Efficacy and safety of adult human bone marrow-derived, cultured, pooled, allogeneic mesenchymal stromal cells (Stempeucel®): preclinical and clinical trial in osteoarthritis of the knee joint

Fostering tissue engineering and regenerative medicine to treat musculoskeletal disorders in bone and muscle

The musculoskeletal system, which is vital for movement, support, and protection, can be impaired by disorders such as osteoporosis, osteoarthritis, and muscular dystrophy. This review focuses on the advances in tissue engineering and regenerative medicine, specifically aimed at alleviating these disorders. It explores the roles of cell therapy, particularly Mesenchymal Stem Cells (MSCs) and Adipose-Derived Stem Cells (ADSCs), biomaterials, and biomolecules/external stimulations in fostering bone and muscle regeneration. The current research underscores the potential of MSCs and ADSCs despite the persistent challenges of cell scarcity, inconsistent outcomes, and safety concerns. Moreover, integrating exogenous materials such as scaffolds and external stimuli like electrical stimulation and growth factors shows promise in enhancing musculoskeletal regeneration. This review emphasizes the need for comprehensive studies and adopting innovative techniques together to refine and advance these multi-therapeutic strategies, ultimately benefiting patients with musculoskeletal disorders.

Decadal analysis of efficacy and safety profiles of mesenchymal stem cells from varied sources in knee osteoarthritis patients: A systematic review and network meta-analysis

OBJECTIVE

Knee Osteoarthritis (KOA) is a debilitating degenerative joint ailment afflicting millions of patients. Numerous studies have assessed the efficacy of mesenchymal stem cells (MSCs) derived from various sources for KOA treatment, yet direct comparisons are scarce and inconsistent. Furthermore, network meta-analysis (NMA) conclusions require updating, while the safety of MSCs therapy remains contentious. This study evaluates therapeutic approaches involving MSCs from different sources in patients with KOA through randomized controlled trials (RCTs) and cohort studies. The objective is to compare the effectiveness and safety of MSCs strategies from various sources for KOA treatment.

METHODS

A systematic literature review was conducted to identify RCTs and cohort studies comparing different sources of MSCs in KOA patients. A randomized effects network meta-analysis was used to concurrently evaluate both direct and indirect comparisons across all protocols.

RESULTS

The NMA included 16 RCTS and reported 1005 participants. Adipose-derived mesenchymal stem cells (AD-MSCs) were the most effective treatment, showing significant improvements in the Visual Analogue Scale (VAS), the Short Form 36 (SF-36 scale), the International Knee Literature Committee Knee Evaluation Scale (IKDC subjective scores), and the Knee Injury and OA Outcome Score (KOOS). The probabilities are P = 85.3, P = 70.5, P = 88 and P = 87, respectively. Compared with placebo, AD-MSCs resulted in a VAS Score (SMD 0.97; 95%CI 0.37, 1.57), IKDC subjective scores (SMD -0.71; 95%CI -1.20, -0.21) was significantly reduced. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) showed significant improvements in the University of Western Ontario and McMaster University OA (WOMAC) (P = 91.4). Compared with placebo, UC-MSCs had a higher WOMAC Score (SMD 1.65; 95%CI 0.27, 3.03) and ranked first. Compared with MSCs, placebo emerged as the safer option (P = 74.9), with a notable reduction in AEs associated with HA treatment (RR 0.77; 95%CI 0.61, 0.97). AD-MSCs were found to have the least favorable impact on AEs with a probability of P = 13.3.

CONCLUSIONS

This network meta-analysis established that MSCs offer pain relief and enhance various knee scores in KOA patients compared to conventional treatment. It also identifies other therapeutic avenues warranting further exploration through high-quality studies. Nonetheless, it underscores the necessity to emphasize the potential complications and safety concerns associated with MSCs.

Efficacy and safety of culture-expanded mesenchymal stromal cell therapy in the treatment of 4 types of inflammatory arthritis: A systematic review and meta-analysis of 36 randomized controlled trials

OBJECTIVE

This study aims to assess the effectiveness and safety of mesenchymal stem cell (MSC) transplantation in the treatment of inflammatory arthritis.

METHODS

Two researchers conducted a comprehensive search of Chinese and English databases from their inception until July 2023. The literature screening and data extraction were then performed. Statistical analysis was carried out using RevMan 5.4 software.

RESULTS

A total of 36 relevant RCTs, involving 2,076 participants, were ultimately included in this study. These RCTs encompassed four types of inflammatory arthritis, namely rheumatoid arthritis (RA), osteoarthritis (OA), ankylosing spondylitis (AS), and systemic sclerosis (SSc). The results demonstrated that MSC therapy exhibited improvements in the Visual Analog Scale (VAS) for pain in OA patients (bone marrow: SMD=-0.95, 95 % CI: -1.55 to -0.36, P = 0.002; umbilical cord: SMD=-2.03, 95 % CI: -2.99 to -1.07, P < 0.0001; adipose tissue: SMD=-1.26, 95 % CI: -1.99 to -0.52, P = 0.0009). Specifically, MSCs sourced from adipose tissue showed enhancements in Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain (P = 0.0001), WOMAC physical function (P = 0.001), and total WOMAC scores (P = 0.0003). As for MSC therapy in RA, AS, and SSc, the current systematic review suggests a potential therapeutic effect of MSCs on these inflammatory arthritic conditions. Safety assessments indicated that MSC therapy did not increase the incidence of adverse events.

CONCLUSION

MSCs have the potential to alleviate joint pain and improve joint function in patients with inflammatory arthritis. Moreover, MSC therapy appears to be relatively safe and could be considered as a viable alternative treatment option for inflammatory arthritis.

Radiofrequency ablation versus intra-articular mesenchymal stem cell injection for knee osteoarthritis: a systematic review and network meta-analysis

BACKGROUND

Knee osteoarthritis (OA) is a prevalent degenerative disease and causes disability, pain and imposes a substantial burden on patients. Conventional treatments for knee OA show limited effectiveness. Consequently, innovative treatments, such as radiofrequency ablation (RFA) and intra-articular mesenchymal stem cells (IA MSC), have gained attention for addressing these limitations.

OBJECTIVE

We compared the efficacy of RFA and IA MSC for knee OA through a network meta-analysis (NMA).

EVIDENCE REVIEW

A literature search was conducted using PubMed, MEDLINE, Embase, Cochrane Library, Web of Science and handsearching. Randomized controlled trials (RCTs) comparing RFA or IA MSC to conventional treatments for knee OA were included. The primary outcomes comprised the pain score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The clinical outcomes were compared using a frequentist approach, and the treatments were ranked using the surface under the cumulative ranking curve (SUCRA) values.

FINDINGS

We included 34 RCTs (n=2371). Our NMA revealed that RFA and IA MSC were significantly more effective than conventional treatments in managing pain at both 3 and 6 months with moderate certainty. Specifically, RFA demonstrated the highest SUCRA values, indicating its superior efficacy. For WOMAC scores, both RFA and MSC showed significant improvements at 3 months, with RFA maintaining its lead at 6 months, although MSC did not display significant superiority at this stage.

CONCLUSIONS

This analysis suggests that RFA and MSC are resilient treatment options in knee OA. Despite some study heterogeneity, these treatments consistently outperformed conventional treatments, particularly in the short to mid-term, although with varying levels of certainty in their efficacy.

PROSPERO REGISTRATION NUMBER

CRD42023492299.

Relative efficacy and safety of mesenchymal stem cells for osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

Introduction

The aim of this meta-analysis was to evaluate the efficacy and safety of mesenchymal stem cells (MSCs) for the treatment of knee osteoarthritis (OA).

Methods

The PubMed, Embase, Cochrane Central Register of Controlled Trials, Scopus and Web of Science databases were searched from inception to May 6, 2024 to identify randomized controlled trials that compared MSCs and placebo or other nonsurgical approaches for treating OA. Two investigators independently searched the literature and extracted data, and conventional meta-analyses were conducted with Review Manager 5.3. The outcomes included pain relief, functional improvement, and risk of adverse events (AEs).

Results

A total of 18 articles were included. Overall, MSCs were superior to placebo in terms of relieving pain and improving function at the 12-month follow-up. However, the differences in treatment-related AEs were not significant.

Conclusion

MSCs may relieving pain and improving function of OA. The limitations of this study include the high heterogeneity of the included studies. Additionally, the follow-up time in the included studies was relatively short, so more clinical trials are needed to predict the long-term efficacy and safety of MSCs.

Systematic review registration

https://doi.org/10.17605/OSF.IO/5BT6E, identifier CRD42022354824.

Advantages of pooling of human bone marrow-derived mesenchymal stromal cells from different donors versus single-donor MSCs

Mesenchymal stromal cells (MSC) from adult bone marrow are the most commonly used cells in clinical trials. MSCs from single donors are the preferred starting material but suffer from a major setback of being heterogeneous that results in unpredictable and inconsistent clinical outcomes. To overcome this, we developed a method of pooling MSCs from different donors and created cell banks to cater clinical needs. Initially, the master cell banks (MCBs) were created at passage 1 (P1) from the bone marrow MSCs isolated from of nine different donors. At this stage, MCBs from three different donors were mixed in equal proportion and expanded till P3 to create working cell banks. Further, the pooled cells and individual donor MSCs were expanded till P5 and cryopreserved and extensively characterised. There was a large heterogeneity among the individual donor MSCs in terms of growth kinetics (90% Coefficient of variation (CV) for cell yield and 44% CV for population doubling time at P5), immunosuppressive ability (30% CV at 1:1 and 300% CV at 1:10 ratio), and the angiogenic factor secretion potential (20% CV for VEGF and71% CV for SDF-1). Comparatively, the pooled cells have more stable profiles (60% CV for cell yield and 7% CV for population doubling time at P5) and exhibit better immunosuppressive ability (15% CV at 1:1 and 32% CV at 1:10 ratio ) and consistent secretion of angiogenic factors (16% CV for VEGF and 51% CV for SDF-1). Further pooling does not compromise the trilineage differentiation capacity or phenotypic marker expression of the MSCs. The senescence and in vitro tumourigenicity characteristics of the pooled cells are also similar to those of individual donor MSCs. We conclude that pooling of MSCs from three different donors reduces heterogeneity among individual donors and produces MSCs with a consistent secretion and higher immunosuppressive profile.

An overview of nasal cartilage bioprinting: from bench to bedside

Nasal cartilage diseases and injuries are known as significant challenges in reconstructive medicine, affecting a substantial number of individuals worldwide. In recent years, the advent of three-dimensional (3D) bioprinting has emerged as a promising approach for nasal cartilage reconstruction, offering potential breakthroughs in the field of regenerative medicine. This paper provides an overview of the methods and challenges associated with 3D bioprinting technologies in the procedure of reconstructing nasal cartilage tissue. The process of 3D bioprinting entails generating a digital 3D model using biomedical imaging techniques and computer-aided design to integrate both internal and external scaffold features. Then, bioinks which consist of biomaterials, cell types, and bioactive chemicals, are applied to facilitate the precise layer-by-layer bioprinting of tissue-engineered scaffolds. After undergoing in vitro and in vivo experiments, this process results in the development of the physiologically functional integrity of the tissue. The advantages of 3D bioprinting encompass the ability to customize scaffold design, enabling the precise incorporation of pore shape, size, and porosity, as well as the utilization of patient-specific cells to enhance compatibility. However, various challenges should be considered, including the optimization of biomaterials, ensuring adequate cell viability and differentiation, achieving seamless integration with the host tissue, and navigating regulatory attention. Although numerous studies have demonstrated the potential of 3D bioprinting in the rebuilding of such soft tissues, this paper covers various aspects of the bioprinted tissues to provide insights for the future development of repair techniques appropriate for clinical use.

Comparative Analysis of Short-Term and Long-Term Clinical Efficacy of Mesenchymal Stem Cells from Different Sources in Knee Osteoarthritis: A Network Meta-Analysis

Background

Joint articular injection of mesenchymal stem cells (MSCs) has emerged as a novel treatment approach for osteoarthritis (OA). However, the effectiveness of MSCs derived from different sources in treating OA patients remains unclear. Therefore, this study aimed to explore the differences between the effectiveness and safety of different sources of MSCs.

Materials and Methods

For inclusion consideration, we searched trial registries and published databases, including PubMed, Cochrane Library, Embase, and Web of Science databases. Revman (V5.3), STATA (V16.0), and R (V4.0) were utilized for conducting data analysis, while the Cochrane Risk of Bias Tool was employed for assessing the quality of the studies. We derived outcome measures at 6 and 12 months based on the duration of study follow-up, including visual analog scale (VAS) score, WOMAC score, WOMAC pain, WOMAC Functional Limitation, and WOMAC stiffness. The evaluation time for short-term effectiveness is set at 6 months, while 12 months is utilized as the longest follow-up time for most studies to assess long-term effectiveness.

Results

The evaluation of literature quality showed that the included studies had excellent methodological quality. A meta-analysis revealed that different sources of MSCs improved knee function and pain more effectively among patients suffering from knee OA (KOA) than controls. The results of the network meta-analysis showed the following: short-term functional improvement (the indexes were evaluated after 6 months of follow-up) (WOMAC total score: bone marrow-derived MSC (BMMSC) vs. adipose-derived MSC (ADMSC) (mean difference (MD) = -20.12, 95% confidence interval (CI) -125.24 to 42.88), umbilical cord-derived MSC (UCMSC) (MD = -7.81, 95% CI -158.13 to 74.99); WOMAC stiffness: BMMSC vs. ADMSC (MD = -0.51, 95% CI -7.27 to 4.29), UCMSC (MD = -0.75, 95% CI -9.74 to 6.63); WOMAC functional limitation: BMMSC vs. ADMSC (MD = -12.22, 95% CI -35.05 to 18.86), UCMSC (MD = -9.31, 95% CI -44.26 to 35.27)). Long-term functional improvement (the indexes were evaluated after 12 months of follow-up) (WOMAC total: BMMSC vs. ADMSC (MD = -176.77, 95% CI -757.1 to 378.25), UCMSC (MD = -181.55, 95% CI -937.83 to 541.13); WOMAC stiffness: BMMSC vs. ADMSC (MD = -0.5, 95% CI -26.05 to 18.61), UCMSC (MD = -1.03, 95% CI -30.44 to 21.69); WOMAC functional limitation: BMMSC vs. ADMSC (MD = -5.18, 95% CI -316.72 to 177.1), UCMSC (MD = -8.33, 95% CI -358.78 to 218.76)). Short-term pain relief (the indexes were evaluated after 6 months of follow-up) (VAS score: UCMSC vs. BMMSC (MD = -10.92, 95% CI -31.79 to 12.03), ADMSC (MD = -14.02, 95% CI -36.01 to 9.81), PLMSC (MD = -17.09, 95% CI -46.31 to 13.17); WOMAC pain relief: BMMSC vs. ADMSC (MD = -11.42, 95% CI -39.52 to 11.77), UCMSC (MD = -6.73, 95% CI -47.36 to 29.15)). Long-term pain relief (the indexes were evaluated after 12 months of follow-up) (VAS score: BMMSC vs. UCMSC (MD = -4.33, 95% CI -36.81 to 27.08), ADMSC (MD = -11.43, 95% CI -37.5 to 13.42); WOMAC pain relief: UCMSC vs. ADMSC (MD = 0.23, 95% CI -37.87 to 38.11), BMMSC (MD = 5.89, 95% CI -25.39 to 51.41)). According to the GRADE scoring system, WOMAC, VAS, and AE scores were of low quality.

Conclusion

Meta-analysis suggests MSCs can effectively treat KOA by improving pain and knee function compared to control groups. In terms of functional improvement in KOA patients, both short-term (6-month follow-up) and long-term (12-month follow-up) results indicated that while the differences between most treatments were not statistically significant, bone marrow-derived MSCs may have some advantages over other sources of MSCs. Additionally, BM-MSCs and UC-MSCs may offer certain benefits over ADMSCs in terms of pain relief for KOA patients, although the variances between most studies were not statistically significant. Therefore, this study suggests that BM-MSCs may present clinical advantages over other sources of MSCs.

Mesenchymal stem cells for chronic knee pain secondary to osteoarthritis: A systematic review and meta-analysis of randomized trials

OBJECTIVE

To assess the effectiveness of mesenchymal stem cells (MSCs) for chronic knee pain secondary to osteoarthritis (OA).

METHODS

We searched MEDLINE, EMBASE, CINAHL, and Cochrane Central to September 2023 for trials that (1) enrolled patients with chronic pain associated with knee OA, and (2) randomized them to MSC therapy vs. placebo or usual care. We performed random-effects meta-analysis and used Grading of Recommendations, Assessment, Development, and Evaluation to assess the certainty of evidence.

RESULTS

We included 16 trials (807 participants). At 3-6 months, MSC therapy probably results in little to no difference in pain relief (weighted mean difference [WMD] -0.74 cm on a 10 cm visual analog scale [VAS], 95% confidence interval [95%CI] -1.16 to -0.33; minimally important difference [MID] 1.5 cm) or physical functioning (WMD 2.23 points on 100-point 36-item Short Form Survey (SF-36) physical functioning subscale, 95%CI -0.97 to 5.43; MID 10-points; both moderate certainty). At 12 months, injection of MSCs probably results in little to no difference in pain (WMD -0.73 cm on a 10 cm VAS, 95%CI -1.69 to 0.24; moderate certainty) and may improve physical functioning (WMD 19.36 points on 100-point SF-36 PF subscale, 95%CI -0.19 to 38.9; low certainty). MSC therapy may increase risk of any adverse events (risk ratio [RR] 2.67, 95%CI 1.19 to 5.99; low certainty) and pain and swelling of the knee joint (RR 1.58, 95%CI 1.04 to 2.38; low certainty).

CONCLUSIONS

Intra-articular injection of MSCs for chronic knee pain associated with OA probably provides little to no improvement in pain or physical function.

Unlocking the full potential of mesenchymal stromal cell therapy for osteoarthritis through machine learning-based in silico trials

Despite the potential of mesenchymal stromal cells (MSCs) in osteoarthritis (OA) treatment, the challenge lies in addressing their therapeutic inconsistency. Clinical trials revealed significantly varied therapeutic outcomes among patients receiving the same allogenic MSCs but different treatment regimens. Therefore, optimizing personalized treatment strategies is crucial to fully unlock MSCs' potential and enhance therapeutic consistency. We employed the XGBoost algorithm to train a self-collected database comprising 37 published clinical reports to create a model capable of predicting the probability of effective pain relief and Western Ontario and McMaster Universities (WOMAC) index improvement in OA patients undergoing MSC therapy. Leveraging this model, extensive in silico simulations were conducted to identify optimal personalized treatment strategies and ideal patient profiles. Our in silico trials predicted that the individually optimized MSC treatment strategies would substantially increase patients' chances of recovery compared to the strategies used in reported clinical trials, thereby potentially benefiting 78.1%, 47.8%, 94.4% and 36.4% of the patients with ineffective short-term pain relief, short-term WOMAC index improvement, long-term pain relief and long-term WOMAC index improvement, respectively. We further recommended guidelines on MSC number, concentration, and the patients' appropriate physical (body mass index, age, etc.) and disease states (Kellgren-Lawrence grade, etc.) for OA treatment. Additionally, we revealed the superior efficacy of MSC in providing short-term pain relief compared to platelet-rich plasma therapy for most OA patients. This study represents the pioneering effort to enhance the efficacy and consistency of MSC therapy through machine learning applied to clinical data. The in silico trial approach holds immense potential for diverse clinical applications.

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

BACKGROUND

Current osteoarthritis (OA) treatments focus on symptom relief without addressing the underlying disease process. In regenerative medicine, current treatments have limitations. In regenerative medicine, more research is needed for intra-articular stromal vascular fraction (SVF) injections in OA, including dosage optimization, long-term efficacy, safety, comparisons with other treatments, and mechanism exploration.

AIM

To compare the efficacy of intra-articular SVF with corticosteroid (ICS) injections in patients with primary knee OA.

METHODS

The study included 50 patients with Kellgren-Lawrence grades II and III OA. Patients were randomly assigned (1:1) to receive either a single intra-articular SVF injection (group A) or a single intra-articular ICS (triamcinolone) (group B) injection. Patients were followed up at 1, 3, 6, 12, and 24 months. Visual analog score (VAS) and International Knee Documentation Committee (IKDC) scores were administered before the procedure and at all 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.

Heterogeneity of mesenchymal stem cells as a limiting factor in their clinical application to inflammatory bowel disease in dogs and cats

Inflammatory bowel disease (IBD) is a major subtype of chronic enteropathies in dogs and cats. Conventional drugs such as immunomodulatory medicines as glucocorticoids and/or other anti-inflammatory are mainly applied for treatment. However, these drugs are not always effective to maintain remission from IBD and are limited by unacceptable side effects. Hence, more effective and safe therapeutic options need to be developed. Mesenchymal stem cells (MSCs) are multipotent stem cells with a self-renewal capacity, and have immunomodulatory, anti-inflammatory, anti-fibrotic, and tissue repair properties. Therefore, the application of MSCs as an alternative therapy for IBD has great potential in veterinary medicine. The efficacy of adipose tissue-derived MSC (ADSC) therapy for IBD in dogs and cats has been reported, including numerous studies in animal models. However, treatment outcomes in clinical trials of human IBD patients have not been consistent with preclinical studies. MSC-based therapy for various diseases has received widespread attention, but various problems in such therapy remain, among which no consensus has been reached on the preparation and treatment procedures for MSCs, and cellular heterogeneity of MSCs may be an issue. This review describes the current status of ADSC therapy for canine and feline IBD and summarizes the cellular heterogeneity of canine ADSCs, to highlight the necessity for further reduction or elimination of MSCs heterogeneity and standardization of MSC-based therapies.

Identification of therapeutic targets in osteoarthritis by combining heterogeneous transcriptional datasets, drug-induced expression profiles, and known drug-target interactions

BACKGROUND

Osteoarthritis (OA) is a multifactorial, hypertrophic, and degenerative condition involving the whole joint and affecting a high percentage of middle-aged people. It is due to a combination of factors, although the pivotal mechanisms underlying the disease are still obscure. Moreover, current treatments are still poorly effective, and patients experience a painful and degenerative disease course.

METHODS

We used an integrative approach that led us to extract a consensus signature from a meta-analysis of three different OA cohorts. We performed a network-based drug prioritization to detect the most relevant drugs targeting these genes and validated in vitro the most promising candidates. We also proposed a risk score based on a minimal set of genes to predict the OA clinical stage from RNA-Seq data.

RESULTS

We derived a consensus signature of 44 genes that we validated on an independent dataset. Using network analysis, we identified Resveratrol, Tenoxicam, Benzbromarone, Pirinixic Acid, and Mesalazine as putative drugs of interest for therapeutics in OA for anti-inflammatory properties. We also derived a list of seven gene-targets validated with functional RT-qPCR assays, confirming the in silico predictions. Finally, we identified a predictive subset of genes composed of DNER, TNFSF11, THBS3, LOXL3, TSPAN2, DYSF, ASPN and HTRA1 to compute the patient's risk score. We validated this risk score on an independent dataset with a high AUC (0.875) and compared it with the same approach computed using the entire consensus signature (AUC 0.922).

CONCLUSIONS

The consensus signature highlights crucial mechanisms for disease progression. Moreover, these genes were associated with several candidate drugs that could represent potential innovative therapeutics. Furthermore, the patient's risk scores can be used in clinical settings.

Extracellular vesicles derived from mesenchymal stem cells mediate extracellular matrix remodeling in osteoarthritis through the transport of microRNA-29a

BACKGROUND

Knee osteoarthritis (KOA) is a common orthopedic condition with an uncertain etiology, possibly involving genetics and biomechanics. Factors like changes in chondrocyte microenvironment, oxidative stress, inflammation, and immune responses affect KOA development. Early-stage treatment options primarily target symptom relief. Mesenchymal stem cells (MSCs) show promise for treatment, despite challenges. Recent research highlights microRNAs (miRNAs) within MSC-released extracellular vesicles that can potentially promote cartilage regeneration and hinder KOA progression. This suggests exosomes (Exos) as a promising avenue for future treatment. While these findings emphasize the need for effective KOA progression management, further safety and efficacy validation for Exos is essential.

AIM

To explore miR-29a's role in KOA, we'll create miR-29a-loaded vesicles, testing for early treatment in rat models.

METHODS

Extraction of bone marrow MSC-derived extracellular vesicles, preparation of engineered vesicles loaded with miR-29a using ultrasonication, and identification using quantitative reverse transcription polymerase chain reaction; after establishing a rat model of KOA, rats were randomly divided into three groups: Blank control group injected with saline, normal extracellular vesicle group injected with normal extracellular vesicle suspension, and engineered extracellular vesicle group injected with engineered extracellular vesicle suspension. The three groups were subjected to general behavioral observation analysis, imaging evaluation, gross histological observation evaluation, histological detection, and immunohistochemical detection to compare and evaluate the progress of various forms of arthritis.

RESULTS

General behavioral observation results showed that the extracellular vesicle group and engineered extracellular vesicle group had better performance in all four indicators of pain, gait, joint mobility, and swelling compared to the blank control group. Additionally, the engineered extracellular vesicle group had better pain relief at 4 wk and better knee joint mobility at 8 wk compared to the normal extracellular vesicle group. Imaging examination results showed that the blank control group had the fastest progression of arthritis, the normal extracellular vesicle group had a relatively slower progression, and the engineered extracellular vesicle group had the slowest progression. Gross histological observation results showed that the blank control group had the most obvious signs of arthritis, the normal extracellular vesicle group showed signs of arthritis, and the engineered extracellular vesicle group showed no significant signs of arthritis. Using the Pelletier gross score evaluation, the engineered extracellular vesicle group had the slowest progression of arthritis. Results from two types of staining showed that the articular cartilage of rats in the normal extracellular vesicle and engineered extracellular vesicle groups was significantly better than that of the blank control group, and the engineered extracellular vesicle group had the best cartilage cell and joint surface condition. Immunohistochemical detection of type II collagen and proteoglycan showed that the extracellular matrix of cartilage cells in the normal extracellular vesicle and engineered extracellular vesicle groups was better than that of the blank control group. Compared to the normal extracellular vesicle group, the engineered extracellular vesicle group had a better regulatory effect on the extracellular matrix of cartilage cells.

CONCLUSION

Engineered Exos loaded with miR-29a can exert anti-inflammatory effects and maintain extracellular matrix stability, thereby protecting articular cartilage, and slowing the progression of KOA.

Combined laser-activated SVF and PRP remodeled spinal sclerosis via activation of Olig-2, MBP, and neurotrophic factors and inhibition of BAX and GFAP

A single injection of platelet-rich plasma (PRP) or stromal vascular fraction (SVF) in treating neurological ailments suggests promise; however, there is limited evidence of the efficacy of combination therapy. This trial aimed to determine whether combining SVF and PRP could provide further therapeutic effects in treating multiple sclerosis (MS). Fifteen Persian cats were separated into three groups (n = 5): group I (control negative), and group II (control positive); EB was injected intrathecally into the spinal cord and then treated 14 days later with intrathecal phosphate buffered saline injection, and group III (SVF + PRP), cats were injected intrathecally with EB through the spinal cord, followed by a combination of SVF and PRP 14 days after induction. Therapeutic effects were evaluated using the Basso-Beattie-Bresnahan scale throughout the treatment timeline and at the end. Together with morphological, MRI scan, immunohistochemical, transmission electron microscopy, and gene expression investigations. The results demonstrated that combining SVF and PRP successfully reduced lesion intensity on gross inspection and MRI. In addition to increased immunoreactivity to Olig2 and MBP and decreased immunoreactivity to Bax and GFAP, there was a significant improvement in BBB scores and an increase in neurotrophic factor (BDNF, NGF, and SDF) expression when compared to the positive control group. Finally, intrathecal SVF + PRP is the most promising and safe therapy for multiple sclerosis, resulting in clinical advantages such as functional recovery, MRI enhancement, and axonal remyelination.

Protecting the regenerative environment: selecting the optimal delivery vehicle for cartilage repair-a narrative review

Focal cartilage defects are common in youth and older adults, cause significant morbidity and constitute a major risk factor for developing osteoarthritis (OA). OA is the most common musculoskeletal (MSK) disease worldwide, resulting in pain, stiffness, loss of function, and is currently irreversible. Research into the optimal regenerative approach and methods in the setting of either focal cartilage defects and/or OA holds to the ideal of resolving both diseases. The two fundamentals required for cartilage regenerative treatment are 1) the biological element contributing to the regeneration (e.g., direct application of stem cells, or of an exogenous secretome), and 2) the vehicle by which the biological element is suspended and delivered. The vehicle provides support to the regenerative process by providing a protective environment, a structure that allows cell adherence and migration, and a source of growth and regenerative factors that can activate and sustain regeneration. Models of cartilage diseases include osteochondral defect (OCD) (which usually involve one focal lesion), or OA (which involves a more diffuse articular cartilage loss). Given the differing nature of these models, the optimal regenerative strategy to treat different cartilage diseases may not be universal. This could potentially impact the translatability of a successful approach in one condition to that of the other. An analogy would be the repair of a pothole (OCD) versus repaving the entire road (OA). In this narrative review, we explore the existing literature evaluating cartilage regeneration approaches for OCD and OA in animal then in human studies and the vehicles used for each of these two conditions. We then highlight strengths and challenges faced by the different approaches presented and discuss what might constitute the optimal cartilage regenerative delivery vehicle for clinical cartilage regeneration.

Engineered stem cell-based strategy: A new paradigm of next-generation stem cell product in regenerative medicine

Stem cells have garnered significant attention in regenerative medicine owing to their abilities of multi-directional differentiation and self-renewal. Despite these encouraging results, the market for stem cell products yields limited, which is largely due to the challenges faced to the safety and viability of stem cells in vivo. Besides, the fate of cells re-infusion into the body unknown is also a major obstacle to stem cell therapy. Actually, both the functional protection and the fate tracking of stem cells are essential in tissue homeostasis, repair, and regeneration. Recent studies have utilized cell engineering techniques to modify stem cells for enhancing their treatment efficiency or imparting them with novel biological capabilities, in which advances demonstrate the immense potential of engineered cell therapy. In this review, we proposed that the "engineered stem cells" are expected to represent the next generation of stem cell therapies and reviewed recent progress in this area. We also discussed potential applications of engineered stem cells and highlighted the most common challenges that must be addressed. Overall, this review has important guiding significance for the future design of new paradigms of stem cell products to improve their therapeutic efficacy.

Advanced Therapeutic Medicinal Products in Bone and Cartilage Defects

The number of patients with functional loss of bone and cartilage tissue has shown an increasing trend. Insufficient or inappropriate conventional treatments applied for trauma, orthopedic diseases, or other bone and cartilage-related disorders can lead to bone and cartilage damage. This represents a worldwide public health issue and a significant economic burden. Advanced therapeutic medicinal products (ATMPs) proposed promising alternative therapeutic modalities by application of cell-based and tissue engineering approaches. Recently, several ATMPs have been developed to promote bone and cartilage tissue regeneration. Fifteen ATMPs, two related to bone and 13 related to cartilage, have received regulatory approval and marketing authorization. However, four ATMPs were withdrawn from the market for various reasons. However, ATMPs that are still on the market have demonstrated positive results, their broad application faced limitations. The development and standardization of methodologies will be a major challenge in the coming decades. Currently, the number of ATMPs in clinical trials using mesenchymal stromal cells or chondrocytes indicates a growing recognition that current ATMPs can be improved. Research on bone and cartilage tissue regeneration continues to expand. Cell-based therapies are likely to be clinically supported by the new ATMPs, innovative fabrication processes, and enhanced surgical approaches. In this study, we highlighted the available ATMPs that have been used in bone and cartilage defects and discussed their advantages and disadvantages in clinical applications.

Cell Therapy Approaches for Articular Cartilage Regeneration

Articular cartilage is a common cartilage type found in a multitude of joints throughout the human body. However, cartilage is limited in its regenerative capacity. A range of methods have been employed to aid adults under the age of 45 with cartilage defects, but other cartilage pathologies such as osteoarthritis are limited to non-steroidal anti-inflammatory drugs and total joint arthroplasty. Cell therapies and synthetic biology can be utilized to assist not only cartilage defects but have the potential as a therapeutic approach for osteoarthritis as well. In this review, we will cover current cell therapy approaches for cartilage defect regeneration with a focus on autologous chondrocyte implantation and matrix autologous chondrocyte implantation. We will then discuss the potential of stem cells for cartilage repair in osteoarthritis and the use of synthetic biology to genetically engineer cells to promote cartilage regeneration and potentially reverse osteoarthritis.

Advances in Stem Cell-Based Therapies in the Treatment of Osteoarthritis

Osteoarthritis (OA) is a chronic, degenerative joint disease presenting a significant global health threat. While current therapeutic approaches primarily target symptom relief, their efficacy in repairing joint damage remains limited. Recent research has highlighted mesenchymal stem cells (MSCs) as potential contributors to cartilage repair, anti-inflammatory modulation, and immune regulation in OA patients. Notably, MSCs from different sources and their derivatives exhibit variations in their effectiveness in treating OA. Moreover, pretreatment and gene editing techniques of MSCs can enhance their therapeutic outcomes in OA. Additionally, the combination of novel biomaterials with MSCs has shown promise in facilitating the repair of damaged cartilage. This review summarizes recent studies on the role of MSCs in the treatment of OA, delving into their advantages and exploring potential directions for development, with the aim of providing fresh insights for future research in this critical field.

Knee Osteoarthritis: Clinical and MRI Outcomes After Multiple Intra-Articular Injections With Expanded Autologous Adipose-Derived Stromal Cells or Platelet-Rich Plasma

OBJECTIVE

To directly compare clinical and MRI outcomes of multiple intra-articular injections of adipose-derived stromal cells (ASCs) or platelet-rich plasma (PRP) in patients with knee osteoarthritis (OA).

DESIGN

We retrospectively compared 24-month outcomes in (1) 27 patients receiving 3-monthly intra-articular injections with a total of 43.8 million ASCs and (2) 23 patients receiving 3-monthly injections of 3-ml preparation of PRP. All patients had Kellgren-Lawrence grade 1, 2, or 3 knee OA with failed conservative medical therapy. The Numeric Pain Rating Scale (NPRS) scores; Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline, 6, 12, and 24 months after the first injection; and the MRI Osteoarthritis Knee Score (MOAKS) at 12 and 24 months were considered as outcomes.

RESULTS

No major complications occurred in any patient. Both groups significantly improved in pain NPRS score and KOOS at 6 months. At 12- and 24-month evaluations, the ASC group significantly decreased scores to a greater degree (P < 0.001) than the PRP group. MOAKS scores indicated a decrease in disease progression in the ASC group.

CONCLUSION

Both ASCs and PRP were safe and resulted in clinical improvement in patients with knee OA at 6 months; however, at 12 and 24 months, ASCs outperformed leukocyte-poor PRP in clinical and radiological outcomes.

StemOneTM/Stempeucel®: CDSCO Approved, Adult Human Bone Marrow-Derived, Cultured, Pooled, Allogenic Mesenchymal Stem Cells for Knee Osteoarthritis

The knee, the most likely joint to present osteoarthritis (OA), is accountable for approximately 80% of the global burden of the OA [...].

What is the optimal dose of adipose-derived mesenchymal stem cells treatment for knee osteoarthritis? A conventional and network meta-analysis of randomized controlled trials

BACKGROUND

Despite increasing clinical investigations underscoring the efficacy and safety of adipose-derived mesenchymal stem cells (AD-MSCs) therapy in knee osteoarthritis (KOA), no article has recently reviewed the cell dosage. This study aimed to evaluate the efficacy and safety of varying doses of AD-MSCs in treating KOA using conventional and network meta-analysis.

METHODS

A search of databases in in Chinese and English was performed to identify randomized controlled trials (RCT) on MSCs for knee osteoarthritis from the inception date to May 1, 2022. This study mainly analyzed the efficacy of AD-MSCs in the treatment of KOA, and subgroup analysis was performed on the therapeutic effects of MSCs from different tissues at the same dose. We divided the different cell doses into low, moderate, and high groups, with the corresponding cell doses: (0-25)*10^6, (25-50)*10^6, and > 50*10^6 cells, respectively. We further analyzed the improvement of improvement of the Visual Analog Scale (VAS) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores and the incidence of adverse events (AEs) after varied dosage injection.

RESULTS

A total of 16 literatures were included in this study, of which 8 literatures were about AD-MSCs. Conventional meta-analysis suggests that AD-MSCs can reduce pain and improve function in KOA patients, regardless of the cell doses, up to 12 months of follow-up. The network meta-analysis showed that intra-articular injection of AD-MSCs significantly improved pain and knee function scores in KOA patients compared with the control group at 3, 6, and 12 months. Among the three groups, the high-dose group had the best treatment effect, and the degree of joint pain and dysfunction indicators improved more significantly in the early stage. For adverse events, there was a dose-response trend that increased with increasing doses.

CONCLUSIONS

Both cell doses reduced pain and improved knee function in KOA patients. The effect surpassed in the high-dose group than in the moderate-dose, low-dose and control groups. However, adverse events also increase with the increase in dose, which should be carefully considered in clinical application, and the side effects still need to be paid attention to. Considering the limitations of this meta-analysis, future studies need to further explore the efficacy and safety of different doses of treatment, and carry out large sample, multi-center, randomized controlled trials to ensure the reliability and promotion value of the research results.

From Teeth to Therapy: A Review of Therapeutic Potential within the Secretome of Stem Cells from Human Exfoliated Deciduous Teeth

Stem cells derived from human exfoliated deciduous teeth (SHED) have emerged as an alternative stem cell source for cell therapy and regenerative medicine because they are readily available, pose fewer ethical concerns, and have low immunogenicity and tumourigenicity. SHED offer a number of advantages over other dental stem cells, including a high proliferation rate with the potential to differentiate into multiple developmental lineages. The therapeutic effects of SHED are mediated by multiple mechanisms, including immunomodulation, angiogenesis, neurogenesis, osteogenesis, and adipogenesis. In recent years, there is ample evidence that the mechanism of action of SHED is mainly due to its paracrine action, releasing a wide range of soluble factors such as cytokines, chemokines, and trophic factors (also known as 'secretome') into the local tissue microenvironment to promote tissue survival and recovery. This review provides an overview of the secretome derived from SHED and highlights the bioactive molecules involved in tissue regeneration and their potential applications in regenerative medicine.

Efficacy and Safety of Stempeucel in Osteoarthritis of the Knee: A Phase 3 Randomized, Double-Blind, Multicenter, Placebo-Controlled Study

BACKGROUND

Osteoarthritis is a chronic, progressive, and degenerative condition with limited therapy options. Recently, biologic therapies have been an evolving option for the management of osteoarthritis.

PURPOSE

To assess whether allogenic mesenchymal stromal cells (MSCs) have the potential to improve functional parameters and induce cartilage regeneration in patients with osteoarthritis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 146 patients with grade 2 and 3 osteoarthritis were randomized to either an MSC group or placebo group with a ratio of 1:1. There were 73 patients per group who received either a single intra-articular injection of bone marrow-derived MSCs (BMMSCs; 25 million cells) or placebo, followed by 20 mg per 2 mL of hyaluronic acid under ultrasound guidance. The primary endpoint was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score. The secondary endpoints were WOMAC subscores for pain, stiffness, and physical function; the visual analog scale score for pain; and magnetic resonance imaging findings using T2 mapping and cartilage volume.

RESULTS

Overall, 65 patients from the BMMSC group and 68 patients from the placebo group completed 12-month follow-up. The BMMSC group showed significant improvements in the WOMAC total score compared with the placebo group at 6 and 12 months (percentage change: -23.64% [95% CI, -32.88 to -14.40] at 6 months and -45.60% [95% CI, -55.97 to -35.23] at 12 months P < .001; percentage change, -44.3%). BMMSCs significantly improved WOMAC pain, stiffness, and physical function subscores as well as visual analog scale scores at 6 and 12 months (P < .001). T2 mapping showed that there was no worsening of deep cartilage in the medial femorotibial compartment of the knee in the BMMSC group at 12-month follow-up, whereas in the placebo group, there was significant and gradual worsening of cartilage (P < .001). Cartilage volume did not change significantly in the BMMSC group. There were 5 adverse events that were possibly/probably related to the study drug and consisted of injection-site swelling and pain, which improved within a few days.

CONCLUSION

In this small randomized trial, BMMSCs proved to be safe and effective for the treatment of grade 2 and 3 osteoarthritis. The intervention was simple and easy to administer, provided sustained relief of pain and stiffness, improved physical function, and prevented worsening of cartilage quality for ≥12 months.

REGISTRATION

CTRI/2018/09/015785 (National Institutes of Health and Clinical Trials Registry-India).

Pharmatherapeutic Treatment of Osteoarthrosis-Does the Pill against Already Exist? A Narrative Review

The aim of this narrative review is to summarize the current pharmacotherapeutic treatment options for osteoarthritis (OA). Is therapy still mainly symptomatic or does the pill against arthrosis already exist? Causal and non-causal, as well as future therapeutic approaches, are discussed. Various surgical and non-surgical treatment options are available that can help manage symptoms, slow down progression, and improve quality of life. To date, however, therapy is still mainly symptomatic, often using painkilling and anti-inflammatory drugs until the final stage, which is usually joint replacement. These "symptomatic pills against" have side effects and do not alter the progression of OA, which is caused by an imbalance between degenerative and regenerative processes. Next to resolving mechanical issues, the goal must be to gain a better understanding of the cellular and molecular basis of OA. Recently, there has been a lot of interest in cartilage-regenerative medicine and in the current style of treating rheumatoid arthritis, where drug therapy ("the pill against") has been established to slow down or even stop the progression of rheumatoid arthritis and has banned the vast majority of former almost regular severe joint destructions. However, the "causal pill against" OA does not exist so far. First, the early detection of osteoarthritis by means of biomarkers and imaging should therefore gain more focus. Second, future therapeutic approaches have to identify innovative therapeutic approaches influencing inflammatory and metabolic processes. Several pharmacologic, genetic, and even epigenetic attempts are promising, but none have clinically improved causal therapy so far, unfortunately.

Clinical Trials with Mesenchymal Stem Cell Therapies for Osteoarthritis: Challenges in the Regeneration of Articular Cartilage

Osteoarthritis (OA) is a whole-joint disease primarily characterized by the deterioration of hyaline cartilage. Current treatments include microfracture and chondrocyte implantation as early surgical strategies that can be combined with scaffolds to repair osteochondral lesions; however, intra-articular (IA) injections or implantations of mesenchymal stem cells (MSCs) are new approaches that have presented encouraging therapeutic results in animal models and humans. We critically reviewed clinical trials with MSC therapies for OA, focusing on their effectiveness, quality, and outcomes in the regeneration of articular cartilage. Several sources of autologous or allogeneic MSCs were used in the clinical trials. Minor adverse events were generally reported, indicating that IA applications of MSCs are potentially safe. The evaluation of articular cartilage regeneration in human clinical trials is challenging, particularly in the inflammatory environment of osteoarthritic joints. Our findings indicate that IA injections of MSCs are efficacious in the treatment of OA and the regeneration of cartilage, but that they may be insufficient for the full repair of articular cartilage defects. The possible interference of clinical and quality variables in the outcomes suggests that robust clinical trials are still necessary for generating reliable evidence with which to support these treatments. We suggest that the administration of just-sufficient doses of viable cells in appropriate regimens is critical to achieve effective and durable effects. In terms of future perspectives, genetic modification, complex products with extracellular vesicles derived from MSCs, cell encapsulation in hydrogels, and 3D bioprinted tissue engineering are promising approaches with which to improve MSC therapies for OA.

Culture-expanded mesenchymal stromal cell therapy: does it work in knee osteoarthritis? A pathway to clinical success

Osteoarthritis (OA) is a degenerative multifactorial disease with concomitant structural, inflammatory, and metabolic changes that fluctuate in a temporal and patient-specific manner. This complexity has contributed to refractory responses to various treatments. MSCs have shown promise as multimodal therapeutics in mitigating OA symptoms and disease progression. Here, we evaluated 15 randomized controlled clinical trials (RCTs) and 11 nonrandomized RCTs using culture-expanded MSCs in the treatment of knee OA, and we found net positive effects of MSCs on mitigating pain and symptoms (improving function in 12/15 RCTs relative to baseline and in 11/15 RCTs relative to control groups at study endpoints) and on cartilage protection and/or repair (18/21 clinical studies). We examined MSC dose, tissue of origin, and autologous vs. allogeneic origins as well as patient clinical phenotype, endotype, age, sex and level of OA severity as key parameters in parsing MSC clinical effectiveness. The relatively small sample size of 610 patients limited the drawing of definitive conclusions. Nonetheless, we noted trends toward moderate to higher doses of MSCs in select OA patient clinical phenotypes mitigating pain and leading to structural improvements or cartilage preservation. Evidence from preclinical studies is supportive of MSC anti-inflammatory and immunomodulatory effects, but additional investigations on immunomodulatory, chondroprotective and other clinical mechanisms of action are needed. We hypothesize that MSC basal immunomodulatory "fitness" correlates with OA treatment efficacy, but this hypothesis needs to be validated in future studies. We conclude with a roadmap articulating the need to match an OA patient subset defined by molecular endotype and clinical phenotype with basally immunomodulatory "fit" or engineered-to-be-fit-for-OA MSCs in well-designed, data-intensive clinical trials to advance the field.

Mesenchymal stem/stromal cells-derived extracellular vesicles as a potentially more beneficial therapeutic strategy than MSC-based treatment in a mild metabolic osteoarthritis model

BACKGROUND

Mesenchymal stromal/stem cells (MSCs) and MSC-derived extracellular vesicles (MSC-EVs) hold promise as a disease modifying treatment in osteoarthritis (OA). Obesity, and its associated inflammation, contribute to OA development and metabolic OA represents a specific and significant group of the OA patient population. Given their immunomodulatory properties, MSC and MSC-EVs are especially interesting for this group of patients as a therapeutic option. Here, we were the first to compare the therapeutic efficacy of MSCs and MSC-EVs in a mild OA model taking these metabolic aspects into consideration.

METHODS

Male Wistar-Han rats (Crl:WI(Han) (n = 36) were fed a high fat diet for 24 weeks, with unilateral induction of OA by groove surgery after 12 weeks. Eight days after surgery rats were randomized in three treatment groups receiving MSCs, MSC-EVs or vehicle injection. Pain-associated behavior, joint degeneration, and local and systemic inflammation were measured.

RESULTS

We demonstrated that despite not having a significant therapeutic effect, MSC-EV treatment results in lower cartilage degeneration, less pain behaviour, osteophytosis and joint inflammation, than MSC treatment. Suggesting that MSC-EVs could be a more promising therapeutic strategy than MSCs in this mild metabolic OA model.

CONCLUSION

In summary, we find that MSC treatment has negative effects on the joint in metabolic mild OA. This is an essential finding for the significant group of patients with metabolic OA phenotype, and might help to understand why clinical translation of MSC treatment shows varying therapeutic efficacy thus far. Our results also suggest that MSC-EV-based treatment might be a promising option for these patients, however MSC-EV therapeutic efficacy will need improvement.

Therapeutic Perspectives for Inflammation and Senescence in Osteoarthritis Using Mesenchymal Stem Cells, Mesenchymal Stem Cell-Derived Extracellular Vesicles and Senolytic Agents

Osteoarthritis (OA) is the most common cause of disability worldwide among the elderly. Alarmingly, the incidence of OA in individuals less than 40 years of age is rising, likely due to the increase in obesity and post-traumatic osteoarthritis (PTOA). In recent years, due to a better understanding of the underlying pathophysiology of OA, several potential therapeutic approaches targeting specific molecular pathways have been identified. In particular, the role of inflammation and the immune system has been increasingly recognized as important in a variety of musculoskeletal diseases, including OA. Similarly, higher levels of host cellular senescence, characterized by cessation of cell division and the secretion of a senescence-associated secretory phenotype (SASP) within the local tissue microenvironments, have also been linked to OA and its progression. New advances in the field, including stem cell therapies and senolytics, are emerging with the goal of slowing disease progression. Mesenchymal stem/stromal cells (MSCs) are a subset of multipotent adult stem cells that have demonstrated the potential to modulate unchecked inflammation, reverse fibrosis, attenuate pain, and potentially treat patients with OA. Numerous studies have demonstrated the potential of MSC extracellular vesicles (EVs) as cell-free treatments that comply with FDA regulations. EVs, including exosomes and microvesicles, are released by numerous cell types and are increasingly recognized as playing a critical role in cell-cell communication in age-related diseases, including OA. Treatment strategies for OA are being developed that target senescent cells and the paracrine and autocrine secretions of SASP. This article highlights the encouraging potential for MSC or MSC-derived products alone or in combination with senolytics to control patient symptoms and potentially mitigate the progression of OA. We will also explore the application of genomic principles to the study of OA and the potential for the discovery of OA phenotypes that can motivate more precise patient-driven treatments.

Intra-articular injection of bone marrow aspirate concentrate (BMAC) or adipose-derived stem cells (ADSCs) for knee osteoarthritis: a prospective comparative clinical trial

BACKGROUND

We determined whether autologous mesenchymal stem cells (MSCs) injections provide clinical and functional improvements in knee osteoarthritis (KOA) patients, and whether the results differ between autologous bone marrow cells (BMAC) and adipose-derived stromal cells (ADSCs).

METHODS

Between January 2021 and April 2022, 51 patients undergoing intra-articular injection of BMAC and 51 patients undergoing intra-articular injection of ADSCs were prospectively recruited. The Kellgren and Lawrence (K-L) classification was used to grade the severity of osteoarthritis. Knee Injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), and visual analog scale (VAS) were collected for all 102 patients in the previous week before the procedures, and at the one and 6 months from injection.

RESULTS

Knee KOOS scores, knee OKS scores, and VAS pain scores changed in similar ways in the two treatment groups. Both treatment groups demonstrated significant improvement pre-procedure to post-procedure in knee KOOS scores (p < 0.0001), knee OKS scores (p < 0.0001), and VAS pain scores (p < 0.0001). Patients with K-L grade 2 showed better functional and clinical outcomes than patients with K-L grades 3 and 4 (p < 0.0001).

CONCLUSION

Both intra-articular BMAC and ADSC injections significantly improved pain and functional outcomes at 6-month follow-up in patients with KOA. The difference between BMAC and ADCSs groups as tissue sources of MSCs was not statistically significant in terms of clinical and functional outcomes.

Mechanisms of analgesic effect of mesenchymal stem cells in osteoarthritis pain

Osteoarthritis (OA) is the most common musculoskeletal disease, and it is a major cause of pain, disability and health burden. Pain is the most common and bothersome presentation of OA, but its treatment is still suboptimal, due to the short-term action of employed analgesics and their poor adverse effect profile. Due to their regenerative and anti-inflammatory properties, mesenchymal stem cells (MSCs) have been extensively investigated as a potential therapy for OA, and numerous preclinical and clinical studies found a significant improvement in joint pathology and function, pain scores and/or quality of life after administration of MSCs. Only a limited number of studies, however, addressed pain control as the primary end-point or investigated the potential mechanisms of analgesia induced by MSCs. In this paper, we review the evidence reported in literature that support the analgesic action of MSCs in OA, and we summarize the potential mechanisms of these antinociceptive effects.

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.

A Review of Recent Innovations in Cartilage Regeneration Strategies for the Treatment of Primary Osteoarthritis of the Knee: Intra-articular Injections

Background

The pathology of primary osteoarthritis (OA) begins with structural cartilage damage, which initiates a self-propagating inflammatory pathway that further exacerbates cartilage deterioration. Current standard of care for knee primary OA involves treating the inflammatory symptoms to manage pain, which includes intra-articular (IA) injections of cortisone, an anti-inflammatory steroid, followed by a series of joint-cushioning hyaluronic acid gel injections. However, these injections do not delay the progression of primary OA. More focus on the underlying cellular pathology of OA has prompted researchers to develop treatments targeting the biochemical mechanisms of cartilage degradation.

Purpose

Researchers have yet to develop a United States Food and Drug Administration (FDA)-approved injection that has been demonstrated to significantly regenerate damaged articular cartilage. This paper reviews the current research on experimental injections aimed at achieving cellular restoration of the hyaline cartilage tissue of the knee joint.

Study Design

Narrative review.

Methods

The authors conducted a narrative literature review examining studies on primary OA pathogenesis and a systematic review of non-FDA-approved IA injections for the treatment of primary OA of the knee, described as "disease-modifying osteoarthritis drugs" in phase 1, 2, and 3 clinical trials.

Conclusion

New treatment approaches for primary OA investigate the potential of genetic therapies to restore native cartilage. It is clear that the most promising IA injections that could improve treatment of primary OA are bioengineered advanced-delivery steroid-hydrogel preparations, ex vivo expanded allogeneic stem cell injections, genetically engineered chondrocyte injections, recombinant fibroblast growth factor therapy, injections of selective proteinase inhibitors, senolytic therapy via injections, injectable antioxidant therapies, injections of Wnt pathway inhibitors, injections of nuclear factor-kappa β inhibitors, injections of modified human angiopoietin-like-3, various potential viral vector-based genetic therapy approaches, and RNA genetic technology administered via injections.

Intra-articular injection of culture-expanded adipose tissue-derived stem cells for knee osteoarthritis: Assessments with clinical symptoms and quantitative measurements of articular cartilage volume

BACKGROUND

Intra-articular administration of adipose tissue-derived stem cells (ADSC) is an alternative treatment option for knee osteoarthritis (OA) after conventional treatment fails; however, the clinical results related to the severity of OA grade and changes of cartilage volumes after the administration of ADSC is unknown. This study aimed to determine 1) clinical outcomes after the ADSC administration in knee OA with consideration of radiographic OA grades and 2) changes in cartilage volumes after ADSC administration.

METHODS

This observational study included 86 knees from 51 patients who underwent intra-articular administration of cultured ADSC; 47 patients (80 knees) completed follow-up for 6 months (follow-up rate: 93%). The Knee injury and Osteoarthritis Outcome Scores (KOOS) were reported at baseline and 1, 3, and 6 months after the administration. The efficacy rate in the Outcome Measures in Arthritis Clinical Trials-Osteoarthritis Research Society International (OMERACT-OARSI) was evaluated using the KOOS. Cartilage volume of the knee joint was measured using quantitative 3-dimensional magnetic resonance imaging (3D-MRI) software at baseline and 6 months in 52 knees in 31 patients (follow-up rate: 61%).

RESULTS

All items on the KOOS except "sports/recreation" improved significantly at 6 months with more significance in knees with a Kellgren-Lawrence (KL) grade 2 or 3 compared with KL grade 4 knees. The OMERACT-OARSI responder at 6 months was significantly greater in knees with KL grade 2 or 3 (64%) than in knees with KL grade 4 (42%, p = 0.045). Cartilage volume changes varied among patients and were not related to the changes in KOOS after ADSC administration.

CONCLUSIONS

Intra-articular administration of ADSC in knee OA improved KOOS at 6 months. The effects were more significant in knees with KL grade 2 or 3 than with KL grade 4. Changes in KOOS were not related to change in cartilage volumes after ADSC administration.

Cell-based therapies have disease-modifying effects on osteoarthritis in animal models. A systematic review by the ESSKA Orthobiologic Initiative. Part 2: bone marrow-derived cell-based injectable therapies

PURPOSE

Aim of this systematic review was to determine if bone marrow-derived cell-based injectable therapies induce disease-modifying effects in joints affected by osteoarthritis (OA) in animal models.

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 animal studies comparing injectable bone marrow-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

Fifty-three studies were included (1819 animals) with an increasing publication trend over time. Expanded cells were used in 48 studies, point-of-care products in 3 studies, and both approaches were investigated in 2 studies. Among the 47 studies presenting results on the disease-modifying effects, 40 studies (85%) reported better results with bone marrow-derived products compared to OA controls, with positive findings evident in 14 out of 20 studies (70%) in macroscopic assessment, in 30 out of 41 studies (73%) in histological assessment, and in 10 out of 13 studies (77%) in immunohistochemical evaluations. Clinical evaluations showed positive results in 7 studies out of 9 (78%), positive imaging results in 11 studies out of 17 (65%), and positive biomarker results in 5 studies out of 10 (50%). While 36 out of 46 studies (78%) reported positive results at the cartilage level, only 3 out of 10 studies (30%) could detect positive changes at the synovial level. The risk of bias was low in 42% of items, unclear in 50%, and high in 8%.

CONCLUSION

This systematic review of preclinical studies demonstrated that intra-articular injections of bone marrow-derived products can induce disease-modifying effects in the treatment of OA, slowing down the progression of cartilage damage with benefits at macroscopic, histological, and immunohistochemical levels. Positive results have been also observed in terms of clinical and imaging findings, as well as in the modulation of inflammatory and cartilage biomarkers, while poor effects have been described on the synovial membrane. These findings are important to understand the potential of bone marrow-derived products and to guide further research to optimise their use in the clinical practice.

LEVEL OF EVIDENCE

II.

Advances in Mesenchymal Stem Cell Therapy for Osteoarthritis: From Preclinical and Clinical Perspectives

The prevalence of osteoarthritis (OA), a degenerative disorder of joints, has substantially increased in recent years. Its key pathogenic hallmarks include articular cartilage destruction, synovium inflammation, and bone remodeling. However, treatment outcomes are unsatisfactory. Until recently, common therapy methods, such as analgesic and anti-inflammatory treatments, were aimed to treat symptoms that cannot be radically cured. Mesenchymal stem cells (MSCs), i.e., mesoderm non-hematopoietic cells separated from bone marrow, adipose tissue, umbilical cord blood, etc., have been intensively explored as an emerging technique for the treatment of OA over the last few decades. According to existing research, MSCs may limit cartilage degradation in OA by interfering with cellular immunity and secreting a number of active chemicals. This study aimed to examine the potential mechanism of MSCs in the treatment of OA and conduct a thorough review of both preclinical and clinical data.

Comparative effectiveness of adipose-derived mesenchymal stromal cells in the management of knee osteoarthritis: A meta-analysis

BACKGROUND

Osteoarthritis (OA) is the most common joint disorder, is associated with an increasing socioeconomic impact owing to the ageing population.

AIM

To analyze and compare the efficacy and safety of bone-marrow-derived mesenchymal stromal cells (BM-MSCs) and adipose tissue-derived MSCs (AD-MSCs) in knee OA management from published randomized controlled trials (RCTs).

METHODS

Independent and duplicate electronic database searches were performed, including PubMed, EMBASE, Web of Science, and Cochrane Library, until August 2021 for RCTs that analyzed the efficacy and safety of AD-MSCs and BM-MSCs in the management of knee OA. The visual analog scale (VAS) score for pain, Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, Tegner score, magnetic resonance observation of cartilage repair tissue score, knee osteoarthritis outcome score (KOOS), and adverse events were analyzed. Analysis was performed on the R-platform using OpenMeta (Analyst) software. Twenty-one studies, involving 936 patients, were included. Only one study compared the two MSC sources without patient randomization; hence, the results of all included studies from both sources were pooled, and a comparative critical analysis was performed.

RESULTS

At six months, both AD-MSCs and BM-MSCs showed significant VAS improvement (P = 0.015, P = 0.012); this was inconsistent at 1 year for BM-MSCs (P < 0.001, P = 0.539), and AD-MSCs outperformed BM-MSCs compared to controls in measures such as WOMAC (P < 0.001, P = 0.541), Lysholm scores (P = 0.006; P = 0.933), and KOOS (P = 0.002; P = 0.012). BM-MSC-related procedures caused significant adverse events (P = 0.003) compared to AD-MSCs (P = 0.673).

CONCLUSION

Adipose tissue is superior to bone marrow because of its safety and consistent efficacy in improving pain and functional outcomes. Future trials are urgently warranted to validate our findings and reach a consensus on the ideal source of MSCs for managing knee OA.

Knee Osteoarthritis-How Close Are We to Disease-Modifying Treatment: Emphasis on Metabolic Type Knee Osteoarthritis

Osteoarthritis (OA) is a whole-joint disease that affects cartilage, bone, and synovium as well as ligaments, menisci, and muscles [...].

Enhanced osteoarthritis therapy by nanoengineered mesenchymal stem cells using biomimetic CuS nanoparticles loaded with plasmid DNA encoding TGF-β1

Mesenchymal stem cells (MSCs) therapy shows the potential benefits to relieve clinical symptoms of osteoarthritis (OA), but it is uncertain if it can repair articular cartilage lesions — the main pathology of OA. Here, we prepared biomimetic cupper sulfide@phosphatidylcholine (CuS@PC) nanoparticles (NPs) loaded with plasmid DNA (pDNA) encoding transforming growth factor-beta 1 (TGF-β1) to engineer MSCs for enhanced OA therapy via cartilage regeneration. We found that the NPs not only promoted cell proliferation and migration, but also presented a higher pDNA transfection efficiency relative to commercial transfection reagent lipofectamine 3000. The resultant CuS/TGF-β1@PC NP-engineered MSCs (termed CTP-MSCs) were better than pure MSCs in terms of chondrogenic gene expression, glycosaminoglycan deposition and type II collagen formation, favoring cartilage repair. Further, CTP-MSCs inhibited extracellular matrix degradation in interleukin-1β-induced chondrocytes. Consequently, intraarticular administration of CTP-MSCs significantly enhanced the repair of damaged cartilage, whereas pure MSCs exhibited very limited effects on cartilage regeneration in destabilization of the medial meniscus (DMM) surgical instability mice. Hence, this work provides a new strategy to overcome the limitation of current stem cell therapy in OA treatment through developing more effective nanoengineered MSCs.

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Biomimetic CuS nanoparticles (NPs) loaded with TGF-β1 pDNA are prepared for nanoengineering of MSCs.

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CuS/TGF-β1@PC NPs are more efficient than commercial transfection agent in terms of pDNA transfection.

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The NP-engineered CTP-MSCs exhibit enhanced migration, chondrogenesis and inhibition of ECM degradation.

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CTP-MSCs effectively treat osteoarthritis (OA) mice models via cartilage regeneration.

Osteoarthritis models: From animals to tissue engineering

Osteoarthritis (OA) is a chronic degenerative osteoarthropathy. Although it has been revealed that a variety of factors can cause or aggravate the symptoms of OA, the pathogenic mechanisms of OA remain unknown. Reliable OA models that accurately reflect human OA disease are crucial for studies on the pathogenic mechanism of OA and therapeutic drug evaluation. This review first demonstrated the importance of OA models by briefly introducing the OA pathological features and the current limitations in the pathogenesis and treatment of OA. Then, it mainly discusses the development of different OA models, including animal and engineered models, highlighting their advantages and disadvantages from the perspective of pathogenesis and pathology analysis. In particular, the state-of-the-art engineered models and their potential were emphasized, as they may represent the future direction in the development of OA models. Finally, the challenges in obtaining reliable OA models are also discussed, and possible future directions are outlined to shed some light on this area.

Potency Assay Considerations for Cartilage Repair, Osteoarthritis and Use of Extracellular Vesicles

Articular cartilage covers the ends of bones in synovial joints acting as a shock absorber that helps movement of bones. Damage of the articular cartilage needs treatment as it does not repair itself and the damage can progress to osteoarthritis. In osteoarthritis all the joint tissues are involved with characteristic progressive cartilage degradation and inflammation. Autologous chondrocyte implantation is a well-proven cell-based treatment for cartilage defects, but a main downside it that it requires two surgeries. Multipotent, aka mesenchymal stromal cell (MSC)-based cartilage repair has gained attention as it can be used as a one-step treatment. It is proposed that a combination of immunomodulatory and regenerative capacities make MSC attractive for the treatment of osteoarthritis. Furthermore, since part of the paracrine effects of MSCs are attributed to extracellular vesicles (EVs), small membrane enclosed particles secreted by cells, EVs are currently being widely investigated for their potential therapeutic effects. Although MSCs have entered clinical cartilage treatments and EVs are used in in vivo efficacy studies, not much attention has been given to determine their potency and to the development of potency assays. This chapter provides considerations and suggestions for the development of potency assays for the use of MSCs and MSC-EVs for the treatment of cartilage defects and osteoarthritis.

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.

Intra-Articular Mesenchymal Stem Cell Injection for Knee Osteoarthritis: Mechanisms and Clinical Evidence

Knee osteoarthritis presents higher incidences than other joints, with increased prevalence during aging. It is a progressive process and may eventually lead to disability. Mesenchymal stem cells (MSCs) are expected to repair damaged issues due to trilineage potential, trophic effects, and immunomodulatory properties of MSCs. Intra-articular MSC injection was reported to treat knee osteoarthritis in many studies. This review focuses on several issues of intra-articular MSC injection for knee osteoarthritis, including doses of MSCs applied for injection and the possibility of cartilage regeneration following MSC injection. Intra-articular MSC injection induced hyaline-like cartilage regeneration, which could be seen by arthroscopy in several studies. Additionally, anatomical, biomechanical, and biochemical changes during aging and other causes participate in the development of knee osteoarthritis. Conversely, appropriate intervention based on these anatomical, biomechanical, biochemical, and functional properties and their interactions may postpone the progress of knee OA and facilitate cartilage repair induced by MSC injection. Hence, post-injection rehabilitation programs and related mechanisms are discussed.

Biologic Therapies for the Treatment of Knee Osteoarthritis: An Updated Systematic Review

BACKGROUND

Use of "orthobiologics" continues to expand for patients who have knee osteoarthritis (OA). We sought to perform a systemic review of biologic therapies relative to comparative groups, including the following: (1) platelet-rich plasma (PRP); (2) bone marrow-derived mesenchymal stem cells (BMSCs); (3) adipose-derived mesenchymal stem cells (ADSCs); and (4) amniotic-derived mesenchymal stem cells (AMSCs). We assessed the following: (1) study methodologies; (2) cell preparations and formulations; (3) patient-reported outcome scores (PROMs); and (4) structural changes.

METHODS

PubMed, Cochrane Library, and Embase databases were queried (2013-2021) to conduct a systematic review of biologic therapies for knee OA, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eighty-two studies were included: PRP (51); BMSC (15); ADSC (11); and AMSC (5). Study evaluations were made using the Modified Coleman Methodology Score. PROMs included the Western Ontario and McMaster Universities Arthritis Index and the Visual Analog Scale. Structural change evaluations included ultrasounds, radiographs, or magnetic resonance imaging.

RESULTS

PRP comprised a majority of the studies (n = 51), most with "fair" to "good" Modified Coleman Methodology Score. Studies had variable cell preparations and formulations, with comparison study results leading to inconsistent PROMs, and structural changes. A limited number of studies were included for BMSC, ADSC, and AMSC, all with similar findings to PRP.

CONCLUSION

Available literature evaluating "orthobiologics" for knee OA remain nonsuperior to comparison cohorts. Higher level studies with larger sample sizes and improved methodologies are warranted to suggest differences. Despite a growth of "orthobiologics" in clinics, this updated systematic review highlights the uncertain efficacy for use in knee OA.

PRISMA-Compliant Meta-Analysis of Randomized Controlled Trials on Osteoarthritis of Knee Managed with Allogeneic vs Autologous MSCs: Efficacy and Safety Analysis

Study Design

Meta-analysis.

Objectives

Our objective is to review the randomized controlled trials (RCTs) that have been conducted previously on the topic of osteoarthritis of the knee to assess and compare the efficacy and safety of autologous and allogeneic sources of mesenchymal stromal cells (MSCs) in the treatment of osteoarthritis.

Materials and methods

We searched the electronic databases PubMed, Embase, Web of Science, and the Cochrane Library until August 2021 for randomised controlled trials (RCTs) analysing the efficacy and safety of autologous and allogeneic sources of MSCs in the management of knee osteoarthritis. These searches were conducted independently and in duplicate. The outcomes that were taken into consideration for analysis were the visual analogue score (VAS) for pain, the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), the Lysholm score, and adverse events. The OpenMeta [Analyst] software was utilised to carry out the analysis in the R platform.

Results

In total, 21 studies with a total of 936 patients were considered for this analysis. Because none of the studies made a direct comparison of the autologous and allogeneic sources of MSCs, we pooled the results of all of the included studies of both sources and made a comparative analysis of how the two types of MSCs fared in their respective applications. Although both allogeneic and autologous sources of MSCs demonstrated significantly better VAS improvement after 6 months (p = 0.006, p = 0.001), this trend was not maintained after 1 year for the allogeneic source (p = 0.171, p = 0.027). When compared to their respective controls based on WOMAC scores after 1 year, autologous sources (p = 0.016) of MSCs performed better than allogeneic sources (p = 0.186).A similar response was noted between the sources at 2 years in their Lysholm scores (p = 0.682, p = 0.017), respectively. Moreover, allogeneic sources (p = 0.039) of MSCs produced significant adverse events than autologous sources (p = 0.556) compared to their controls.

Conclusion

Our analysis of literature showed that autologous sources of MSCs stand superior to allogeneic sources of MSC with regard to their consistent efficacy for pain, functional outcomes, and safety. However, we strongly recommend that further studies be conducted that are of a high enough quality to validate our findings and reach a consensus on the best source of MSCs for use in cellular therapy treatments for knee osteoarthritis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00751-z.

Cellular therapy and tissue engineering for cartilage repair

Articular cartilage (AC) has limited capacity for repair. The first attempt to repair cartilage using tissue engineering was reported in 1977. Since then, cell-based interventions have entered clinical practice in orthopaedics, and several tissue engineering approaches to repair cartilage are in the translational pipeline towards clinical application. Classically, these involve a scaffold, substrate or matrix to provide structure, and cells such as chondrocytes or mesenchymal stromal cells to generate the tissue. We discuss the advantages and drawbacks of the use of various cell types, natural and synthetic scaffolds, multiphasic or gradient-based scaffolds, and self-organizing or self-assembling scaffold-free systems, for the engineering of cartilage constructs. Several challenges persist including achieving zonal tissue organization and integration with the surrounding tissue upon implantation. Approaches to improve cartilage thickness, organization and mechanical properties include mechanical stimulation, culture under hypoxic conditions, and stimulation with growth factors or other macromolecules. In addition, advanced technologies such as bioreactors, biosensors and 3D bioprinting are actively being explored. Understanding the underlying mechanisms of action of cell therapy and tissue engineering approaches will help improve and refine therapy development. Finally, we discuss recent studies of the intrinsic cellular and molecular mechanisms of cartilage repair that have identified novel signals and targets and are inspiring the development of molecular therapies to enhance the recruitment and cartilage reparative activity of joint-resident stem and progenitor cells. A one-fits-all solution is unrealistic, and identifying patients who will respond to a specific targeted treatment will be critical.

Intra-articular injection choice for osteoarthritis: making sense of cell source-an updated systematic review and dual network meta-analysis

BACKGROUND

Intra-articular injection is indicated for mild or moderate osteoarthritis (OA). However, the superiority of cell-based injection and the role of diverse cell sources are still unclear. This study aimed to compare the therapeutic effect of intra-articular injection with mesenchymal stem cells (MSCs) and cell-free methods for OA treatment.

METHODS

A literature search of published scientific data was carried out from PubMed, MEDLINE, Embase, Cochrane Library, Web of Science, and China National Knowledge Internet (CNKI). Randomized controlled trials (RCTs) compared the efficacy and safety of MSC and cell-free intra-articular injection treatments for OA with at least 6-month follow-up.

RESULTS

Dual network meta-analysis validated the therapeutic advantages of MSC treatments (VAS, Bayesian: 90% versus 10% and SUCRA: 94.9% versus 5.1%; WOMAC total, Bayesian: 83% versus 17% and SUCRA: 90.1% versus 9.9%) but also suggested a potential negative safety induced by cell injection (adverse events, Bayesian: 100% versus 0% and SUCRA: 98.2% versus 1.8%). For the MSC source aspect, adipose mesenchymal stem cells (ADMSCs) and umbilical cord mesenchymal stem cells (UBMSCs) showed a better curative effect on pain relief and function improvement compared with bone marrow mesenchymal stem cells (BMMSCs).

CONCLUSION

Intra-articular injection of MSCs is associated with more effective pain alleviation and function improvement than cell-free OA treatment. However, the potential complications induced by MSCs should be emphasized. A comparative analysis of the MSC sources showed that ADMSCs and UBMSCs exerted a better anti-arthritic efficacy than BMMSCs. Schematic illustration of MSC-based intra-articular injection for treating OA. Three major MSCs (UBMSCs, ADMSCs, and BMMSCs) are extracted and expanded in vitro. Subsequently, the amplified MSCs are concentrated and injected into the knee joint to treat OA.

Modification of mesenchymal stem cells for cartilage-targeted therapy

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the destruction of the articular cartilage, sclerosis of the subchondral bone, and joint dysfunction. Its pathogenesis is attributed to direct damage and mechanical destruction of joint tissues. Mesenchymal stem cells (MSCs), suggested as a potential strategy for the treatment of OA, have shown therapeutic effects on OA. However, the specific fate of MSCs after intraarticular injection, including cell attachment, proliferation, differentiation, and death, is still unclear, and there is no guarantee that stem cells can be retained in the cartilage tissue to enact repair. Direct homing of MSCs is an important determinant of the efficacy of MSC-based cartilage repair. Recent studies have revealed that the unique homing capacity of MSCs and targeted modification can improve their ability to promote tissue regeneration. Here, we comprehensively review the homing effect of stem cells in joints and highlight progress toward the targeted modification of MSCs. In the future, developments of this targeting system that accelerate tissue regeneration will benefit targeted tissue repair.

Randomized control trial of mesenchymal stem cells versus hyaluronic acid in patients with knee osteoarthritis - A Hong Kong pilot study

Objective

This pilot study evaluated the efficacy of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) versus hyaluronic acid (HA) in surgically naïve patients with knee osteoarthritis (OA).

Methods

Single-centre, single-blind randomized study of patients with knee OA. Twenty patients were randomized into groups of 10 each for intra-articular injection of cultured BM-MSCs (6 ​ml of BM-MSCs at 1 ​× ​10⁶ ​cells/mL) or HA (6 ​ml). Clinical assessments of pain, quality of life, radiographic imaging, and magnetic resonance imaging (MRI) compositional change were performed at baseline and 12 months follow-up.

Results

Compared with HA, BM-MSCs injection resulted in significant improvement in qualify of life and reduction in pain as reflected by visual analogue scale (VAS) pain score, Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and 36-Item Short Form Survey (SF-36) score collectively. T2-relaxation time tended to decrease more in the BM-MSCs group with a 38 ​± ​24.0% reduction in 6 out of 10 BM-MSC participants; while there was only a 12 ​± ​7.9% reduction in 4 out of 10 HA participants at the end of follow-up. The remaining participants showed either no response or had relaxation time increased on MRI assessment.

Conclusions

This pilot study found that autologous BM-MSCs significantly reduced pain, improved functional assessment score, and improved quality of life parameters comparing with HA at one year follow-up. Further clinical trial with larger sample size and longer follow up duration is warranted.

The Translational Potential of this Article

This pilot RCT demonstrated the feasibility and potential effectiveness of BM-MSCs advanced therapy for patients with knee OA compared to HA injection. Further multi-center clinical trial with a larger sample size and longer follow up duration in accordance with latest regulatory guidelines is warranted to ascertain the long term safety and effectiveness of MSCs therapy for cartilage regeneration in OA.

Registration

The study was registered in the Centre for Clinical Research Biostatistics - Clinical Trials Registry (CUHK_CCT00469).