Comparative technical analysis of lipoaspirate mechanical processing devices

Not Stromal Vascular Fraction (SVF) or Nanofat, but Total Stromal-Cells (TOST): A New Definition. Systemic Review of Mechanical Stromal-Cell Extraction Techniques

The most important and greatest source in the body for regenerative cells is fat tissue. Obtaining regenerative cells from adipose tissue can be done in two ways: Enzymatic and mechanical. The regenerative cell cocktail obtained by the enzymatic method, including stem cells, is called Stromal vascular fracture (SVF). In the literature, there is no clear definition of regenerative cells obtained by mechanical method. We systematically searched the techniques and definitions for stromal cells obtained from adipose tissue by scanning different databases. To evaluate the mechanical stromal-cell isolation techniques and end products from adipose tissue. Systematic review of English and non-English articles using Embase, PubMed, Web of Science and Google scholar databases. Search terms included Nanofat, fragmented fat, mechanical stromal / stem cell, mechanical SVF, SVF gel. We screened all peer-reviewed articles related with mechanical stromal-cell isolation. Author performed a literature query with the aforementioned key words and databases. A total of 276 publications containing the keywords we searched were reached. In these publications, there are 46 different definitions used to obtain mechanical stromal cells. The term SVF is only suitable for enzymatic methods. A different definition is required for mechanical. The most used term nanofat is also not suitable because the product is not in both "fat" and in "nanoscale". We think that the term total stromal-cells would be the most appropriate definition since both extracellular matrix and all stromal cells are protected in mechanical methods.

Simple and Rapid Non-Enzymatic Procedure Allows the Isolation of Structurally Preserved Connective Tissue Micro-Fragments Enriched with SVF

The stromal vascular fraction (SVF) consists of a heterogeneous population of stem and stromal cells, generally obtained from adipose tissue by enzymatic digestion. For human cell-based therapies, mechanical process methods to obtain SVF represent an advantageous approach because they have fewer regulatory restrictions for their clinical use. The aim of this study was to characterize a novel commercial system for obtaining SVF from adipose tissue by a mechanical approach without substantial manipulations. Lipoaspirate samples collected from 27 informed patients were processed by a simple and fast mechanical system (by means of Hy-Tissue SVF). The Hy-Tissue SVF product contained a free cell fraction and micro-fragments of stromal connective tissue. The enzymatic digestion of the micro-fragments increased the yield of free cells (3.2 times) and CFU-F (2.4 times). Additionally, 10% of free cells from SVF were positive for CD34+, suggesting the presence of endothelial cells, pericytes, and potential adipose-derived stem cells (ADSC). Moreover, the SVF cells were able to proliferate and differentiate in vitro toward adipocytes, osteocytes, and chondrocytes. The immunophenotypic analysis of expanded cells showed positivity for typical mesenchymal stem cell markers. The Hy-Tissue SVF system allows the isolation of stromal vascular fraction, making this product of potential interest in regenerative medicine.