Greffe de chondrocytes autologues dans le traitement des pertes de substance condylienne du genou

Stearic acid methyl ester ​promotes migration of mesenchymal stem cells and accelerates cartilage defect repair

Background

Mesenchymal stem cells (MSCs) can be easily expanded without losing the ability of multilineage differentiation, including oesteogenic, chondrogenic and adipogenic differentiation. These characters make MSCs a promising cell resource for cartilage defect repair. MSCs could be recruited by inflammatory stimulation, then home to the injury tissues. However, its capacity of homing is extremely limited. Thus, it has become extremely necessary to develop an agent or a method, which can be used to enhance the efficiency of MSCs homing. This study investigates the effect of stearic acid methyl ester (SAME) on MSCs mobilisation and cartilage regeneration.

Methods

MSCs were isolated from femurs of Sprague-Dawley (SD) rats. MTT assay was used to detect effect of SAME on viability of MSCs. Transwell assay and wound healing assay were used to detect effect of SAME on migration of MSCs. RNA-seq, quantitative real-time PCR and western blot were performed to analyze the expression of RNAs and proteins. Colony forming assay and flow cytometry were used to evaluate the effect of SAME on MSCs mobilisation in vivo. A rat cartilage defect model was created to evaluate the effect of SAME on cartilage regeneration.

Results

We found that SAME could promote the migration of MSCs. Interestingly, we found SAME significantly increased the expression levels of Vav1 in MSCs. On the other hand, the enhanced migration ability of MSCs induced by SAME was retarded by Vav1 small interfering RNA (siRNA) and Rho-associated protein kinase 2 (ROCK2) inhibitor. In addition, we also checked the effect of SAME on mobilisation of MSCs in vivo. The results showed that SAME increased the number of MSCs in peripheral blood and enhanced the capacity of colony formation. Finally, using a cartilage defect model in rats, we found SAME could improve cartilage repair.

Conclusion

Our study demonstrates that SAME can enhance MSCs migration ability mainly through the Vav1/ROCK2 signaling pathway, which could contribute to the accelerated cartilage regeneration.

The translational potential of this article

These findings provide evidence that SAME could be used as a therapeutic reagent for MSCs mobilisation and cartilage regeneration.

Advances in Regenerative Medicine and Tissue Engineering: Innovation and Transformation of Medicine

Humans and animals lose tissues and organs due to congenital defects, trauma, and diseases. The human body has a low regenerative potential as opposed to the urodele amphibians commonly referred to as salamanders. Globally, millions of people would benefit immensely if tissues and organs can be replaced on demand. Traditionally, transplantation of intact tissues and organs has been the bedrock to replace damaged and diseased parts of the body. The sole reliance on transplantation has created a waiting list of people requiring donated tissues and organs, and generally, supply cannot meet the demand. The total cost to society in terms of caring for patients with failing organs and debilitating diseases is enormous. Scientists and clinicians, motivated by the need to develop safe and reliable sources of tissues and organs, have been improving therapies and technologies that can regenerate tissues and in some cases create new tissues altogether. Tissue engineering and/or regenerative medicine are fields of life science employing both engineering and biological principles to create new tissues and organs and to promote the regeneration of damaged or diseased tissues and organs. Major advances and innovations are being made in the fields of tissue engineering and regenerative medicine and have a huge impact on three-dimensional bioprinting (3D bioprinting) of tissues and organs. 3D bioprinting holds great promise for artificial tissue and organ bioprinting, thereby revolutionizing the field of regenerative medicine. This review discusses how recent advances in the field of regenerative medicine and tissue engineering can improve 3D bioprinting and vice versa. Several challenges must be overcome in the application of 3D bioprinting before this disruptive technology is widely used to create organotypic constructs for regenerative medicine.

Engineering Stem Cells for Biomedical Applications

Stem cells are characterized by a number of useful properties, including their ability to migrate, differentiate, and secrete a variety of therapeutic molecules such as immunomodulatory factors. As such, numerous pre-clinical and clinical studies have utilized stem cell-based therapies and demonstrated their tremendous potential for the treatment of various human diseases and disorders. Recently, efforts have focused on engineering stem cells in order to further enhance their innate abilities as well as to confer them with new functionalities, which can then be used in various biomedical applications. These engineered stem cells can take on a number of forms. For instance, engineered stem cells encompass the genetic modification of stem cells as well as the use of stem cells for gene delivery, nanoparticle loading and delivery, and even small molecule drug delivery. The present Review gives an in-depth account of the current status of engineered stem cells, including potential cell sources, the most common methods used to engineer stem cells, and the utilization of engineered stem cells in various biomedical applications, with a particular focus on tissue regeneration, the treatment of immunodeficiency diseases, and cancer.

Comparison of growth factor adsorbed scaffold and conventional scaffold with growth factor supplemented media for primary human articular chondrocyte 3D culture

Background

Cartilage tissue engineering offers new strategies in repairing damaged cartilage. Scaffolds have been used for the in vitro and in vivo procedures for this application, which demonstrates the compatible biological and physical properties that mimic natural tissues. Several types of scaffolds were used and had different effects on cell functions. The study was designed to develop a functional gelatin scaffold by adsorption of hyaluronan (HA) and the transforming growth factor β3 (TGF-β3) in a commercially available gelatin scaffold.

Results

The biological properties of human articular chondrocytes were investigated during a 21-day cultivation embedded in either HA + TGF-β3 adsorbed scaffolds or the conventional supplemented method. The rising of proliferation of chondrocytes embedded in adsorbed scaffolds was observed at day 17 and 21 of cultivation (1.27 and 1.28 fold, respectively). The chondrogenic gene expression of the chondrocytes embedded in HA + TGF-β3 adsorbed scaffolds significantly increased: SOX-9 (1.65 fold), ACAN (7.65 fold) and COL2A1 (1.83 fold). Remarkably, over the 21 days of cultivation, HA + TGF-β3 adsorbed scaffolds promoted the extracellular matrix molecules production with higher accumulation of HA (1.2 fold), collagen (1.42 fold) and uronic acid (1.41 fold). Moreover, the cell population and extracellular matrix production, which were examined by a histological analysis and a scanning electron microscope, were correlated with the biochemical analysis.

Conclusion

A small amount of HA and TGF-β3 initially adsorbed in the scaffolds (70 μg and 10 ng, respectively) was consumed over the 21-day cultivation. The HA + TGF-β3 adsorbed gelatin scaffold is effective and more suitable than the conventional supplemented method for the in vitro assessment of human chondrocyte 3D culture.

Autologous chondrocyte implantation for traumatic full-thickness cartilage defects of the knee in 14 patients: 6-year functional outcomes

BACKGROUND

Autologous chondrocyte implantation (ACI) was introduced in 1987 in Sweden by Brittberg and Peterson for the treatment of severe chondral defects of the knee. Here, our objective was to evaluate mid-term outcomes of ACI in young athletic patients with deep chondral defects of the knee after trauma.

HYPOTHESIS

ACI is effective in filling full-thickness chondral defects of the knee.

PATIENTS AND METHODS

We prospectively monitored 14 patients, with International Cartilage Repair Society grade III or IV lesions, who underwent ACI between 2001 and 2006. Standard evaluation measurements were used. Mean age at surgery was 37.7 years (range, 30-45). A history of surgery on the same knee was noted in ten (67%) patients. The defect was on the medial femoral condyle in 11 patients, lateral femoral condyle in two patients, and both femoral condyles in one patient. Mean defect surface area after debridement was 2.1cm(2) (1-6.3).

RESULTS

After a mean follow-up of six years, improvements were noted in 12 (86%) patients, with an International Knee Documentation Committee (IKDC) score increase from 40 (27.6-65.5) to 60.2 (35.6-89.6) (P=0.003) and a Brittberg-Perterson score decrease from 54.4 (11.8-98.2) to 32.9 (0-83.9) (P=0.02), between the preoperative assessment and last follow-up. The visual analogic scale pain score decreased from 66.3 (44-89) to 23.2 (0-77) (P=0.0006). In two (14%) patients, no improvements were detectable at last follow-up. The remaining 12 patients were satisfied and able to resume sporting activities, albeit at a less strenuous level. Two ACI-specific complications occurred, namely, periosteal hypertrophy treated with debridement in one patient and transplant delamination in another.

DISCUSSION

Our findings are consistent with previous reports but cover a longer follow-up period. Although the outcomes are promising, longer follow-ups are needed to confirm the long-term effectiveness of ACI.

LEVEL OF EVIDENCE

IV, prospective therapeutic study.

Mosaic osteochondral transplantations in the knee joint, midterm results of the SFA multicenter study

INTRODUCTION

There are several possible options to treat focal articular cartilage defects of the knee. The aim of this study was to evaluate the results and prognostic factors cartilage defects of the knee treated by autologous osteochondral mosaicplasty after more than five years of follow-up.

PATIENTS AND METHODS

One hundred forty-two cases were included in this retrospective multicenter study. Etiologies included osteochondral fractures (n=79), and osteochondritis dissecans (n=61). Mean age of patients was 31. There was a majority of men (76%). Mean BMI was 25 (range: 21-41). Fifty-three percent of the knees had a history of surgery. Mean delay between the accident and surgery was 2.5 years. Mean area of the defect was 2.29 cm(2) (range: 0.3-12.25 cm(2)). The depth of the defect was 3 or 4 on the ICRS score in 97% of cases. An additional surgical procedure was associated with mosaicplasty in 14% of the cases. The follow-up evaluation was based on the Hughston score, the ICRS score, the IKDC subjective score, and the IKDC radiological score. Evaluation of control MRI was based on a modified MOCART score.

RESULTS

The mean follow-up was 96 ± 28 months. There were complications in 19 patients. Patients were able to begin athletic activities again after a mean 35 weeks. Most patients (81.8%) were satisfied or very satisfied. There was a significant improvement (p<0.001) in the ICRS, IKDC function and Hughston scores at follow-up. The factors for a good prognosis were: male gender, medial femoral condyle defects, osteochondritis dissecans, deep, small defects, and the shortest possible delay to surgery. Obesity, smoking, work-related accidents, the level of sports practiced, the percentage of coverage of the defect, the number of plugs, and associated lesions did not have a statistically significant effect on the functional results in the final follow-up.

DISCUSSION

Autologous osteochondral mosaicplasty seems to be a reliable technique in the short and intermediate term. It has the advantage of being less expensive than reconstructive techniques, is a one-step surgical procedure and results in immediate restoration of cartilage surface. Nevertheless, this is a difficult technique, which may result in complications and requires articular harvesting. This technique is limited by the size of the defect to be treated. The primary indication is deep, small defects on the medial femoral condyle.

We do not have evidence based methods for the treatment of cartilage defects in the knee

PURPOSE

The aim of this study was to perform a systematic review of studies concerning current treatment of chondral defects of the knee.

METHODS

The relevance for evidence based data and for successful surgical treatment of cartilage defects was evaluated. From 56,098 evaluated studies, 133 studies could be further pursued. These supplied data concerning microfracturing, the osteochondral autograft transplantation system (OATS), the autologous chondrocyte implantation (ACI) and the matrix induced chondrocyte implantation (MACI). The modified Coleman Methodical Score (CMS) and the Level of Evidence (LOE) were applied to evaluate the quality.

RESULTS

In these studies, a total of 6,920 patients were reviewed with a median of 32 patients per study and a mean follow-up of 24 months. The mean CMS was 58 of 100 points. No study reached 100 points in the CMS. Three studies reached a level above 90. Ten studies were Level I, five studies reached Level II. Seven studies reached Level III, 111 studies Level IV. MRI scans to verify the clinical data were used by only 72 studies. The means in the modified CMS were for the different procedures as follows: ACI 58 points, MACI 57 points, microfracturing 68 points and OATS 50 points. 24 studies applied the Lysholm Score (LS) for clinical evaluation of cartilage surgery. All operative procedures yielded comparable improvements of the LS (n.s.) meaning that no operative procedure proved superior.

CONCLUSION

As the majority of studies evaluated by this review is insufficient for EBM purposes more coherent studies with LOE of I or II are needed. Co-relating the systems of CMS and LOE and validating the applied scores seems desirable.

Cell transplantation for articular cartilage defects: principles of past, present, and future practice

As articular cartilage has very limited self-repair capability, the repair and regeneration of damaged cartilage is a major challenge. This review aims to outline the past, present, and future of cell therapies for articular cartilage defect repair. Autologous chondrocyte implantation (ACI) has been used clinically for more than 20 years, and the short, medium, and long-term clinical outcomes of three generation of ACI are extensively overviewed. Also, strategies of clinical outcome evaluation, ACI limitations, and the comparison of ACI clinical outcomes with those of other surgical techniques are discussed. Moreover, mesenchymal stem cells and pluripotent stem cells for cartilage regeneration in vitro, in vivo, and in a few clinical studies are reviewed. This review not only comprehensively analyzes the ACI clinical data but also considers the findings from state-of-the-art stem cell research on cartilage repair from bench and bedside. The conclusion provides clues for the future development of strategies for cartilage regeneration.