Adipose-derived Stromal Vascular Fraction Research Articles

The Effects of Adipose Derived Stromal Vascular Fraction and Platelet-Rich Plasma on Bone Healing of a Rat Model With Chronic Kidney Disease.

Chronic kidney disease (CKD) impairs osteoblast/osteoclast balance and damages bone structure with diminished mineralization and results in bone restoration disorders. In this study, we investigate the effects of adipose-derived stromal vascular fraction and platelet-rich plasma (PRP) on bone healing model in rats with CKD. Sprague-Dawley rats were separated into 4 groups. All groups except group I (healthy control) had CKD surgery using 5/6 nephrectomy model. All groups had intramedullary pin fixation after receiving bone fracture using drilling tools. Group II rats were used as control group for CKD. Group III rats received PRP treatment on fracture site. Group IV rats received PRP and stromal vascular fraction treatment on fracture site.Weight loss and blood samples were followed at the time of kidney surgery, third, sixth, and 12th weeks. Bone healing and callus formations were compared, biomechanically, radiologically, histopathologically, and immunohistochemically. Osteoblastic transformation of stem cells was assessed with DiI staining. Negative effects of CKD on bone healing were reduced by increasing mechanical, histological, radiological, and biochemical properties of the bone with stromal vascular fraction and PRP treatments. Although thickness of callus tissue delayed bone healing process, it also enhanced biomechanical features and bone tissue organization. Platelet-rich plasma and adipose-derived stromal vascular fraction treatments were effective for bone healing in animal model, which can be promising for clinical trials.

Lipoaspirate Storage Time and Temperature: Effects on Stromal Vascular Fraction Quality and Cell Composition

The adipose tissue-derived stromal vascular fraction (SVF) is a promising candidate for use in cell therapy and tissue engineering due to its regenerative and immunomodulatory properties. Some therapies are based on using the complete SVF product, whereas others depend on the expansion of adipose-derived stromal cells (ASCs) in culture. The latter application often involves a time delay between adipose tissue harvest and SVF isolation. This study investigated how storage time and temperature affected cell quality and composition. Aliquots of lipoaspirate were stored cold (4°C), at room temperature (18–20°C), or at 37°C. SVF was isolated on sequential time points over a period of 48 h, and the following were assessed: cell viability, vitality, composition, and the proliferative potential of the ASCs. When the lipoaspirate was stored cold, the viability of the SVF remained stable for up to 48 h; however, the vitality of the SVF decreased significantly after 24 h. When stored at higher temperatures (room temperature or 37°C), the vitality of the SVF decreased after 8 h. The ASC fraction in the SVF decreased rapidly after 8 h when stored at higher temperatures, whereas this change was delayed significantly when the lipoaspirate was stored cold. Tendencies towards increases in the lag phase, population doubling time (PDt), and time to reach confluency were observed when the lipoaspirate was stored at higher temperatures. The vitality of the SVF was correlated significantly with the time of the lag phase and the time required to reach confluence, whereas no correlation was observed with the PDt. Both prolonged storage time and increased temperature during lipoaspirate storage negatively affected the quality of the obtained SVF. Our results suggest that lipoaspirate should be stored for no longer than 24 h at 4°C to maintain the optimal quality for the isolation of SVF and the expansion of ASCs.

Non enzymatic isolation of adipose tissue and stromal vascular fraction derived cells

The therapeutic potential of the adipose tissue is also supported by a source of mesenchymal stem cells (MSCs), endothelial progenitor cells, mast cells, T- lymphocyte, B lymphocyte, and adipose-resident macrophages with repairing and regenerative ability. The purpose of this study was to compare adipose tissue derived mesenchymal stem cells (ADSCs) and stromal vascular fraction cells (SVF cells) in terms of the usage of non-enzymatic isolation, detection of cell adhesion, fibroblastoid cell formation, properties of cell population, cell culture duration until 3rd passages under in-vitro culture condition. We used 3 months old, 4 male Sprague Dawley rats (mean of live weight about 250 g) to examined the variation of the cell population, cell properties, phases of cellular formation, cell culturing time, subculturing duration, differences in confluency between SVF cells and ADSCs. In in-vitro expansion, ADSCs displayed higher rate of adhesiveness, homogenous cell population, faster proliferation and formation of fibroblast like cells compared to SVF cells. As a result, we showed that ADSCs have better adhesive ability, higher proliferative capacity in all of the 3 passages and require shorter time to reach confluency compared with SVF cells in vitro. These findings may contribute to future studies that deal with isolation and selection of stem cells from various tissues, as well as design clinical trials based on ADSCs and SVF cells.

Human adipose-derived stromal vascular fraction: characterization, safety and therapeutic potential in an experimental mouse model of articular injury.

Due to their capacity to self-renew, proliferate and generate multi-lineage cells, adult-derived stem cells offer great potential in regenerative therapies to treat maladies such as diabetes, cardiac disease, neurological disorders and orthopedic injuries. Commonly derived from adipose tissue, the stromal vascular fraction (SVF), a heterogeneous cell population enriched with mesenchymal stem cells (MSCs), has garnered interest as a cellular therapy due to ease of accessibility as an autologous, point-of-care application. However, the heterogeneous cell population within SVF is not historically taken into consideration when injecting into patients. Here, we characterized SVF, determined its safety and verify its therapeutic effects in a NOD/scid mouse model of articular injury. SVF were isolated from lipoaspirates utilizing a commercially available system (InGeneron Inc.), while MSCs were isolated from SVF via cell culture. Flow cytometry showed that neither age nor BMI affects the frequency of progenitor cells-like (CD31+CD34+), immune cells-like (CD4+) T cells, (CD14+) monocytes and total number of cells obtained. However, there was a negative correlation between donor BMI and MSC frequency within the SVF. ELISAs showed that following LPS activation in SVF, there were low levels of TNF-α and high levels of IL-10 secreted. However, T cell activation with anti-CD3 or anti-CD3+ anti-CD28, while leading to expected high levels of IFN-γ, did not lead to significant levels of TGF-β. PCR analysis showed no significant numbers of cells outside the joint 1-hour post injection, moreover, no engraftment or abnormal growth in other organs 60-days post injection. Finally, both cell populations were able to ameliorate disease progression, as confirmed by the increase in movement of treated groups compared to injured groups. Noteworthy, the histological analysis indicated that there was no cartilage growth, suggesting an alternative therapeutic mechanism to cartilage regeneration.

Effects of adipose- derived stromal vascular fraction on asherman syndrome model

Asherman’s syndrome (AS) is an endometrial damage that results in infertility in women. Although stem cell therapy has been introduced as a potential treatment for this syndrome, its use in clinical settings remains challenging because of the likelihood of contamination and cell differentiation. Herein, we investigated the effects of adipose-derived stromal vascular fraction (SVF) transplantation on proliferation and angiogenesis in the endometrium in an AS model. The AS model was induced using scratch method in adult male Wistar rats, and SVF (5 × 10 (Simsir et al., 2019) cells) was locally administered into the damaged horns. Two weeks after cell transplantation, endometrial thickness, fibrosis, and expression of vascular endothelial growth factor (VEGF) were assessed by Hematoxylin & Eosin, Masson's trichrome, and immunofluorescence staining, respectively. We found thin endometrium, increased fibrosis, and decreased VEGF following AS induction all of which were reversed after SVF transplantation. We concluded that the local injection of SVF may serve as an effective alternative therapy for AS.

Surgical Injury and Ischemia Prime the Adipose Stromal Vascular Fraction and Increase Angiogenic Capacity in a Mouse Limb Ischemia Model.

The adipose-derived stromal vascular fraction (SVF) is an effective source for autologous cell transplantation. However, the quality and quantity of SVFs vary depending on the patient's age, complications, and other factors. In this study, we developed a method to reproducibly increase the cell number and improve the quality of adipose-derived SVFs by surgical procedures, which we term “wound repair priming.” Subcutaneous fat from the inguinal region of BALB/c mice was surgically processed (primed) by mincing adipose parenchyma (injury) and ligating the subcutaneous fat-feeding artery (ischemia). SVFs were isolated on day 0, 1, 3, 5, or 7 after the priming procedures. Gene expression levels of the primed SVFs were measured via microarray and pathway analyses which were performed for differentially expressed genes. Changes in cellular compositions of primed SVFs were analyzed by flow cytometry. SVFs were transplanted into syngeneic ischemic hindlimbs to measure their angiogenic and regeneration potential. Hindlimb blood flow was measured using a laser Doppler blood perfusion imager, and capillary density was quantified by CD31 staining of ischemic tissues. Stabilization of HIF-1 alpha and VEGF-A synthesis in the SVFs were measured by fluorescent immunostaining and Western blotting, respectively. As a result, the number of SVFs per fat weight was increased significantly on day 7 after priming. Among the differentially expressed genes were innate immunity-related signals on both days 1 and 3 after priming. In primed SVFs, the CD45-positive blood mononuclear cell fraction decreased, and the CD31-CD45-double negative mesenchymal cell fraction increased on day 7. The F4/80-positive macrophage fraction was increased on days 1 and 7 after priming. There was a serial decrease in the mesenchymal-gated CD34-positive adipose progenitor fraction and mesenchymal-gated CD140A-positive/CD9-positive preadipocyte fraction on days 1 and 3. Transplantation of primed SVFs resulted in increased capillary density and augmented blood flow, improving regeneration of the ischemic limbs. HIF-1 alpha was stabilized in the primed cutaneous fat in situ, and VEGF-A synthesis of the primed SVFs was on a peak on 5 days after priming. Wound repair priming thus resulted in SVFs with increased number and augmented angiogenic potential.

Stromal vascular fraction for the treatment of the radiation-induced gastrointestinal syndrome

Background & Aim Accidental or intended high doses radiation exposures have serious consequences for the health of exposed people and may impact a large number of people (as well as military than civil). Exposure of a large volume at high irradiation doses induces multiple tissue lesions grouped under the name of Acute Radiation Syndrome (ARS). The gastro-intestinal tract is especially sensitive to irradiation. At dose more than 10 Gy results in diarrhea, dehydration, sepsis and intestinal bleeding with death within 10 to 15 days post-exposure. Radiation-induced gastrointestinal syndrome results from direct cytocidal effects on intestinal stem cells and crypt stromal impairing epithelial regeneration. Irradiation rapidly reduces the mucosal integrity and promotes systemic bacteria influx resulting in sepsis and death. In this context, there is an urgent need for effective, rapid and applicable therapeutic measures for a large number of victims. Adipose-derived stromal vascular fraction (ADSVF) is an easily accessible source of cells with angiogenic, anti-inflammatory, immunomodulatory, and regenerative properties. We examined whether ADSVF protect irradiated intestinal cells niche and mitigate gastrointestinal syndrome. Methods, Results & Conclusion At the day of the abdominal irradiation (18Gy) mice were injected in systemic by the stromal vascular fraction (ADSVF) (2.5 106 cells), obtained through enzymatic digestion of inguinal adipose tissue. We found that, at 7 days post-irradiation, treatment with ADSVF limited the weight loss of mice and reduced the intestinal permeability. Immunohistological analyses in intestinal tissues revealed an increase of regenerating crypts, a restoration of the stromal compartment and an increase of Ki67+ proliferating cells in response to ADSVF treatment. In addition, the treatment reduced significantly the expression of cytokines associated to inflammatory response in intestine and normalized the splenic immune cells (CD4, CD8, CD19) populations and increased the C11b/Ly6Clow/Cx3cr1 population. Treatment in emergency of gastrointestinlal syndrome could be achieved by intravenous injection of ADSVF inducing regeneration of intestine.

Evaluation of Stromal Vascular Fraction Properties and Histological Changes of Regenerating Tissue during Healing of Radiation-Induced Lesions in the Rectum.

We analyzed the main properties of autologous adipose-derived stromal vascular fraction (SVF) used for the treatment of radiation-induced lesions in the rectum. No statistically significant correlation between the main characteristics of the cell product (cell number, viability) and patient's age or donor area were revealed. The stages and peculiarities of histological changes in the regenerating tissue after injection of autologous adipose tissue cells were analyzed. Morphological changes at the stages of granulation, early and complete epithelialization, and tissue maturation were described.

Intra-articular infiltration of adipose-derived stromal vascular fraction cells slows the clinical progression of moderate-severe knee osteoarthritis: hypothesis on the regulatory role of intra-articular adipose tissue

BackgroundThe infiltration of the stromal vascular fraction (SVF) of autologous adipose tissue to treat osteoarthritis has been used for several years demonstrating its safety and noticeable efficacy. This article presents clinical data from patients afftected by moderate and severe knee osteoarthritis demonstrating safety and clinical efficacy of the treatment when this autologous cell product is injected in the knee joint and patients evaluated post-operatively after 1 year. However, what do we know about the mechanism that underlies this clinical improvement? This article proposes, for the first time in our opinion, a hypothesis of the mode of action that involves structural and molecular interactions between SVF and infrapatellar fat pad (IFP). As consequence, there would be a re-education of intra-articular adipose tissue, which we consider a key player for the clinical effect observed in the mid and long term mainly due to immuno-regulatory mechanisms.MethodsThis is a retrospective and not controlled study that evaluated 50 patients (100 joints) ranging from 50 to 89 years old, separated by age cohorts. Clinical efficacy was assessed using the Lequesne, WOMAC, and VAS scales, by ultrasound control and quantification of the biochemical profiles of synovial fluid.ResultsThere were no serious adverse effects. All the indexes studied showed a significant clinical improvement after 1-year follow-up for all ages and OA degree groups. This finding was correlated with the ultrasound observations and biochemical data, which show a marked decrease in catabolic and pro-inflammatory molecules (MMP-2, IL-1B, IL-6, and IL-8) and significant increase for anabolic and anti-inflammatory molecules (IGF-1 and IL-10).ConclusionsWe conclude that intra-articular SVF infiltration for knee OA treatment is safe and effective during 1 year. We propose that applied SVF cells cause a cascade of molecular and structural events that, through complex interactions between IFP and SVF, re-educating the intra-articular fatty tissue towards a homeostatic, protective, and anti-inflammatory function, which will ultimately promote the restructuring and regeneration of damaged tissues.

The influence of adipose-derived stromal vascular fraction cells on the treatment of knee osteoarthritis

BackgroundAdipose-derived stromal vascular fraction (SVF) cells are a mixed cell population that includes cells with multilineage potential, similar to bone marrow-derived mesenchymal stem cells. Our purpose is to investigate the influence of SVF cells in patients with knee osteoarthritis (OA) and the short-term treatment effects.MethodsFifty-seven patients were enrolled and treated with intra-articular injection of 2.5 × 107 SVF cells into the knee joint between September 2017 and March 2018. All patients were followed up for 12 months or longer. Mean age at treatment and follow-up period were 69.4 ± 6.9 years and 13.7 ± 2.0 months, respectively. The mean preoperative hip-knee-ankle angle was 6.7 ± 3.6°. SVF cells were prepared using the Celution®800/CRS system from the patients’ abdominal or breech subcutaneous fat. The mean SVF cell viability was 90.6 ± 2.7%. Clinical evaluations were performed for range of motion, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and the Knee injury and Osteoarthritis Score (KOOS). Imaging evaluations, which included the hip-knee-ankle angle assessed via radiography, and T2 mapping value using a 1.5-T magnetic resonance imaging unit were also assessed. Both clinical and imaging evaluations were performed preoperatively, 1, 3, 6, and 12 months postoperatively, and compared among all timepoints (p < 0.05).ResultsKnee extension angle at 6 and 12 months postoperatively was significantly better than the preoperative angle. Total WOMAC, VAS, and KOOS scores at 1, 3, 6 and 12 months postoperatively were significantly better than preoperative scores. There was no significant difference in hip-knee-ankle angle among the five time periods. T2 mapping values of lateral femur and tibia were significantly higher 12 months postoperatively than preoperatively.ConclusionsThe short-term clinical effects of intra-articular SVF cell injection on knee OA were excellent. Intra-articular SVF cell injection is a novel and innovative approach for treating patients with knee OA.

Safety of Human Adipose Stromal Vascular Fraction Cells Isolated with a Closed System Device in an Immunocompetent Murine Pressure Ulcer Model.

Pressure ulcers (PUs) result in part due to ischemia-reperfusion injury to the skin and present frequently in elderly or quadriplegic patients with reduced mobility. Despite the high economic and societal cost of this condition, PU therapy relies primarily on preventive strategies and invasive surgical intervention. A growing body of clinical literature suggests that localized injection of adipose-derived cells can accelerate and enhance the closure of PUs. The current study systematically evaluated the safety of human adipose stromal vascular fraction (SVF) cells isolated using a closed system device when injected into a murine PU injury model. The human SVF cells were characterized by colony-forming unit-fibroblast and differentiation assays before use. Young (2 months) immunocompetent C57BL/6 mice subjected to a magnet-induced ischemia-reperfusion injury were injected subcutaneously with human SVF cells at increasing doses (0.25-2 million cells). The size of the PU was monitored over a 20-day period. Both female and male mice tolerated the concentration-dependent injection of the SVF cells without complications. While male mice trended toward more rapid wound closure rates in response to lower SVF cell concentrations (0.25-0.5 million cells), female mice responded favorably to higher SVF cell concentrations (1-2 million cells); however, outcomes did not reach statistical significance in either sex. Overall, the study demonstrates that human SVF cells prepared with a closed system device designed for use at point of care can be safely administered for PU therapy in an immunocompetent host animal model.

A 3-step Mechanical Digestion Method to Harvest Adipose-derived Stromal Vascular Fraction.

Adipose 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. A 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. The 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. Mechanically 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.

Abstract WP147: Cell-Free Fat Extract Promotes Angiogenesis in a Mouse Model of Cerebral Ischemia

Background: Adipose tissue and its derivatives including adipose-derived stem cells and stromal vascular fraction (SVF) showed effective in the treatment of ischemic stroke. However, cell-based therapy for clinical application has been hindered by limitations such as safety, immunogenicity issues, and difficulties in cell preservation, transportation, and phenotype control. Here, we aimed to produce a cell-free extract directly from human fat tissue and evaluate its potential therapeutic efficacy for treating ischemic stroke. Methods: Cell-free aqueous extract from human fat tissue was obtained using mechanical emulsification method. Twenty adult CD-1 mice were subjected to 60-minute middle cerebral artery occlusion. Immediately after ischemia, 0.1 ml fat extract was intravenously injected into ischemic mice through tail vein every other day for 14 days. Brain atrophy volume and neurobehavioral outcomes were examined at 14 days after focal ischemia. The occurrence of angiogenesis was evaluated by immunostaining and ELISA, and growth factors contained in the fat extract was analyzed to explore the molecular mechanism of fat extract treatment. Results: Our results showed that brain atrophy volume reduced and neurobehavioral outcomes improved at 3 ,7 and 14 days of focal ischemia in the fat extract treated mice compared to the controls ( p &lt;0.05). Furthermore, fat extract treatment increased microvessel density at 14 days after focal ischemia (p&lt;0.05). ELISA showed that fat extract contained high levels of several growth factors such as HGF, VEGF, bFGF, BDNF, and GDNF. Conclusions: We developed a novel cell-free therapeutic agent, fat extract, produced from human adipose tissue. The fat extract contained high level of growth factors such as HGF, VEGF, bFGF, BDNF, and GDNF, which plays important role of promoting angiogenesis and reduced ischemic brain injury in the mouse brain, suggesting that the fat extract is a novel cell-free therapeutic agent in the treatment of ischemic stroke.

Use of Adipose-Derived Orthobiologics for Musculoskeletal Injuries: A Narrative Review.

Musculoskeletal injuries are among the most prevalent, disabling, and costly conditions that Americans face, affecting over half of those over 18 and nearly 75% of those over 65 years old. Current treatments are largely palliative for many of these conditions and unmet needs have warranted the emergence of alternative treatments. Orthobiologics, such as adipose tissue derivatives (ATDs), are of high interest because they can be obtained in the office setting and their cellular components, including adipose stem cells and stromal cells, are thought to be beneficial in the treatment of musculoskeletal injuries. Microfragmented adipose tissue (MFAT) and stromal vascular fraction (SVF) are two ATD injectates that are used in the clinical setting to treat musculoskeletal conditions. Our review aimed to clarify the terminology describing the various ATDs used for orthopedic indications while discussing the promising but low-quality evidence, heterogeneity in MFAT and SVF processing methods, and inconsistencies in reported information such as injectate characterization with cell counts, injection technique, and postprocedural rehabilitation.

Evaluation of Enhanced Therapeutic Effect of Adipose Stromal Vascular Fraction Added With Human Platelet Lysate in Treatment of Osteoarthritis

Evaluation of Enhanced Therapeutic Effect of Adipose Stromal Vascular Fraction Added With Human Platelet Lysate in Treatment of Osteoarthritis

The effect of adipose-derived stem cells in healing refractory wounds based on clinical outcomes

ABSTRACT Refractory wounds can be a serious threat to the quality of life and survival of patients. Various surgical methods have been attempted; however, they do not cure these refractory wounds; therefore, new and promising treatment methods to improve wound healing and angiogenesis are urgently warranted. Adipose-derived stromal vascular fraction (SVF) cells have been clinically used to promote healing. Hence, we aimed to evaluate the clinical efficacy of SVF cells for the treatment of refractory wounds. Forty patients with refractory wounds were randomly divided into two groups: patients in the experimental group were treated with SVFs (n = 20) and those in the control group were given conventional treatment (n = 20). The general data of age, sex ratio, wound size, frequency of every caused wound, and etiology were compared between the two groups. No significant difference was found between the two groups (P = 0.089). Clinical efficacy was also evaluated between the two groups. The experimental group had a shorter wound healing time and a significantly higher healing rate than the control group (P = 0.023 and P = 0.035, respectively). Therefore, SVFs may be a new and effective treatment for refractory wounds (P = 0.043).

Effect of Autologous Adipose-Derived Stromal Vascular Fraction Transplantation on Endometrial Regeneration in Patients of Asherman's Syndrome: a Pilot Study.

This study aimed to investigate the efficacy of the transplantation of autologous adipose-derived stromal vascular fraction (AD-SVF) containing adipose stem cells (ASCs) in regenerating functional endometrium in patients with severe Asherman's syndrome (AS). This was a prospective clinical study involving six infertile women aged 20-44years who were diagnosed with severe AS by hysteroscopy. Autologous AD-SVF were isolated from patient's adipose tissue obtained by liposuction and then transplanted into uterus by transcervical instillation using an embryo transfer catheter followed by estrogen hormone therapy. Endometrial growth and pregnancy outcomes were assessed after fresh or frozen embryo transfer. Of the five patients who remained in the study, two women who had amenorrhea resumed their menstruation with irregular scant bleeding. Three women with oligomenorrhea had increased menstrual amount. Before therapy, the maximum EMT measured ultrasonographically was 3.0 ± 1.0mm (range: 1.7 to 4.4mm), which significantly increased to 6.9 ± 2.9mm (range: 5.2 to 12.0mm, p = 0.043) after cell transplantation and hormone therapy. Five women had embryo transfer after therapy: one fresh and four frozen-thawed. One woman conceived but aborted spontaneously at 9-week gestation. AD-SVF is a safe and easily available cell product containing adipose-derived stem cells. Autologous transplantation of AD-SVF may regenerate damaged human endometrium and increase endometrial receptivity. Our study showed the feasibility of AD-SVF in restoring endometrial function and increasing endometrial thickness. This cell therapy may become a promising treatment for infertile women with endometrial dysfunction and needs further investigation.

Regulatory, ethical, and technical considerations on regenerative technologies and adipose-derived mesenchymal stem cells

Since the early days of molecular biology, organ and tissue regeneration represents a challenging medical goal. However, only recently the advances in the understanding of the cellular components have enabled the promise to become a reality. In this vast panorama of new technologies, stem cells have progressively established themselves as the most effective and user-friendly regenerative therapeutic tool. Scientific meetings, workshops, conferences, and forums focused on translational science of regenerative technologies are today blooming all over the world. The audience questions and, even more, the very often controversial and conflicting explanations highlight the great deal of confusion regarding this new discipline that should be considered today a real independent medical specialty, requiring long-term studies and dedication. All the technologies able to separate and concentrate the adipose tissue (AT) and the stromal vascular fraction (SVF) and their related clinical applications need to comply with a complex but still unclear regulatory frame, becoming everyday more severe and restrictive, this limiting their practical use. The aim of this manuscript is to overview the current status of the regulatory frame and few related ethical considerations and to describe the evolution in the way the adipose-derived stromal vascular fraction (SVF) is isolated, extracted, and concentrated, as well as, of the ongoing researches and related future perspectives. Considerations on the most controversial and still unclear points related to the regenerative medicine and surgery, seen from the perspective of a research group who dedicated their entire professional life to this field, are also provided. Level of evidence: Not ratable.

Impact of the Different Preparation Methods to Obtain Human Adipose-Derived Stromal Vascular Fraction Cells (AD-SVFs) and Human Adipose-Derived Mesenchymal Stem Cells (AD-MSCs): Enzymatic Digestion Versus Mechanical Centrifugation.

Autologous therapies using adipose-derived stromal vascular fraction (AD-SVFs) and adult adipose-derived mesenchymal stem cells (AD-MSCs) warrant careful preparation of the harvested adipose tissue. Currently, no standardized technique for this preparation exists. Processing quantitative standards (PQSs) define manufacturing quantitative variables (such as time, volume, and pressure). Processing qualitative standards (PQLSs) define the quality of the materials and methods in manufacturing. The purpose of the review was to use PQSs and PQLSs to report the in vivo and in vitro results obtained by different processing kits that use different procedures (enzymatic vs. non-enzymatic) to isolate human AD-SVFs/AD-MSCs. PQSs included the volume of fat tissue harvested and reagents used, the time/gravity of centrifugation, and the time, temperature, and tilt level/speed of incubation and/or centrifugation. PQLSs included the use of a collagenase, a processing time of 30 min, kit weight, transparency of the kit components, the maintenance of a closed sterile processing environment, and the use of a small centrifuge and incubating rocker. Using a kit with the PQSs and PQLSs described in this study enables the isolation of AD-MSCs that meet the consensus quality criteria. As the discovery of new critical quality attributes (CQAs) of AD-MSCs evolve with respect to purity and potency, adjustments to these benchmark PQSs and PQLs will hopefully isolate AD-MSCs of various CQAs with greater reproducibility, quality, and safety. Confirmatory studies will no doubt need to be completed.

Comparable effect of adipose-derived stromal vascular fraction and mesenchymal stem cells for wound healing: An in vivo study

Introduction: Mesenchymal stem cells (MSCs) have been known to have angiogenic potency, particularly for wound healing. However, it is such a cumbersome procedure to obtain a large amount of MSCs due to the culture process. The stromal vascular fraction (SVF), or so called nonexpanded MSCs, of adipose tissue is gaining increased interest in the field of cell therapy. An optimized method that takes only 2 hours to produce a large amount of stromal cells from adipose tissue has been developed. Burn wound model was used to assess the efficacy of SVF produced by our method. This study aimed to evaluate the efficacy of SVF compared to MSCs. Methods: Male Sprague-Dawley rats with second degree burn wound were divided into the study groups: SVF, MSCs and saline control. The wound was photographed and evaluated weekly up to 5 weeks. The comparative analysis consisted of healing time, histology of skin tissue, as well as rat and human vascular endothelial growth factor (VEGF) expression. Results: In this study, wounds treated with SVF and MSCs were smaller after 14-21 days, compared to the untreated group. Expression of rat VEGF in SVF and MSC- treated groups after seven days post-wounded were also higher than the untreated group. No human VEGF was found expressed in the skin biopsies. Conclusion: This suggests that SVF and MSCs promote wound healing via a paracrine effect. The results suggest that SVF may be useful for wound healing and may be used as a promising alternative to MSC-based therapy. &nbsp;