Preclinical Studies

TITLE: “Validation of an automated procedure to isolate human adipose tissue-derived cells by using the Sepax® technology”

SOURCE: Güven S, Karagianni M, Schwalbe M, Schreiner S, Farhadi J, Bula S, Bieback K, Martin I, Scherberich A. Validation of an automated procedure to isolate human adipose tissue-derived cells by using the Sepax® technology. Tissue Eng Part C Methods. 2012 Aug;18(8):575-82.

SUMMARY: The stromal vascular fraction of adipose tissue has gained popularity as a source of autologous progenitor cells for tissue engineering and regenerative medicine applications. The aim of this study was to validate a newly developed, automated procedure to isolate adipose-derived mesenchymal stem/stromal cells (ASCs) from adult human lipoaspirates in a closed and clinical-grade device, based on the Sepax(®) technology. Using a total of 11 donors, this procedure was compared with the standard operator-based manual separation in terms of isolation yield, clonogenic fraction, phenotype, and differentiation potential of ASCs. As compared with the manual process, automation resulted in a 62% higher isolation yield, with 2.6±1.2×10(5) nucleated cells per mL of liposuction, and a 24% higher frequency of clonogenic progenitors. The variability in the isolation yield and clonogenicity across different preparations was reduced by 18% and 50%, respectively. The cytofluorimetric profile and in vitro differentiation capacity into mesenchymal lineages were comparable in the cells isolated using the two procedures. The new Sepax-based process thus allows an efficient isolation of ASCs with higher and more reproducible yields than the standard manual procedure, along with minimal operator intervention. These results are expected to facilitate the use of ASCs for clinical purposes, either within an intraoperative setting or in combination with further in vitro cell expansion/cultivation.

PUBLIC DOWNLOAD OF FULL MANUSCRIPT: Guven 2012 PDF


TITLE: “Development of a System and Method for Automated Isolation of Stromal Vascular Fraction from Adipose Tissue Lipoaspirate”

SOURCE: SundarRaj S, Deshmukh A, Priya N, Krishnan VS, Cherat M, Majumdar AS. Development of a System and Method for Automated Isolation of Stromal Vascular Fraction from Adipose Tissue Lipoaspirate. Stem Cells Int. 2015;2015:109353.

SUMMARY: Autologous fat grafting for soft tissue reconstruction is challenged by unpredictable long-term graft survival. Fat derived stromal vascular fraction (SVF) is gaining popularity in tissue reconstruction as SVF-enriched fat grafts demonstrate improved engraftment. SVF also has potential in regenerative medicine for remodeling of ischemic tissues by promoting angiogenesis. Since SVF cells do not require culture expansion, attempts are being made to develop automated devices to isolate SVF at the point of care. We report development of a closed, automated system to process up to 500 mL lipoaspirate using cell size-dependent filtration technology. The yield of SVF obtained by automated tissue digestion and filtration (1.17 ± 0.5 × 10(5) cells/gram) was equivalent to that obtained by manual isolation (1.15 ± 0.3 × 10(5); p = 0.8), and the viability of the cells isolated by both methods was greater than 90%. Cell composition included CD34+CD31- adipose stromal cells, CD34+CD31+ endothelial progenitor cells, and CD34-CD31+ endothelial cells, and their relative percentages were equivalent to SVF isolated by the manual method. CFU-F capacity and expression of angiogenic factors were also comparable with the manual method, establishing proof-of-concept for fully automated SVF isolation, suitable for use in reconstructive surgeries and regenerative medicine applications.

PUBLIC DOWNLOAD OF FULL MANUSCRIPT: SundarRaj 2015 PDF


TITLE: “Stromal vascular fraction isolated from lipo-aspirates using an automated processing system: bench and bed analysis”

SOURCE: Doi K, Tanaka S, Iida H, Eto H, Kato H, Aoi N, Kuno S, Hirohi T, Yoshimura K. Stromal vascular fraction isolated from lipo-aspirates using an automated processing system: bench and bed analysis. J Tissue Eng Regen Med. 2013 Nov;7(11):864-70.

SUMMARY: The heterogeneous stromal vascular fraction (SVF), containing adipose-derived stem/progenitor cells (ASCs), can be easily isolated through enzymatic digestion of aspirated adipose tissue. In clinical settings, however, strict control of technical procedures according to standard operating procedures and validation of cell-processing conditions are required. Therefore, we evaluated the efficiency and reliability of an automated system for SVF isolation from adipose tissue. SVF cells, freshly isolated using the automated procedure, showed comparable number and viability to those from manual isolation. Flow cytometric analysis confirmed an SVF cell composition profile similar to that after manual isolation. In addition, the ASC yield after 1 week in culture was also not significantly different between the two groups. Our clinical study, in which SVF cells isolated with the automated system were transplanted with aspirated fat tissue for soft tissue augmentation/reconstruction in 42 patients, showed satisfactory outcomes with no serious side-effects. Taken together, our results suggested that the automated isolation system is as reliable a method as manual isolation and may also be useful in clinical settings. Automated isolation is expected to enable cell-based clinical trials in small facilities with an aseptic room, without the necessity of a good manufacturing practice-level cell processing area.

PUBLIC DOWNLOAD OF FULL MANUSCRIPT: Not publicly available


TITLE: “Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: a systematic review”

SOURCE: van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: a systematic review. J Tissue Eng Regen Med. 2018 Jan;12(1):e261-e274.

SUMMARY: Intraoperative application of the stromal vascular fraction (SVF) of adipose tissue requires a fast and efficient isolation procedure of adipose tissue. This review was performed to systematically assess and compare procedures currently used for the intraoperative isolation of cellular SVF (cSVF) and tissue SVF (tSVF) that still contain the extracellular matrix. Pubmed, EMBASE and the Cochrane central register of controlled trials databases were searched for studies that compare procedures for intraoperative isolation of SVF (searched 28 September 2016). Outcomes of interest were cell yield, viability of cells, composition of SVF, duration, cost and procedure characteristics. Procedures were subdivided into procedures resulting in a cSVF or tSVF. Thirteen out of 3038 studies, evaluating 18 intraoperative isolation procedures, were considered eligible. In general, cSVF and tSVF intraoperative isolation procedures had similar cell yield, cell viability and SVF composition compared to a nonintraoperative (i.e. culture laboratory-based collagenase protocol) control group within the same studies. The majority of intraoperative isolation procedures are less time consuming than nonintraoperative control groups, however. Intraoperative isolation procedures are less time-consuming than nonintraoperative control groups with similar cell yield, viability of cells and composition of SVF, and therefore more suitable for use in the clinic. Nevertheless, none of the intraoperative isolation procedures could be designated as the preferred procedure to isolate SVF.

PUBLIC DOWNLOAD OF FULL MANUSCRIPT: Not publicly available