Project description:BackgroundAdipose stromal vascular fraction (SVF) isolation with enzymatic digestion is the gold standard, but is expensive, having practical and legal concerns. The alternative mechanical SVF isolation methods provide lower cell yields as they employ either centrifugation, emulsification, or digestion steps alone. We combined mechanical processing with buffer incubation and centrifugation steps into an isolation method called "mechanical digestion" and compared the cell yields with that of enzymatic digestion.MethodsA total of 40-mL lipoaspirate was harvested from 35 women undergoing liposuction and was submitted to conventional enzymatic digestion for SVF isolation or mechanical digestion using a closed unit harnessing 3 ports with blades, followed by buffer incubation and centrifugation. Culture of the SVFs and flow cytometry were performed.ResultsThe SVF cell yield obtained by enzymatic digestion was significantly higher 3.38 × 106/mL (±3.63; n = 35) than that obtained by mechanical digestion 1.34 × 106/mL (±1.69; n = 35), P = 0.015. The average cell viability was 82.86% ± 10.68 after enzymatic digestion versus 85.86% ± 5.74 after mechanical digestion, which was not significant. Mechanical digested SVF expressed 2-fold higher stem cell surface markers compared with enzymatically digested SVF. Mechanical digestion was less time consuming, cost effective, and did not require a specific laboratory environment.ConclusionsMechanically digested SVF was comparable to enzymatically digested SVF in terms of stromal cell composition and viability. With mechanical digestion, we can isolate 30%-50% SVF cells of that isolated with enzymatic digestion. Further studies are warranted to determine the clinical outcomes.
Project description:Adipose-derived stromal vascular fraction (SVF) is a heterogeneous cell source that contains endothelial cells, pericytes, smooth muscle cells, stem cells, and other accessory immune and stromal cells. The SVF cell population has been shown to support vasculogenesis in vitro as well vascular maturation in vivo. Matrigel, an extracellular matrix (ECM) mixture has been utilized in vitro to evaluate tube formation of purified endothelial cell systems. We have developed an in vitro system that utilizes freshly isolated SVF and ECM molecules both in pure form (fibrin, laminin, collagen) as well as premixed form (Matrigel) to evaluate endothelial tip cell formation, endothelial stalk elongation, and early stages of branching and inosculation. Freshly isolated SVF rat demonstrate cell aggregation and clustering (presumptive vasculogenesis) on Matrigel ECM within the first 36 h of seeding followed by tip cell formation, stalk cell formation, branching, and inosculation (presumptive angiogenesis) during the subsequent 4 days of culture. Purified ECM molecules (laminin, fibrin, and collagen) promote cell proliferation but do not recapitulate events seen on Matrigel. We have created an in vitro system that provides a functional assay to study the mechanisms of vasculogenesis and angiogenesis in freshly isolated SVF to characterize SVF's blood vessel forming potential prior to clinical implantation.
Project description:The stromal vascular fraction of adipose tissue has gained popularity as regenerative therapy for tissue repair. Both enzymatic and mechanical intraoperative SVF isolation procedures exist. To date, the quest for the preferred isolation procedure persists, due to the absence of standardised yield measurements and a defined clinical threshold. This systematic review is an update of the systematic review published in 2018, where guidelines were proposed to improve and standardise SVF isolation procedures. An elaborate data search in MEDLINE (PubMed), EMBASE (Ovid) and the Cochrane Central Register of Controlled Trials was conducted from September 2016 to date. A total of 26 full-text articles met inclusion criteria, evaluating 33 isolation procedures (11 enzymatic and 22 mechanical). In general, enzymatic and mechanical SVF isolation procedures yield comparable outcomes concerning cell yield (2.3-18.0 × 105 resp. 0.03-26.7 × 105 cells/ml), and cell viability (70%-99% resp. 46%-97.5%), while mechanical procedures are less time consuming (8-20 min vs. 50-210 min) and cost-efficient. However, as most studies used poorly validated outcome measures on SVF characterisation, it still remains unclear which intraoperative SVF isolation method is preferred. Future studies are recommended to implement standardised guidelines to standardise methods and improve comparability between studies.
Project description:Background: Nanofat grafting (NG) is a simple and cost-effective method of lipoaspirates with inter-syringe passages, to produce stromal vascular fraction (SVF) and isolate adipose-derived stem cells (ASCs). This represents a tremendous interest in the future clinical needs of tissue engineering. In this study, we optimized the NG technique to increase the yield of ASC extractions. Methods: We analyzed three groups of SVF obtained by 20, 30, and 40 inter-syringe passages. The control group was an SVF obtained by enzymatic digestion with Celase. We studied their cell composition by flow cytometry, observed their architecture by confocal microscopy, and observed immunomodulatory properties of the ASCs from each of the SVFs by measuring inflammatory markers of macrophages obtained by an ASC monocyte co-culture. Results: We have established the first cell mapping of the stromal vascular fraction of adipose tissue. The results showed that SVF obtained by 20 inter-syringe passages contains more statistically significant total cells, more cells expressing the ASC phenotype, more endothelial cells, and produces more CFU-F than the SVF obtained by 30 and 40 passages and by enzymatic digestion. Confocal microscopy showed the presence of residual adipocytes in SVF obtained by inter-syringe passages but not by enzymatic digestion. The functional study indicates an orientation toward a more anti-inflammatory profile and homogenization of their immunomodulatory properties. Conclusion: This study places mechanically dissociated SVF in the center of approaches to easily extract ASCs and a wide variety and number of other progenitor cells, immediately available in a clinical setting to provide both the amount and quality of cells required for decellularized tissues.
Project description:Microarray studies were performed to identify expression patterns by cryopreserved adipose stromal vascular fraction (SVF) preparations that were prepared by three different veterinary stem cell companies from the same source of canine adipose tissue. [Samples 1 - 3] Three equal samples of approximately 20 grams of adipose tissue were shipped on ice to 3 different companies which specialize in adipose-derived veterinary stem cell therapy. All 3 SVF preparations were cryopreserved at their respective facilities. Approximately one month later, cryopreserved samples were retrieved from all companies and transported frozen to the University of Kentucky for gene profiling and viability analysis. [Samples 4 - 11] Groups of cells (samples 5, 7, 9, 11) were treated by the stem cell company with photo-activated platelet-rich plasma (PRP) according to their proprietary procedures in order to enhance regenerative properties of the adipose stem cells. These PRP-treated cells were incubated in the investigator's lab for 6 hours at 37 degrees Celsius to allow for expression of genes that were induced by PRP treatment.
Project description:Microarray studies were performed to identify expression patterns by cryopreserved adipose stromal vascular fraction (SVF) preparations that were prepared by three different veterinary stem cell companies from the same source of canine adipose tissue.
Project description:BackgroundRegenerative cell therapies, such as adipose-derived stromal vascular fraction (SVF), have been postulated as potential treatments for knee osteoarthritis (KOA).ObjectivesTo assess the efficacy and safety of SVF treatment against placebo and other standard therapies for treating KOA in adult patients.DesignA systematic review.Data sources and methodsWe searched the following databases: MEDLINE via PubMed, Epistemonikos, PEDro, DynaMed, TripDatabase, Elsevier via Clinicalkey and Cochrane Controlled Trials Register. We included prospective interventional studies where treatment with SVF in adults with KOA was compared against placebo or other standard therapies, and results were objectively measured with at least one widely recognised osteoarthritis scale.ResultsAmong 266 studies published until May 2021, nine met our inclusion criteria. A total of 239 patients (274 knees) were included in our study. The follow-up ranged from 6 to 24 months. Six studies had a control group (only one being placebo). All studies showed that SVF improved pain and functionality measured, in most cases, with the visual analogue scale and the Western Ontario and McMaster Universities Osteoarthritis Index. In addition, five studies reported an improvement in anatomical structures, as detected in MR images. However, the number of cells contained in SVF varied substantially between different studies, which could induce a comparison bias.ConclusionAlthough based on a small number of dissimilar studies, SVF was considered a safe treatment for KOA and could be promising in terms of pain, functionality and anatomical structure improvement. However, SVF products need to be standardised, the number of cells homogenised and the use of concomitant treatments reduced to establish proper comparisons.RegistrationPROSPERO registration number: CRD42021284187.
Project description:Mesenchymal stem/stromal cells or medicinal signaling cells (MSC)-based therapy holds promise as a beneficial strategy for treating knee OA (osteoarthritis), but there is no standardized protocols nor mechanistic understanding. In order to gain a better insight into the human MSC from adipose tissue applied for autologous OA treatment, we performed extensive comparative immunophenotyping of the stromal vascular fraction from lipoaspirate or microfragmented lipoaspirates by polychromatic flow cytometry and investigated the cellular components considered responsible for cartilage regeneration. We found an enrichment of the regenerative cellular niche of the clinically applied microfragmented stromal vascular fraction. Sex-related differences were observed in the MSC marker expression and the ratio of the progenitor cells from fresh lipoaspirate, which, in female patients, contained a higher expression of CD90 on the three progenitor cell types including pericytes, a higher expression of CD105 and CD146 on CD31highCD34high endothelial progenitors as well as of CD73 on supra-adventitialadipose stromal cells. Some of these MSC-expression differences were present after microfragmentation and indicated a differential phenotype pattern of the applied MSC mixture in female and male patients. Our results provide a better insight into the heterogeneity of the adipose MSC subpopulations serving as OA therapeutics, with an emphasis on interesting differences between women and men.
Project description:Adipose tissue from 6 non-obese patients was collagenase treated and adipocytes separated from the stromal vascular fraction(SVF). SVF was then FACS sorted for the following fractions CD45-/CD34+/CD31+ (endothelial), CD45-/CD34+/CD31- (progenitor), CD45+/CD14+ (monocyte/macrophage), CD45+/CD14-(Leukocyte). RNA was isolated from adipocyte, SVF, progenitor, macrophage/monocyte and leukocyte fractions and analyzed on the Affymetrix Human Transcriptome 2.0 array. We also sorted SVF from an additional 13 (10 non-obese, 9 obese) patients and sent progenitor RNA for Affymetrix Human Transcriptome 2.0 array analysis.
Project description:Subcutanesouly tumors from both Bmal1+/+ and Bmal1-/- mice were used to isolated stromal vascular fractions (SVF). Tumor cells with GFP+ signals were exclusive. Remain GFP- cells were collected to do RNAseq.