Mesenchymal stem cell therapy in the sports knee: where are we in 2011?

Mesenchymal Stem Cell Therapy in Chondral Defects of Knee: Current Concept Review

PURPOSE

Full-thickness cartilage defects if left alone would increase the risk of osteoarthritis (OA) with severe associated pain and functional disability. Articular cartilage defect may result from direct trauma or chronic degeneration. The capability of the mesenchymal stem cells (MSCs) to repair and regenerate cartilage has been widely investigated. This review describes current trends in MSC biology, the sourcing, expansion, application and role of MSCs in chondral defects of human knees.

METHODS

The studies referencing MSCs and knee osteoarthritis were searched (from1998 to 2020) using PubMed, EMBASE, Cochrane Library, Web of Science and the ClinicalTrials.gov with keywords (MSCs, chondral defects or cartilage degeneration of knee, cartilage regeneration, chondrogenesis, tissue engineering, efficacy and safety). The inclusion criteria were based on use of MSCs for treatment of chondral defects and osteoarthritis of the knee, English language and human studies.

RESULTS

The history of MSC research from the initial discovery of their multipotency to the more recent recognition of their role in cartilage defects of knee is elucidated. Several studies have demonstrated promising results in the clinical application for repair of chondral defects as an adjuvant or independent procedure. Intra-articular MSCs provide improvements in pain and function in knee osteoarthritis at short-term follow-up in many studies. The tendency of MSCs to differentiate into fibrocartilage affecting the outcome is a common issue faced by researchers.

CONCLUSION

Some efficacy has been shown of MSCs for cartilage repair in osteoarthritis; however, the evidence of efficacy of intra-articular MSCs on both clinical outcomes and cartilage repair remains limited. Despite the high quality of evidence to support, MSC therapy has emerged but further refinement of methodology will be necessary to support its routine clinical use.

Gene expression profiles of the meniscus avascular phenotype: A guide for meniscus tissue engineering

Avascular (Avas) meniscus regeneration remains a challenge, which is partly a consequence of our limited knowledge of the cells that maintain this tissue region. In this study, we utilized microarrays to characterize gene expression profiles of intact human Avas meniscus tissue and of cells following culture expansion. Using these data, we examined various 3D culture conditions to redifferentiate Avas cells toward the tissue phenotype. RNA was isolated from either the tissue directly or following cell isolation and 2 weeks in monolayer culture. RNA was hybridized on human genome arrays. Differentially expressed (DE) genes were identified by ranking analysis. DAVID pathway analysis was performed and visualized using STRING analysis. Quantitative PCR (qPCR) on additional donor menisci (tissues and cells) were used to validate array data. Avas cells cultured in 3D were subjected to qPCR to compare with the array-generated data. A total of 387 genes were DE based on differentiation state (>3-fold change; p < 0.01). In Avas-cultured cells, the upregulated pathways included focal adhesion, ECM-receptor interaction, regulation of actin cytoskeleton, and PDGF Signaling. In 3D-cultured Avas cells, TGFβ1 or combinations of TGFβ1 and BMP6 were most effective to promote an Avas tissue phenotype. THBS2 and THBS4 expression levels were identified as a means to denote meniscus cell phenotype status. We identified the key gene expression profiles, new markers and pathways involved in characterizing the Avas meniscus phenotype in the native state and during in vitro dedifferentiation and redifferentiation. These data served to screen 3D conditions to generate meniscus-like neotissues. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1947-1958, 2018.

Safety, tolerability, clinical, and joint structural outcomes of a single intra-articular injection of allogeneic mesenchymal precursor cells in patients following anterior cruciate ligament reconstruction: a controlled double-blind randomised trial

Background

Few clinical trials have investigated the safety and efficacy of mesenchymal stem cells for the management of post-traumatic osteoarthritis. The objectives of this pilot study were to determine the safety and tolerability and to explore the efficacy of a single intra-articular injection of allogeneic human mesenchymal precursor cells (MPCs) to improve clinical symptoms and retard joint structural deterioration over 24 months in patients following anterior cruciate ligament (ACL) reconstruction.

Methods

In this phase Ib/IIa, double-blind, active comparator clinical study, 17 patients aged 18–40 years with unilateral ACL reconstruction were randomized (2:1) to receive either a single intra-articular injection of 75 million allogeneic MPCs suspended in hyaluronan (HA) (MPC + HA group) (n = 11) or HA alone (n = 6). Patients were monitored for adverse events. Immunogenicity was evaluated by anti-HLA panel reactive antibodies (PRA) against class I and II HLAs determined by flow cytometry. Pain, function, and quality of life were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and SF-36v2 scores. Joint space width was measured from radiographs, and tibial cartilage volume and bone area assessed from magnetic resonance imaging (MRI).

Results

Moderate arthralgia and swelling within 24 h following injection that subsided were observed in 4 out of 11 in the MPC + HA group and 0 out of 6 HA controls. No cell-related serious adverse effects were observed. Increases in class I PRA >10% were observed at week 4 in the MPC + HA group that decreased to baseline levels by week 104. Compared with the HA group, MPC + HA-treated patients showed greater improvements in KOOS pain, symptom, activities of daily living, and SF-36 bodily pain scores (p < 0.05). The MPC + HA group had reduced medial and lateral tibiofemoral joint space narrowing (p < 0.05), less tibial bone expansion (0.5% vs 4.0% over 26 weeks, p = 0.02), and a trend towards reduced tibial cartilage volume loss (0.7% vs –4.0% over 26 weeks, p = 0.10) than the HA controls.

Conclusions

Intra-articular administration of a single allogeneic MPC injection following ACL reconstruction was safe, well tolerated, and may improve symptoms and structural outcomes. These findings suggest that MPCs warrant further investigations as they may modulate some of the pathological processes responsible for the development of post-traumatic osteoarthritis following ACL reconstruction.

Trial registration

ClinicalTrials.gov (NCT01088191) registration date: March 11, 2010

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1391-0) contains supplementary material, which is available to authorized users.

Meniscal Tissue Engineering Using Aligned Collagen Fibrous Scaffolds: Comparison of Different Human Cell Sources

Hydrogel and electrospun scaffold materials support cell attachment and neotissue development and can be tuned to structurally and mechanically resemble native extracellular matrix by altering either electrospun fiber or hydrogel properties. In this study, we examined meniscus tissue generation from different human cell sources including meniscus cells derived from vascular and avascular regions, human bone marrow-derived mesenchymal stem cells, synovial cells, and cells from the infrapatellar fat pad (IPFP). All cells were seeded onto aligned electrospun collagen type I scaffolds and were optionally encapsulated in a tricomponent hydrogel. Single or multilayered constructs were generated and cultivated in defined medium with selected growth factors for 2 weeks. Cell viability, cell morphology, and gene-expression profiles were monitored using confocal microscopy, scanning electron microscopy, and quantitative polymerase chain reaction (qPCR), respectively. Multilayered constructs were examined with histology, immunohistochemistry, qPCR, and for tensile mechanical properties. For all cell types, TGFβ1 and TGFβ3 treatment increased COL1A1, COMP, Tenascin C (TNC), and Scleraxis (SCX) gene expression and deposition of collagen type I protein. IPFP cells generated meniscus-like tissues with higher meniscogenic gene expression, mechanical properties, and better cell distribution compared to other cell types studied. We show proof of concept that electrospun collagen scaffolds support neotissue formation and IPFP cells have potential for use in cell-based meniscus regeneration strategies.

Current Concepts in Treatment of Patellofemoral Osteochondritis Dissecans

Identification, protection, and management of patellofemoral articular cartilage lesions continue to remain on the forefront of sports medicine rehabilitation. Due to high-level compression forces that are applied through the patellofemoral (PF) joint, managing articular cartilage lesions is challenging for sports medicine specialists. Articular cartilage damage may exist in a wide spectrum of injuries ranging from small, single areas of focal damage to wide spread osteoarthritis involving large chondral regions. Management of these conditions has evolved over the last two centuries, most recently using biogenetic materials and cartilage replacement modalities. The purpose of this clinical commentary is to discuss PF articular cartilage injuries, etiological variables, and investigate the evolution in management of articular cartilage lesions. Rehabilitation of these lesions will also be discussed with a focus on current trends and return to function criteria.

LEVEL OF EVIDENCE

5.

Future trends for unicompartmental arthritis of the knee: injectables & stem cells

Arthritis is one of the most frequent musculoskeletal problems, causing pain, disability, and a significant economic burden. In this article, we discuss current nonsurgical injectable treatment options as well as future trends for cartilage lesions and early arthritis of the knee. We cover some potential treatments for knee osteoarthritis, including stem cell and gene therapies.