Good mid-term outcomes after adipose-derived culture-expanded mesenchymal stem cells implantation in knee focal cartilage defects

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.

Stem cells for the treatment of early to moderate osteoarthritis of the knee: a systematic review

PURPOSE

Mesenchymal stem cells (MSCs) present a valuable treatment option for knee osteoarthritis with promising results. The purpose of the present study was to systematically review the clinical and functional outcomes following mesenchymal stem cell application focusing on early to moderate knee osteoarthritis.

METHODS

A systematic search was done using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in Pubmed, Scopus, Web of Science, and Cochrane Library databases. All Studies published between 2017 and March 2023 on patients treated with single mesenchymal stem cell injection for Kellgren-Lawrence grade I-III knee osteoarthritis reported on clinical and functional outcomes were included.

RESULTS

Twelve articles comprising 539 patients and 576 knees treated with a single intraarticular injection of MSCs for knee osteoarthritis were included in the current systematic review. In eligible studies, the reported outcomes were improved concerning patient-reported outcomes measures, knee function, pain relief, and quality of patient's life.

CONCLUSION

Based on high-level evidence studies, single intraarticular injection of MSCs is a safe, reliable, and effective treatment option for Kellgren-Lawrence grade I-III knee osteoarthritis. However, the lack of homogeneity in the included studies and the variance in MSCs sources and preparations should be noted.

LEVEL OF EVIDENCE

III.

Combined subchondral and intra-articular injections of bone marrow aspirate concentrate provide stable results up to 24 months

PURPOSE

The aim of this study was to evaluate the clinical and imaging findings up to 24 months of follow-up in patients treated with combined subchondral and intra-articular bone marrow aspirate concentrate (BMAC) injections for the treatment of knee osteoarthritis (OA).

METHODS

Thirty consecutive patients (19 males, 11 females) aged between 40 and 75 years (mean age 56.4 ± 8.1 years) with unilateral symptomatic knee OA (Kellgren-Lawrence 2-3) were included in the study. Patients were treated with combined intra-articular and subchondral bone BMAC injections (total 9 ml) under fluoroscopic control. IKDC subjective score, VAS for pain, KOOS, and EQ-VAS were prospectively evaluated up to 24 months. Radiographs were performed at baseline and at 24 months after the procedure. MRI was evaluated with the WORMS score at baseline, 6-12 months, and 24 months of follow-up. The statistical analysis was performed using SPSS v.19.0 and for all tests p < 0.05 was considered significant.

RESULTS

No major complications and a 13% failure rate were reported. The IKDC subjective score remained stable from 62.6 ± 19.4 at 12 months to 63.4 ± 17.1 at 24 months (both p < 0.0005 compared to baseline, 40.5 ± 12.5). Similar improvements were reported for all KOOS subscales, while EQ-VAS did not report any significant improvement. VAS pain worsened from 3.0 ± 1.9 at 12 months to 4.4 ± 1.8 at the final follow-up (p = 0.0001), although remaining lower compared to the baseline value of 6.3 ± 1.8 (p = 0.002). The radiographic evaluation did not reveal signs of improvement or deterioration of the OA grade. The MRI findings showed a worsening in marginal osteophytes and synovitis, but a significant reduction of bone marrow edema at 24 months (p < 0.0005).

CONCLUSION

Combined intra-articular and subchondral BMAC injections provided clinical and imaging benefits up to 24 months for the treatment of symptomatic knee OA, with durable clinical results, a low failure rate, and a significant reduction of bone marrow edema.

Isolation and Characterization of Cat Olfactory Ecto-Mesenchymal Stem Cells

Simple Summary

Cat’s health is impacted by several diseases and lesions for which cell therapy could be an interesting treatment. Mesenchymal stem cells or adult stem cells are found in developed tissue. Olfactory mucosa contains stem cells called olfactory ecto-mesenchymal stem cells which have already been isolated from various animals as dogs and horses. The aim of this study was to evaluate the feasibility of collecting olfactory ecto-mesenchymal stem cells in cats. For that purpose, four cats were biopsied; the cells were collected and characterized. They show stemness features and differentiation capabilities as all the other mammals previously studied. Therefore, olfactory ecto-mesenchymal stem cells could be a promising tool for feline regenerative medicine.

Abstract

The olfactory mucosa contains olfactory ecto-mesenchymal stem cells (OE-MSCs) which show stemness features, multipotency capabilities, and have a therapeutic potential. The OE-MSCs have already been collected and isolated from various mammals. The aim of this study was to evaluate the feasibility of collecting, purifying and amplifying OE-MSCs from the cat nasal cavity. Four cats were included in the study. Biopsies of olfactory mucosa were performed on anesthetized animals. Then, the olfactory OE-MSCs were isolated, and their stemness features as well as their mesodermal differentiation capabilities were characterized. Olfactory mucosa biopsies were successfully performed in all subjects. From these biopsies, cellular populations were rapidly generated, presenting various stemness features, such as a fibroblast-like morphology, nestin and MAP2 expression, and sphere and colony formation. These cells could differentiate into neural and mesodermal lineages. This report shows for the first time that the isolation of OE-MSCs from cat olfactory mucosa is possible. These cells showed stemness features and multilineage differentiation capabilities, indicating they may be a promising tool for autologous grafts and feline regenerative medicine.

Adipose Tissue-Derived Mesenchymal Stem Cells as a Potential Restorative Treatment for Cartilage Defects: A PRISMA Review and Meta-Analysis

Cartilage defects are a predisposing factor for osteoarthritis. Conventional therapies are mostly palliative and there is an interest in developing newer therapies that target the disease’s progression. Mesenchymal stem cells (MSCs) have been suggested as a promising therapy to restore hyaline cartilage to cartilage defects, though the optimal cell source has remained under investigation. A PRISMA systematic review was conducted utilising five databases (MEDLINE, EMBASE, Cochrane Library, Scopus, Web of Science) which identified nineteen human studies that used adipose tissue-derived MSC (AMSC)-based therapies, including culture-expanded AMSCs and stromal vascular fraction, to treat cartilage defects. Clinical, imaging and histological outcomes, as well as other relevant details pertaining to cartilage regeneration, were extracted from each study. Pooled analysis revealed a significant improvement in WOMAC scores (mean difference: −25.52; 95%CI (−30.93, −20.10); p < 0.001), VAS scores (mean difference: −3.30; 95%CI (−3.72, −2.89); p < 0.001), KOOS scores and end point MOCART score (mean: 68.12; 95%CI (62.18, 74.05)), thus showing improvement. The studies in this review demonstrate the safety and efficacy of AMSC-based therapies for cartilage defects. Establishing standardised methods for MSC extraction and delivery, and performing studies with long follow-up should enable future high-quality research to provide the evidence needed to bring AMSC-based therapies into the market.

Biological Augments for Acetabular Chondral Defects in Hip Arthroscopy-A Scoping Review of the Current Clinical Evidence

PURPOSE OF REVIEW

A wide array of joint-preserving surgical techniques exists in the management of acetabular chondral defects (ACDs). The purpose of this review is to summarize the clinical outcomes of the recent biologics used to treat ACDs during hip arthroscopy.

RECENT FINDINGS

Increasing evidence is available for different biological solutions used in the hip. Studies have shown promising outcomes with minimal complications when using biologics as augmentation to microfracture (MF), including different scaffolds or stem cells, or to enhance autologous chondrocyte implantation (ACI). However, data so far is scarce, and more trials and longer follow-ups are needed to better delineate the appropriate indications and benefits for each technique. Presently, the level of evidence is low, but in general, biologics appear safe and trend toward beneficial compared to standard surgical techniques. Augmented MF is recommended for small to medium ACDs, and matrix-assisted ACI or three-dimensional ACI is recommended for medium to large defects.

Cell Therapy: Types, Regulation, and Clinical Benefits

Cell therapy practices date back to the 19th century and continue to expand on investigational and investment grounds. Cell therapy includes stem cell- and non-stem cell-based, unicellular and multicellular therapies, with different immunophenotypic profiles, isolation techniques, mechanisms of action, and regulatory levels. Following the steps of their predecessor cell therapies that have become established or commercialized, investigational and premarket approval-exempt cell therapies continue to provide patients with promising therapeutic benefits in different disease areas. In this review article, we delineate the vast types of cell therapy, including stem cell-based and non-stem cell-based cell therapies, and create the first-in-literature compilation of the different "multicellular" therapies used in clinical settings. Besides providing the nuts and bolts of FDA policies regulating their use, we discuss the benefits of cell therapies reported in 3 therapeutic areas-regenerative medicine, immune diseases, and cancer. Finally, we contemplate the recent attention shift toward combined therapy approaches, highlighting the factors that render multicellular therapies a more attractive option than their unicellular counterparts.

Mesenchymal Stem Cells in the Treatment of Cartilage Defects of the Knee: A Systematic Review of the Clinical Outcomes

BACKGROUND

Osteochondral lesions are a common clinical problem and their management has been historically challenging. Mesenchymal stem cells have the potential to differentiate into chondrocytes and thus restore hyaline cartilage to the defect, theoretically improving clincal outcomes in these patients. They can also be harvested with minimal donor site morbidity.

PURPOSE

To assess the clinical and functional outcomes of mesenchymal stem cell implantation to treat isolated osteochondral defects of the knee. A secondary purpose is to assess the quality of the current available evidence as well as the radiological and histological outcomes. We also reviewed the cellular preparation and operative techniques for implantation.

STUDY DESIGN

Systematic review.

METHODS

A comprehensive literature search of 4 databases was carried out: CINAHL, Embase, MEDLINE, and PubMed. We searched for clinical studies reporting the outcomes on a minimum of 5 patients with at least 12 months of follow-up. Clinical, radiological, and histological outcomes were recorded. We also recorded demographics, stem cell source, culture technique, and operative technique. Methodological quality of each study was assessed using the modified Coleman methodology score, and risk of bias for the randomized controlled studies was assessed using the Cochrane Collaboration tool.

RESULTS

Seventeen studies were found, encompassing 367 patients. The mean patient age was 35.1 years. Bone marrow was the most common source of stem cells utilized. Mesenchymal stem cell therapy consistently demonstrated good short- to medium-term outcomes in the studies reviewed with no serious adverse events being recorded. There was significant heterogeneity in cell harvesting and preparation as well as in the reporting of outcomes.

CONCLUSION

Mesenchymal stem cells demonstrated a clinically relevant improvement in outcomes in patients with osteochondral defects of the knee. More research is needed to establish an optimal treatment protocol, long-term outcomes, and superiority over other therapies.

REGISTRATION

CRD42020179391 (PROSPERO).

Cell Sources for Cartilage Repair-Biological and Clinical Perspective

Cell-based therapy represents a promising treatment strategy for cartilage defects. Alone or in combination with scaffolds/biological signals, these strategies open many new avenues for cartilage tissue engineering. However, the choice of the optimal cell source is not that straightforward. Currently, various types of differentiated cells (articular and nasal chondrocytes) and stem cells (mesenchymal stem cells, induced pluripotent stem cells) are being researched to objectively assess their merits and disadvantages with respect to the ability to repair damaged articular cartilage. In this paper, we focus on the different cell types used in cartilage treatment, first from a biological scientist’s perspective and then from a clinician’s standpoint. We compare and analyze the advantages and disadvantages of these cell types and offer a potential outlook for future research and clinical application.

Tendon-Derived Progenitor Cells With Multilineage Potential Are Present Within Human Patellar Tendon

Background:

Progenitor cells serve as a promising source of regenerative potential in a variety of tissue types yet remain underutilized in tendinopathy. Tendon-derived progenitor cells (TDPCs) have previously been isolated from hamstring tendon but only as part of a concomitant medical procedure. Determining the presence of TDPCs in patellar tendon may facilitate clinical utilization of these cells because of the relative accessibility of this location for tissue harvest.

Purpose:

To characterize TDPCs in human patellar tendon samples.

Study Design:

Descriptive laboratory study.

Methods:

Human patellar tendon samples were obtained during elective knee surgery. TDPCs were isolated and seeded at an optimal low cell density and subcultured to confluence for up to 2 passages. Flow cytometry was used to analyze for the expression of CD90+, CD105+, CD44+, and CD31–, CD34–, and CD45– markers. The multilineage differentiation potential of TDPCs was tested in vitro via adipogenic, osteogenic, and chondrogenic culture with subsequent cytochemical staining for Oil Red O, Alizarin Red, and Alcian Blue, respectively. Enzyme-linked immunosorbent assay was used to quantify the amount of adiponectin, alkaline phosphatase, and SRY-box transcription factor 9 secreted into cell culture supernatant for further confirmation of lineage differentiation. Results were analyzed statistically using the 2-tailed Student t test.

Results:

TDPCs demonstrated near-uniform expression of CD90, CD105, and CD44 with minimal expression of CD34, CD31, and CD45. Adipogenic, osteogenic, and chondrogenic differentiation of TDPCs was confirmed using qualitative analysis. The expression of adiponectin, alkaline phosphatase, and SRY-box transcription factor 9 were significantly increased in differentiated cells versus undifferentiated TDPCs (P < .05).

Conclusion:

TDPCs can be successfully isolated from human patellar tendon samples, and they exhibit characteristics of multipotent progenitor cells.

Clinical Relevance:

These data demonstrate the promise of patellar tendon tissue as a source of progenitor cells for use in biologic therapies for the treatment of tendinopathy.

[Update on the Operative Treatment of Cartilage Defects]

Focal cartilage defects lead to swelling, significant pain and loss of function of the affected joint. Additionally, they are linked to early onset of osteoarthritis. Often young and active patients are especially susceptible due to the high stress placed on their joints. A vast amount of treatment options is available to orthopaedic surgeons to cure cartilage defects of the knee, hip, shoulder, elbow and ankle joints. This article serves to give an overview of these available treatment options and to explain the expected outcomes.

Is Extracellular Vesicle-Based Therapy the Next Answer for Cartilage Regeneration?

"Extracellular vesicles" (EVs) is a term gathering biological particles released from cells that act as messengers for cell-to-cell communication. Like cells, EVs have a membrane with a lipid bilayer, but unlike these latter, they have no nucleus and consequently cannot replicate. Several EV subtypes (e.g., exosomes, microvesicles) are described in the literature. However, the remaining lack of consensus on their specific markers prevents sometimes the full knowledge of their biogenesis pathway, causing the authors to focus on their biological effects and not their origins. EV signals depend on their cargo, which can be naturally sourced or altered (e.g., cell engineering). The ability for regeneration of adult articular cartilage is limited because this avascular tissue is partly made of chondrocytes with a poor proliferation rate and migration capacity. Mesenchymal stem cells (MSCs) had been extensively used in numerous in vitro and preclinical animal models for cartilage regeneration, and it has been demonstrated that their therapeutic effects are due to paracrine mechanisms involving EVs. Hence, using MSC-derived EVs as cell-free therapy tools has become a new therapeutic approach to improve regenerative medicine. EV-based therapy seems to show similar cartilage regenerative potential compared with stem cell transplantation without the associated hindrances (e.g., chromosomal aberrations, immunogenicity). The aim of this short review is to take stock of occurring EV-based treatments for cartilage regeneration according to their healing effects. The article focuses on cartilage regeneration through various sources used to isolate EVs (mature or stem cells among others) and beneficial effects depending on cargos produced from natural or tuned EVs.

Scaffold-Dependent Mechanical and Architectural Cues Guide Osteochondral Defect Healing in silico

Osteochondral defects in joints require surgical intervention to relieve pain and restore function. However, no current treatment enables a complete reconstitution of the articular surface. It is known that both mechanical and biological factors play a key role on osteochondral defect healing, however the underlying principles and how they can be used in the design of treatment strategies remain largely unknown. To unravel the underlying principles of mechanobiology in osteochondral defect healing, i.e., how mechanical stimuli can guide biological tissue formation, we employed a computational approach investigating the scaffold-associated mechanical and architectural properties that would enable a guided defect healing. A previous computer model of the knee joint was further developed to simulate healing of an empty osteochondral defect. Then, scaffolds were implanted in the defect and their architectures and material properties were systematically varied to identify their relevance in osteochondral defect healing. Scaffold mechanical and architectural properties were capable of influencing osteochondral defect healing. Specifically, scaffold material elastic modulus values in the range of cancellous bone (low GPa range) and a scaffold architecture that provided stability, i.e., resistance against displacement, in both the main loading direction and perpendicular to it supported the repair process. The here presented model, despite its simplifications, is regarded as a powerful tool to screen for promising properties of novel scaffold candidates fostering osteochondral defect regeneration prior to their implementation in vivo.

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

BACKGROUND

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

[In vitro study on promoting migration ability of rat adipose derived stem cells modified by stromal cell-derived factor 1α]

Objective

To explored the effect of stromal cell-derived factor 1α (SDF-1α) on promoting the migration ability of rat adipose derived stem cells (rADSCs) by constructed the rADSCs overexpression SDF-1α via adenovirus transfection.

Methods

rADSCs were isolated from adipose tissue of 6-week-old SPF Sprague Dawley rats. Morphological observation, multi-directional differentiations (osteogenic, adipogenic, and chondrogenic inductions), and flow cytometry identification were performed. Transwell cell migration experiment was used to observe and screen the optimal concentration of exogenous SDF-1α to optimize the migration ability of rADSCs; the optimal multiplicity of infection (MOI) of rADSCs was screened by observing the cell status and fluorescence expression after transfection. Then the third generation of rADSCs were divided into 4 groups: group A was pure rADSCs; group B was rADSCs co-cultured with SDF-1α at the best concentration; group C was rADSCs infected with recombinant adenovirus-mediated green fluorescent protein (Adv-GFP) with the best MOI; group D was rADSCs infected with Adv-GFP-SDF-1α overexpression adenovirus with the best MOI. Cell counting kit 8 (CCK-8) and Transwell cell migration experiment were preformed to detect and compare the effect of exogenous SDF-1α and SDF-1α overexpression on the proliferation and migration ability of rADSCs.

Results

The cell morphology, multi-directional differentiations, and flow cytometry identification showed that the cultured cells were rADSCs. After screening, the optimal stimulating concentration of exogenous SDF-1α was 12.5 nmol/L; the optimal MOI of Adv-GFP adenovirus was 200; the optimal MOI of Adv-GFP-SDF-1α overexpression adenovirus was 400. CCK-8 method and Transwell cell migration experiment showed that compared with groups A and C, groups B and D could significantly improve the proliferation and migration of rADSCs ( P<0.05); the effect of group D on enhancing the migration of rADSCs was weaker than that of group B, but the effect of promoting the proliferation of rADSCs was stronger than that of group D ( P<0.05).

Conclusion

SDF-1α overexpression modification on rADSCs can significantly promote the proliferation and migration ability, which may be a potential method to optimize the application of ADSCs in tissue regeneration and wound repair.

Mesenchymal Stem Cells Beyond Regenerative Medicine

Mesenchymal stem cells (MSCs) are competent suitors of cellular therapy due to their therapeutic impact on tissue degeneration and immune-based pathologies. Additionally, their homing and immunomodulatory properties can be exploited in cancer malignancies to transport pharmacological entities, produce anti-neoplastic agents, or induce anti-tumor immunity. Herein, we create a portfolio for MSC properties, showcasing their distinct multiple therapeutic utilities and successes/challenges thereof in both animal studies and clinical trials. We further highlight the promising potential of MSCs not only in cancer management but also in instigating tumor-specific immunity - i.e., cancer vaccination. Finally, we reflect on the possible reasons impeding the clinical advancement of MSC-based cancer vaccines to assist in contriving novel methodologies from which a therapeutic milestone might emanate.