Therapeutic applications of adipose-derived stromal vascular fractions in osteoarthritis

Osteoarthritis(OA)is considered to be a highly heterogeneous disease with progressive cartilage loss,subchondral bone remodeling,and low-grade inflammation.It is one of the world's leading causes of disability.Most conventional clinical treatments for OA are palliative drugs,which cannot fundamentally cure this disease.The stromal vascular fraction(SVF)from adipose tissues is a heterogeneous cell population.According to previous studies,it contains a large number of mesenchymal stem cells,which have been used to treat OA with good therapeutic results.This safe,simple,and effective therapy is expected to be applied and promoted in the future.In this paper,the detailed pathogenesis,diagnosis,and current clinical treatments for OA are introduced.Then,clinical studies and the therapeutic mechanism of SVF for the treatment of OA are summarized.

Ultrasound-assisted isolation:A new method to isolate stromal vascular fraction

Background:The stromal vascular fraction(SVF),a cluster of stem and progenitor cells isolated from adipose tissue,holds significant promise for application in regenerative medicine.However,the existing methods for SVF isolation are time-consuming and expensive.Thus,in this study,we explored a new method of SVF extrac-tion-ultrasound-assisted SVF isolation(USASI)-and compared the viability and characteristics of SVF isolated using different methods.Methods:SVF extraction methods using different combinations of ultrasound power,ultrasound time,collagenase dosage,and collagenase digestion time were compared with those of the control group(collagenase digestion method).The cell yield and vitality of the SVF were evaluated via cell counting and trypan blue staining.The cell components and immunophenotypes of freshly isolated SVF were analyzed using flow cytometry.The prolifer-ative capacity and differentiation potential of the SVF were also identified.Results:Ultrasonication at 95 W-20 kHz for 30 s followed by digestion with 0.15%collagenase for 30 min was identified as the most suitable parameter for the USASI method in isolating SVF,as recommended based on the evaluation of various tested conditions.The USASI method significantly reduced the collagenase dosage and shortened the digestion time.Compared to the collagenase digestion method,the USASI method had a higher cell yield and cell viability,with no adverse effects on cell components,proliferative capacity,or multipotential differentiation capacity.Conclusion:With reduced processing time,lower collagenase dosage,and increased cell yield without impairing the viability and characteristics of SVF,USASI holds the potential to emerge as a time-saving and cost-effective method for future clinical applications.

Efficacy of stromal vascular fraction for knee osteoarthritis:A prospective,single-centre,non-randomized study with 2 years follow-up

BACKGROUND Current osteoarthritis(OA)treatments focus on symptom relief without addressing the underlying disease process.In regenerative medicine,current treatments have limitations.In regenerative medicine,more research is needed for intra-articular stromal vascular fraction(SVF)injections in OA,including dosage optimization,long-term efficacy,safety,comparisons with other treatments,and mechanism exploration.AIM To compare the efficacy of intra-articular SVF with corticosteroid(ICS)injections in patients with primary knee OA.METHODS The study included 50 patients with Kellgren-Lawrence grades II and III OA.Patients were randomly assigned(1:1)to receive either a single intra-articular SVF injection(group A)or a single intra-articular ICS(triamcinolone)(group B)injection.Patients were followed up at 1,3,6,12,and 24 months.Visual analog score(VAS)and International Knee Documentation Committee(IKDC)scores were administered before the procedure and at all followups.The safety of SVF in terms of adverse and severe adverse events was recorded.Statistical analysis was performed with SPSS Version 26.0,IBM Corp,Chicago,IL,United States.RESULTS Both groups had similar demographics and baseline clinical characteristics.Follow-up showed minor patient loss,resulting in 23 and 24 in groups A and B respectively.Group A experienced a notable reduction in pain,with VAS scores decreasing from 7.7 to 2.4 over 24 months,compared to a minor reduction from 7.8 to 6.2 in Group B.This difference in pain reduction in group A was statistically significant from the third month onwards.Additionally,Group A showed significant improvements in knee functionality,with IKDC scores rising from 33.4 to 83.10,whereas Group B saw a modest increase from 36.7 to 45.16.The improvement in Group A was statistically significant from 6 months and maintained through 24 months.CONCLUSION Our study demonstrated that intra-articular administration of SVF can lead to reduced pain and improved knee function in patients with primary knee OA.More adequately powered,multi-center,double-blinded,randomised clinical trials with longer follow-ups are needed to further establish safety and justify its clinical use.

Understanding and controlling the variables for stromal vascular fraction therapy

In regenerative medicine,the isolation of mesenchymal stromal cells(MSCs)from the adipose tissue’s stromal vascular fraction(SVF)is a critical area of study.Our review meticulously examines the isolation process of MSCs,starting with the extraction of adipose tissue.The choice of liposuction technique,anatomical site,and immediate processing are essential to maintain cell functionality.We delve into the intricacies of enzymatic digestion,emphasizing the fine-tuning of enzyme concentrations to maximize cell yield while preventing harm.The review then outlines the filtration and centrifugation techniques necessary for isolating a purified SVF,alongside cell viability assessments like flow cytometry,which are vital for confirming the efficacy of the isolated MSCs.We discuss the advantages and drawbacks of using autologous vs allogeneic SVF sources,touching upon immunocompatibility and logistical considerations,as well as the variability inherent in donor-derived cells.Anesthesia choices,the selection between hypo-dermic needles vs liposuction cannulas,and the role of adipose tissue lysers in achieving cellular dissociation are evaluated for their impact on SVF isolation.Centrifugation protocols are also analyzed for their part in ensuring the integrity of the SVF.The necessity for standardized MSC isolation protocols is highlighted,promoting reproducibility and successful clinical application.We encourage ongoing research to deepen the understanding of MSC biology and therapeutic action,aiming to further the field of regenerative medicine.The review concludes with a call for rigorous research,interdisciplinary collaboration,and strict adherence to ethical and regulatory standards to safeguard patient safety and optimize treatment outcomes with MSCs.

Emergence of the stromal vascular fraction and secretome in regenerative medicine

Recently,we read a mini-review published by Jeyaraman et al.The article explored the optimal methods for isolating mesenchymal stromal cells from adipose tissue-derived stromal vascular fraction(SVF).Key factors include tissue source,processing techniques,cell viability assessment,and the advantages/disadvantages of autologous vs allogeneic use.The authors emphasized the need for standardized protocols for SVF isolation,ethical and regulatory standards for cell-based therapy,and safety to advance mesenchymal stromal cell-based therapies in human patients.This manuscript shares our perspective on SVF isolation in canines.We discussed future directions to potentiate effective regenerative medicine therapeutics in human and veterinary medicine.

Non-enzymatic methods for isolation of stromal vascular fraction and adipose-derived stem cells:A systematic review

BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.

Activity of the Mechanically Isolated Hybrid Stromal Vascular Fraction on Osteoarthritis

Background: Regenerative medicine holds promise for treating degenerative and inflammatory conditions like osteoarthritis (OA). However, the complex molecular mechanisms of OA and the limitations of current therapies remain challenges. Adipose-derived stem cells (ADSC) and stromal vascular fraction (SVF) are gaining attention for OA treatment due to their abundance in adipose tissue. The literature delineates two primary techniques for SVF extraction from adipose tissue: enzymatic digestion and mechanical methods. The Lipocube Hybrid SVF presents a straightforward and secure mechanical isolation method for SVF, enhancing its regenerative potential for various applications. Purpose: This study aims to provide valuable insights into the potential of Lipocube Hybrid SVF as a regenerative therapy for OA, contributing to the broader understanding of its applicability in addressing this debilitating condition. Method: To assess the effectiveness and safety of the Lipocube Hybrid SVF, we have designed a comparative study that evaluates cellular activity and viability, phenotypic characterization, and differentiation potential. The in vitro activity of mechanically isolated SVF is compared to the established gold standard enzymatic digestion method. After in vitro studies, Lipocube Hybrid mechanical isolation method was used to isolate SVF and applied in 42 knee and 7 hip joints of 28 patients with Grade II, Grade III, and Grade IV OA. Results: The Lipocube Hybrid group had slightly lower viable cell numbers but higher cell viability. Flow cytometry analysis showed the Lipocube Hybrid group exhibited more favorable markers for regenerative potential and reduced inflammatory response. Additionally, both groups demonstrated successful osteogenic differentiation, with the Lipocube Hybrid group excelling in chondrogenic and adipogenic differentiation. The clinical application of the Lipocube Hybrid SVF in OA patients resulted in significant improvements in WOMAC and VAS scores across different OA grades. Conclusions: This comparative study was conducted to evaluate the effectiveness and safety of the Lipocube Hybrid SVF, which has shown promise in laboratory settings, for different stages of osteoarthritis. The study findings provide valuable insights into the potential of Lipocube Hybrid SVF as a regenerative therapy for OA, highlighting its suitability for addressing this debilitating condition.

Fat Grafting for Rejuvenation and Regeneration with Stromal Vascular Fraction Gel

Lipotransfer has become a powerful regenerative tool,largely because of its cellular components,the stromal vascular fraction(SVF).However,the clinical separation of cells with collagenase is strictly legislated.In 2017,Yao et al.postulated a novel fat-derived product mechanically concentrating SVF cells and an extracellular matrix(ECM)and named it stromal vascular fraction gel(SVF-gel).This review discussed the protocol of SVF-gel and its component as well as its inner structure.The histologic examination and the retention rate after the transplantation of SVF-gel were also rendered.Moreover,we summed up the rejuvenating and regenerative use of SVF-gel and introduced its possible mechanism.

Evaluation of TransFix^(■) Mediated Stabilisation of Adipose-Derived Stromal Vascular Fraction for Delayed Flow Cytometry Analysis

The increasing implementation of multicentre studies has led to a need for the optimization of a method that allows for accurate post-hoc analysis of patient biological samples. Assessment of total cell number, viability and immunophenotype can present logistical challenges which can be aided by batch processing. The increased sample storage time that this requires necessitates the use of reagents to preserve cellular integrity, viability and immunophenotype. TransFix is a stabilising reagent that has been developed for the preservation of cell numbers and cell marker expression in peripheral whole blood for up to ten days. This study investigated the use of TransFix reagent for the preservation of the stromal vascular fraction (SVF) of collagenase digested adipose tissue. It was demonstrated that TransFix was suitable for accurately measuring nucleated SVF cell numbers for up to seven days as well as back calculating original cell viability. It also stabilised three CD markers commonly used to identify populations within SVF (CD90, CD31 and CD45) for up to seven days. There was no significant difference between the number of CD90, CD31 and CD45 positive cells after stabilisation at Day 7 compared to Day 0 unstabilised samples. The results suggest that TransFix can be used to preserve a biological mixed cell population from human adipose-derived SVF for up to seven days for accurate post-hoc analysis.

Experimental study of the effect of adipose stromal vascular fraction cells on the survival rate of fat transplantation

Objective To investigate the effect of adipose stromal vascular fraction cells(SVFs)on the survival rate of fat ransplantation.Methods 0.5mL autologous fat tissue was mixed with: ① DiI-labeled autologous SVFs (Group A);②

Adipose-derived regenerative therapies for the treatment of knee osteoarthritis

Knee osteoarthritis is a degenerative condition with a significant disease burden and no disease-modifying therapy.Definitive treatment ultimately requires joint replacement.Therapies capable of regenerating cartilage could significantly reduce financial and clinical costs.The regenerative potential of mesenchymal stromal cells(MSCs)has been extensively studied in the context of knee osteoarthritis.This has yielded promising results in human studies,and is likely a product of immunomodulatory and chondroprotective biomolecules produced by MSCs in response to inflammation.Adipose-derived MSCs(ASCs)are becoming increasingly popular owing to their relative ease of isolation and high proliferative capacity.Stromal vascular fraction(SVF)and micro-fragmented adipose tissue(MFAT)are produced by the enzymatic and mechanical disruption of adipose tissue,respectively.This avoids expansion of isolated ASCs ex vivo and their composition of heterogeneous cell populations,including immune cells,may potentiate the reparative function of ASCs.In this editorial,we comment on a multicenter randomized trial regarding the efficacy of MFAT in treating knee osteoarthritis.We discuss the study’s findings in the context of emerging evidence regarding adipose-derived regenerative therapies.An underlying mechanism of action of ASCs is proposed while drawing important distinctions between the properties of isolated ASCs,SVF,and MFAT.

Adipose-derived stem cells and knee osteoarthritis:New perspectives,old concerns

In this editorial,we comment on the paper by Muthu et al published in the recent issue of the journal.This editorial review focusses on the use of adipose-derived stem cells(ADSCs)in knee osteoarthritis treatment.We discuss the differences between the stromal vascular fraction and microfragmented adipose tissue and highlight the results of clinical studies comparing both treatments and the use of hyaluronic acid,platelet-rich plasma,and bone marrow aspirate concentrate.The use of expanded ADSCs is also discussed;moreover,concerns regarding treatment with ADSCs,particularly the heterogeneity of published studies and the need to standardize protocols to explore clinical potential is explored.

How to preserve the native or reconstructed esophagus after perforations or postoperative leaks: A multidisciplinary 15-year experience

BACKGROUND Esophageal perforation or postoperative leak after esophageal surgery remain a life-threatening condition.The optimal management strategy is still unclear.AIM To determine clinical outcomes and complications of our 15-year experience in the multidisciplinary management of esophageal perforations and anastomotic leaks.METHODS A retrospective single-center observational study was performed on 60 patients admitted at our department for esophageal perforations or treated for an anastomotic leak developed after esophageal surgery from January 2008 to December 2023.Clinical outcomes were analyzed,and complications were evaluated to investigate the efficacy and safety of our multidisciplinary management based on the preservation of the native or reconstructed esophagus,when feasible.RESULTS Among the whole series of 60 patients,an urgent surgery was required in 8 cases due to a septic state.Fifty-six patients were managed by endoscopic or hybrid treatments,obtaining the resolution of the esophageal leak/perforation without removal of the native or reconstructed esophagus.The mean time to resolution was 54.95±52.64 days,with a median of 35.5 days.No severe complications were recorded.Ten patients out of 56(17.9%)developed pneumonia that was treated by specific antibiotic therapy,and in 6 cases(10.7%)an atrial fibrillation was recorded.Seven patients(12.5%)developed a stricture within 12 months,requiring one or two endoscopic pneumatic dilations to solve the problem.Mortality was 1.7%.CONCLUSION A proper multidisciplinary approach with the choice of the most appropriate treatment can be the key for success in managing esophageal leaks or perforations and preserving the esophagus.

Advancements in adipose-derived stem cell therapy for skin fibrosis

Pathological scarring and scleroderma,which are the most common conditions of skin fibrosis,pathologically manifest as fibroblast proliferation and extracellular matrix(ECM)hyperplasia.Fibroblast proliferation and ECM hyperplasia lead to fibrotic tissue remodeling,causing an exaggerated and prolonged wound-healing response.The pathogenesis of these diseases has not been fully clarified and is unfortunately accompanied by exceptionally high medical needs and poor treatment effects.Currently,a promising and relatively low-cost treatment has emerged-adipose-derived stem cell(ASC)therapy as a branch of stem cell therapy,including ASCs and their derivatives-purified ASC,stromal vascular fraction,ASC-conditioned medium,ASC exosomes,etc.,which are rich in sources and easy to obtain.ASCs have been widely used in therapeutic settings for patients,primarily for the defection of soft tissues,such as breast enhancement and facial contouring.In the field of skin regeneration,ASC therapy has become a hot research topic because it is beneficial for reversing skin fibrosis.The ability of ASCs to control profibrotic factors as well as anti-inflammatory and immunomodulatory actions will be discussed in this review,as well as their new applications in the treatment of skin fibrosis.Although the long-term effect of ASC therapy is still unclear,ASCs have emerged as one of the most promising systemic antifibrotic therapies under development.

Adipose-derived stem cells:Pathophysiologic implications vs therapeutic potential in systemic sclerosis

Adipose-derived stem cells(ADSCs)residing in the stromal vascular fraction(SVF)of white adipose tissue are recently emerging as an alternative tool for stem cell-based therapy in systemic sclerosis(SSc),a complex connective tissue disorder affecting the skin and internal organs with fibrotic and vascular lesions.Several preclinical and clinical studies have reported promising therapeutic effects of fat grafting and autologous SVF/ADSC-based local treatment for facial and hand cutaneous manifestations of SSc patients.However,currently available data indicate that ADSCs may represent a double-edged sword in SSc,as they may exhibit a pro-fibrotic and anti-adipogenic phenotype,possibly behaving as an additional pathogenic source of pro-fibrotic myofibroblasts through the adipocyte-to-myofibroblast transition process.Thus,in the perspective of a larger employ of SSc-ADSCs for further therapeutic applications,it is important to definitely unravel whether these cells present a comparable phenotype and similar immunosuppressive,anti-inflammatory,anti-fibrotic and pro-angiogenic properties in respect to healthy ADSCs.In light of the dual role that ADSCs seem to play in SSc,this review will provide a summary of the most recent insights into the preclinical and clinical studies employing SVF and ADSCs for the treatment of the disease and,at the same time,will focus on the main findings highlighting the possible involvement of these stem cells in SSc-related fibrosis pathogenesis.

Combination of stromal vascular fraction and Ad-COMP-Angl gene therapy improves long-term therapeutic efficacy for diabetes-induced erectile dysfunction

Men with diabetic erectile dysfunction （ED） respond poorly to the currently available oral phosphodiesterase-5 inhibitors. Therefore, functional therapies for diabetic ED are needed. Stromal vascular fraction （SVF） and the adenovirus-mediated cartilage oligomeric matrix angiopoietin-1 （Ad-COMP-Angl） gene are known to play critical roles in penile erection. We previously reported that SVF and Ad-COMP-Ang1 have only a short-term effect in restoring erectile function. Further improvements to ED therapy are needed for long-lasting effects. In the present study, we aimed to test if the combination of SVF and Ad-COMP-Ang1 could extend the erection effect in diabetic ED. We found that the combination therapy showed a long-term effect in restoring erectile function through enhanced penile endothelial and neural cell regeneration. Combination therapy with SVF and Ad-COMP-Angl notably restored cavernous endothelial cell numbers, pericyte numbers, endothelial cell-cell junctions, decreased cavernous endothelial cell permeability, and promoted neural regeneration for at least 4 weeks in diabetic mice, In summary, this is an initial description of the long-term effect of combination therapy with SVF and Ad-COMP-Ang1 in restoring erectile function through a dual effect on endothelial and neural cell regeneration. Such combination therapy may have therapeutic potential for the treatment of diabetic ED.

Intra-articular injection of stromal vascular fraction for knee degenerative joint disease:a concise review of preclinical and clinical evidence

Autologous fat-derived stromal vascular fraction(SVF) is a mixed cell population that has been used for many years in regenerative plastic surgery.In terms of animal and clinical research,this concise review was performed to evaluate the efficacy of SVF in knee degenerative joint disease(KDJD),which could cause pain,disability and severely affect patients’ lives.Thirteen studies retrieved and screened from the databases were included,including six animal studies and seven clinical trials.The metaanalysis of clinical research shows that intra-articular injection of SVF,in combination with adjuvant surgery,could alleviate pain and improve early functional recovery for patients with KDJD at Kellgren-Lawrence(KL) grades Ⅱ–Ⅲ.

Current Status of ADSCs-Enriched Fat Grafts in Plastic Surgery

Autologous fat grafting is an increasingly popular technique in plastic surgery for volume augmentation and rejuvenation.However,the unpredictability of long-term volume retention limits its clinical application.Various animal studies have documented the positive effects of adipose tissue-derived stem cells(ADSCs)on the acceleration of lipofilling.However,the results have been inconsistent,and there is an insufficient number of high-quality clinical studies to formulate evidence-based recommendations for ADSC-enriched fat grafts.Moreover,related technical standards,such as the final count of harvested ADSCs and the enrichment ratio,have not yet been established.This systematic review included all clinical trials on ADSC-enriched fat grafts in plastic surgery from PubMed in the past 10 years,as well as all registered clinical trials on ClinicalTrials.Gov.To examine the current landscape of ADSCs harvest,we summarize the current applications of ADSCs in the field of plastic surgery and discuss the current barriers to universal clinical use.

Enzymatic and non-enzymatic isolationsystems for adipose tissue-derived cells:current state of the art

In the past decade, adipose tissue became a highly interesting source of adult stem cells for plastic surgery andregenerative medicine. The isolated stromal vascular fraction (SVF) is a heterogeneous cell population including theadipose-derived stromal/stem cells (ASC), which showed regenerative potential in several clinical studies and trials.SVF should be provided in a safe and reproducible manner in accordance with current good manufacturing practices(cGMP). To ensure highest possible safety for patients, a precisely defined procedure with a high-quality control isrequired. Hence, an increasing number of adipose tissue-derived cell isolation systems have been developed.These systems aim for a closed, sterile, and safe isolation process limiting donor variations, risk for contaminations,and unpredictability of the cell material. To isolate SVF from adipose tissue, enzymes such as collagenase are used.Alternatively, in order to avoid enzymes, isolation systems using physical forces are available. Here, we provide anoverview of known existing enzymatic and non-enzymatic adipose tissue-derived cell isolation systems, which arepatented, published, or already on the market.

Adipose-derived cells:building blocks of three-dimensional microphysiological systems

Microphysiological systems(MPS)created with human-derived cells and biomaterial scaffolds offer a potential in vitro alternative to in vivo animal models.The adoption of three-dimensional MPS models has economic,ethical,regulatory,and scientific implications for the fields of regenerative medicine,metabolism/obesity,oncology,and pharmaceutical drug discovery.Key opinion leaders acknowledge that MPS tools are uniquely positioned to aid in the objective to reduce,refine,and eventually replace animal experimentation while improving the accuracy of the finding’s clinical translation.Adipose tissue has proven to be an accessible and available source of human-derived stromal vascular fraction(SVF)cells,a heterogeneous population available at point of care,and adipose-derived stromal/stem cells,a relatively homogeneous population requiring plastic adherence and culture expansion of the SVF cells.The adipose-derived stromal/stem cells or SVF cells,in combination with human tissue or synthetic biomaterial scaffolds,can be maintained for extended culture periods as three-dimensional MPS models under angiogenic,stromal,adipogenic,or osteogenic conditions.This review highlights recent literature relating to the versatile use of adipose-derived cells as fundamental components of three-dimensional MPS models for discovery research and development.In this context,it compares the merits and limitations of the adipose-derived stromal/stem cells relative to SVF cell models and considers the likely directions that this emerging field of scientific discovery will take in the near future.