Ilyas Khan

Swansea University | SWAN · Institute of Life Science "ILS"

We have discovered that a combination of fibroblast growth factor 2 and transforming growth factor β1 induce profound morphologic changes in immature articular cartilage. The purpose of this study was to test the hypothesis that these changes represent accelerated postnatal maturation. Histochemical and biochemical assays were used to confirm the n...

Experimental data suggests that tissue-specific progenitors are present within hyaline articular cartilage with the potential to contribute to growth, maintenance, and repair. In this chapter, we show how colony-forming progenitor-like cells can be isolated from bovine articular cartilage using differential adhesion to fibronectin. Furthermore, we...

Osteoarthritis (OA) is a multifactorial disease leading to degeneration of articular cartilage, causing morbidity in approximately 8.5 million of the UK population. As the dense extracellular matrix of articular cartilage is primarily composed of collagen, cartilage repair strategies have exploited the biocompatibility and mechanical strength of bo...

Osteoarthritis (OA) is a joint degenerative disease that is an exceedingly common problem associated with aging. Aging is the principal risk factor for OA, but damage-related physiopathology of articular chondrocytes probably drives the mechanisms of joint degeneration by a progressive decline in the homeostatic and regenerative capacity of cells....

Cartilage repair in osteoarthritic patients remains a challenge. Identifying resident or donor stem/progenitor cell populations is crucial for augmenting the low intrinsic repair potential of hyaline cartilage. Furthermore, mediating the interaction between these cells and the local immunogenic environment is thought to be critical for long term re...

We report a conductive and biodegradable 3D printed polymer scaffold that promotes chondrogenic differentiation of chondroprogenitor cells. The conductive material consists of tetraniline- b -polycaprolactone- b -tetraaniline and polycaprolactone.

Articular cartilage contains a subpopulation of tissue-specific progenitors that are an ideal cell type for cell therapies and generating neo-cartilage for tissue engineering applications. However, it is unclear whether the standard chondrogenic medium employing transforming growth factor-β (TGFβ) isoforms is optimal to differentiate these cells. W...

Intense pulsed light (IPL) has been used therapeutically in a number of clinical settings and has been shown to have a photobiomodulatory effect on connective tissue cells, such as those derived from skin and tendon. In vitro cell culture models are essential tools preclinically in investigating such treatment modalities, as they help in optimising...

The immunomodulatory properties of mesenchymal stem cells (MSCs) from autologous and allogeneic sources are useful in stimulating tissue regeneration and repair. To obtain a high number of MSCs for transplantation requires extensive in vitro expansion with culture media supplements that can cause xeno-contamination of cells potentially compromising...

The speciation of highly-diluted elements by X-ray absorption spectroscopy in a diverse range of materials is extremely challenging, especially in biological matrices such as articular cartilage. Here we show that using a high energy resolution fluorescence detected X-ray absorption spectroscopy (HERFD-XAS) technique coupled to an array of crystal...

Background: Flexor tendon injuries are extremely common and they are usually the result of incised traumatic glass or knife injury. The process of tendon healing is a complicated and exceptionally-regimented mechanism that is originated and monitored by a vast number of diverse molecules. One of the most pivotal groups of mediators that are crucia...

High Resolution X-Ray Phase Contrast Imaging of Maturating Cartilage. - Volume 24 Supplement - Hélène Labriet, Caroline Bissardon, Hervé Mathieu, Ilyas Khan, Laurent Charlet, Sébastien Bérujon, Sylvain Bohic, Emmanuel Brun

The neonate transitions from placenta-derived oxygen, to supply from the pulmonary system, moments after birth. This requires a series of structural developments to divert more blood through the right heart and onto the lungs, with the tissue quickly remodelling to the changing ventricular workload. In some cases, however, the heart structure does...

Paramount for the generation of auricular structures of clinically-relevant size is the acquisition of a large number of cells maintaining an elastic cartilage phenotype, which is the key in producing a tissue capable of withstanding forces subjected to the auricle. Current regenerative medicine strategies utilize chondrocytes from various location...

Tendons are dense, fibrous connective tissues which carry out the essential physiological role of transmitting mechanical forces from skeletal muscle to bone. From a clinical perspective, tendinopathy is very common, both within the sporting arena and amongst the sedentary population. Studies have shown that light therapy may stimulate tendon heali...

Statement of significance: Despite its limited ability to repair, articular cartilage harbors an endogenous population of progenitor cells (ACPCs), that to date, received limited attention in biomaterials and tissue engineering applications. Harnessing the potential of these cells in 3D hydrogels can open new avenues for biomaterial-based regenera...

INTRODUCTION In China, a strong correlation exists between the location of selenium (Se) deficient soils and the distribution of KBD (musculoskeletal disease) in the population. Present within organisms as a trace element, Se remains an essential component of antioxidant and anti-inflammatory-related proteins which seems to be indirectly involved (...

Platelet-rich plasma (PRP) is used to stimulate the repair of acute and chronic cartilage damage even though there is no definitive evidence of how this is achieved. Chondrocytes in injured and diseased situations frequently re-express phenotypic biomarkers of immature cartilage so tissue maturation is a potential pathway for restoration of normal...

The use of microcarriers has been extensively researched as a means of expanding cells in 3D‐culture systems. However, the utilization of such microcarriers as a bioscaffold on which cells can be differentiated prior to implantation holds much potential. The use of such microcarrier‐based systems allows for a structural support and also removes the...

In recent years it has become increasingly clear that articular cartilage harbours a viable pool of progenitor cells and interest has focussed on their role during development and disease. Analysis of progenitor numbers using fluorescence-activated sorting techniques has resulted in wide-ranging estimates, which may be the result of context-depende...

Current cell-based repair strategies have proven unsuccessful for treating cartilage defects and osteoarthritic lesions, consequently advances in innovative therapeutics are required and mesenchymal stem cell-based (MSC) therapies are an expanding area of investigation. MSCs are capable of differentiating into multiple cell lineages and exerting pa...

Recent advances in regenerative medicine place us in a unique position to improve the quality of engineered tissue. We use auricular cartilage as an exemplar to illustrate how the use of tissue-specific adult stem cells, assembly through additive manufacturing and improved understanding of postnatal tissue maturation will allow us to more accuratel...

Introduction Manufactured allogeneic tissue-engineering based technologies have the potential to avoid donor site morbidity. In the case of cartilage, the use of non-related stem cell sources (eg: ADSCs) produces inelastic cartilage, prone to calcification. We present a novel protocol for isolation and characterization of chondroprogenitors (CDSCs)...

Introduction Manufactured allogeneic tissue-engineering based technologies have the potential to avoid donor site morbidity. In the case of cartilage, the use of non-related stem cell sources (eg: ADSCs) produces inelastic cartilage, prone to calcification. We present a novel protocol for isolation and characterization of chondroprogenitors (CDSCs)...

Articular cartilage maturation is the postnatal development process that adapts joint surfaces to their site-specific biomechanical demands. Maturation involves gross morphological changes that occur through a process of synchronised growth and resorption of cartilage and generally ends at sexual maturity. The inability to induce maturation in biom...

The finding of increased signal in the MRI T2 weighted imaging of bone is common and was initially described as "bone marrow oedema" by Wilson in 1986. The use of the Greek word οίδημα/oedema (swelling) is, however, inaccurate since in the confined space between the trabecular bones, swelling cannot occur. Consequently, Bone Marrow Lesion (BML) is...

Postnatal articular cartilage is relatively unstructured; with a high chondrocyte density and cells distributed evenly throughout the tissue. In the months following birth, the articular cartilage starts the transformation to mature tissue, developing distinct zonal stratification and establishing high matrix to cell volume ratio. This forms a high...

The poor reparative potential of articular cartilage is largely attributed to its avascular and aneural status combined with low cellularity; chondrocytes only occupy 10% of the tissue volume. Consequently, there have been a number of strategies developed to augment repair most notably through microfracture and Autologous Chondrocyte Implanation (A...

The failure of cartilages to fuse, particularly in the case of articular cartilage under conditions of repair is due to morphological and structural constraints of the tissue. Factors that impede integration include, non-vascularisation, low cellularity, and proteoglycan in the surrounding extracellular matrix acting as a natural barrier to cellula...

Cytogenetic Analysis. (0.04 MB DOC)

Immunohistochemistry. (0.04 MB DOC)

Telomere length analysis. (0.04 MB DOC)

RTQ-TRAP. (0.04 MB DOC)

Background: Articular cartilage displays a poor repair capacity. The aim of cell-based therapies for cartilage defects is to repair damaged joint surfaces with a functional replacement tissue. Currently, chondrocytes removed from a healthy region of the cartilage are used but they are unable to retain their phenotype in expanded culture. The resul...

BACKGROUND: Articular cartilage displays a poor repair capacity. The aim of cell-based therapies for cartilage defects is to repair damaged joint surfaces with a functional replacement tissue. Currently, chondrocytes removed from a healthy region of the cartilage are used but they are unable to retain their phenotype in expanded culture. The result...

The osteoinductive and conductive capabilities of commercially pure titanium and its alloys is well documented, as is their ability to provide long-term stability for permanent implantable devices. Fracture fixation in paediatric and trauma patients generally requires transient fixation after which the implant becomes redundant and requires removal...

Basic fibroblast growth factor (FGF2) is a mitogen for articular chondrocytes. Cell death frequently occurs upon cartilage wounding and is evident during the progression of osteoarthritis. We hypothesised that incubation of wounded articular cartilage with exogenously added FGF2 would enhance cartilage repair, replacing dead cells through increased...

To analyse the heterogeneity at the single-cell level of human mesenchymal progenitor cells from SM. Cell populations were enzymatically released from the knee joint synovium of adult human individuals. Single cell-derived clonal populations were obtained by limiting dilution and serially passaged to determine growth rates. Phenotypic analysis was...

Articular cartilage is the target tissue of osteoarthritis (OA), a degenerative disease with no cure. In this issue of Cell Stem Cell, Miosge and colleagues (Koelling et al., 2009) report that migratory progenitor cells occupy degenerating OA tissue but that this population is not present in healthy cartilage.

Experimental wounding of articular cartilage results in cell death at the lesion edge. The objective of this study was to investigate whether inhibition of this cell death results in enhanced integrative cartilage repair. Bovine articular cartilage discs (6 mm) were incubated in media containing inhibitors of necrosis (Necrostatin-1, Nec-1) or apop...

Articular cartilage contains mesenchymally derived chondroprogenitor cells that have the potential to be used for stem cell therapy. The aim of this study was to characterise the growth kinetics and properties of in vitro expanded cloned chondroprogenitors and determine if critical determinants of the progenitor phenotype were maintained or lost in...

Oxidative stress occurs when the metabolic balance of a cell is disrupted through exposure to excess pro-oxidant. Whilst it is known that unregulated production or exposure to exogenous sources of pro-oxidants induces chondrocyte cell death and degrades matrix components in vitro, relatively little is known of the effects of pro-oxidants on articul...

Articular cartilage is a challenging tissue to reconstruct or replace principally because of its avascular nature; large chondral lesions in the tissue do not spontaneously heal. Where lesions do penetrate the bony subchondral plate, formation of hematomas and the migration of mesenchymal stem cells provide an inferior and transient fibrocartilagen...

Objective To develop a biomarker-based model to predict osteogenic potency of human mesenchymal stem cells (MSCs) from synovial membrane and periosteum.MethodsMSC populations were derived from adult synovium and periosteum. Phenotype analysis was performed by fluorescence-activated cell sorting and real-time reverse transcriptase–polymerase chain r...

Necrosis and apoptosis have been demonstrated in articular cartilage in response to trauma and disease. However, cell death in articular cartilage may also be thought of as a scale of cell death culminating in secondary necrosis with the failure to remove apoptotic cells from the tissue. The in situ detection of cell death is an important technique...

During vertebrate evolution, successful adaptation of animal limbs to a variety of ecological niches depended largely on the formation and positioning of synovial joints. The function of a joint is to allow smooth articulation between opposing skeletal elements and to transmit biomechanical loads through the structure, and this is achieved through...

Background Preparation of Media and ReagentsIsolation of Chondroprogenitor Cells from Normal and Osteoarthritic Human Articular CartilageIsolation of Chondroprogenitor Cells from Fetal Human CartilageIsolation of Progenitor Cells from Human SynoviumSources of MaterialsReferences

Arguably, the gold standard of biological repair of articular cartilage lesions is autologous chondrocyte transplantation. Although the clinical outcomes appear to range between good and excellent in most cases, there are, nevertheless, both clinical and biological challenges that remain to improve rehabilitation and clinical outcome. One of the ma...