Mesenchymal stem cell injections improve symptoms of knee osteoarthritis

Mesenchymal stem/stromal cells as a valuable source for the treatment of immune-mediated disorders

Over recent years, mesenchymal stem/stromal cells (MSCs) and their potential biomedical applications have received much attention from the global scientific community in an increasing manner. Firstly, MSCs were successfully isolated from human bone marrow (BM), but in the next steps, they were also extracted from other sources, mostly from the umbilical cord (UC) and adipose tissue (AT). The International Society for Cellular Therapy (ISCT) has suggested minimum criteria to identify and characterize MSCs as follows: plastic adherence, surface expression of CD73, D90, CD105 in the lack of expression of CD14, CD34, CD45, and human leucocyte antigen-DR (HLA-DR), and also the capability to differentiate to multiple cell types including adipocyte, chondrocyte, or osteoblast in vitro depends on culture conditions. However, these distinct properties, including self-renewability, multipotency, and easy accessibility are just one side of the coin; another side is their huge secretome which is comprised of hundreds of mediators, cytokines, and signaling molecules and can effectively modulate the inflammatory responses and control the infiltration process that finally leads to a regulated tissue repair/healing or regeneration process. MSC-mediated immunomodulation is a direct result of a harmonic synergy of MSC-released signaling molecules (i.e., mediators, cytokines, and chemokines), the reaction of immune cells and other target cells to those molecules, and also feedback in the MSC-molecule-target cell axis. These features make MSCs a respectable and eligible therapeutic candidate to be evaluated in immune-mediated disorders, such as graft versus host diseases (GVHD), multiple sclerosis (MS), Crohn's disease (CD), and osteoarthritis (OA), and even in immune-dysregulating infectious diseases such as the novel coronavirus disease 2019 (COVID-19). This paper discussed the therapeutic applications of MSC secretome and its biomedical aspects related to immune-mediated conditions. Sources for MSC extraction, their migration and homing properties, therapeutic molecules released by MSCs, and the pathways and molecular mechanisms possibly involved in the exceptional immunoregulatory competence of MSCs were discussed. Besides, the novel discoveries and recent findings on immunomodulatory plasticity of MSCs, clinical applications, and the methods required for their use as an effective therapeutic option in patients with immune-mediated/immune-dysregulating diseases were highlighted.

Recent Updates of Diagnosis, Pathophysiology, and Treatment on Osteoarthritis of the Knee

Osteoarthritis (OA) is a degenerative and chronic joint disease characterized by clinical symptoms and distortion of joint tissues. It primarily damages joint cartilage, causing pain, swelling, and stiffness around the joint. It is the major cause of disability and pain. The prevalence of OA is expected to increase gradually with the aging population and increasing prevalence of obesity. Many potential therapeutic advances have been made in recent years due to the improved understanding of the underlying mechanisms, diagnosis, and management of OA. Embryonic stem cells and induced pluripotent stem cells differentiate into chondrocytes or mesenchymal stem cells (MSCs) and can be used as a source of injectable treatments in the OA joint cavity. MSCs are known to be the most studied cell therapy products in cell-based OA therapy owing to their ability to differentiate into chondrocytes and their immunomodulatory properties. They have the potential to improve cartilage recovery and ultimately restore healthy joints. However, despite currently available therapies and advances in research, unfulfilled medical needs persist for OA treatment. In this review, we focused on the contents of non-cellular and cellular therapies for OA, and briefly summarized the results of clinical trials for cell-based OA therapy to lay a solid application basis for clinical research.

Two-year clinical outcomes of autologous microfragmented adipose tissue in elderly patients with knee osteoarthritis: a multi-centric, international study

PURPOSE

The aim of this study is to evaluate the outcomes of autologous microfragmented adipose tissue (MFAT) injection in elderly patients with knee osteoarthritis (OA). We hypothesized that MFAT knee infiltration for the treatment of knee OA would yield good clinical results out to two years follow-up.

METHODS

Multi-centric, international, open-label study conducted by orthopedic surgery, and/or regenerative medicine facilities utilizing patient registries. Subjects recruited for eligibility. The primary outcome measure was Knee Injury and Osteoarthritis Outcome Score (KOOS). Outcomes and patient factors were compared to baseline, at six, 12, and 24 months. Statistical models were used to assess KOOS subscores and probability of exceeding the Minimally Clinically Important Difference (MCID) or Patient Acceptable Symptom State (PASS), and to assess the effect of the treatment variables on KOOS - Pain.

RESULTS

Seventy-five patients, 120 primary treatments, mean age 69.6 years, (95%CI 68.3-70.9), BMI 28.4 (95%CI 27.3-29.6), with KL grade 2 to 4 knee OA treated with a single MFAT injection. KL grades 2 (15.1%), 3 (56.3%), and 4 (28.6%), with 20.8% of knees having previously undergone surgery. Patients with KL grade 2 disease had the best results in KOOS - Pain (P = 0.001), at six, 12, and 24 months. Including advanced KL grade 3 and 4 osteoarthritis patients, significant functional and quality of life success was seen in 106/120 treatments (88.3%, 66 patients) at all follow-up time points. Fourteen treatments (11.7%, 9 patients) failed prior to the study endpoint.

CONCLUSION

This study shows that a single-dose MFAT injection leads to clinical, functional, and quality of life improvement at two years in elderly patients, in KL grades 2 to 4 of knee osteoarthritis. These findings provide evidence that this treatment modality could be a safe and effective option to other commonly available treatments in carefully selected patients.

The clinical efficacy of arthroscopic therapy with knee infrapatellar fat pad cell concentrates in treating knee cartilage lesion: a prospective, randomized, and controlled study

Introduction

To evaluate the clinical efficacy of arthroscopic therapy with infrapatellar fat pad cell concentrates in treating knee cartilage lesions, we conducted a prospective randomized single-blind clinical study of controlled method.

Methods

Sixty cases from Shanghai Changzheng Hospital from April 2018 to December 2019 were chosen and randomly divided into 2 groups equally. Patients in the experiment group were treated through knee arthroscopy with knee infrapatellar fat pad cell concentrates containing mesenchymal stromal cells, while patients in the control group were treated through regular knee arthroscopic therapy. VAS and WOMAC scores were assessed at pre-operation, and 6 weeks, 12 weeks, 6 months, and 12 months after intervention. MORCART scores were assessed at pre-operation and 12 months after intervention.

Results

Twenty-nine cases in the experiment group and 28 cases in the control group were followed up. No significant difference in VAS, WOMAC, and MOCART scores were found between the two groups before surgery (P > 0.05). The WOMAC total and WOMAC function scores of the experiment group were significantly lower than those of the control group 6 months and 12 months after surgery (P < 0.05). The VAS rest and VAS motion scores of the experiment group were found significantly lower than those of the control group 12 months after surgery (P < 0.05). The MOCART scores of the experiment group were found significantly higher compared with the control group 12 months after surgery (P < 0.05). No significant difference in WOMAC stiffness scores were found between the two groups.

Conclusions

The short-term results of our study are encouraging and demonstrate that knee arthroscopy with infrapatellar fat pad cell concentrates containing mesenchymal stromal cells is safe and provides assistance in reducing pain and improving function in patients with knee cartilage lesions.

Trial registration

ChiCTR1800015379. Registered on 27 March 2018, http://www.chictr.org.cn/showproj.aspx?proj=25901.

Assessment of safety and efficacy of intra-articular injection of stromal vascular fraction for the treatment of knee osteoarthritis-a systematic review

PURPOSE

Stromal vascular fraction (SVF) as an injectable regenerative therapy for knee osteoarthritis (OA) has gained recent popularity. However, there is no clear consensus on the outcomes of such treatment. We systematically reviewed available evidence on the use of SVF injection in the treatment of knee OA.

METHODS

The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with keyword search in PubMed, Scopus, and the Cochrane Library Database and related article search in Google Scholar. Clinical studies demonstrating effects of SVF in knee OA and published in English literature were included. Risk of bias assessment was done with modified Coleman Methodology Scoring (CMS).

RESULTS

Eleven studies (9 prospective, 2 retrospective) that contributed to 290 knees in 200 patients were included. Two studies that contributed to 3718 knee injections were excluded from pooled analysis and were scrutinized separately. Majority of patients reported improvement in pain, range of motion (ROM), functional rating, six metre walking distance, and functional outcome scores. There was no major donor-site morbidity. There was only one reported case of knee joint infection and no case of tumour formation in relation to SVF injection.

DISCUSSION

Intra-articular injection of SVF can be a simple, affordable, and minimally invasive treatment that could serve as an interim option for patients who failed other conservative and arthroscopic options.

CONCLUSION

Intra-articular injection of SVF is a safe and effective technique for the management of knee OA. However, comparative Level I studies are needed to support the use of adjuvants with SVF and also to compare the use of SVF (with or without adjuvants) with ADMSCs, PRP, and bone marrow concentrate.

Development of an Ex Vivo Murine Osteochondral Repair Model

OBJECTIVE

Mouse models are commonly used in research applications due to the relatively low cost, highly characterized strains, as well as the availability of many genetically modified phenotypes. In this study, we characterized an ex vivo murine osteochondral repair model using human infrapatellar fat pad (IPFP) progenitor cells.

DESIGN

Femurs from euthanized mice were removed and clamped in a custom multidirectional vise to create cylindrical osteochondral defects 0.5 mm in diameter and 0.5 mm deep in both condyles. The IPFP contains progenitors that are a promising cell source for the repair of osteochondral defects. For proof of concept, human IPFP-derived progenitor cells, from osteoarthritic (OA) patients, cultured as pellets, were implanted into the defects and cultured in serum-free medium with TGFβ3 for 3 weeks and then processed for histology and immunostaining.

RESULTS

The custom multidirectional vise enabled reproducible creation of osteochondral defects in murine femoral condyles. Implantation of IPFP-derived progenitor cells led to development of cartilaginous tissue with Safranin O staining and deposition of collagen type II in the extracellular matrix.

CONCLUSIONS

We showed feasibility in creating ex vivo osteochondral defects and demonstrated the regenerative potential of OA human IPFP-derived progenitors in mouse femurs. The murine model can be used to study the effects of aging and OA on tissue regeneration and to explore molecular mechanisms of cartilage repair using genetically modified mice.

Allogeneic umbilical cord blood-derived mesenchymal stem cells combined with high tibial osteotomy: a retrospective study on safety and early results

BACKGROUND

Cartilage repair performed as a single-stage procedure is an important advancement in the treatment of full-thickness cartilage injury and has potential for widespread clinical use.

PURPOSE

To investigate the short-term outcomes and cartilage regeneration after implantation of allogeneic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in patients who received high tibial osteotomy (HTO) for symptomatic medial knee osteoarthritis.

METHODS

Patients underwent treatment of full-thickness chondral injury in the osteoarthritic knee with HTO and implantation of hUCB-MSCs and were followed prospectively for a minimum of one year. Ninety-three patients were followed for a mean 1.7 years (range, 1.0-3.5). Median cartilage lesion size was 6.5 cm² (range, 2.0-12.8). Clinical outcomes were examined with patient-reported scoring instruments that consisted of the International Knee Documentation Committee (IKDC) subjective score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, Knee Society Score (KSS), and Hospital for Special Surgery (HSS) score. Cartilage regeneration was evaluated using the International Cartilage Repair Society (ICRS) cartilage repair assessment grading (CRA) system and the Koshino regeneration staging system in 49 patients who underwent second look arthroscopic assessment when their HTO plates were removed.

RESULTS

At final follow-up, the median IKDC subjective score had significantly improved from 39.0 to 71.3; the WOMAC score from 44.5 to 11.0; the KSS pain and function scores from 29.8 to 43.2 and 61.0 to 81.2, respectively; and the HSS from 61.6 to 82.7 (p < 0.05). Pre-operative examination showed ICRS grade IV cartilage injury in all knees, and cartilage regeneration at 2nd look arthroscopy showed improvements (8.2% of patients improved to ICRS grade I, 69.3% to grade II, and 22.5% to grade III). Moreover, Koshino stage was B in 24.5% and C in 75.5% of patients (p < 0.05).

CONCLUSION

Allogeneic hUCB-MSC implantation combined with HTO for medial knee osteoarthritis was safe and showed signs of cartilage status improvement. Furthermore, randomized controlled studies with a control group are necessary to determine the real effectiveness and indications of this new combined procedure for patients with osteoarthritis.

Association Between Acupuncture and Knee Surgery for Osteoarthritis: A Korean, Nationwide, Matched, Retrospective Cohort Study

Objectives: The present study was undertaken to investigate the relationship between acupuncture therapy and surgery rate. Design: Matched, retrospective cohort study. Materials and Methods: From nationwide health insurance data (2002-2013 cohort data published by the National Health Insurance Service of Korea), patients with new cases of knee osteoarthritis that occurred between January 1, 2004 and December 31, 2010 were analyzed. Patients were divided into an acupuncture group (AG) and a control group (CG), based on records of acupuncture therapy. Propensity scores were calculated by using gender, age, income level, and Charlson comorbidity index (CCI), with the groups matched at a ratio of 1:3 (AG:CG). The final analysis period was 2 years after the first acupuncture therapy for AG and 2 years after initial diagnosis for CG; surgery rates were compared between the two groups. Stratified analyses were performed based on age, gender, and income level; sensitivity analyses were performed based on the frequency and duration of acupuncture therapy. Results: Propensity score-matched AG and CG included 8,605 and 25,815 subjects, respectively. Post-matching surgery rates were 0.26 and 0.93% in AG and CG, respectively. For all age groups, AG showed a lower surgery rate than CG. In the analysis based on gender, the female group showed a significantly lower hazard ratio of 0.225. In analysis based on income level, the results of the entire group were significant, with the lower income group showing the lowest hazard ratio. In sensitivity analyses, AG tended to show a lower surgery rate than CG. Conclusions: The present study demonstrated that acupuncture therapy is associated with a low rate of surgery for knee osteoarthritis. Additional studies are needed to support this conclusion.

Machine learning to predict mesenchymal stem cell efficacy for cartilage repair

Inconsistent therapeutic efficacy of mesenchymal stem cells (MSCs) in regenerative medicine has been documented in many clinical trials. Precise prediction on the therapeutic outcome of a MSC therapy based on the patient's conditions would provide valuable references for clinicians to decide the treatment strategies. In this article, we performed a meta-analysis on MSC therapies for cartilage repair using machine learning. A small database was generated from published in vivo and clinical studies. The unique features of our neural network model in handling missing data and calculating prediction uncertainty enabled precise prediction of post-treatment cartilage repair scores with coefficient of determination of 0.637 ± 0.005. From this model, we identified defect area percentage, defect depth percentage, implantation cell number, body weight, tissue source, and the type of cartilage damage as critical properties that significant impact cartilage repair. A dosage of 17 - 25 million MSCs was found to achieve optimal cartilage repair. Further, critical thresholds at 6% and 64% of cartilage damage in area, and 22% and 56% in depth were predicted to significantly compromise on the efficacy of MSC therapy. This study, for the first time, demonstrated machine learning of patient-specific cartilage repair post MSC therapy. This approach can be applied to identify and investigate more critical properties involved in MSC-induced cartilage repair, and adapted for other clinical indications.

Mesenchymal stem cells - a promising strategy for treating knee osteoarthritis

AIMS

The purpose of our study was to determine whether mesenchymal stem cells (MSCs) are an effective and safe therapeutic agent for the treatment of knee osteoarthritis (OA), owing to their cartilage regeneration potential.

METHODS

We searched PubMed, Embase, and the Cochrane Library, with keywords including "knee osteoarthritis" and "mesenchymal stem cells", up to June 2019. We selected randomized controlled trials (RCTs) that explored the use of MSCs to treat knee OA. The visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), adverse events, and the whole-organ MRI score (WORMS) were used as the primary evaluation tools in the studies. Our meta-analysis included a subgroup analysis of cell dose and cell source.

RESULTS

Seven trials evaluating 256 patients were included in the meta-analysis. MSC treatment significantly improved the VAS (mean difference (MD), -13.24; 95% confidence intervals (CIs) -23.28 to -3.20, p = 0.010) and WOMAC (MD, -7.22; 95% CI -12.97 to -1.47, p = 0.010). The low-dose group with less than 30 million cells showed lower p-values for both the VAS and WOMAC. Adipose and umbilical cord-derived stem cells also had lower p-values for pain scores than those derived from bone marrow.

CONCLUSION

Overall, MSC-based cell therapy is a relatively safe treatment that holds great potential for OA, evidenced by a positive effect on pain and knee function. Using low-dose (25 million) and adipose-derived stem cells is likely to achieve better results, but further research is needed. Cite this article: Bone Joint Res 2020;9(10):719-728.

Intra-articular Injection of Culture-Expanded Mesenchymal Stem Cells Without Adjuvant Surgery in Knee Osteoarthritis: A Systematic Review and Meta-analysis

BACKGROUND

Although many clinical studies have assessed the efficacy of mesenchymal stem cells (MSCs) in knee osteoarthritis, evidence on their efficacy remains unclear owing to heterogeneity of cell entity and concomitant procedures.

PURPOSE

To determine the efficacy of culture-expanded MSCs in knee osteoarthritis in terms of clinical outcome and cartilage repair via meta-analysis of randomized controlled trials (RCTs) without adjuvant surgery.

STUDY DESIGN

Meta-analysis.

METHODS

PubMed, Embase, the Cochrane Library, CINAHL, and Scopus were searched from inception to December 31, 2018. RCTs with culture-expanded MSCs for treating knee osteoarthritis were included. Studies with adjuvant surgery or cell concentrate were excluded. Quality was assessed by the Cochrane Collaboration risk-of-bias tool. For meta-analysis, data on clinical outcomes were measured using a visual analog scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and data on cartilage repair were measured using the Whole-Organ Magnetic Resonance Imaging Score (WORMS); categorization related to improvement was extracted.

RESULTS

Six RCTs (203 patients) were included. Two studies were deemed to have a low risk of bias. In pooled analysis, the only significant difference was in the VAS score (mean difference, -13.55; 95% CI, -22.19 to -4.9). In cumulative pain analysis with VAS and WOMAC pain scores, there was significant improvement after treatment (standardized mean difference, -0.54; 95% CI, -0.85 to -0.23). There was no significant difference in cartilage repair assessed by magnetic resonance imaging (standardized mean difference, 0.11; 95% CI, -0.51 to 0.73), WORMS (standardized mean difference, 1.68; 95% CI -14.84 to 18.21), or categorical results (odds ratio, 1.56; 95% CI, 0.32-7.59).

CONCLUSION

Intra-articular injection of culture-expanded MSCs without adjuvant surgery can improve pain for patients experiencing knee osteoarthritis at short-term follow-up (6-12 months). However, evidence regarding function and cartilage repair remains limited.

Degenerative osteoarthritis a reversible chronic disease

Osteoarthritis (OA) is the most common chronic musculoskeletal disorder. It can affect any joint and is the most frequent single cause of disability in older adults.

OA is a progressive degenerative disease involving the entire joint structure in a vicious circle that includes the capsule-bursa tissue inflammation, synovial fluid modifications, cartilage breakdown and erosions, osteochondral inflammatory damage leading to bone erosion and distortion.

Research has identified the initial inflammatory-immunologic process that starts this vicious cycle leading to so-called early OA. Research has also identified the role played in the disease advancement by synoviocytes type A and B, chondrocytes, extracellular matrix, local immune-inflammatory mediators and proteases.

This article investigates the joint-resident MSCs that play an essential local homeostatic role and regulate cell turn over and tissue repair. Resident MSCs establish and maintain a local regenerative microenvironment.

The understanding of OA physiopathology clarifies the core mechanisms by which minimally invasive interventions might be able to halt and reverse the course of early stage OA. Interventions employing PRP, MSCs and exosomes are considered in this article.

Using iron sucrose-labeled adipose-derived mesenchymal stem cells in 1.5 and 3 T MRI tracking: An in vitro study

Objectives

The objective of this study was to investigate iron sucrose labeling in mesenchymal stem cell (MSCs) tracking.

Background

Adipose-derived mesenchymal stem cell-based therapy is a promising strategy for promoting musculoskeletal repair.

Methods

Iron sucrose-labeled adipose-derived mesenchymal stem cells (IS-labeled ASCs) were tracked using T2-and T2∗-weighted sequences by 1.5 and 3 T MRI in an in vitro model. ASCs were isolated from cosmetic liposuction specimens. ASCs from passages 4-6 were labeled with iron sucrose (Venofer®) which was added to the cell culture medium. Pre- and post-iron sucrose labeled ASCs were evaluated for cell surface immunophenotypes. Cell viability as well as chondrogenic, adipogenic and osteogenic differentiation of IS-labeled-ASCs were evaluated. The IS-labeled ASCs were titrated into microtubes at 1 × 10³, 1 × 10⁴, 1 × 10⁵ and 1 × 10⁶ cells/ml/microtube and their intensities were determined by 1.5 and 3T MRI using T2-and T2∗-weighted sequences.

Results

The expression markers of IS-labeled ASCs from flow cytometry were equivalent to control. The mean cell viability was 97.73 ± 2.06%. Cell differentiations of IS-labeled ASCs were confirmed in each lineage using specific staining solutions. T2∗-weighted sequences (T2∗) were able to detect iron sucrose labeled-ASCs at a minimum of 1 × 10⁵ cells/ml/microtube using 1.5 and 3T MRI, but the detection sensitivity was lower with T2-weighted sequences (T2).

Conclusions

Iron sucrose incubation is a safe alternative method for ASCs labeling and tracking using MRI following treatment. Clinicians and researchers should be able to visualize the location of ASCs engraftment without secondary surgical investigation involving tissue sampling.

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.

Infrapatellar Fat Pad/Synovium Complex in Early-Stage Knee Osteoarthritis: Potential New Target and Source of Therapeutic Mesenchymal Stem/Stromal Cells

The infrapatellar fat pad (IFP) has until recently been viewed as a densely vascular and innervated intracapsular/extrasynovial tissue with biomechanical roles in the anterior compartment of the knee. Over the last decade, secondary to the proposition that the IFP and synovium function as a single unit, its recognized tight molecular crosstalk with emerging roles in the pathophysiology of joint disease, and the characterization of immune-related resident cells with varying phenotypes (e.g., pro and anti-inflammatory macrophages), this structural complex has gained increasing attention as a potential therapeutic target in patients with various knee pathologies including osteoarthritis (KOA). Furthermore, the description of the presence of mesenchymal stem/stromal cells (MSC) as perivascular cells within the IFP (IFP-MSC), exhibiting immunomodulatory, anti-fibrotic and neutralizing activities over key local mediators, has promoted the IFP as an alternative source of MSC for cell-based therapy protocols. These complementary concepts have supported the growing notion of immune and inflammatory events participating in the pathogenesis of KOA, with the IFP/synovium complex engaging not only in amplifying local pathological responses, but also as a reservoir of potential therapeutic cell-based products. Consequently, the aim of this review is to outline the latest discoveries related with the IFP/synovium complex as both an active participant during KOA initiation and progression thus emerging as a potential target, and a source of therapeutic IFP-MSCs. Finally, we discuss how these notions may help the design of novel treatments for KOA through modulation of local cellular and molecular cascades that ultimately lead to joint destruction.

Patient-Reported Outcomes After Platelet-Rich Plasma, Bone Marrow Aspirate, and Adipose-Derived Mesenchymal Stem Cell Injections for Symptomatic Knee Osteoarthritis

Objective:

The objective of this study was to compare platelet-rich plasma (PRP), bone marrow aspirate concentrate (BMAC), and adipose-derived mesenchymal stem cell (MSC) injections in the treatment of osteoarthritis (OA) of the knee using functional scores.

Methods:

A total of 89 patients with painful knee OA were included in this study. Patients were assigned to one of the 3 treatments according to severity of OA as indicated by symptoms and radiography to PRP (stage I), BMAC (stage II), or adipose-derived MSC (stage III). Clinical assessment was performed using the Knee Society Score, which combines the Knee Score, based on the clinical parameters, and the Functional Score, and IKDC score. Surveys were completed at preoperative and at 90, 180, and 265 days postoperative. The follow-up responses were compared with baseline and between treatment groups.

Results:

Treatment with PRP, BMAC, and adipose-derived MSC included 29 (32.6%), 27 (30.3%), and 33 (37.1%) patients, respectively. For the total group, median age was 61 years (range: 22-84 years). Score values were comparable among treatment groups at baseline. Statistically significant improvement was observed in the 3 groups according to the 3 scores at all time points during follow-up compared with baseline. No difference was found among treatment type.

Conclusions:

Our findings support previous reports and encourage further research on the use of these cost-effective treatments for OA of the knee.

Mesenchymal Stromal Cell-Based Therapy-An Alternative to Arthroplasty for the Treatment of Osteoarthritis? A State of the Art Review of Clinical Trials

Osteoarthritis (OA) is the most common degenerative joint disorder worldwide and to date no regenerative treatment has been established in clinical practice. This review evaluates the current literature on the clinical translation of mesenchymal stromal cell (MSC)-based therapy in OA management with a focus on safety, outcomes and procedural specifics. PubMed, Cochrane Library and clinicaltrials.gov were searched for clinical studies using MSCs for OA treatment. 290 articles were initially identified and 42 articles of interest, including a total of 1325 patients, remained for further examination. Most of the included studies used adipose tissue-derived MSCs or bone-marrow-derived MSCs to treat patients suffering from knee OA. MSC-based therapy for knee OA appears to be safe and presumably effective in selected parameters. Yet, a direct comparison between studies was difficult due to a pronounced variance regarding methodology, assessed outcomes and evidence levels. Intensive scientific engagement is needed to identify the most effective source and dosage of MSCs for OA treatment in the future. Consent on outcome measures has to be reached and eventually patient sub-populations need to be identified that will profit most from MSC-based treatment for OA.

A Patch of Detachable Hybrid Microneedle Depot for Localized Delivery of Mesenchymal Stem Cells in Regeneration Therapy

Mesenchymal stem cells (MSCs) have been widely used for regenerative therapy. In most current clinical applications, MSCs are delivered by injection but face significant issues with cell viability and penetration into the target tissue due to a limited migration capacity. Some therapies have attempted to improve MSC stability by their encapsulation within biomaterials; however, these treatments still require an enormous number of cells to achieve therapeutic efficacy due to low efficiency. Additionally, while local injection allows for targeted delivery, injections with conventional syringes are highly invasive. Due to the challenges associated with stem cell delivery, a local and minimally invasive approach with high efficiency and improved cell viability is highly desired. In this study, we present a detachable hybrid microneedle depot (d-HMND) for cell delivery. Our system consists of an array of microneedles with an outer poly(lactic-co-glycolic) acid (PLGA) shell and an internal gelatin methacryloyl (GelMA)-MSC mixture (GMM). The GMM was characterized and optimized for cell viability and mechanical strength of the d-HMND required to penetrate mouse skin tissue was also determined. MSC viability and function within the d-HMND was characterized in vitro and the regenerative efficacy of the d-HMND was demonstrated in vivo using a mouse skin wound model.

Mesenchymal stromal cell and bone marrow concentrate therapies for musculoskeletal indications: a concise review of current literature

The interest on applying mesenchymal stromal cells (MSCs) in orthopedic disorders has risen tremendously in the last years due to scientific successes in preclinical in vitro and animal model studies. In a wide range of diseases and injuries of the musculoskeletal system, MSCs are currently under evaluation, but so far have found access to clinical use only in few cases. The current assignment is to translate the acquired knowledge into clinical practice. Therefore, this review aims at presenting a synopsis of the up-to-date status of the use of MSCs and MSC related cell products in musculoskeletal indications. Clinical studies were included, whereas preclinical and animal study data not have been considered. Most studies published so far investigate the final outcome applying bone marrow derived MSCs. In fewer trials the use of adipose tissue derived MSCs and allogenic MSCs was investigated in different applications. Although the reported results are equivocal in the current literature, the vast majority of the studies shows a benefit of MSC based therapies depending on the cell sources and the indication in clinical use. In summary, the clinical use of MSCs in patients in orthopedic indications has been found to be safe. Standardized protocols and clear definitions of the mechanisms of action and the mode and timing of application as well as further coordinated research efforts will be necessary for finally adding MSC based therapies in standard operating procedures and guidelines for the clinicians treating orthopedic disorders.

Mesenchymal stromal cells; a new horizon in regenerative medicine

In recent decades, mesenchymal stromal cells (MSCs) biomedical utilizing has attracted worldwide growing attention. After the first report of the human MSCs obtaining from the bone marrow (BM) tissue, these cells were isolated from wide types of the other tissues, ranging from adipose tissue to dental pulp. Their specific characteristics, comprising self-renewality, multipotency, and availability accompanied by their immunomodulatory properties and little ethical concern denote their importance in the context of regenerative medicine. Considering preclinical studies, MSCs can modify immune reactions during tissue repair and restoration, providing suitable milieu for tissue recovery; on the other hand, they can be differentiated into comprehensive types of the body cells, such as osteoblast, chondrocyte, hepatocyte, cardiomyocyte, fibroblast, and neural cells. Though a large number of studies have investigated MSCs capacities in regenerative medicine in varied animal models, the oncogenic capability of unregulated MSCs differentiation must be more assessed to enable their application in the clinic. In the current review, we provide a brief overview of MSCs sources, isolation, and expansion as well as immunomodulatory activities. More important, we try to collect and discuss recent preclinical and clinical research and evaluate current challenges in the context of the MSC-based cell therapy for regenerative medicine.

Adipose-Derived Mesenchymal Stem Cell Treatments and Available Formulations

PURPOSE OF REVIEW

The use of human adipose-derived mesenchymal stem cells (ADSCs) has gained attention due to its potential to expedite healing and the ease of harvesting; however, clinical evidence is limited, and questions concerning optimal method of delivery and long-term outcomes remain unanswered.

RECENT FINDINGS

Administration of ADSCs in animal models has been reported to aid in improved healing benefits with enhanced repair biomechanics, superior gross histological appearance of injury sites, and higher concentrations of growth factors associated with healing compared to controls. Recently, an increasing body of research has sought to examine the effects of ADSCs in humans. Several available processing techniques and formulations for ADSCs exist with evidence to suggest benefits with the use of ADSCs, but the superiority of any one method is not clear. Evidence from the most recent clinical studies available demonstrates promising outcomes following treatment of select musculoskeletal pathologies with ADSCs despite reporting variability among ADSCs harvesting and processing; these include (1) healing benefits and pain improvement for rotator cuff and Achilles tendinopathies, (2) improvements in pain and function in those with knee and hip osteoarthritis, and (3) improved cartilage regeneration for osteochondral focal defects of the knee and talus. The limitation to most of this literature is the use of other therapeutic biologics in combination with ADSCs. Additionally, many studies lack control groups, making establishment of causation inappropriate. It is imperative to perform higher-quality studies using consistent, predictable control populations and to standardize formulations of ADSCs in these trials.

Intra-articular delivery of umbilical cord-derived mesenchymal stem cells temporarily retard the progression of osteoarthritis in a rat model

AIM

Mesenchymal stem cell (MSC)-based therapy is being explored in treating osteoarthritis (OA). Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are least reported. In this study, we investigated the effects of single intra-articular injections of hUC-MSCs on a rat OA model.

METHOD

hUC-MSCs were isolated from the Wharton's jelly of the human umbilical cord and identified. Eighteen Sprague-Dawley rats were used for the OA model. All rats were divided into 3 groups: hyaluronic acid (HA)+MSCs (n = 6), HA (n = 6), and control group (n = 6). One by 10⁶ hUC-MSCs in 100 μL HA, 100 μL HA or 100 μL saline were injected into the knee joint 4 weeks post-surgery as a single dose. Cartilage degeneration was evaluated at 6 and 12 weeks after treatment with macroscopic examination, micro-computed tomography analysis, behavioral analysis, and histology.

RESULTS

At 6 weeks, the HA + MSCs group had a significantly better International Cartilage Repair Society score in the femoral condyle compared to the HA and control groups. Histological analysis also showed more proteoglycan and less cartilage loss, with lower modified Mankin score in the HA + MSCs group. However, at 12 weeks there were no significant differences between groups from macroscopic examination and histological analysis. Subchondral bone sclerosis of the medial femoral condyle and behavioral tests showed no significant differences between groups at 6 and 12 weeks.

CONCLUSION

These findings indicate that single injection of hUC-MSCs can have temporary effects on decelerating the progression of cartilage degeneration in OA rats, but may not inhibit OA progression in the long-term.

Where is human-based cellular pharmaceutical R&D taking us in cartilage regeneration?

Lately, cellular-based cartilage joint therapies have gradually gained more attention, which leads to next generation bioengineering approaches in the development of cell-based medicinal products for human use in cartilage repair. The greatest hurdles of chondrocyte-based cartilage bioengineering are: (i) preferring the cell source; (ii) differentiation and expansion processes; (iii) the time necessary for chondrocyte expansion pre-implantation; and (iv) fixing the chondrocyte count in accordance with the lesion surface area of the patient in question. The chondrocyte presents itself to be the focal starting material for research and development of bioengineered cartilage-based medicinal products which promise the regeneration and restoration of non-orthopedic cartilage joint defects. Even though chondrocytes seem to be the first choice, inevitable complications related to proliferation, dedifferentation and redifferentiation are probable. Detailed studies are a necessity to fully investigate detailed culturing conditions, the chondrogenic strains of well-defined phenotypes and evaluation of the methods to be used in biomaterial production. Despite a majority of the current methods which aid amelioration of joint functionality, they are insufficient in fully restoring the natural structure and composition of the joint cartilage. Hence current studies have trended towards gene therapy, mesenchymal stem cells and tissue engineering practices. There are many studies addressing the outcomes of chondrocytes in the clinical scene, and many vital biomaterials have been developed for structuring the bioengineered cartilage. This study aims to convey to the audience the practical significance of chondrocyte-based clinical applications.

The cell yields and biological characteristics of stromal/stem cells from lipoaspirate with different digestion loading ratio

Effective harvesting procedure for adipose tissue is demanded by the affordable Good Manufacturing Practice-Compliant Production of clinical-grade adipose tissue-derived stem cells (hADSCs). Enzymatic digestion using collagenase is the most reliable method of adipose tissue-derived stem cells (hADSCs) isolation, while the optimized loading volume ratios of digestion to container during the shaking process of adipose tissue and collagenase mixture are still lacking. This study was conducted to determine the optimized loading volume ratio (mixture to container) for enzymatic digestion of Stromal/Stem Cells from lipoaspirate. Lipoaspirates were obtained from twelve women immediately after liposuction. Then tissue from each patient was divided into four groups according to different loading volume ratios in 50 ml centrifugal tube: 0.2 group, 0.4 group, 0.6 group, 0.8 group. Stromal vascular fractions (SVF) were obtained from each group, then total cell counts, viability and viable cell count were performed. hADSCs were harvested at passage (P) 2, whose morphologies, immunophenotypes, proliferation, and tri-differentiation abilities were compared. 0.4 loading volume ratio provided the highest cell yield, favorable viability and viable cell yield. The proliferation and triple differentiation ability of hADSCs obtained by 0.4 group was not inferior to that of other groups. Therefore, 0.4 may be the optimal loading volume ratio for hADSCs isolation from lipoaspirate by enzymatic digestion in current setting.

Assessment of Enrichment of Human Mesenchymal Stem Cells Based on Plasma and Mitochondrial Membrane Potentials

Background: Human mesenchymal stem cells (hMSCs) are utilized preclinically and clinically as a candidate cell therapy for a wide range of inflammatory and degenerative diseases. Despite promising results in early clinical trials, consistent outcomes with hMSC-based therapies have proven elusive in many of these applications. In this work, we attempt to address this limitation through the design of a stem cell therapy to enrich hMSCs for desired electrical and ionic properties with enhanced stemness and immunomodulatory/regenerative capacity. Materials and Methods: In this study, we sought to develop initial protocols to achieve electrically enriched hMSCs (EE-hMSCs) with distinct electrical states and assess the potential relationship with respect to hMSC state and function. We sorted hMSCs based on fluorescence intensity of tetramethylrhodamine ethyl ester (TMRE) and investigated phenotypic differences between the sorted populations. Results: Subpopulations of EE-hMSCs exhibit differential expression of genes associated with senescence, stemness, immunomodulation, and autophagy. EE-hMSCs with low levels of TMRE, indicative of depolarized membrane potential, have reduced mRNA expression of senescence-associated markers, and increased mRNA expression of autophagy and immunomodulatory markers relative to EE-hMSCs with high levels of TMRE (hyperpolarized). Conclusions : This work suggests that the utilization of EE-hMSCs may provide a novel strategy for cell therapies, enabling live cell enrichment for distinct phenotypes that can be exploited for different therapeutic outcomes.

Recent Advance in Source, Property, Differentiation, and Applications of Infrapatellar Fat Pad Adipose-Derived Stem Cells

Infrapatellar fat pad (IPFP) can be easily obtained during knee surgery, which avoids the damage to patients for obtaining IPFP. Infrapatellar fat pad adipose-derived stem cells (IPFP-ASCs) are also called infrapatellar fat pad mesenchymal stem cells (IPFP-MSCs) because the morphology of IPFP-ASCs is similar to that of bone marrow mesenchymal stem cells (BM-MSCs). IPFP-ASCs are attracting more and more attention due to their characteristics suitable to regenerative medicine such as strong proliferation and differentiation, anti-inflammation, antiaging, secreting cytokines, multipotential capacity, and 3D culture. IPFP-ASCs can repair articular cartilage and relieve the pain caused by osteoarthritis, so most of IPFP-related review articles focus on osteoarthritis. This article reviews the anatomy and function of IPFP, as well as the discovery, amplification, multipotential capacity, and application of IPFP-ASCs in order to explain why IPFP-ASC is a superior stem cell source in regenerative medicine.

Current solutions for the treatment of chronic articular cartilage defects in the knee

Chondral and osteochondral defects in the knee are common and may lead to degenerative joint disease if treated inappropriately.

Conventional treatments such as microfracture often result in fibrocartilage formation and are associated with inferior results. Additionally, microfracture is generally unsuitable for the treatment of defects larger than 2–4 cm².

The osteochondral autograft transfer system (OATS) has been shown to produce superior clinical outcomes to microfracture but is technically difficult and may be associated with donor-site morbidity. Osteochondral allograft use is limited by graft availability and failure of cartilage incorporation is an issue.

Autologous chondrocyte implantation (ACI) has been shown to result in repair with hyaline-like cartilage but involves a two-stage procedure and is relatively expensive.

Rehabilitation after ACI takes 12 months, which is inconvenient and not feasible for athletic patients.

Newer methods to regenerate cartilage include autologous stem cell transplantation, which may be performed as a single-stage procedure, can have a shorter rehabilitation period and is less expensive than ACI. Longer-term studies of these methods are needed.

Cite this article: EFORT Open Rev 2020;5:156-163. DOI: 10.1302/2058-5241.5.190031

Clinical Efficacy of Intra-articular Mesenchymal Stromal Cells for the Treatment of Knee Osteoarthritis: A Double-Blinded Prospective Randomized Controlled Clinical Trial

BACKGROUND

Currently, there are limited nonoperative treatment options available for knee osteoarthritis (OA). Cell-based therapies have emerged as promising treatments for knee OA. Autologous stromal vascular fraction (SVF) has been identified as an efficient medium for intra-articular administration of progenitor cells and mesenchymal stem cells derived from adipose tissue.

HYPOTHESIS

Patients receiving intra-articular SVF would show significantly greater improvement than patients receiving placebo injections, and this improvement would be dose dependent.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This was a multisite prospective double-blinded randomized placebo-controlled clinical trial. Adult patients with symptomatic knee OA were eligible. Thirty-nine patients were randomized to high-dose SVF, low-dose SVF, or placebo (1:1:1). SVF was obtained via liposuction, processed to create the cellular implant, and injected during the same clinical visit. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and magnetic resonance images were obtained preoperatively and at 6 and 12 months after injection. The Wilcoxon rank sum nonparametric test was utilized to assess statistical significance, and the Hodges-Lehmann location shift was used to assess superiority.

RESULTS

The median percentage change in WOMAC score at 6 months after injection for the high-dose, low-dose, and placebo groups was 83.9%, 51.5%, and 25.0%, respectively. The high- and low-dose groups had statistically significant changes in WOMAC scores when compared with the placebo group (high dose, P = .04; low dose, P = .02). The improvements were dose dependent. The median percentage change in WOMAC score from baseline to 1 year after injection for the high-dose, low-dose, and placebo groups was 89.5%, 68.2%, and 0%, respectively. The high- and low-dose groups displayed a greater percentage change at 12 months when compared with the placebo group (high dose, P = .006; low dose, P = .009). Magnetic resonance image review revealed no changes in cartilage thickness after treatment. No serious adverse events were reported.

CONCLUSION

Intra-articular SVF injections can significantly decrease knee OA symptoms and pain for at least 12 months. The efficacy and safety demonstrated in this placebo-controlled trial support its implementation as a treatment option for symptomatic knee OA.

REGISTRATION

NCT02726945 (ClinicalTrials.gov identifier).

Interleukin-4 Gene Transfection and Spheroid Formation Potentiate Therapeutic Efficacy of Mesenchymal Stem Cells for Osteoarthritis

Osteoarthritis (OA) is a painful intractable disease that significantly affects patients' quality of life. However, current therapies, such as pain killers and joint replacement surgery, do not lead to cartilage protection. Mesenchymal stem cells (MSCs) have been proposed as an alternative strategy for OA therapy because MSCs can secrete chondroprotective and anti-inflammatory factors. However, interleukin-4 (IL-4), a potent anti-inflammatory cytokine, is barely produced by MSCs, and MSC therapy suffers from rapid MSC death following intra-articular implantation. MSCs in spheroids survive better than naïve MSCs in vitro and in vivo. IL-4-transfected MSCs in spheroids (IL-4 MSC spheroid) show increased chondroprotective and anti-inflammatory effects in an OA chondrocyte model in vitro. Following intra-articular implantation in OA rats, IL-4 MSC spheroids show better cartilage protection and pain relief than naïve MSCs. Thus, IL-4 MSC spheroid may potentiate the therapeutic efficacy of MSCs for OA.

Secreted Factors and EV-miRNAs Orchestrate the Healing Capacity of Adipose Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis

Mesenchymal stem cells (MSCs) derived from adipose tissue and used either as expanded cells or minimally manipulated cell preparations showed positive clinical outcomes in regenerative medicine approaches based on tissue restoration and inflammation control, like in osteoarthritis (OA). Recently, MSCs’ healing capacity has been ascribed to the large array of soluble factors, including soluble cytokines/chemokines and miRNAs conveyed within extracellular vesicles (EVs). Therefore, in this study, 200 secreted cytokines, chemokines and growth factors via ELISA, together with EV-embedded miRNAs via high-throughput techniques, were scored in adipose-derived MSCs (ASCs) cultivated under inflammatory conditions, mimicking OA synovial fluid. Both factors (through most abundantly expressed TIMP1, TIMP2, PLG and CTSS) and miRNAs (miR-24-3p, miR-222-3p and miR-193b-3p) suggested a strong capacity for ASCs to reduce matrix degradation activities, as those activated in OA cartilage, and switch synovial macrophages, often characterized by an M1 inflammatory polarization, towards an M2 phenotype. Moreover, the crucial importance of selecting the target tissue is discussed, showing how a focused search may greatly improve potency prediction and explain clinical outcomes. In conclusion, herein presented data shed light about the way ASCs regulate cell homeostasis and regenerative pathways in an OA-resembling environment, therefore suggesting a rationale for the use of MSC-enriched clinical products, such as stromal vascular fraction and microfragmented adipose tissue, in joint pathologies.

Human adipose-derived mesenchymal progenitor cells plus microfracture and hyaluronic acid for cartilage repair: a Phase IIa trial

Aim: This study aimed to preliminarily evaluate the safety and efficacy of human adipose-derived mesenchymal progenitor cells (haMPCs) in combination with microfracture and hyaluronic acid (HA) for treating cartilage defects. Materials & methods: A total of 30 patients with medial femoro-tibial condylar cartilage defects were randomized into three groups: arthroscopic microfracture group and normal saline injection, arthroscopic microfracture and intra-articular injection of HA, or arthroscopic microfracture in combination with intra-articular injection of HA and haMPCs. Results & conclusions: The data demonstrated that intra-articular injection of haMPCs plus microfracture and HA is a safe procedure to improve joint function in patients with knee cartilage defects. These findings provide an impetus for future research on this treatment. ClinicalTrials.gov Identifier: NCT02855073.

Stem Cell Treatment for Knee Articular Cartilage Defects and Osteoarthritis

PURPOSE OF REVIEW

To review the current basic science and clinical literature on mesenchymal stem cell (MSC) therapy for articular cartilage defects and osteoarthritis of the knee.

RECENT FINDINGS

MSCs derived from bone marrow, adipose, and umbilical tissue have the capacity for self-renewal and differentiation into the chondrocyte lineage. In theory, MSC therapy may help restore cartilage focally or diffusely where nascent regenerative potential in the intra-articular environment is limited. Over the last several years, in vitro and animal studies have elucidated the use of MSCs in isolation as injectables, in combination with biological delivery media and scaffolding, and as surgical adjuvants for cartilage regeneration and treatment of knee degenerative conditions. More recently, clinical and translational literature has grown more convincing from early descriptive case series to randomized controlled trials showing promise in efficacy and safety. Studies describing MSC for knee cartilage regeneration applications are numerous and varied in quality. Future research directions should include work on elucidating optimal cell concentration and dosing, as well as standardization in methodology and reporting in prospective trials. Backed by promise from in vitro and animal studies, preliminary clinical evidence on MSC therapy shows promise as a nonoperative therapeutic option or an adjuvant to existing surgical cartilage restoration techniques. While higher quality evidence to support MSC therapy has emerged over the last several years, further refinement of methodology will be necessary to support its routine clinical use.

Online Direct-to-Consumer Advertising of Stem Cell Therapy for Musculoskeletal Injury and Disease: Misinformation and Violation of Ethical and Legal Advertising Parameters

BACKGROUND

There has been a recent surge in health-care providers offering stem cell therapy (SCT) to patients with musculoskeletal disease. The purpose of this study was to identify and quantify the misinformation present in online direct-to-consumer (DTC) advertising of SCT targeting patients with musculoskeletal disease in the U.S. It was hypothesized that DTC advertising of SCT contains substantial misinformation.

METHODS

A list of keywords was used to identify web sites of practices advertising SCT directly to patients with musculoskeletal disease. Web sites were evaluated to determine the specialties of providers offering SCT, types of SCT being advertised, and misinformation presented. Categories of misinformation included false general claims, inaccurate statements regarding mechanism of action, unfounded results, and scare tactics.

RESULTS

Of the 896 practice web sites included in the analysis, 95.9% contained at least 1 statement of misinformation, with a mean of 4.65 ± 3.66 statements of misinformation among the sites. Practices associated with an orthopaedic surgeon provided 22% fewer statements of misinformation than practices without an orthopaedic surgeon when we controlled for the effects of other specialties. Practices associated with a podiatrist also provided 22% fewer statements of misinformation.

CONCLUSIONS

Nearly all practices failed to accurately represent the clinical efficacy of SCT in DTC advertising. While practices associated with an orthopaedic surgeon were less likely to provide misinformation, the majority of all web sites contained some type of misinformation, ranging from errors in the basic science of stem cells to outright false and misleading claims of their clinical effectiveness.

Contribution of adipocyte precursors in the phenotypic specificity of intra-articular adipose tissues in knee osteoarthritis patients

Background

Intra-articular adipose tissues (IAATs) are involved in osteoarthritis (OA) pathophysiology. We hypothesize that mesenchymal cells residing in IAATs may account for the specific inflammatory and metabolic patterns in OA patients.

Methods

Adipocyte precursors (preadipocytes and dedifferentiated fat cells (DFATc)) from IAATs (infrapatellar and suprapatellar fat pads) and autologous subcutaneous adipose tissues (SCATs) were isolated from knee OA patients. The ability of these precursors to differentiate into adipocytes was assessed by oil red O staining after 14 days of culture in adipogenic medium. The gene expression of adipocyte-related transcription factors (C/EBP-α and PPAR-γ) and development-related factors (EN1 and SFRP2) were analyzed. The inflammatory pattern was assessed by RT-qPCR and ELISA (interleukin 6 (IL-6), IL-8, Cox2, and prostaglandin E2 (PGE₂)) after a 24-h stimulation by IL-1β (1 ng/mL) and by conditioned medium from OA synovium.

Results

IAAT preadipocytes displayed a significantly higher ability to differentiate into adipocytes and expressed significantly more C/EBP-α mRNA than SCAT preadipocytes. IAAT preadipocytes expressed significantly less EN-1 and SFRP2 mRNA than SCAT preadipocytes. Unstimulated IAAT preadipocytes displayed a less inflammatory pattern (IL-6, IL-8, and Cox2/PGE₂) than SCAT preadipocytes. In contrast, the response of IAAT preadipocytes to an inflammatory stimulus (IL-1β and conditioned media of OA synovium) was exacerbated compared to that of SCAT preadipocytes. Similar results were obtained with DFATc.

Conclusion

IAAT adipocyte precursors from OA patients have a specific phenotype, which may account for the unique phenotype of OA IAATs. The exacerbated response of IAAT preadipocytes to inflammatory stimulation may contribute to OA pathophysiology.

Cell-to-Cell Culture Inhibits Dedifferentiation of Chondrocytes and Induces Differentiation of Human Umbilical Cord-Derived Mesenchymal Stem Cells

Background

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) possess great promise as a therapeutic to repair damaged cartilage. Direct intra-articular injection of mesenchymal stem cells has been shown to reduce cartilage damage and is advantageous as surgical implantation and associated side effects can be avoided using this approach. However, the efficacy of stem cell-based therapy for cartilage repair depends highly on the direct interactions of these stem cells with chondrocytes in the joint. In this study, we have carried out an in vitro cell-to-cell contact coculture study with human articular chondrocytes (hACs) and hUC-MSCs, with the goal of this study being to evaluate interactions between hACs and hUC-MSCs.

Methods

Low-density monolayer cultures of hUC-MSCs and hACs were mixed at a ratio of 1 : 1 in direct cell-to-cell contact groups. Results were analyzed using quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence.

Results

A mixed coculture of hUC-MSCs and hACs was found to exhibit synergistic interactions with enhanced differentiation of hUC-MSCs and reduced dedifferentiation of chondrocytes. Mixed cultures after 21 days were found to exhibit sufficient chondrogenic induction.

Conclusions

The results from this study suggest the presence of mutual effects between hUC-MSCs and hACs even culture at low density and provide further support for the use of intra-articular injection strategies for cartilage defect treatment.

Donor-matched comparison of chondrogenic progenitors resident in human infrapatellar fat pad, synovium, and periosteum - implications for cartilage repair

Purpose: There is a clinical need to better characterize tissue sources being used for stem cell therapies. This study focuses on comparison of cells and connective tissue progenitors (CTPs) derived from native human infrapatellar fatpad (IPFP), synovium (SYN), and periosteum (PERI). Materials and Methods: IPFP, SYN, PERI were harvested from twenty-eight patients undergoing arthroplasty. CTPs were quantitatively characterized using automated colony-forming-unit assay to compare total nucleated cell concentration-[Cell], cells/mg; prevalence-(P_CTP), CTPs/million nucleated cells; CTP concentration-[CTP], CTPs/mg; proliferation and differentiation potential; and correlate outcomes with patient's age and gender. Results: [Cell] did not differ between IPFP, SYN, and PERI. P_CTP was influenced by age and gender: patients >60 years, IPFP and SYN had higher P_CTP than PERI (p < 0.001) and females had higher P_CTP in IPFP (p < 0.001) and SYN (p = 0.001) than PERI. [CTP] was influenced by age: patients <50 years, SYN (p = 0.0165) and PERI (p < 0.001) had higher [CTP] than IPFP; patients between 60 and 69 years, SYN (p < 0.001) had higher [CTP] than PERI; patients >70 years, IPFP (p = 0.006) had higher [CTP] than PERI. In patients >60 years, proliferation potential of CTPs differed significantly (SYN>IPFP>PERI); however, differentiation potentials were comparable between all three tissue sources. Conclusion: SYN and IPFP may serve as a preferred tissue source for patients >60 years, and PERI along with SYN and IPFP may serve as a preferred tissue source for patients <60 years for cartilage repair. However, the heterogeneity among the CTPs in any given tissue source suggests performance-based selection might be useful to optimize cell-sourcing strategies to improve efficacy of cellular therapies for cartilage repair.

Effects of Conditioned Medium From Osteoarthritic Cartilage Fragments on Donor-Matched Infrapatellar Fat Pad-Derived Mesenchymal Stromal Cells

BACKGROUND

Mesenchymal stromal cell (MSC)-based therapies have emerged as a promising strategy for osteoarthritis (OA) treatment. In particular, infrapatellar fat pad (IPFP)-derived MSCs have become a good option to treat knee OA.

PURPOSE

To investigate the influence of the local microenvironment of the knee joint, especially OA cartilage, on the bioactivities of injected/implanted IPFP MSCs.

STUDY DESIGN

Controlled laboratory study.

METHODS

Conditioned medium (CM) derived from OA cartilage fragments was collected and characterized. Donor-matched IPFP MSCs were treated with control medium (Dulbecco's modified Eagle medium (DMEM)/F-12 or chondrogenic medium), control medium + CM, or CM alone; and a series of behaviors including the viability, migration, chondrogenic and hypertrophic differentiation, and catabolic activity of IPFP MSCs were evaluated among groups.

RESULTS

There were 14 cytokines detected in CM. CM treatment improved the viability of IPFP MSCs. CM hindered the migration of IPFP MSCs. In chondrogenic differentiation, the presence of CM increased the expression of chondrogenic markers but also enhanced the state of hypertrophy and catabolism.

CONCLUSION

OA cartilage-secreted factors could induce chondrogenic differentiation but also resulted in negative effects including the weakened migration, increased hypertrophy, and catabolism of IPFP MSCs in vitro.

CLINICAL RELEVANCE

These findings provide an insight on the fate of IPFP MSCs after intra-articular injections.

Quantitative T2 MRI Mapping and 12-Month Follow-up in a Randomized, Blinded, Placebo Controlled Trial of Bone Marrow Aspiration and Concentration for Osteoarthritis of the Knees

OBJECTIVE

Bone marrow aspiration and concentration (BMAC) is becoming a more common regenerative therapy for musculoskeletal pathology. In our current pilot study, we studied patients with mild-to-moderate bilateral knee osteoarthritis, compared pain at 12-month follow-up between BMAC-injected and saline-injected knees, and examined cartilage appearance measured by magnetic resonance imaging (MRI) T2 quantitative mapping.

DESIGN

Twenty-five patients with mild-to-moderate bilateral osteoarthritic knee pain were randomized to receive BMAC into one knee and saline placebo into the other. Bone marrow was aspirated from the iliac crests, concentrated in an automated centrifuge, combined with platelet-poor plasma for knee injection, and compared with saline injection into the contralateral knee. Primary outcome measures were T2 MRI cartilage mapping at 6-month and Visual Analog Scale and Osteoarthritis Research Society International Intermittent and Constant Osteoarthritis Pain scores and radiographs at 12-month follow-up.

RESULTS

Constant, intermittent, and overall knee pain remained significantly decreased from baseline at 12-month follow-up (all P ⩽ 0.01), with no apparent difference between BMAC- and saline-treated knees (all P ⩾ 0.54). A similar significant increase from baseline to 12-month follow-up regarding quality of life was observed for both BMAC- and saline-treated knees (all P ⩽ 0.04). T2 quantitative MRI mapping showed no significant changes as a result of treatment.

CONCLUSIONS

BMAC is safe to perform and relieves pain from knee arthritis but showed no superiority to saline injection at 12-month follow-up. MRI cartilage sequences failed to show regenerative benefit with single BMAC injection. The mechanisms of action that led to pain relief remain unclear and warrant further studies.

Stromal vascular fraction technologies and clinical applications

Introduction: The heterogeneous pool of cells found in the stromal vascular fraction of adipose tissue (SVF) and the purified mesenchymal stromal/stem cells (ASCs) isolated from this pool have increasingly been used as therapeutic tools in regenerative medicine.Areas covered: As SVF and ASCs are different, and should be used in different manners according to various clinical and biological indications, we reviewed the current literature, and focused on the clinical use of SVF to appraise the main medical fields for development. Both enzymatic digestion and mechanical disruption have been used to obtain SVF for non-homologous use. The safety and/or benefits of SVF have been examined in 71 clinical studies in various contexts, mainly musculoskeletal conditions, wound healing, urogenital, and cardiovascular and respiratory diseases. The use of SVF as a therapy remains experimental, with few clinical trials.Expert opinion: SVF provides a cellular and molecular microenvironment for regulation of ASC' activities under different clinical conditions. SVF may enhance angiogenesis and neovascularization in wound healing, urogenital and cardiovascular diseases. In joint conditions, therapeutic benefits may rely on paracrine immune-modulatory and anti-inflammatory mechanisms. Novel point of care methods are emerging to refine SVF in ways that meet the regulatory requirements for minimal manipulation.

Early results of intra-articular micro-fragmented lipoaspirate treatment in patients with late stages knee osteoarthritis: a prospective study

Aim

To analyze clinical and functional effects of intra-articular injection of autologous micro-fragmented lipoaspirate (MLA) in patients with late stage knee osteoarthritis (KOA). Secondary aims included classifying cell types contributing to the treatment effect, performing detailed MRI-based classification of KOA, and elucidating the predictors for functional outcomes.

Methods

This prospective, non-randomized study was conducted from June 2016 to February 2018 and enrolled 20 patients with late stage symptomatic KOA (Kellgren Lawrence grade III, n = 4; and IV, n = 16) who received an intra-articular injection of autologous MLA in the index knee joint. At baseline radiological KOA grade and MRI were assessed in order to classify the morphology of KOA changes. Stromal vascular fraction cells obtained from MLA samples were stained with antibodies specific for cell surface markers. Patients were evaluated at baseline and 12-months after treatment with visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Injury and Osteoarthritis Outcome Score (KOOS).

Results

Three patients (15%) received a total knee replacement and were not followed up completely. Seventeen patients (85%) showed a substantial pattern of KOOS and WOMAC improvement, significant in all accounts. KOOS score improved from 46 to 176% when compared with baseline, WOMAC decreased from 40 to 45%, while VAS rating decreased from 54% to 82% (all P values were <0.001). MLA contained endothelial progenitor cells, pericytes, and supra-adventitial adipose stromal cells as most abundant cell phenotypes.

Conclusion

This study is among the first to show a positive effect of MLA on patients with late stages KOA.

ISRCTN registration ID: ISRCTN13337022.

Role of infrapatellar fat pad in pathological process of knee osteoarthritis: Future applications in treatment

It has been found that obese people have a higher proportion in suffering from osteoarthritis (OA), not only in the weight-bearing joints like knee and hip joints, even in non-weight-bearing joints such as hand joints. One of the reasons is because the large amount of adipose tissue secretes some factors, which can promote the occurrence of arthritis. As an important structure of the knee joint, the infrapatellar fat pad (IPFP) is actually a piece of adipose tissue. The aim of this review is to offer a comprehensive view of the anatomy and physiological characteristics of IPFP and its relationship with the pathological process of OA, indicating the important function of IPFP in OA. At the same time, with the development of adipose derived stem cells in the treatment of OA, owing to its special advantages, the IPFP is becoming a kind of important, minimally invasive fat stem cell source, providing a new approach for the treatment of OA. We hope that this review will offer an overview of all published data regarding the IPFP and will indicate novel directions for future research.

Minimally Manipulated Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis: A Systematic Review of Clinical Evidence

Background

The use of laboratory-expanded mesenchymal stem cells (MSCs) is subject to several restrictions, resulting in “minimal manipulation” methods becoming the current most popular strategy to increase the use of MSCs in an orthopaedic practice. The aim of the present systematic review is to assess the clinical applications of “minimally” manipulated MSCs, either as bone marrow aspirate concentrate (BMAC) or as stromal vascular fraction (SVF), in the treatment of knee osteoarthritis (OA).

Methods

A systematic review of three databases (PubMed, ScienceDirect, and Google Scholar) was performed using the following keywords: “Knee Osteoarthritis” with “(Bone marrow aspirate) OR (bone marrow concentrate)” or with “(adipose-derived mesenchymal stem cells) OR (adipose derived stromal cells) OR (stromal vascular fraction) OR (SVF)” as either keywords or MeSH terms. The reference lists of all retrieved articles were further reviewed for identification of potentially relevant studies.

Results

Twenty-three papers were included in the final analysis (10 on BMAC and 13 on SVF). Of these, only 4 were randomized controlled trials (RCTs). Bias risk evaluation, performed using a modified Coleman score, revealed an overall poor quality of the studies. In terms of clinical application, despite the apparent safety of minimally manipulated MSCs and the short-term positive clinical outcomes associated with their use, clinicians reported different preparation and administration methods, ranging from single intra-articular injections to intraosseous applications to administration in combination with other surgical procedures.

Conclusions

The available literature is undermined by both the lack of high-quality studies and the varied clinical settings and different protocols reported in the few RCTs presently published. This prevents any recommendation on the use of either product in a clinical practice. Nevertheless, the use of minimally manipulated MSCs (in the form of BMAC or SVF) has been shown to be safe and have some short-term beneficial effects.

Functional Outcomes Following Microfragmented Adipose Tissue Versus Bone Marrow Aspirate Concentrate Injections for Symptomatic Knee Osteoarthritis

This study aimed to determine whether autologous orthobiologic tissue source affects pain and functional outcomes in patients with symptomatic knee osteoarthritis (OA) who received microfragmented adipose tissue (MFAT) or bone marrow aspirate concentrate (BMAC) injection. We retrospectively reviewed prospectively collected data from patients who received BMAC or MFAT injection for symptomatic knee OA. Patients completed baseline and follow-up surveys. Each survey included the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, Emory Quality of Life (EQOL) questionnaire, and Visual Analog Scale (VAS) for pain. The follow-up responses were compared with baseline for all patients and between BMAC and MFAT groups. A total of 110 patients met inclusion criteria, with 76 patients (BMAC 41, MFAT 35) and 106 knees (BMAC 58, MFAT 48) having appropriate follow-up data. The BMAC group included 17 females and 24 males, with a mean age of 59 ± 11 years. The MFAT group included 23 females and 12 males, with a mean age of 63 ± 11 years. Minimum follow-up time was 0.5 years. Mean follow-up time was 1.80 ± 0.88 years for BMAC and 1.09 ± 0.49 years for MFAT. Both groups had significant improvement in EQOL, VAS, and all KOOS parameters preprocedure versus postprocedure (p < .001). There was not a significant difference when comparing postprocedure scores between groups (p = .09, .38, .63, .94, .17, .15, .70, respectively). These data demonstrate significant improvement in pain and function with both MFAT and BMAC injections in patients with symptomatic knee OA without a significant difference in improvement when comparing the two autologous tissue sources. Stem Cells Translational Medicine 2019;8:1149-1156.