Cartilage repair techniques in the knee: stem cell therapies

Autologous Mesenchymal Stromal Cells Immobilized in Plasma-Based Hydrogel for the Repair of Articular Cartilage Defects in a Large Animal Model

The treatment of cartilage defects in trauma injuries and degenerative diseases represents a challenge for orthopedists. Advanced mesenchymal stromal cell (MSC)-based therapies are currently of interest for the repair of damaged cartilage. However, an approved system for MSC delivery and maintenance in the defect is still missing. This study aimed to evaluate the effect of autologous porcine bone marrow MSCs anchored in a commercially available polyglycolic acid-hyaluronan scaffold (Chondrotissue®) using autologous blood plasma-based hydrogel in the repair of osteochondral defects in a large animal model. The osteochondral defects were induced in twenty-four minipigs with terminated skeletal growth. Eight animals were left untreated, eight were treated with Chondrotissue® and eight received Chondrotissue® loaded with MSCs. The animals were terminated 90 days after surgery. Macroscopically, the untreated defects were filled with newly formed tissue to a greater extent than in the other groups. The histological evaluations showed that the defects treated with Chondrotissue® and Chondrotissue® loaded with pBMSCs contained a higher amount of hyaline cartilage and a lower amount of connective tissue, while untreated defects contained a higher amount of connective tissue and a lower amount of hyaline cartilage. In addition, undifferentiated connective tissue was observed at the edges of defects receiving Chondrotissue® loaded with MSCs, which may indicate the extracellular matrix production by transplanted MSCs. The immunological analysis of the blood samples revealed no immune response activation by MSCs application. This study demonstrated the successful and safe immobilization of MSCs in commercially available scaffolds and defect sites for cartilage defect repair.

Donor variability of ovine bone marrow derived mesenchymal stem cell - implications for cell therapy

It is assumed that all species, including sheep, demonstrate significant variation between individuals including the characteristics of their bone marrow-derived mesenchymal stem cells (BM-MSCs). These differences may account for limited success in pre-clinical animal studies and may also impact on treatment strategies that are used within regenerative medicine. This study investigates variations between ovine MSCs (oMSCs) isolated from 13 English Mule sheep donors by studying cell viability, expansion, the cells' trilineage differentiation potential and the expression of cell surface markers. In addition to the primary objective, this article also compares various differentiation media used for the trilineage differentiation of oMSCs. In this study, a clear individual variation between the sheep donors regarding oMSCs characterization, tri-lineage differentiation potential and marker expression was effectively demonstrated. The results set out to systematically explore the ovine mesenchymal stem cell population derived from multiple donors. With this information, it is possible to start addressing the issues of personalized approaches to regenerative therapies.

Development of an Ex Vivo Murine Osteochondral Repair Model

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

BM-MSCs differentiated to chondrocytes for treatment of full-thickness cartilage defect of the knee

Background

Full-thickness articular cartilage injury of the knee is a major cause of disability. The aim of this study is to assess the outcome of patients treated with differentiated to chondrocytes bone marrow mesenchymal stem cells (BM-MSCs) cultured on a collagen type I/III (Chondro-Gide®) scaffold. The secondary aim was to confirm the absence of adverse events.

Methods

Fifteen patients (19 knees) with symptomatic full-thickness cartilage defects of the knee were enrolled. Bone marrow was harvested from the iliac crest, BM-MSCs were prepared, and expanded cells were grown in a standard medium or in a standard culture medium containing TGF-β. BM-MSCs differentiated to chondrocytes were seeded in a porcine collagen type I/III scaffold (Chondro-Gide®) and cultured in TGF-β containing media. After 4 weeks, the membrane was sutured on the cartilage defect. All patients underwent plain radiographs (antero-posterior, lateral, and axial view of the patella) and MRI of the affected knee. The Oxford knee score, the Lyhsolm scale, and the VAS score were administered to all patients. At final follow-up a MRI for the study of articular cartilage was undertaken.

Results

The mean size of the cartilage lesions was 20 × 17 mm (range, 15 × 10 mm–30 × 30 mm). At final follow-up, the median Oxford knee score and Lyhsolm scale scores significantly improved from 29 (range 12–39; SD 7.39) to 45 (range 24–48; SD 5.6) and from 55.5 (range 25–81; SD 17.7) to 94.5 (58–100; SD 10.8), respectively. Pain, according to the VAS score, significantly improved. Sixty percent of patients reported their satisfaction as excellent, 20% as good, 14% as fair, and 1 patient as poor.

Conclusion

The treatment of full-thickness chondral injuries of the knee with differentiated to chondrocytes BM-MSCs and Chondro-Gide® scaffold showed encouraging outcomes. Further studies involving more patients, and with longer follow-up, are required to evaluate the effectiveness of the treatment and the long-term results.

The Potential of Menstrual Blood-Derived Mesenchymal Stem Cells for Cartilage Repair and Regeneration: Novel Aspects

Menstrual blood is a unique body fluid that contains mesenchymal stem cells (MSCs). These cells have attracted a great deal of attention due to their exceptional advantages including easy access and frequently accessible sample source and no need for complex ethical and surgical interventions, as compared to other tissues. Menstrual blood-derived MSCs possess all the major stem cell properties and even have a greater proliferation and differentiation potential as compared to bone marrow-derived MSCs, making them a perspective tool in a further clinical practice. Although the potential of menstrual blood stem cells to differentiate into a large variety of tissue cells has been studied in many studies, their chondrogenic properties have not been extensively explored and investigated. Articular cartilage is susceptible to traumas and degenerative diseases, such as osteoarthritis, and has poor self-regeneration capacity and therefore requires more effective therapeutic technique. MSCs seem promising candidates for cartilage regeneration; however, no clinically effective stem cell-based repair method has yet emerged. This chapter focuses on studies in the field of menstrual blood-derived MSCs and their chondrogenic differentiation potential and suitability for application in cartilage regeneration. Although a very limited number of studies have been made in this field thus far, these cells might emerge as an efficient and easily accessible source of multipotent cells for cartilage engineering and cell-based chondroprotective therapy.

Type III Transforming Growth Factor-β Receptor RNA Interference Enhances Transforming Growth Factor β3-Induced Chondrogenesis Signaling in Human Mesenchymal Stem Cells

The type III transforming growth factor-β (TGF-β) receptor (TβRIII), a coreceptor of the TGF-β superfamily, is known to bind TGF-βs and regulate TGF-β signaling. However, the regulatory roles of TβRIII in TGF-β-induced mesenchymal stem cell (MSC) chondrogenesis have not been explored. The present study examined the effect of TβRIII RNA interference (RNAi) on TGF-β3-induced human MSC (hMSC) chondrogenesis and possible signal mechanisms. A lentiviral expression vector containing TβRIII small interfering RNA (siRNA) (SiTβRIII) or a control siRNA (SiNC) gene was constructed and infected into hMSCs. The cells were cultured in chondrogenic medium containing TGF-β3 or control medium. TβRIII RNAi significantly enhanced TGF-β3-induced chondrogenic differentiation of hMSCs, the ratio of type II (TβRII) to type I (TβRI) TGF-β receptors, and phosphorylation levels of Smad2/3 as compared with cells infected with SiNC. An inhibitor of the TGF-β signal, SB431542, not only inhibited TβRIII RNAi-stimulated TGF-β3-mediated Smad2/3 phosphorylation but also inhibited the effects of TβRIII RNAi on TGF-β3-induced chondrogenic differentiation. These results demonstrate that TβRIII RNAi enhances TGF-β3-induced chondrogenic differentiation in hMSCs by activating TGF-β/Smad2/3 signaling. The finding points to the possibility of modifying MSCs by TβRIII knockdown as a potent future strategy for cell-based cartilage tissue engineering.

Applications of Tissue Engineering in Joint Arthroplasty: Current Concepts Update

Research in tissue engineering has undoubtedly achieved significant milestones in recent years. Although it is being applied in several disciplines, tissue engineering's application is particularly advanced in orthopedic surgery and in degenerative joint diseases. The literature is full of remarkable findings and trials using tissue engineering in articular cartilage disease. With the vast and expanding knowledge, and with the variety of techniques available at hand, the authors aimed to review the current concepts and advances in the use of cell sources in articular cartilage tissue engineering.