Clinical results and second-look arthroscopic findings after treatment with adipose-derived stem cells for knee osteoarthritis

Therapeutic Effects of Mesenchymal Stem Cells Derived from Bone Marrow and Adipose Tissue in a Rat Model of Temporomandibular Osteoarthritis

OBJECTIVES

To examine the potential of intra-articular administration of mesenchymal stem cells (MSCs) derived from bone marrow or adipose tissue to mitigate synovial inflammation in a rat model of temporomandibular joint (TMJ) osteoarthritis (OA).

METHODS

In this experimental study, 40 rats were divided into 4 groups: (1) Control group; (2) Untreated TMJ-OA group; (3) TMJ-OA group treated with bone marrow-derived MSCs; (4) TMJ-OA group treated with adipose tissue-derived MSCs. The TMJ-OA model was established by inducing synovial inflammation through the intra-articular administration of complete Freund's adjuvant (CFA). After 8 weeks of TMJ-OA establishment, the animals were sacrificed and each mandibular condyle was extracted for histological evaluation.

RESULTS

The untreated TMJ-OA group had significantly higher synovial inflammation, as indicated microscopically by higher grades of synovial membrane hyperplasia and adhesion, vascular vasodilation, and fibrin deposition than the control group (p < 0.001). Both TMJ-OA groups treated with MSCs had lower grades of synovial inflammation and less severe synovitis than the untreated TMJ-OA group (p < 0.001). The TMJ-OA group treated with adipose tissue-derived MSCs showed lower grades of synovial membrane hyperplasia and higher grades of fibrin deposition than the that treated with bone marrow-derived MSCs (p < 0.001). Other indicators of synovial inflammation and synovitis severity were comparable between the two treatment groups.

CONCLUSIONS

Administration of CFA to the TMJ-OA rat model augmented synovial inflammation. Intra-articular administration of MSCs derived from either bone marrow or adipose tissue attenuated the microscopic manifestations of this inflammation, indicating the therapeutic potential of this treatment for TMJ-OA.

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 follow-ups. 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.

Intra-Articular Application of Autologous, Fat-Derived Orthobiologics in the Treatment of Knee Osteoarthritis: A Systematic Review

The aim of this study was to review the current literature regarding the effects of intra-articularly applied, fat-derived orthobiologics (FDO) in the treatment of primary knee osteoarthritis over a mid-term follow-up period. A systematic literature search was conducted on the online databases of Scopus, PubMed, Ovid MEDLINE, and Cochrane Library. Studies investigating intra-articularly applied FDO with a minimum number of 10 knee osteoarthritis patients, a follow-up period of at least 2 years, and at least 1 reported functional parameter (pain level or Patient-Reported Outcome Measures) were included. Exclusion criteria encompassed focal chondral defects and techniques including additional arthroscopic bone marrow stimulation. In 28 of 29 studies, FDO showed a subjective improvement in symptoms (pain and Patient-Reported Outcome Measures) up to a maximum follow-up of 7.2 years. Radiographic cartilage regeneration up to 3 years postoperatively, as well as macroscopic cartilage regeneration investigated via second-look arthroscopy, may corroborate the favorable clinical findings in patients with knee osteoarthritis. The methodological heterogeneity in FDO treatments leads to variations in cell composition and represents a limitation in the current state of knowledge. However, this systematic review suggests that FDO injection leads to beneficial mid-term results including symptom reduction and preservation of the affected joint in knee osteoarthritis patients.

Autologous microfragmented adipose tissue treatment of knee osteoarthritis demonstrates effectiveness in 68% of patients at 4-year follow-up

BACKGROUND

Adipose tissue-derived stem cells are an interesting therapeutic option for early knee osteoarthritis (OA) treatment due to their high plasticity, easiness of harvesting and rapidity of administration. The aim of this study was to evaluate the medium-term effectiveness and safety of Microfragmented Autologous Fat Tissue (MFAT) injection treatment at 4-year follow-up and to investigate potential correlations among patients' pre-treatment clinical condition and clinical outcomes to identify possible predicting factors for procedure success or failure.

PATIENTS AND METHODS

This is a prospective trial enrolling 46 patients with diagnosis of symptomatic knee OA and failure of previous conservative measures who underwent diagnostic arthroscopy and single autologous MFAT injection between June 2017 and July 2018. Patients were assessed with repeated clinical scoring systems at baseline, 6 months, 1 and 4 years after surgery. The evaluation included demographic characteristics, arthroscopic findings, and stem cell number from injected tissue.

RESULTS

No major complications were reported during follow-up period and there was a significant increase of Lysholm knee score from baseline value of 61.7 ± 13.8 to 79.5 ± 16.9 at 4 years (p < 0.001). The WOMAC score increased from a baseline value of 66.5 ± 14.7 to 82.8 ± 15.7 at 4 years (p < 0.001) and there was a significant decrease of VAS pain score from baseline value of 6.3 ± 1.5 to 3.5 ± 2.6 at 4-year follow-up (p < 0.001). ROM improved significantly from 118.4 ± 2.6 to 122.5 ± 2.5 at 12 months (p < 0.001), but did not improve at 4 years (p > 0.05). 15 patients (32.6%) were considered treatment failures, because they required secondary surgery, further injection therapy or experienced symptoms persistence. Patient with synovitis had 75% failure rate, although synovitis did not result as a statistically significant factor influencing clinical outcome up to 4-year follow-up (p = 0.058). Age, cartilage defects severity, BMI, concomitant procedures, and stem cell number from injected MFAT did not show any significant correlation with the results.

CONCLUSIONS

MFAT intra-articular injection is a safe procedure with positive improvements up to 4-year follow-up in patients with early knee OA. These findings suggest MFAT could be a minimally invasive treatment of early knee OA with durable benefits at mid-term evaluation.

TRIAL REGISTRATION

IRB number ID-3522.

Stromal Vascular Fraction Therapy for Knee Osteoarthritis: A Systematic Review

Background and Objectives: Knee osteoarthritis (OA) is a widespread joint disease, set to increase due to aging and rising obesity. Beyond cartilage degeneration, OA involves the entire joint, including the synovial fluid, bones, and surrounding muscles. Existing treatments, such as NSAIDs and corticosteroid injections, mainly alleviate symptoms but can have complications. Joint replacement surgeries are definitive but carry surgical risks and are not suitable for all. Stromal vascular fraction (SVF) therapy is a regenerative approach using cells from a patient's adipose tissue. SVF addresses as degenerative and inflammatory aspects, with potential for cartilage formation and tissue regeneration. Unlike traditional treatments, SVF may reverse OA changes. Being autologous, it reduces immunogenic risks. Materials and Methods: A systematic search was undertaken across PubMed, Medline, and Scopus for relevant studies published from 2017 to 2023. Keywords included "SVF", "Knee Osteoarthritis", and "Regenerative Medicine". Results: This systematic search yielded a total of 172 articles. After the removal of duplicates and an initial title and abstract screening, 94 full-text articles were assessed for eligibility. Of these, 22 studies met the inclusion criteria and were subsequently included in this review. Conclusions: This review of SVF therapy for knee OA suggests its potential therapeutic benefits. Most studies confirmed its safety and efficacy, and showed improved clinical outcomes and minimal adverse events. However, differences in study designs and sizes require a careful interpretation of the results. While evidence supports SVF's positive effects, understanding methodological limitations is key. Incorporating SVF is promising, but the approach should prioritize patient safety and rigorous research.

Midterm results of intra-articular stromal vascular fraction injection for the treatment of knee osteoarthritis

PURPOSE

This study aimed to evaluate the safety and efficacy of intra-knee stromal vascular fraction (SVF) injection in patients with symptomatic knee osteoarthritis at the midterm (3-year) follow-up.

METHODS

SVF injection was applied to 25 knees of 20 patients. Eighteen patients (90%) were female, and the means ± standard deviations of age was 61.9 ± 7.8 (range, 50-76) years. Patients who received conservative treatment for at least 6 months and had radiographic Kellgren-Lawrence (K-L) grades 2 and 3 varus gonarthrosis were included in the study. SVF was obtained from the umbilical region by liposuction using local anaesthesia. Patients were followed-up for 36 months. Their visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Lysholm scores were evaluated before and at 6, 12, 24 and 36 months post-SVF injection.

RESULTS

A statistically significant improvement (p < 0.05) was observed in VAS, WOMAC and Lysholm scores at the first 2-year follow-up compared to baseline. However, no statistically significant difference (n.s.) was observed in VAS, WOMAC and Lysholm scores at the 3-year follow-up compared with baseline.

CONCLUSION

Intra-articular SVF injection decreased pain and significantly improved the functional outcomes in the first 2 years in knees with grade 2-3 osteoarthritis; however, these positive effects of the injection disappeared in the 3rd year. Although short-term successful results of SVF have been reported in the literature, prospective studies are needed for medium- and long-term results.

Using Pre-Clinical Studies to Explore the Potential Clinical Uses of Exosomes Secreted from Induced Pluripotent Stem Cell-Derived Mesenchymal Stem cells

Recent studies of exosomes derived from mesenchymal stem cells (MSCs) have indicated high potential clinical applications in many diseases. However, the limited source of MSCs impedes their clinical research and application. Most recently, induced pluripotent stem cells (iPSCs) have become a promising source of MSCs. Exosome therapy based on iPSC-derived MSCs (iMSCs) is a novel technique with much of its therapeutic potential untapped. Compared to MSCs, iMSCs have proved superior in cell proliferation, immunomodulation, generation of exosomes capable of controlling the microenvironment, and bioactive paracrine factor secretion, while also theoretically eliminating the dependence on immunosuppression drugs. The therapeutic effects of iMSC-derived exosomes are explored in many diseases and are best studied in wound healing, cardiovascular disease, and musculoskeletal pathology. It is pertinent clinicians have a strong understanding of stem cell therapy and the latest advances that will eventually translate into clinical practice. In this review, we discuss the various applications of exosomes derived from iMSCs in clinical medicine.

Clinical Outcome of Minimally Manipulated, Mechanically Isolated Autologous Adipose Tissue-Derived Stromal Vascular Fraction (Sahaj Therapy®) in Knee Osteoarthritis-Randomized Controlled Trial

Introduction

Regenerative therapy has shown promising results in the treatment of osteoarthritis (OA) knee with Kellgren-Lawrence (KL) Grades I-III. We compared the safety, efficacy, functional, and clinical outcomes of intra-articular implantation of autologous adipose tissue-derived stromal vascular fraction (SVF) isolated using direct ultrasonic cavitation (Sahaj therapy-Cell Innovation Patented Technology) and saline injection in knee osteoarthritis.

Materials and Methods

The present prospective observational study was conducted over 3 years. We enrolled 120 patients in our study, where four patients got excluded as they did not meet the inclusion criteria. The remaining 116 patients were randomized into two groups, one with autologous adipose tissue-derived SVF and the other group with saline injection. A comparison of mean KOOS and VAS scores at different follow-ups was done using Paired 't' test. A p value of < 0.05 was considered significant.

Results

The results show that the SVF group had significantly higher KOOS scores (78.49 ± 6.54 in the SVF group vs 59.19 ± 5.14 in the saline group), respectively (p < 0.001). Similarly, the SVF group had significantly lesser VAS scores (3.17 ± 0.94 in the SVF group vs 3.89 ± 1.04 in the saline group), respectively (p < 0.001).

Conclusions

Autologous adipose tissue-derived SVF is a better choice for treating knee osteoarthritis. For individuals with degenerative osteoarthritis, autologous SVF grafting in the same surgical procedure is an innovative and promising treatment modality. Even after 3 years of follow-up, the study participants with OA knee have shown a good clinical and functional outcome.

The Use of Stromal Vascular Fraction in Long Bone Defect Healing in Sheep

The objectives of the present study were to evaluate (a) the feasibility of using stromal vascular fraction (SVF) and nanocrystalline hydroxyapatite (nHA) paste in combination for the treatment of segmental bone defect, (b) the quality of the callus produced, (c) the potential improvement of the autograft technique, and (d) the direct comparison of the biomaterial to the use of autogenous cancellous bone. Unilateral, segmental mid-diaphyseal bone defect was created on the right metatarsus of skeletally mature sheep animals (n = 24) under anesthesia (D0). Residual segments were stabilized by stainless-steel plates and appropriate screws. Defects were managed as follows: group A: use of nHA paste to filling, group B: use of autogenous bone graft mixed with nHA bone paste, placed in defect, group C: use of SVF mixed with nHA bone paste injected into defect, group D: use of bone graft and SVF with nHA paste before apposition in bone defect. SVF had been previously isolated from adipose tissue of the animals intra-operatively after digestion with collagenase solution and neutralization. Animals were evaluated clinically and by X-raying and ultrasonographic examination of the defect, at regular intervals, until D90. Ultrasonographic assessment performed along the length of the defect included calculation of the length of the bone defect and assessment of vascularization. SVF was successfully isolated from group C and D animals, with the average yield being 1.77 × 106 cells. The comparison of clinical scores (based on the 'Kaler scale') on each post-operative day indicated significant differences between the four groups on D1 to D30 (p < 0.01); the median clinical score within group A was 2.5 for D1-D30 and 1 for the entire period; respective scores for other groups were 1.5 (p = 0.07) and 0 (p = 0.033). Differences in radiographic assessment scores were significant for scores obtained on D60 (p = 0.049) and D90 (p = 0.006). There was a significant difference between the four groups in the length of the bone defect, as assessed ultrasonographically, for the entire length of the study; median values were 8, 8.5, 6, and 8 mm for groups A, B, C, and D, respectively (p = 0.008). There was a significance in the differences between median scores obtained during the histopathological examination: 2, 11, 13.5, and 12 for group A, B, C, and D (p = 0.022). There was an inverse correlation between the overall scores of histopathological evaluations and the length of the bone defect (observed on D90) (p < 0.0001) and a correlation between the overall scores and the radiographic assessment scores (obtained on D90) (p < 0.0001). This is the first study in which the efficacy of fresh autologous Stromal Vascular Fraction (SVF) from adipose tissue in enhancing bone healing in a long, weight-bearing, diaphyseal bone was evaluated. It is concluded that the lumbosacral region was an attractive site for harvesting adipose tissue, the use of SVF contributed to faster rehabilitation post-operatively, and SVF significantly enhanced bone formation; in general, the results indicated an osteogenic potential of SVF comparable to the gold standard autologous bone graft.

Placenta-Derived Products Demonstrate Good Safety Profile and Overall Satisfactory Outcomes for Treating Knee Osteoarthritis: A Systematic Review of Clinical Evidence

PURPOSE

To summarize the available evidence regarding the clinical application of placenta-derived products to treat knee osteoarthritis (OA), underlining the differences existing among products, their preparation methods, and the clinical results reported so far.

METHODS

A research on PubMed, Cochrane, and Google Scholar databases was performed. The following inclusion criteria for relevant articles were used: (1) randomized controlled trials (RCTs), prospective and retrospective studies, on humans; (2) written in English; (3) published in indexed journals in the last 10 years (2011-2022); and (4) dealing with the use of placenta-derived products for the treatment of knee OA. Exclusion criteria were articles written in other languages; animals or in vitro trials; reviews; and trials analyzing other applications of placenta-derived products not related to knee OA.

RESULTS

In total, 16 studies were included in the present systematic review. Five studies investigated placenta-derived products as an augmentation during surgical procedures, whereas 11 studies were focused on the injective approach only. Of these, only 4 were RCTs and were all from the injective approach group. Potential risk of bias was carried out using Cochrane Risk of Bias 2 tool for RCTs and a modified Coleman approach for nonrandomized studies, revealing for both an overall insufficient quality. Clinical outcomes reveal excellent safety profile and notable efficacy, despite the different types of products used and different administration methods adopted.

CONCLUSIONS

Placental products showed a good safety profile and overall satisfactory outcomes for the treatment of knee OA.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III and IV studies.

Stromal Vascular Fraction in Osteoarthritis of the Knee

In the United States, osteoarthritis (OA) affects 30 million people among the population and poses a major disability and financial burden that impact functional quality of life among the affected individuals [...].

A systematic review, umbrella review, and quality assessment on clinical translation of stem cell therapy for knee osteoarthritis: Are we there yet?

BACKGROUND

The success of stem cell therapy for knee osteoarthritis (KOA) in preclinical animal models has accelerated the pace of clinical translation. However, it remains uncertain whether the current scientific evidence supports the clinical application of stem cells in treating KOA. A comprehensive evaluation of the safety and efficacy of stem cell therapies and scientific evidence quality is necessary.

METHODS

Using "stem cells" and "knee osteoarthritis" as the search terms, several databases, including PubMed, Web of Science, Cochrane, Embase, and Clinicaltrials.gov, were searched on August 25, 2022, and updated on February 27, 2023. Clinical studies that reported adverse reactions (ARs) of stem cell therapy in KOA patients were included without limiting the type of studies. Quantitative systematic reviews of stem cell therapy for KOA that conducted meta-analysis were included. Two researchers conducted literature screening and data extraction independently, and the evidence quality was evaluated according to the Institute of Health Economics and AMSTAR 2 criteria.

RESULTS

Fifty clinical studies and 13 systematic reviews/meta-analyses (SRs/MAs) were included. Nineteen ARs were reported in 50 studies, including five knee-related ARs, seven common ARs, and seven other ARs. Some studies reported over 10% prevalence of knee pain (24.5%; 95% CI [14.7%, 35.7%]), knee effusion (12.5%; 95% CI [4.8%, 22.5%]), and knee swelling (11.9%; 95% CI [3.5%, 23.5%]). Additionally, two studies have reported cases of prostate cancer and breast tumors, respectively. However, these two studies suggest that stem cell therapy does not bring significant ARs to patients. SRs/MAs results revealed that stem cell therapy relieved pain in patients over time but did not improve knee function. However, current clinical studies have limited evidence regarding study objectives, test designs, and patient populations. Similarly, SRs/MAs have inadequate evidence regarding study design, risk of bias assessment, outcome description, comprehensive discussion, and potential conflicts of interest.

CONCLUSIONS

The inefficacy of stem cells, the risk of potential complications, and the limited quality of evidence from current studies precluded any recommendation for using stem cell products in patients with KOA. Clinical translation of stem cell therapies remains baseless and should be cautiously approached until more robust evidence is available. PROSPERO registration number: CRD42022355875.

Clinical phase I/II trial of SVF therapy for cartilage regeneration: A cellular therapy with novel 3D MRI imaging for evaluating chondral defect of knee osteoarthritis

Background: The clinical applications of stromal vascular fraction (SVF) therapy for osteoarthritis (OA) have attracted academic and clinical attention. However, data of the effects of stromal vascular fraction therapy on regeneration of degenerated cartilage are limited in the literature. Meanwhile, there is a great need for a simple and non-invasive evaluation method to analyze the changes of joint cartilage qualitatively and quantitatively in clinical trials. This study entitled "stromal vascular fraction Therapy for Human Knee Osteoarthritis" was registered in ClinicalTrial.gov # NCT05019378. Materials and Methods: We designed and conducted a single center, open labeled clinical phase I/II study, and 6 osteoarthritis patients with both knee cartilage defect I-II were enrolled in this study. The two knees of each patient were randomly assigned to autologous stromal vascular fraction treatment group or non-treatment control group to evaluate the safety and therapeutic effect of stromal vascular fraction therapy for human knee osteoarthritis. We have also established a novel protocol to provide 3D MRI imaging for human knee cartilage enabling us to qualitatively and quantitatively evaluate cartilage degeneration and regeneration in this study. Results: The qualitative and quantitative evaluation of 3D Magnetic Resonance Imaging (MRI) imaging of knee cartilage demonstrated that the stromal vascular fraction therapy reduced the cartilage defects; and significant increase of cartilage value both in defect cartilage area and whole cartilage area of treated group and significant increase of thickness and area of both femoral and tibia cartilage in vertical sections of the stromal vascular fraction treated Group at 12 and 24 W post treatment in cartilage defect I-II osteoarthritis patients. Conclusion: This clinical phase I/II study indicated that stromal vascular fraction therapy is a safe clinical procedure and provided evidence that the stromal vascular fraction therapy significantly facilitated cartilage regeneration, opening the opportunity to a phase III trial investigating authentic efficacy of the procedure. This study is the first qualitative and quantitative evaluation of the efficacy of autologous stromal vascular fraction cellular therapy on cartilage regeneration. Through early and definite diagnosis of knee osteoarthritis patients, and providing safe and efficient therapy to facilitate cartilage regeneration, we will be able to control or reverse cartilage degeneration and completely change the epidemiology of osteoarthritis worldwide.

Cell-based therapies have disease-modifying effects on osteoarthritis in animal models. A systematic review by the ESSKA Orthobiologic Initiative. Part 1: adipose tissue-derived cell-based injectable therapies

PURPOSE

The aim of this systematic review was to determine if adipose tissue-derived cell-based injectable therapies can induce disease-modifying effects in joints affected by osteoarthritis (OA).

METHODS

A systematic review was performed on three electronic databases (PubMed, Web of Science, Embase) according to PRISMA guidelines. A synthesis of the results was performed investigating disease-modifying effects in preclinical studies comparing injectable adipose-derived products with OA controls or other products, different formulations or injection intervals, and the combination with other products. The risk of bias was assessed according to the SYRCLE's tool.

RESULTS

Seventy-one studies were included (2,086 animals) with an increasing publication trend over time. Expanded cells were used in 65 studies, 3 studies applied point of care products, and 3 studies investigated both approaches. Overall, 48 out of 51 studies (94%) reported better results with adipose-derived products compared to OA controls, with positive findings in 17 out of 20 studies (85%) in macroscopic, in 37 out of 40 studies (93%) in histological, and in 22 out of 23 studies (96%)  in immunohistochemical evaluations. Clinical and biomarker evaluations showed positive results in 14 studies out of 18 (78%) and 12 studies out of 14 (86%), while only 9 studies out of 17 (53%) of the imaging evaluations were able to detect differences versus controls. The risk of bias was low in 38% of items, unclear in 51%, and high in (11%).

CONCLUSION

The current preclinical models document consistent evidence of disease-modifying effects of adipose-derived cell-based therapies for the treatment of OA. The high heterogeneity of the published studies highlights the need for further targeted research to provide recommendations on the optimal methodologies for a more effective application of these injective therapies for the treatment of OA in clinical practice.

LEVEL OF EVIDENCE

II.

Results of Treating Mild to Moderate Knee Osteoarthritis with Autologous Conditioned Adipose Tissue and Leukocyte-Poor Platelet-Rich Plasma

Knee osteoarthritis (KOA) is one of the most common musculoskeletal disorders. Much progress has been made in regenerative medicine for the symptomatic treatment of KOA, including products containing stromal vascular fraction (SVF) and platelet-rich plasma (PRP). The aim of this study was to evaluate clinical and radiological findings after the application of autologous conditioned adipose tissue (ACA) and leukocyte-poor PRP (LP-PRP) in patients with mild to moderate KOA. A total of 16 patients (eight male and eight female) with changes related to KOA on the magnetic resonance imaging (MRI), but without severe osteophytosis, full-thickness cartilage loss, or subchondral bone involvement were included in this study. Patients received an intraarticular, ultrasound-guided injection of ACA and LP-PRP. Clinical scores, including a visual analog scale for pain (VAS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evaluated at baseline and at the three and six month follow-ups showing a statistically significant improvements at three and six months post-intervention. Furthermore, the delayed gadolinium-enhanced MRI of the cartilage (dGEMRIC) indices were evaluated at baseline and at the three and six month follow-ups showing no significant changes after treatment with ACA and LP-PRP, which were actually equal to the dGEMRIC indices measured in the control group (hyaluronic acid applied in contralateral knees without osteoarthritis). ACA with LP-PRP presents a viable minimally invasive therapeutic option for the clinical improvement of mild to moderate KOA. However, MFAT produced by different systems is likely to differ in cellular content, which can directly affect the paracrine effect (cytokine secretion) of mesenchymal stem cells and consequently the regeneration process.

Autologous Adipose-Derived Tissue Stromal Vascular Fraction (AD-tSVF) for Knee Osteoarthritis

Adipose tissue contains adult mesenchymal stem cells that may modulate the metabolism when applied to other tissues. Stromal vascular fraction (SVF) can be isolated from adipose tissue mechanically and/or enzymatically. SVF was recently used to decrease the pain and improve the function of knee osteoarthritis (OA) patients. Primary and/or secondary OA causes inflammation and degeneration in joints, and regenerative approaches that may modify the natural course of the disease are limited. SVF may modulate inflammation and initiate regeneration in joint tissues by initiating a paracrine effect. Chemokines released from SVF may slow down degeneration and stimulate regeneration in joints. In this review, we overviewed articular joint cartilage structures and functions, OA, and macro-, micro-, and nano-fat isolation techniques. Mechanic and enzymatic SVF processing techniques were summarized. Clinical outcomes of adipose tissue derived tissue SVF (AD-tSVF) were evaluated. Medical devices that can mechanically isolate AD-tSVF were listed, and publications referring to such devices were summarized. Recent review manuscripts were also systematically evaluated and included. Transferring adipose tissues and cells has its roots in plastic, reconstructive, and aesthetic surgery. Micro- and nano-fat is also transferred to other organs and tissues to stimulate regeneration as it contains regenerative cells. Minimal manipulation of the adipose tissue is recently preferred to isolate the regenerative cells without disrupting them from their natural environment. The number of patients in the follow-up studies are recently increasing. The duration of follow up is also increasing with favorable outcomes from the short- to mid-term. There are however variations for mean age and the severity of knee OA patients between studies. Positive outcomes are related to the higher number of cells in the AD-tSVF. Repetition of injections and concomitant treatments such as combining the AD-tSVF with platelet rich plasma or hyaluronan are not solidified. Good results were obtained when combined with arthroscopic debridement and micro- or nano-fracture techniques for small-sized cartilage defects. The optimum pressure applied to the tissues and cells during filtration and purification of the AD-tSVF is not specified yet. Quantitative monitoring of articular joint cartilage regeneration by ultrasound, MR, and synovial fluid analysis as well as with second-look arthroscopy could improve our current knowledge on AD-tSVF treatment in knee OA. AD-tSVF isolation techniques and technologies have the potential to improve knee OA treatment. The duration of centrifugation, filtration, washing, and purification should however be standardized. Using gravity-only for isolation and filtration could be a reasonable approach to avoid possible complications of other methodologies.

Comparative Efficacy of the Stromal-Vascular Fraction Cells of Lipoaspirate and Hyaluronic Acid in the Treatment of Gonarthrosis: Results of an Interim Analysis

The use of cell technologies, in particular the stromal-vascular fraction of adipose tissue, is a new direction in the treatment of osteoarthritis of the weight-bearing joints. Stromal-vascular fraction cells have anti-inflammatory and immunomodulatory effects and are able to differentiate into connective tissue cells, including cartilage, tendons, and ligaments. Our clinical study showed the safety and good tolerability of intra-articular administration of autologous stromal-vascular fraction cells in 16 patients with severe manifestations of osteoarthritis. Single administration of stromal-vascular fraction cells led to more pronounced and stable (up to 12 months) clinical improvement in the main symptoms of the disease, including pain and functional activity of the affected joints, in comparison with intra-articular injection of hyaluronic acid (10 patients of the comparison group).

Stromal vascular fraction therapy for knee osteoarthritis: a systematic review

Background:

Regenerative cell therapies, such as adipose-derived stromal vascular fraction (SVF), have been postulated as potential treatments for knee osteoarthritis (KOA).

Objectives:

To assess the efficacy and safety of SVF treatment against placebo and other standard therapies for treating KOA in adult patients.

Design:

A systematic review.

Data sources and methods:

We 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.

Results:

Among 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.

Conclusion:

Although 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.

Registration:

PROSPERO registration number: CRD42021284187.

Clinical Safety and Effectiveness of Adipose-Derived Stromal Cell vs Stromal Vascular Fraction Injection for Treatment of Knee Osteoarthritis: 2-Year Results of Parallel Single-Arm Trials

BACKGROUND

There are currently no disease-modifying treatments available for knee osteoarthritis (OA), although cultured adipose-derived stromal cells (ASCs) have shown promise in experimental models. However, given the regulatory limits on the use of cultured cells in humans, previous trials have focused primarily on the stromal vascular fraction (SVF) intra-articular injection. Therefore, the therapeutic value of ASCs for knee OA remains unknown.

PURPOSE

To study ASC versus SVF intra-articular injection in patients with Kellgren-Lawrence (KL) knee OA grades 2 to 4 in parallel single-arm trials.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 80 patients were enrolled, with 42 (72 knees) receiving ASC intra-articular injection and 38 (69 knees) receiving SVF. Patient-reported outcome measures were assessed at 1, 3, 6, 12, and 24 months using the Knee injury and Osteoarthritis Outcome Score 5 (KOOS5) and pain visual analog scale (VAS). The percentages of patients achieving the minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) were also calculated. Per protocol, a subset of the ASC group received an ASC booster injection after 6 months. A repeated-measures analysis of variance compared results between treatment arms and by KL grade over time.

RESULTS

Patient-reported outcome measures improved substantially after both treatments (P < .05 at all time points), with the ASC group more likely to achieve the MCID (50% vs 24%; P = .01) and PASS (45% vs 24%; P = .04) for the pain VAS and the MCID (43% vs 16%; P = .02) for the KOOS5 at 12 months, although not at 24 months. Knees treated with ASC for KL grade 2/3 OA had significantly superior outcomes compared with those with KL grade 4 OA for the KOOS5 (P = .01) and pain VAS (P = .03), but no such difference was observed in knees treated with SVF. Three patients receiving ASCs (7%; all KL grade 3) sought additional nonoperative treatment by 24 months versus 9 patients receiving SVF (24%; all KL grade 3) (P = .06). ASC booster injections conferred no additional benefit. Notably, patients in the ASC cohort reported more injection-site pain and swelling after the booster injection than after the initial injection (P < .01).

CONCLUSION

This represents the first head-to-head comparison of ASCs and SVF for the treatment of knee OA in humans. ASC and SVF injections both substantially improved knee pain and function at all follow-up time points, although ASC injections demonstrated significantly better improvements with regard to the MCID and PASS for the pain VAS and the MCID for the KOOS5 at 12 months. There appears to be no benefit to a booster ASC injection after initial treatment. Given less donor-site morbidity and equivalent superior outcomes at 2 years, the use of ASCs over SVF in the treatment of knee OA may be warranted.

Mechanically Derived Tissue Stromal Vascular Fraction Acts Anti-inflammatory on TNF Alpha-Stimulated Chondrocytes In Vitro

Enzymatically isolated stromal vascular fraction (SVF) has already shown to be effective as a treatment for osteoarthritis (OA). Yet, the use of enzymes for clinical purpose is highly regulated in many countries. Mechanical preparation of SVF results in a tissue-like SVF (tSVF) containing intact cell−cell connections including extracellular matrix (ECM) and is therefore less regulated. The purpose of this study was to investigate the immunomodulatory and pro-regenerative effect of tSVF on TNFα-stimulated chondrocytes in vitro. tSVF was mechanically derived using the Fractionation of Adipose Tissue (FAT) procedure. Characterization of tSVF was performed, e.g., cellular composition based on CD marker expression, colony forming unit and differentiation capacity after enzymatic dissociation (from heron referred to as tSVF-derived cells). Different co-cultures of tSVF-derived cells and TNFα-stimulated chondrocytes were analysed based on the production of sulphated glycosaminoglycans and the anti-inflammatory response of chondrocytes. Characterization of tSVF-derived cells mainly contained ASCs, endothelial cells, leukocytes and supra-adventitial cells. tSVF-derived cells were able to form colonies and differentiate into multiple cell lineages. Co-cultures with chondrocytes resulted in a shift of the ratio between tSVF cells: chondrocytes, in favor of chondrocytes alone (p < 0.05), and IL-1β and COX2 gene expression was upregulated in TNFα-treated chondrocytes. After treatment with (a conditioned medium of) tSVF-derived cells, IL-1β and COX2 gene expression was significantly reduced (p < 0.01). These results suggest mechanically derived tSVF stimulates chondrocyte proliferation while preserving the function of chondrocytes. Moreover, tSVF suppresses TNFα-stimulated chondrocyte inflammation in vitro. This pro-regenerative and anti-inflammatory effect shows the potential of tSVF as a treatment for osteoarthritis.

Research progress in the use of mesenchymal stem cells and their derived exosomes in the treatment of osteoarthritis

Osteoarthritis (OA), as a common orthopedic disease with cartilage injury as its main pathological feature, has a complex pathogenesis and existing medical technology remains unable to reverse the progress of cartilage degeneration caused thereby. In recent years, mesenchymal stem cells (MSCs) and their secreted exosomes have become a focus of research into cartilage regeneration. MSCs have the potential to differentiate into a variety of cells. Under specific conditions, they can be promoted to differentiate into chondrocytes and maintain the function and stability of chondrocytes. Exosomes secreted by MSCs, as an intercellular messenger, can treat OA in a variety of ways through bioactive factors carried therewith, such as protein, lipid, mRNA, and miRNA. This study reviewed the application of MSCs and their exosomes from different sources in the prevention of OA, which provides a new idea for the treatment of OA.

Mid-term prognosis of the stromal vascular fraction for knee osteoarthritis: a minimum 5-year follow-up study

Background

The short-term safety and efficacy of stromal vascular fraction (SVF) in treating knee osteoarthritis (KOA) have been extensively studied but the mid-term and long-term prognoses remain unknown.

Methods

126 KOA patients were recruited and randomly assigned to SVF group and hyaluronic acid (HA) group (control group). The scores of visual analogue scale (VAS) and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) were assessed and compared between the two groups 1, 2, 3, and 5 years after treatment. The endpoint was defined as surgeries related to KOA or clinical scores exceeding the patient acceptable symptom state (PASS).

Results

The VAS and WOMAC scores in the SVF group were significantly better than those in the HA group during the 5-year follow-up after treatment. The average responsive time to SVF treatment (61.52 months) was significantly longer than HA treatment (30.37 months). The adjusted Cox proportional hazards model showed that bone marrow lesion (BML) severity, body mass index (BMI) and treatment were independent risk factors and that the use of SVF reduced the risk of clinical failure by 2.602 times. The cartilage volume was reduced in both the SVF and control groups at 5 years but reduced less in the SVF group.

Conclusions

Up to 5 years after SVF treatment, acceptable clinical state was present for approximately 60% of patients. BML severity and BMI were independent predictors of the prognosis.

Trial Registry: This study was retrospectively registered at Chinses Clinical Trial Registry with identifier ChiCTR2100052818 and was approved by ethics committee of the First Affiliated Hospital of Zhejiang Chinese Medical University, number 2013-X-063.

Methodological Flaws in Meta-Analyses of Clinical Studies on the Management of Knee Osteoarthritis with Stem Cells: A Systematic Review

(1) Background: Conclusions of meta-analyses of clinical studies may substantially influence opinions of prospective patients and stakeholders in healthcare. Nineteen meta-analyses of clinical studies on the management of primary knee osteoarthritis (pkOA) with stem cells, published between January 2020 and July 2021, came to inconsistent conclusions regarding the efficacy of this treatment modality. It is possible that a separate meta-analysis based on an independent, systematic assessment of clinical studies on the management of pkOA with stem cells may reach a different conclusion. (2) Methods: PubMed, Web of Science, and the Cochrane Library were systematically searched for clinical studies and meta-analyses of clinical studies on the management of pkOA with stem cells. All clinical studies and meta-analyses identified were evaluated in detail, as were all sub-analyses included in the meta-analyses. (3) Results: The inconsistent conclusions regarding the efficacy of treating pkOA with stem cells in the 19 assessed meta-analyses were most probably based on substantial differences in literature search strategies among different authors, misconceptions about meta-analyses themselves, and misconceptions about the comparability of different types of stem cells with regard to their safety and regenerative potential. An independent, systematic review of the literature yielded a total of 183 studies, of which 33 were randomized clinical trials, including a total of 6860 patients with pkOA. However, it was not possible to perform a scientifically sound meta-analysis. (4) Conclusions: Clinicians should interpret the results of the 19 assessed meta-analyses of clinical studies on the management of pkOA with stem cells with caution and should be cautious of the conclusions drawn therein. Clinicians and researchers should strive to participate in FDA and/or EMA reviewed and approved clinical trials to provide clinically and statistically valid efficacy.

Preclinical studies and clinical trials on mesenchymal stem cell therapy for knee osteoarthritis: A systematic review on models and cell doses

AIM

To provide a systematic analysis of the study design in knee osteoarthritis (OA) preclinical studies, focusing on the characteristics of animal models and cell doses, and to compare these to the characteristics of clinical trials using mesenchymal stem cells (MSCs) for the treatment of knee OA.

METHOD

A systematic and comprehensive search was conducted using the PubMed, Web of Science, Ovid, and Embase electronic databases for research papers published in 2009-2020 on testing MSC treatment in OA animal models. The PubMed database and ClinicalTrials.gov website were used to search for published studies reporting clinical trials of MSC therapy for knee OA.

RESULTS

In total, 9234 articles and two additional records were retrieved, of which 120 studies comprising preclinical and clinical studies were included for analysis. Among the preclinical studies, rats were the most commonly used species for modeling knee OA, and anterior cruciate ligament transection was the most commonly used method for inducing OA. There was a correlation between the cell dose and body weight of the animal. In clinical trials, there was large variation in the dose of MSCs used to treat knee OA, ranging from 1 × 10⁶ to 200 × 10⁶ cells with an average of 37.91 × 10⁶ cells.

CONCLUSION

Mesenchymal stem cells have shown great potential in improving pain relief and tissue protection in both preclinical and clinical studies of knee OA. Further high-quality preclinical and clinical studies are needed to explore the dose effectiveness relationship of MSC therapy and to translate the findings from preclinical studies to humans.

Alleviation of renal ischemia/reperfusion injury by exosomes from induced pluripotent stem cell-derived mesenchymal stem cells

BACKGROUND/AIMS

Renal ischemia followed by reperfusion (I/R) is a leading cause of acute kidney injury (AKI), which is closely associated with high morbidity and mortality. Studies have shown that induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) exert powerful therapeutic effects in renal ischemia. However, the efficacy of iMSC-derived exosomes (iExo) on I/R injuries remains largely unknown.

METHODS

Human iPSCs were differentiated into iMSCs using a modified one-step method. Ultrafiltration, combined with purification, was used to isolate iExo from iMSCs. iExo was administered following I/R injury in a mouse model. The effect of iExo on I/R injury was assessed through changes in renal function, histology, and expression of oxidative stress, inflammation, and apoptosis markers. Further, we evaluated its association with the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway.

RESULTS

Mice subjected to I/R injury exhibited typical AKI patterns; serum creatinine level, tubular necrosis, apoptosis, inflammatory cytokine production, and oxidative stress were markedly increased compared to sham mice. However, treatment with iExo attenuated these changes, significantly improving renal function and tissue damage, similar to the renoprotective effects of iMSCs on I/R injury. Significant induction of activated ERK 1/2 signaling molecules was observed in mice treated with iExo compared to those in the I/R injury group.

CONCLUSION

The present study demonstrates that iExo administration ameliorated renal damage following I/R, suggesting that iMSC-derived exosomes may provide a novel therapeutic approach for AKI treatment.

Injectable amnion hydrogel-mediated delivery of adipose-derived stem cells for osteoarthritis treatment

Current treatment strategies for osteoarthritis (OA) predominantly address symptoms with limited disease-modifying potential. There is a growing interest in the use of adipose-derived stem cells (ADSCs) for OA treatment and developing biomimetic injectable hydrogels as cell delivery systems. Biomimetic injectable hydrogels can simulate the native tissue microenvironment by providing appropriate biological and chemical cues for tissue regeneration. A biomimetic injectable hydrogel using amnion membrane (AM) was developed which can self-assemble in situ and retain the stem cells at the target site. In the present study, we evaluated the efficacy of intraarticular injections of AM hydrogels with and without ADSCs in reducing inflammation and cartilage degeneration in a collagenase-induced OA rat model. A week after the induction of OA, rats were treated with control (phosphate-buffered saline), ADSCs, AM gel, and AM-ADSCs. Inflammation and cartilage regeneration was evaluated by joint swelling, analysis of serum by cytokine profiling and Raman spectroscopy, gross appearance, and histology. Both AM and ADSC possess antiinflammatory and chondroprotective properties to target the sites of inflammation in an osteoarthritic joint, thereby reducing the inflammation-mediated damage to the articular cartilage. The present study demonstrated the potential of AM hydrogel to foster cartilage tissue regeneration, a comparable regenerative effect of AM hydrogel and ADSCs, and the synergistic antiinflammatory and chondroprotective effects of AM and ADSC to regenerate cartilage tissue in a rat OA model.

The Effect of Autologous Adipose-Derived Stromal Vascular Fractions on Cartilage Regeneration Was Quantitatively Evaluated Based on the 3D-FS-SPGR Sequence: A Clinical Trial Study

Background

Numerous reports confirmed the safety and clinical efficacy of autologous adipose-derived stromal vascular fractions (SVF), which have recently been used to treat osteoarthritis (OA). However, there is still no consensus as to whether SVF can promote cartilage regeneration. Herein, the purpose of our study was to evaluate the effectiveness of SVF versus hyaluronic acid (HA) in cartilage regeneration by establishing a cartilage model based on the three-dimensional fat-suppressed spoiled gradient recalled echo (3D-FS-SPGR) sequence.

Methods

Patients with symptomatic OA were recruited in our research, who were randomized into two groups. Meanwhile, patients in Kellgren-Lawrence (K-L) grades 2 and 3 were distinguished in each group. In the test group, patients received SVF injections of the knee, while patients in the control group received the same dose of HA. Each patient underwent the 3D-FS-SPGR sequence to establish a cartilage model at baseline, 6 months, and 12 months, respectively. The cartilage was characterized into six regions, and relevant parameters of the cartilage model were counted. Clinical and radiographic scores were recorded in one-year follow-up.

Results

In all regions, the thickness and volume of cartilage defect and the volume of healthy cartilage were improved to some extent in the test group, especially the medial femoral condyle (MF) and medial tibial condyle (MT). In grades 2 and 3, the thickness and volume of cartilage defect decreased by 0.92 ± 0.18 mm and 1.03 ± 0.23 mm and 84.00 ± 32.30 mm³ and 130.30 ± 49.56 mm³ in MF and by 0.96 ± 0.22 mm and 0.99 ± 0.14 mm and 64.18 ± 21.40 mm³ and 95.11 ± 19.93 mm³ in MT, respectively. No such phenomenon was observed in the control group. Meanwhile, the SVF-treated knees showed significant improvement in clinical and radiographic scores at 12 months. Nevertheless, these scores of the control group became worse at 12-month follow-up visit.

Conclusion

Taken together, this study shows that intra-articular injection of SVF markedly improved the clinical symptoms without adverse events, thereby repairing the damaged articular cartilage through cartilage regeneration.

Dendrimer-modified gelatin methacrylate hydrogels carrying adipose-derived stromal/stem cells promote cartilage regeneration

Background

Cartilage defects pose a significant burden on medical treatment, leading to an urgent need to develop regenerative medicine approaches for cartilage repair, such as stem cell therapy. However, the direct injection of stem cells can result in insufficient delivery or inaccurate differentiation. Hence, it is necessary to choose appropriate stem cell delivery scaffolds with high biocompatibility, injectability and chondral differentiation induction ability for cartilage regeneration.

Methods

In this study, the photocrosslinked gelatin methacrylate (GelMA) hydrogel with high cell affinity and plasticity was selected and strengthened by incorporating methacrylic anhydride-modified poly(amidoamine) (PAMAM-MA) to fabricate an adipose-derived stromal/stem cells (ASCs) delivery scaffold for cartilage repair. The physiochemical properties of the GelMA/PAMAM-MA hydrogel, including the internal structure, stability and mechanical properties, were tested. Then, ASCs were encapsulated into the hydrogels to determine the in vitro and in vivo chondrogenic differentiation induction abilities of the GelMA/PAMAM-MA hydrogel.

Results

Compared with the GelMA hydrogel, the GelMA/PAMAM-MA hydrogel exhibited more uniform structure, stability and mechanical properties. Moreover, on the basis of good biocompatibility, the hybrid hydrogel was proven to exert a sufficient ability to promote cartilage regeneration by in vitro three-dimensional (3D) culture of rASCs and in vivo articular cartilage defect repair.

Conclusions

The injectable photocrosslinked GelMA/PAMAM-MA hydrogel was proven to be a capable stem cell carrier for cartilage repair and provides new insight into the design strategy of stem cell delivery scaffolds.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02705-6.

Knee intra-articular administration of stromal vascular fraction obtained from adipose tissue: A systematic review

Osteoarthritis is a debilitating chronic degenerative disease of cartilage joint surfaces and the knee is the weight-bearing joint most frequently plagued. Intra-articular cell therapies have recently emerged as a method to manage knee osteoarthritis. A literature search identifying all articles involving use of SVF to treat knee osteoarthritis was performed, consulting several databases. In conclusion, 24 clinical trials analysed report good to excellent clinical and radiographic results for the treatment of knee OA with the use of intraarticular administration of SVF.

Second-look Arthroscopic Findings and Clinical Outcomes after Adipose-derived Regenerative Cell Injection in Knee Osteoarthritis

Background

To evaluate the clinical outcomes and second-look arthroscopic findings after intra-articular adipose-derived regenerative cell (ADRC) injection as treatment for knee osteoarthritis (OA).

Methods

ADRCs were administered to 11 patients (19 knees; mean age, 61.7 years) with knee OA. Subcutaneous adipose tissue was harvested by liposuction from both thighs, and arthroscopic lavage was performed, followed by ADRC injection (mean dose, 1.40 × 10⁷ cells) into the synovial fluid. Outcome measures included the Knee Injury and Osteoarthritis Outcome Score, Lysholm score, and visual analog scale score. Arthroscopic examinations were performed to assess the International Cartilage Repair Society cartilage injury grade preoperatively and overall repair postoperatively. Noninvasive assessments were performed at baseline and at 1-, 3-, and 6-month follow-ups; arthroscopic assessments were performed at baseline and at 6 months.

Results

All outcome measures significantly improved after treatment. This improvement was evident 1 month after treatment and was sustained until the 6-month follow-up. Data from second-look arthroscopy showed better repair in low-grade cartilage lesions than in lesions with a greater degree of damage. No patients demonstrated worsening of Kellgren-Lawrence grade, and none underwent total knee arthroplasty during this period.

Conclusions

Clinical outcomes were improved in patients with knee OA after ADRC administration. Cartilage regeneration was more effective in smaller damaged lesions than in bigger lesions.

Adipose Tissue-Derived Mesenchymal Stem Cells

The long-held belief about adipose tissue was that it was relatively inert in terms of biological activity. It was believed that its primary role was energy storage; however, that was shattered with the discovery of adipokines. Scientists interested in regenerative medicine then reported that adipose tissue is rich in adult stromal/stem cells. Following these initial reports, adipose stem cells (ASCs) rapidly garnered interest for use as potential cellular therapies. The primary advantages of ASCs compared to other mesenchymal stem cells (MSCs) include the abundance of the tissue source for isolation, the ease of methodologies for tissue collection and cell isolation, and their therapeutic potential. Studies conducted both in vitro and in vivo have demonstrated that ASCs are multipotent, possessing the ability to differentiate into cells of mesodermal origins, including adipocytes, chondrocytes, osteoblast and others. Moreover, ASCs produce a broad array of cytokines, growth factors, nucleic acids (miRNAs), and other macromolecules into the surrounding milieu by secretion or in the context of microvesicles. The secretome of ASCs has been shown to alter tissue biology, stimulate tissue-resident stem cells, change immune cell activity, and mediate therapeutic outcomes. The quality of ASCs is subject to donor-to-donor variation driven by age, body mass index, disease status and possibly gender and ethnicity. This review discusses adipose stromal/stem cell action mechanisms and their potential utility as cellular therapeutics.

Treatment of Osteochondral Femoral Head Defect by Human Umbilical Cord Mesenchymal Stem Cell Sheet Transplantation: An Experimental Study in Rats

INTRODUCTION

Articular cartilage is limited in self-repair following injuries due to avascular, lymphatic, and nerve absence. Recent treatments for cartilage injuries, such as physical therapy, anti-inflammatory medication, chondrocyte implantation, and joint replacement, still have limitations. This study aimed to evaluate the treatment efficacy of human umbilical cord-derived mesenchymal stem cell sheet (UCMSCS) transplantation in rat models of the osteochondral femoral head defect.

METHODS

Models of osteochondral femoral head defect were produced in rats by drilling in order to reach the femoral bone tissue through the cartilage layer. Then, UCMSCS was implanted in the created cartilage lesion. The treatment efficacy was monitored by X-ray imaging. The cartilage regeneration was evaluated based on the hematoxylin and eosin staining, and proteoglycan accumulation was detected by staining Safranin O and Fast Green. The physiological, weight, or movement activity of rats were recorded during the treatment period.

RESULTS

UCMSCS transplantation showed positive effects on the cartilage regeneration in osteochondral femoral head defect grade 4 (according to ICRS score/grade). Particularly, after 12 weeks of implantation of UCMSCS, the defect was filled with hyaline cartilage-like cells and accumulated a large density of proteoglycan. The osteochondral defect score significantly increased in the treated rats compared to the untreated rats (11.67 ± 0.6 and 9.67 ± 0.6, respectively) (p < 0.05). The histological score also increased in treated rats compared to untreated rats (21.33 ± 1.53 vs. 18.00 ± 1.00) (p < 0.0001). The accumulation of proteoglycan was higher in treated rats (20.50 ± 2.23) than untreated rats (5.38 ± 0.36) (p < 0.05). There was no change in the physiological activities between treated and untreated rats recorded during the study.

CONCLUSION

MSCS transplantation could promote regeneration in advanced cartilage injury.

American Medical Society for Sports Medicine Position Statement: Principles for the Responsible Use of Regenerative Medicine in Sports Medicine

ABSTRACT

Many sports medicine physicians are currently considering introducing regenerative medicine into their practice. Regenerative medicine and the subclassification of orthobiologics are a complicated topic and have produced widely varying opinions. Although there is concern by government regulators, clinicians, scientists, patient advocacy organizations, and the media regarding the use of regenerative medicine products, there is also excitement about the potential benefits with growing evidence that certain regenerative medicine products are safe and potentially efficacious in treating musculoskeletal conditions. Sports medicine physicians would benefit from decision-making guidance about whether to introduce orthobiologics into their practice and how to do it responsibly. The purpose of this position statement is to provide sports medicine physicians with information regarding regenerative medicine terminology, a brief review of basic science and clinical studies within the subclassification of orthobiologics, regulatory considerations, and best practices for introducing regenerative medicine into clinical practice. This information will help sports medicine physicians make informed and responsible decisions about the role of regenerative medicine and orthobiologics in their practice.

Investigation of miR-126-3p loaded on adipose stem cell-derived exosomes for wound healing of full-thickness skin defects

OBJECTIVE

To investigate the function of miR-126-3p loaded on adipose stem cell (ADSC)-derived exosomes (ADSC-Exos) in wound healing of full-thickness skin defects.

METHODS

ADSCs transfected with miR-126-3p mimic, miR-126-3p inhibitor or pcDNA3.1-PIK3R2, or PKH26-marked ADSC-Exos were cultured with fibroblasts or human umbilical vein endothelial cells (HUVECs). The proliferation and migration rates of fibroblasts and angiogenesis of HUVECs were measured. Rats with full-thickness skin defects were injected with ADSC-Exos or exosomes extracted from ADSCs transfected with miR-126-3p inhibitor and the wound healing rates were measured. The wound bed, collagen deposition and angiogenesis in injured rats were assessed.

RESULTS

ADSC-Exos could be ingested by fibroblasts and HUVECs. Co-incubation with ADSCs or ADSC-Exos promoted the proliferation and migration of fibroblasts and angiogenesis of HUVECs, which was further enhanced by miR-126-3p overexpression. Inhibition of ADSC-Exos or miR-126-3p or PIK3R2 overexpression suppressed the proliferation and migration of fibroblasts and angiogenesis of HUVECs. ADSC-derived exosomal miR-126-3p increased wound healing rate, collagen deposition and newly formed vessels in injured rats.

CONCLUSION

ADSC-derived exosomal miR-126-3p promotes wound healing of full-thickness skin defects by targeting PIK3R2.

A Comparative Study on the Effect of Exosomes Secreted by Mesenchymal Stem Cells Derived from Adipose and Bone Marrow Tissues in the Treatment of Osteoarthritis-Induced Mouse Model

BACKGROUND

Exosomes as extracellular vesicles (EVs) are nanoscale intercellular messengers secreted from cells to deliver biological signals. Today, exosomes have become a new field of research in regenerative medicine and are considered as potential therapies to control inflammation and wound healing and enhance and improve healing in many diseases. Given the global burden of osteoarthritis (OA) as the fastest-growing health condition and one of the major causes of physical disability in the aging population, research to establish EVs as therapeutic products can meet the basic clinical needs in the management of osteoarthritis and provide a therapeutic solution.

OBJECTIVES

The present study is aimed at evaluating the regenerative potentials of the exosomes secreted from adipose and bone marrow tissue-derived mesenchymal stem cells (AD- and BM-MSCs) in ameliorating the symptoms of OA.

METHOD

In this experimental study, AD- and BM-MSCs were isolated and cultured in the laboratory until passage 3. Finally, these cells' secreted exosomes were isolated from their conditioned medium. Ciprofloxacin-induced OA mouse models underwent intra-articular injection of exosomes from AD-MSCs and BM-MSCs. Finally, the expression levels of collagen I and II, sox9, and aggrecan genes using real-time PCR, histological analysis, and immunohistochemical (IHC) studies were performed.

RESULTS

Real-time PCR data showed that although the expression level of collagen type II was lower in both exosome-treated groups than the normal, but it was significantly increased in comparison with the sham and OA, with higher expression in BM-Exo rather than AD-Exo group. Similarly, the histological staining and IHC results have provided almost identical data, emphasizing on better therapeutic effect of BM-MSCs-exosome than AD-MSCs-exosome.

CONCLUSION

BM-MSCs secreted exosomes in comparison with AD-MSCs could be considered as a better therapeutic option to improve osteoarthritis and exhibit potential as a disease-modifying osteoarthritis cell-free product.

Cell Sources for Cartilage Repair-Biological and Clinical Perspective

Cell-based therapy represents a promising treatment strategy for cartilage defects. Alone or in combination with scaffolds/biological signals, these strategies open many new avenues for cartilage tissue engineering. However, the choice of the optimal cell source is not that straightforward. Currently, various types of differentiated cells (articular and nasal chondrocytes) and stem cells (mesenchymal stem cells, induced pluripotent stem cells) are being researched to objectively assess their merits and disadvantages with respect to the ability to repair damaged articular cartilage. In this paper, we focus on the different cell types used in cartilage treatment, first from a biological scientist’s perspective and then from a clinician’s standpoint. We compare and analyze the advantages and disadvantages of these cell types and offer a potential outlook for future research and clinical application.

The enzymatic disaggregation by trypsin does not alter cell quality and genomic stability of adipose-derived stem cells cultivated for human cell therapy

There is no consensus between the protocols used for the isolation, maintenance and cultivation of Adipose-derived stem cells (ADSCs) for therapeutic purposes. Thus, was evaluated the maintenance method of ADSCs submitted to enzymatic disaggregation by trypsin. Was made (1st until 10th passage) immunophenotyping, cell differentiation assays, comet assay, differential cell death, apoptosis, cell viability and membrane integrity by flow cytometry.The results showded that trypsinization,did not induce genomic instability, also did not alter the tail moment. The cell death assay, showed that only on the 10th passage there was a significant reduction and was cofirmed by flow cytometry that is apoptosis. The viability showded significant reduction only in 10th passage, this was related to the loss of integrity of membrane, proven by flow cytometry. The quantities varied along the passages (11 × 10⁵ to 2 × 10⁵). Qualitatively, it can be observed that as the number of cells decreases, there is also a reduction in the juxtaposition of ADSCs and increased of the cell size, it is started in 6th passage. In view of the results, it is suggested for more safety, that ADSCs cultured until the 5th passage being used in human transplantation procedures.

Safety and Efficacy of Kartigen® in Treating Cartilage Defects: A Randomized, Controlled, Phase I Trial

Here, we aimed to investigate the safety and preliminary efficacy of Kartigen^®, a matrix with autologous bone marrow mesenchymal stem cell-derived chondrocyte precursors embedded in atelocollagen. As a surgical graft, Kartigen^® was implanted onto the cartilage defects at the weight-bearing site of the medial femoral condyle of the knee. Fifteen patients were enrolled and stratified into two groups, undergoing either Kartigen^® implantation (n = 10) or microfracture (control group, n = 5). The primary endpoint was to evaluate the safety of Kartigen^® by monitoring the occurrence of adverse events through physician queries, physical examinations, laboratory tests, and radiological analyses for 2 years. There were no infections, inflammations, adhesions, loose body, or tumor formations in the Kartigen^®-implanted knees. The preliminary efficacy was assessed using the International Knee Documentation Committee (IKDC) score, visual analog scale, and second-look arthroscopy. The postoperative IKDC scores of the Kartigen^® group significantly improved in the 16th week (IKDC = 62.1 ± 12.8, p = 0.025), kept increasing in the first year (IKDC = 78.2 ± 15.4, p < 0.005), and remained satisfactory in the second year (IKDC = 73.6 ± 13.8, p < 0.005), compared to the preoperative condition (IKDC = 47.1 ± 17.0), while the postoperative IKDC scores of the control group also achieved significant improvement in the 28th week (IKDC = 68.5 ± 6.1, p = 0.032) versus preoperative state (IKDC = 54.0 ± 9.1). However, the IKDC scores decreased in the first year (IKDC = 63.5 ± 11.6) as well as in the second year (IKDC = 52.6 ± 16.4). Thirteen patients underwent second-look arthroscopy and biopsy one year after the operation. The Kartigen^® group exhibited integration between Kartigen^® and host tissue with a smooth appearance at the recipient site, whereas the microfracture group showed fibrillated surfaces. The histological and immunohistochemical analyses of biopsy specimens demonstrated the columnar structure of articular cartilage and existence of collagen type II and glycosaminoglycan mimic hyaline cartilage. This study indicates that Kartigen^® is safe and effective in treating cartilage defects.

Pain relief and cartilage repair by Nanofat against osteoarthritis: preclinical and clinical evidence

Background

Osteoarthritis (OA) is the most common joint degenerative disorder, with little effective therapy to date. Nanofat is a cocktail of cells obtained from fat tissue, which possesses regenerative capacity and has a potential in treating OA. This study aimed to determine the anti-OA efficacy of Nanofat from basic and clinical aspects and explore its action mode.

Methods

Flow cytometry was performed to characterize Nanofat. A monoiodoacetate-induced OA rat model was employed for in vivo study. Cell viability and wound healing assays were conducted for in vitro study. Real-time PCR and Western blot assays were applied to explore the molecular action mode of Nanofat. Moreover, a retrospective analysis was conducted to determine the clinical efficacy and safety of Nanofat on knee OA patients.

Results

The in vivo results showed that Nanofat significantly attenuated pain symptoms and protected cartilage ECM (Col2) from damage, and its effects were not significantly differed with adipose tissue-derived stem cells (both P > 0.05). The in vitro results showed that Nanofat promoted the cell viability and migration of chondrocytes and significantly restored the IL-1β-induced abnormal gene expressions of Col2, Aggrecan, Sox9, Adamts5, Mmp3, Mmp9 Mmp13, IL-6 and Col10 and protein expressions of Col2, MMP9, MMP13, and Sox9 of chondrocytes. The regulatory actions of Nanofat on these anabolic, catabolic, and hypertrophic molecules of chondrocytes were similar between two treatment routes: co-culture and conditioned medium, suggesting a paracrine-based mode of action of Nanofat. Moreover, the clinical data showed that Nanofat relieved pain and repaired damaged cartilage of OA patients, with no adverse events.

Conclusion

In sum, this study demonstrated the anti-OA efficacy as well as a paracrine-based action mode of Nanofat, providing novel knowledge of Nanofat and suggesting it as a promising and practical cell therapy for clinical treatment of OA.

Comparison of Bone Marrow Aspirate Concentrate and Allogenic Human Umbilical Cord Blood Derived Mesenchymal Stem Cell Implantation on Chondral Defect of Knee: Assessment of Clinical and Magnetic Resonance Imaging Outcomes at 2-Year Follow-Up

Biological repair of cartilage lesions remains a significant clinical challenge. A wide variety of methods involving mesenchymal stem cells (MSCs) have been introduced. Because of the limitation of the results, most of the treatment methods have not yet been approved by the Food and Drug Administration (FDA). However, bone marrow aspirate concentrate (BMAC) and human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) implantation were approved by Korea FDA. The aim of this study was to evaluate clinical and magnetic resonance imaging (MRI) outcomes after two different types of MSCs implantation in knee osteoarthritis. Fifty-two patients (52 knees) who underwent cartilage repair surgery using the BMAC (25 knees) and hUCB-MSCs (27 knees) were retrospectively evaluated for 2 years after surgery. Clinical outcomes were evaluated according to the score of visual analogue scale (VAS), the International Knee Documentation Committee (IKDC) subjective, and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Cartilage repair was assessed according to the modified Magnetic Resonance Observation of Cartilage Repair Tissue (M-MOCART) score and the International Cartilage Repair Society (ICRS) cartilage repair scoring system. At 2-year follow-up, clinical outcomes including VAS, IKDC, and KOOS significantly improved (P < 0.05) in both groups; however, there were no differences between two groups. There was no significant difference in M-MOCART [1-year (P = 0.261), 2-year (P = 0.351)] and ICRS repair score (P = 0.655) between two groups. Both groups showed satisfactory clinical and MRI outcomes. Implantation of MSCs from BMAC or hUCB-MSCs is safe and effective for repairing cartilage lesion. However, large cases and a well-controlled prospective design with long-term follow-up studies are needed.

Atelocollagen-Embedded Chondrocyte Precursors as a Treatment for Grade-4 Cartilage Defects of the Femoral Condyle: A Case Series with up to 9-Year Follow-Up

We demonstrated the safety and efficacy of autologous chondrocyte precursor (CP) cell therapy in repairing Grade 4 cartilage defects of medial femoral condyles. The autologous bone marrow mesenchymal stem cells of each participant were isolated, amplified, and then differentiated into CPs in atelocollagen. Neotissues made of CPs were implanted into cartilage defects with an average cell density of 4.9 ± 2.1 × 10⁶ cells/cm² through arthrotomy. The knee function was evaluated with the International Knee Documentation Committee (IKDC) subjective knee form. Patients' knee functions significantly improved by the 28th week (IKDC score = 68.3 ± 12.1), relative to the initial functionality before the CP therapy (IKDC score = 46.1 ± 16.4, p-value = 0.0014). Nine of these twelve patients maintained good knee functions for 9 years post-implantation (IKDC score = 69.8 ± 12.3) at levels higher than the pre-implantation values (p-value = 0.0018). Patients were evaluated with MRI and arthroscopy, and the defective sites exhibited a smooth surface without a gap between the implant and host tissue. This study demonstrates that autologous CPs successfully engraft into the host tissue and result in the re-formation of hyaline-like cartilage, thereby improving the impaired knee functions. Most importantly, no adverse event was reported during this long-term follow-up period.

Patients' expectations and experiences of stem cell therapy for the treatment of knee osteoarthritis

BACKGROUND

Stem cell therapy is a novel treatment option for people living with osteoarthritis. Research investigating stem cell therapy for this debilitating condition has predominantly involved the pathogenesis of the cells and efficacy of the treatment. There is little understanding of patients' expectations and experiences of stem cell therapy treatment.

OBJECTIVE

To explore the expectations and experiences of people undergoing stem cell therapy for the treatment of knee osteoarthritis.

DESIGN

An exploratory, descriptive, qualitative study using semi-structured interviews was conducted.

SETTING AND PARTICIPANTS

Participants were recruited into two groups: (a) Expectations Group (n = 15); the expectations of stem cell treatment were explored with participants that were yet to commence stem cell therapy. (b) Experiences Group (n = 15); the experiences of stem cell therapy were explored with participants 12 months after their initial stem cell treatment. Transcripts were analysed using thematic analysis to identify themes in both groups.

RESULTS

Themes for the Expectations Group were active involvement in the treatment; treatment will improve symptoms; and benefits of treatment outweigh the risks. Themes for the Experiences Group were symptoms of treatment; satisfaction with treatment; and anticipation of further improvement.

DISCUSSION AND CONCLUSIONS

The findings are the first qualitative study to represent patients' perspective on expectations and experiences of stem cell therapy for knee osteoarthritis. They provide insight into the potential areas for improvement within this field to aid patients' preparation and approach to the treatment, promoting patient-centred care.

Treatment of Grade 3 and 4 Osteoarthritis with Intraoperatively Separated Adipose Tissue-Derived Stromal Vascular Fraction: A Comparative Case Series

Osteoarthritis (OA) is the most common form of arthritis of the joints. The stromal vascular fraction (SVF) is a regenerative cell population that can be isolated from adipose tissue. It is the immunomodulatory properties of the stromal vascular fraction that make it a promising candidate for the regenerative treatment of OA. Patients with grade 3 and 4 osteoarthritis were treated with the stromal vascular fraction with and without platelet-rich plasma (PRP) and followed up on their Knee Injury and Osteoarthritis Outcome Score (KOOS) score for 12 months, with MRI and subjective evaluation of the procedure. Magnetic resonance imaging (MRI) revealed a widening of the joint space, a restructuring of the cartilage, and an alleviation of effusions in the treated joints. In three of the four treatment groups, a substantial improvement of the KOOS scores was documented at the 12-month follow-up time point. According to the subjective evaluation, 67% of the patients were satisfied or very satisfied with the procedure and would recommend it to others. No serious adverse events or unwanted side effects related to the SVF treatment were observed or reported. Prior to an invasive artificial joint replacement, the treatment of arthritic knee joints with the intraarticular injection of autologous adipose tissue-derived SVF should be considered a regenerative treatment option.

Study of bilateral elbow joint osteoarthritis treatment using conditioned medium from allogeneic adipose tissue-derived MSCs in Labrador retrievers

Canine elbow dysplasia is a common cause of forelimb lameness in dogs and can lead to development of osteoarthritis (OA). A potential alternative to pain management is the use of a safe cell-free based therapy through trophic and paracrine factors of mesenchymal stem cells (MSCs). The aim of study was to identify the profile of selected mediators of potential clinical relevance in synovial fluid (SF) samples of dogs with elbow OA and analyse the range of motion (ROM) before and after cell-free MSCs-based treatment. In this study, conditioned medium from allogeneic canine adipose tissue - derived MSC (CM-AD-MSC) was prepared and administered into both elbow joints with OA in six Labrador retriever dogs (n = 6) on day 0 and 14 without creating a control group with a placebo. The SF of the elbow joints was analysed for the presence of several biomolecules (IL-6, IL-10, IL-8, IL-2, IL-12, TNF-αIFN-γ, MMP-3TIMP-1) before and after intraarticular applications of CM-AD-MSC. Kinematic analysis was used to assess the clinical effect of CM-AD-MSC. Analyses of SF and ROM were performed on days 0, 14 and 42. Concentration levels of MMP-3, TIMP-1, IL-6 and TNF-α in SF showed significant differences before and after the treatment (P < .05). There was a significant improvement in ROM between day 0 and 42 (P < .001). No severe adverse events were observed during the study. Results support the potential supportive effect of CM-AD-MSC as a noninvasive therapeutic tool for pain management of OA elbow joints in dogs.

Development and Prospect of Intra-Articular Injection in the Treatment of Osteoarthritis: A Review

Osteoarthritis (OA) is a common degenerative disease that affects the vast majority of the elderly and may eventually embark on the road of the total knee arthroplasty (TKA), although controversy still exists in the medical community about the best therapies for osteoarthritis. Compared with physical therapy, oral analgesics and other non-operative treatments, intra-articular injection is more safe and effective. Moreover, intra-articular injection is much less invasive and has fewer adverse reactions than surgical treatment. This article reviews mechanism, benefits and adverse reactions of corticosteroids (CS), hyaluronic acid (HA), platelet-rich plasma (PRP), mesenchymal stem cell (MSCs), stromal vascular fraction (SVF) and other new therapies (for example: gene therapy). The application prospect of intra-articular injection was analyzed according to the recent progress in drug research.