Adipose tissue contains multipotent elements with phenotypic and gene expression profiles similar to human mesenchymal stem cells (hMSCs) and pericytes. The chance of clinical translation of the multilineage potential of these cells is delayed by the poor/negligible cell survival within cryopreserved lipoaspirates, the difficulty of ex vivo expansion, and the complexity of current Good Manufacturing Practice (cGMP) requirements for expanded cells. Hence, availability of a minimally manipulated, autologous, hMSC/pericyte-enriched fat product would have remarkable biomedical and clinical relevance. Here, we present an innovative system, named Lipogems, providing a nonexpanded, ready-to-use fat product. The system uses mild mechanical forces in a completely closed system, avoiding enzymes, additives, and other manipulations. Differently from unprocessed lipoaspirate, the nonexpanded Lipogems product encompasses a remarkably preserved vascular stroma with slit-like capillaries wedged between adipocytes and stromal stalks containing vascular channels with evident lumina. Immunohistochemistry revealed that Lipogems stromal vascular tissue included abundant cells with pericyte/hMSC identity. Flow cytometry analysis of nonexpanded, collagenase-treated Lipogems product showed that it was comprised with a significantly higher percentage of mature pericytes and hMSCs, and lower amount of hematopoietic elements, than enzymatically digested lipoaspirates. Differently from the lipoaspirate, the distinctive traits of freshly isolated Lipogems product were not altered by cryopreservation. Noteworthy, the features of fresh product were retained in the Lipogems product obtained from human cadavers, paving the way to an off-the-shelf strategy for reconstructive procedures and regenerative medicine. When placed in tissue culture medium, the Lipogems product yielded a highly homogeneous adipose tissue-derived hMSC population, exhibiting features of hMSCs isolated from other sources, including the classical commitment to osteogenic, chondrogenic, and adipogenic lineages. Moreover, the transcription of vasculogenic genes in Lipogems-derived adipose tissue hMSCs was enhanced at a significantly greater extent by a mixture of natural provasculogenic molecules, when compared to hMSCs isolated from enzymatically digested lipoaspirates.

In the past few years, interest in adipose tissue as an ideal source of mesenchymal stem cells (MSCs) has increased. These cells are multipotent and may differentiate in vitro into several cellular lineages, such as adipocytes, chondrocytes, osteoblasts, and myoblasts. In addition, they secrete many bioactive molecules and thus are considered “mini-drugstores.” MSCs are being used increasingly for many clinical applications, such as orthopedic, plastic, and reconstructive surgery. Adipose-derived MSCs are routinely obtained enzymatically from fat lipoaspirate as SVF and/or may undergo prolonged ex vivo expansion, with significant senescence and a decrease in multipotency, leading to unsatisfactory clinical results. Moreover, these techniques are hampered by complex regulatory issues. Therefore, an innovative technique (Lipogems®; Lipogems International SpA, Milan, Italy) was developed to obtain microfragmented adipose tissue with an intact stromal vascular niche and MSCs with a high regenerative capacity. The Lipogems® technology, patented in 2010 and clinically available since 2013, is an easy-to-use system designed to harvest, process, and inject refined fat tissue and is characterized by optimal handling ability and a great regenerative potential based on adipose-derived MSCs. In this novel technology, the adipose tissue is washed, emulsified, and rinsed and adipose cluster dimensions gradually are reduced to about 0.3 to 0.8 mm. In the resulting Lipogems® product, pericytes are retained within an intact stromal vascular niche and are ready to interact with the recipient tissue after transplantation, thereby becoming MSCs and starting the regenerative process. Lipogems® has been used in more than 7000 patients worldwide in aesthetic medicine and surgery, as well as in orthopedic and general surgery, with remarkable and promising results and seemingly no drawbacks. Now, several clinical trials are under way to support the initial encouraging outcomes. Lipogems® technology is emerging as a valid intraoperative system to obtain an optimal final product that may be used immediately for regenerative purposes.

Autologous adipose tissue is used for tissue repletion and/or regeneration as an intact lipoaspirate or as enzymatically derived stromal vascular fraction (SVF), which may be first cultured into mesenchymal stem cells (MSCs). Alternatively, transplant of autologous adipose tissue mechanically fragmented into submillimeter clusters has recently showed remarkable efficacy in diverse therapeutic indications. To document the biologic basis of the regenerative potential of microfragmented adipose tissue, we first analyzed the distribution of perivascular presumptive MSCs in adipose tissue processed with the Lipogems technology, observing a significant enrichment in pericytes, at the expense of adventitial cells, as compared to isogenic enzymatically processed lipoaspirates. The importance of MSCs as trophic and immunomodulatory cells, due to the secretion of specific factors, has been described. Therefore, we investigated protein secretion by cultured adipose tissue clusters or enzymatically derived SVF using secretome arrays. In culture, microfragmented adipose tissue releases many more growth factors and cytokines involved in tissue repair and regeneration, noticeably via angiogenesis, compared to isogenic SVF. Therefore, we suggest that the efficient tissue repair/regeneration observed after transplantation of microfragmented adipose tissue is due to the secretory ability of the intact perivascular niche. Stem Cells Translational Medicine 2018;7:876–886

(2015) Mesenchymal stem cells: potential for therapy and treatment of chronic non-healing skin wounds, Organogenesis, 11:4, 183-206, DOI: 10.1080/15476278.2015 ABSTRACT. Wound healing is a complex physiological process including overlapping phases (hemostatic/inflammatory, proliferating and remodeling phases). Every alteration in this mechanism might lead to pathological conditions of different medical relevance. Treatments for chronic nonhealing wounds are expensive because reiterative treatments are needed. Regenerative medicine and in particular mesenchymal stem cells approach is emerging as new potential clinical application in wound healing. In the past decades, advance in the understanding of molecular mechanisms underlying wound healing process has led to extensive topical administration of growth factors as part of wound care. Currently, no definitive treatment is available and the research on optimal wound care depends upon the efficacy and cost-benefit of emerging therapies.Here we provide an overview on the novel approaches through stem cell therapy to improve cutaneous wound healing, with a focus on diabetic wounds and Systemic Sclerosis-associated ulcers, which are particularly challenging. Current and future treatment approaches are discussed with an emphasis on recent advances.

The technologies for adipose tissue harvesting, processing, and transplantation have substantially evolved in the past two decades. Clinically driven advancements have paralleled a significant improvement in the understanding of cellular, molecular, and immunobiological events surrounding cell and tissue transplantation. These new mechanistic insights could be of assistance to better understand the mechanisms underlying some of the observed clinical improvements. In addition to plastic and reconstructive surgical applications, adipose tissue has become central to an increasing number of translational efforts involving adipose tissue-derived progenitor cells. The growing interest in this area of research has resulted in the exploration of many novel research and clinical applications that utilize adipose tissue grafting and/or progenitor/stem cell-derived cell products obtained from this tissue source. Progenitor, endothelial, and mesenchymal stem cells derived from adipose tissue could therefore not only be central to plastic and reconstructive surgery applications, but also become the focus of an array of therapeutic solutions for many disease conditions, such as those affecting bone, cartilage, muscle, liver, kidney, cardiac, neural, and the pancreas, expanding the possible indications and translational potential of tissue, cell-based, and regenerative medicine strategies.