of the grafts. This study showed, at both 6 and 9 months after transplantation, ADRCs not only increased graft retention by 2-fold but also improved the quality of the grafts. ADRC-supplemented grafts had a higher capillary density, indicating ADRCs could promote neovascularization. Further cell tracking and gene expression studies suggest ADRCs may promote angiogenesis and adipocyte differentiation and prevent apoptosis through the expression of various growth factors, including VEGFA and IGF-1. Taken together, these results suggest a potential clinical utility of ADRCs in facilitating autologous fat transfer for soft tissue augmentation.

Plasticity of human adipose stem cells toward endothelial cells and cardiomyocytes.

Recent preclinical and clinical studies have suggested that adult stem cells have the ability to promote the retention or restoration of cardiac function in acute and chronic ischemia. Published clinical studies have used autologous donor cells, including skeletal muscle myoblasts, cultured peripheral blood cells, or bone marrow cells. However, our research and that of others indicates that human adipose tissue is an alternative source of cells with potential for cardiac cell therapy. These findings include the presence of cells within adipose tissue that can differentiate into cells expressing a cardiomyocytic or endothelial phenotype, as well as angiogenic and antiapoptotic growth factors. This potential is supported by preclinical studies in large animals.

Multipotential differentiation of adipose tissue-derived stem cells.

Tissue engineering offers considerable promise in the repair or replacement of diseased and/or damaged tissues. The cellular component of this regenerative approach will play a key role in bringing these tissue engineered constructs from the laboratory bench to the clinical bedside. However, the ideal source of cells still remains unclear and may differ depending upon the application. Current research for many applications is focused on the use of adult stem cells. The properties of adult stem cells that make them well-suited for regenerative medicine are (1) ease of harvest for autologous transplantation, (2) high proliferation rates for ex vivo expansion and (3) multilineage differentiation capacity. This review will highlight the use of adipose tissue as a reservoir of adult stem cells and draw conclusions based upon comparisons with bone marrow stromal cells.

Adult stem cell therapy for the heart.

The purpose of this review is to summarize current data leading to and arising from recent clinical application of cellular therapy for acute myocardial infarct (heart attack) and congestive heart failure. We specifically focus on use of adult stem cells and compare and contrast bone marrow and adipose tissue; two different sources from which stem cells can be harvested in substantial numbers with limited morbidity. Cellular therapy is the latest in a series of strategies applied in an effort to prevent or mitigate the progressive and otherwise irreversible loss of cardiac function that frequently follows a heart attack. Unlike surgical, pharmacologic, and gene transfer approaches, cellular therapy has the potential to restore cardiac function by providing cells capable of regenerating damaged myocardium and/or myocardial function. Skeletal muscle myoblast expansion and transfer allows delivery of cells with contractile function, albeit without any evidence of cardiomyogenesis or electrical coupling to remaining healthy myocardium. Delivery of endothelial progenitor cells (EPCs) which drive reperfusion of infarct zone tissues is also promising, although this mechanism is directed at halting ongoing degeneration rather than initiating a regenerative process. By contrast, demonstration of the ability of adult stem cells to undergo cardiomyocyte differentiation both in vitro and in vivo suggests a potential for regenerative medicine. This potential is being examined in early clinical studies.