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Objective In end-stage knee osteoarthritis, total knee arthroplasty (TKA) may finally become inevitable. At a relatively young age, this comes with the risk of future revision surgery. Therefore, in these cases, joint preserving surgery such as knee joint distraction (KJD) is preferred. Here we present 5-year follow-up data of KJD. Design Patients ( n = 20; age Results Five-years posttreatment, patients still reported clinical improvement from baseline: ΔWOMAC (Western Ontario and McMaster Universities Arthritis Index) +21.1 points (95% CI +8.9 to +33.3; P = 0.002), ΔVAS (visual analogue scale score) pain −27.6 mm (95%CI −13.3 to −42.0; P < 0.001), and minimum radiographic joint space width (JSW) of the most affected compartment (MAC) remained increased as well: Δ +0.43 mm (95% CI +0.02 to +0.84; P = 0.040). Improvement of mean JSW (x-ray) and mean cartilage thickness (MRI) of the MAC, were not statistically different from baseline anymore (Δ +0.26 mm; P = 0.370, and Δ +0.23 mm; P = 0.177). Multivariable linear regression analysis indicated that KJD treatment was associated with significantly less progression in mean and min JSW (x-ray) and mean cartilage thickness (MRI) compared with natural progression (all Ps Conclusions KJD treatment results in prolonged clinical benefit, potentially explained by an initial boost of cartilaginous tissue repair that provides a long-term tissue structure benefit as compared to natural progression. Level of evidence, II.

Aim of investigation . To prove the usefulness of the use of embryonic fibroblasts for the regeneration of cartilaginous tissue. Material and methods . New experimental model of symphysis pubis rupture followed by its recovery was employed in 24 male Shinshilla rabbits (2.3—3.5 kg body mass) in 3 series of experiments. In the first series, reconstruction was not employed. In the 2nd series, the reconstruction of symphisis was performed with the aid of tantal wired cerclage (d=1.2 mm). In the 3d series, the reconstitution was the same as in the previous series of experiments with addition of grown embrional allofibroblast tissue pieces. Duration of experiments was 7, 14, 21and 30 days. After each experiment, pieces of cartilaginous tissue were fixed with 10% neutral formalin and embedded in paraffin. Histological sections were stained with hematoxylin, eosin and VanGieson. Results. After the rupture of symphysis pubis of the pelvic bone, the cartilaginous tissue undergone alterations followed by formation of chondromatous nodules of different sizes and sclerosis of surrounding muscular and osseous tissues. In the second series of experiment after pelvis symphysis pubis rupture and symphysis recovery with the help of cerclage, the morphologic investigation revealed the formation of mixed initial callus consisting of connective and chondromatous tissue elements. In the third series of experiment it has been shown that within 4 weeks of experiment, the connective tissue with intensive basophil stain is formed in the area of symphysis pubisrupture. Connective tissue formation in surrounding soft tissue structures was associated with the formation of cartilaginous cells. Conclusion. Process of formation of cartilaginous tissue in the area of symphysis pubis rupture as evident by the experimental observation demonstrates the stimulating influence of allogeneic fibroblasts on process of cartilaginous tissue regeneration that ensures premises for clinical development of suggested method of regeneration.

Our skeletons evolved from cartilaginous tissue, but it remains a mystery how cartilage itself first arose in evolution. Characterization of cartilage in cuttlefish and horseshoe crabs reveals surprising commonalities with chordate chondrocytes, suggesting a common evolutionary origin.

Engineering tissues with a structure and spatial composition mimicking those of native articular cartilage (AC) remains a challenge. This study examined if infrapatellar fat pad-derived stem cells (FPSCs) can be used to engineer cartilage grafts with a bulk composition and a spatial distribution of matrix similar to the native tissue. In an attempt to mimic the oxygen gradients and mechanical environment within AC, FPSC-laden hydrogels (either 2 mm or 4 mm in height) were confined to half of their thickness and/or subjected to dynamic compression (DC). Confining FPSC-laden hydrogels was predicted to accentuate the gradient in oxygen tension through the depth of the constructs (higher in the top and lower in the bottom), leading to enhanced glycosaminoglycan (GAG) and collagen synthesis in 2 mm high tissues. When subjected to DC alone, both GAG and collagen accumulation increased within 2 mm high unconfined constructs. Furthermore, the dynamic modulus of constructs increased from 0.96 MPa to 1.45 MPa following the application of DC. There was no synergistic benefit of coupling confinement and DC on overall levels of matrix accumulation; however in all constructs, irrespective of their height, the combination of these boundary conditions led to the development of engineered tissues that spatially best resembled native AC. The superficial region of these constructs mimicked that of native tissue, staining weakly for GAG, strongly for type II collagen, and in 4 mm high tissues more intensely for proteoglycan 4 (lubricin). This study demonstrated that FPSCs respond to joint-like environmental conditions by producing cartilage tissues mimicking native AC. Copyright © 2016 John Wiley & Sons, Ltd.

Chondrosarcomas are malignant tumors arising from cartilaginous tissues. Myxoid chondrosarcoma is rare histological variant of chondrosarcoma that usually occurs in limbs. Head and neck is an extremely rare site for this kind of tumor with very few cases reported till date. We hereby report a case of myxoid chondrosarcoma involving the maxilla of an adult patient.

The use of mesenchymal stem cells (MSCs), which can be differentiated into chondrocytes under specific conditions, has been proposed for the treatment of cartilage defects. Blood-derived platelet-rich fibrin releasate (PRFr), which is rich in growth factors and cytokines, may improve cartilage regeneration. In this study, the therapeutic effects of PRFr in combination with bone marrow-derived MSCs for articular cartilage regeneration were evaluated in a rabbit model. Critical osteochondral defects were surgically created in the femoral condyle of the rabbits, and 3 × 106 of MSCs, 0.8 mL of PRFr, or a combination of MSCs and PRFr were injected intra-articularly and one week after first administration. The animals were sacrificed 12 weeks postoperatively, and the regenerated cartilages were assessed by gross inspection and histological examination. No treatment-related adverse events were noted in any of the rabbits. The size of the defect decreased and the volume of regenerated cartilage increased in the medial femoral condyles of the MSCs + PRFr group. Relative to the MSCs or PRFr group, histological examination demonstrated that the MSCs + PRFr group had thicker hyaline-like cartilaginous tissue with normal glycosaminoglycan production. Grading scores revealed that MSCs + PRFr injection had better matrix, cell distribution, and surface indices than other groups. The results showed that intra-articular injections of MSCs + PRFr into the knee can reduce cartilage defects by regenerating hyaline-like cartilage without adverse events. This approach may provide an alternative method of autologous chondrocyte implantation to repair cartilage defects with an unlimited source of cells and releasate. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1536-1543, 2017.

There is little evidence demonstrating the effects of electromagnetic fields (EMFs) generated within the biological entity and the effect of extrinsic fields on cellular programing. Taking the path of the more studied stimuli into attention, mechanical forces, it could be understood that nonchemical factors play a consequential role in transcriptional regulatory networks. Cartilaginous tissue consists of collagen protein that is considered as a piezoelectric substrate and is influenced by electric fields making chondrogenic specific genes an exciting candidate for bioelectromagnetic studies. As electromagnetic properties highly depend on the frequencies applied, this study delves into the ability of two EMFs with the frequency of 25 Hz and 50 Hz in inducing SOX9 and COL2 gene expressions in a three-dimensional (3D) mesenchymal stem cell (MSC)-alginate construct. Cell-alginate beads were divided into six groups and treated for a time period of 21 days. To determine the results, qualitative and quantitative data were both reviewed. On observation of real-time polymerase chain reaction (PCR) data, it was apparent that TGF-β1 treatment had a greater COL2 and SOX9 gene expression impact on MSCs compared to pulsed electromagnetic field (PEMF) treatments alone. COL2 was shown to have a greater transcriptional tendency to PEMF, whereas under defined electromagnetic parameters applied in this study, no significant difference was detected in SOX9 gene expressions compared to the control group. PEMF co-treatments enhanced the deposition of extracellular matrix molecules, as the matrix-rich beads were positively stained by Alcian blue. This genre of study is the venue for the control and healing of connective tissue defects.

A complex morphological study of the auricle to determine the human age was performed by evaluating the metric sizes between fixed points in each auricle with axial guidelines. The auricular elastic cartilage in different age periods was characterized by thickening of the cartilaginous plate, different mature and immature cartilage zone ratio, variations in the volume density of the intercellular substance and elastic fibers, and change in the numerical density of individual chondrocytes and isogroups. Aggrecan content in the cartilage was shown to increase in different age periods. Age-related structural changes in the auricular cartilage expand the possibilities of forensic medical examination and hold much promise for the identification of personality.

A photothermal study of laser effects on the electrical conductivity of an articular cartilage impregnated with magnetite nanoparticles is conducted. The behavior of the electric conductivity of cartilage impregnated with magnetite nanoparticles from solutions of different concentrations (0.4 to 10 mg/mL) and depending on the dynamics of laser heating from 20 to 40°C is studied. The growth kinetics of the electrical conductivity induced by laser heating in samples of intact cartilage tissue of animals and those of the same tissue impregnated with magnetite nanoparticles are compared.

We previously showed that repetitive cyclic loading of the mouse knee joint causes changes that recapitulate the features of osteoarthritis (OA) in humans. By applying a single loading session, we characterized the temporal progression of the structural and compositional changes in subchondral bone and articular cartilage. We applied loading during a single 5-minute session to the left tibia of adult (26-week-old) C57Bl/6 male mice at a peak load of 9.0N for 1,200 cycles. Knee joints were collected at times 0, 1, and 2 weeks after loading. The changes in articular cartilage and subchondral bone were analyzed by histology, immunohistochemistry (caspase-3 and cathepsin K), and microcomputed tomography. At time 0, no change was evident in chondrocyte viability or cartilage or subchondral bone integrity. However, cartilage pathology demonstrated by localized thinning and proteoglycan loss occurred at 1 and 2 weeks after the single session of loading. Transient cancellous bone loss was evident at 1 week, associated with increased osteoclast number. Bone loss was reversed to control levels at 2 weeks. We observed formation of fibrous and cartilaginous tissues at the joint margins at 1 and 2 weeks. Our findings demonstrate that a single session of noninvasive loading leads to the development of OA-like morphological and cellular alterations in articular cartilage and subchondral bone. The loss in subchondral trabecular bone mass and thickness returns to control levels at 2 weeks, whereas the cartilage thinning and proteoglycan loss persist. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1941-1949, 2016.

Fibrous dysplasia (FD) is a monostotic or polyostotic benign bone lesion with spindle-cell proliferation in woven bone and stroma. Rarely, cartilaginous differentiation can be seen in the lesions of FD. FD with massive cartilaginous differentiation is called fibrocartilaginous dysplasia (FCD) and is considered a rare variant of FD. Although pathological findings of FD show irregular immature bone formation without osteoblastic rimming in fibrous tissue, and rarely show very small amounts of cartilage, histological images of FCD are said to show that cartilage with a relatively high cell density is present in the majority and that FD-like findings are seen in parts of it. The most characteristic feature of FCD on images is calcification in the lesions reflecting cartilaginous tissue. On the other hand, typical radiographic findings of FD include shadows with a ground-glass appearance and thinning and bulging of the cortical bone, the observation if calcification is not usual. Therefore, in the diagnosis of FCD, differentiation from multiple enchondromatosis, Ollier disease, chondrosarcoma, and chondrosarcoma secondary to FD is necessary, and it seems important to make a careful diagnosis based not only on the pathological findings but also on imaging and clinical findings. Herein, we report on a case of FD of the proximal femur associated with intralesional extensive cartilaginous differentiation in which a pathological fracture occurred during follow-up, with a review of the literature.

The influence of mechanical stability on fracture healing has previously been studied in adult mice, but is poorly understood in aged animals. Therefore, we herein studied the effect of stabilization on the healing process of femur fractures in aged mice.Twenty-four 18-month-old CD-1 mice were stabilized after midshaft fracture of the femur with an intramedullary screw. In another 24 18-month-old mice, the femur fractures were left unstabilized. Bone healing was studied by radiological, biomechanical, histomorphometric, and protein expression analyses.After 2 and 5 weeks of healing, the callus of nonstabilized fractures compared to stabilized fractures was significantly larger, containing a significantly smaller amount of osseous tissue and a higher amount of cartilaginous tissue. This was associated with a significantly lower biomechanical stiffness during the early phase of healing. However, during the late phase of fracture healing both nonstabilized and stabilized fractures showed a biomechanical stiffness of ∼40%. Of interest, Western blot analyses of callus tissue demonstrated that the expression of proteins related to angiogenesis, bone formation and remodeling, i.e. VEGF, CYR61, BMP-2, BMP-4, Col-2, Col-10, RANKL, OPG, did not differ between nonstabilized and stabilized fractures.Nonstabilized fractures in aged mice show delayed healing and remodeling. This is not caused by an altered protein expression in the callus but rather by the excessive interfragmentary movements.

New cartilaginous tissues in lizards is formed during the regeneration of the tail or after vertebral damage. In order to understand the origin of new cartilaginous cells in the embryo and after injury of adult vertebrae we have studied the distribution of proliferating cartilaginous cells in the vertebral column of embryos and adults of the lizard Anolis lineatopus using autoradiography for H3-thymidine and light and ultrastructural immunocytochemistry for 5BrdU. Proliferating sclerotomal cells initially surround the notochord in a segmental pattern and give rise to the chondrocytes of the vertebral centrum that replace the original chordal cells. Qualitative observations show that proliferating sclerotomal cells dilute the labeling up to 13 days post-injection but a few maintain the labeling as long labeling retention cells and remain in the inter-centra and perichondrium after birth. These cells supply new chondroblasts for post-natal growth of vertebrae but can also proliferate in case of vertebral damage or tail amputation in lizards, a process that sustains tail regeneration. The lack of somitic organization in the regenerating tail impedes the re-formation of a segmental vertebral column that is instead replaced by a continuous cartilaginous tube. It is hypothesized that long labeling retaining cells might represent stem/primordial cells, and that their permanence in the inter-vertebral cartilages and the nearby perichondrium in adult lizards pre-adapt these reptiles to elicit a broad cartilage regeneration in case of injury of the vertebrae.

Introduction Collagen hydrolysate is recognized as a safe nutraceutical, whose combination of amino acids stimulates the synthesis of collagen in the extracellular matrix of cartilage and other tissues. Objective to conduct a systematic review of literature on the action of collagen hydrolysate in bone and cartilaginous tissue and its therapeutic use against osteoporosis and osteoarthritis. Method a study of the PubMed, MEDLINE, LILACS, and SciELO databases was performed. Articles published in English and Portuguese in the period of 1994 to 2014 were considered. Results: the sample comprised nine experimental articles with in vivo (animals and humans) and in vitro (human cells) models, which found that the use of different doses of collagen hydrolysate were associated with the maintenance of bone composition and strength, and the proliferation and cell growth of cartilage. Conclusion hydrolyzed collagen has a positive therapeutic effect on osteoporosis and osteoarthritis with a potential increase in bone mineral density, a protective effect on articular cartilage, and especially in the symptomatic relief of pain. Introdução O colágeno hidrolisado é reconhecido como um nutracêutico seguro, cuja combinação de aminoácidos estimula a síntese de colágeno nas cartilagens e na matriz extracelular de outros tecidos. Objetivo Realizar uma revisão sistemática da literatura sobre a ação do colágeno hidrolisado no tecido ósseo e cartilaginoso e suas finalidades terapêuticas na osteoporose e osteoartrite. Método A pesquisa foi realizada nas bases de dados Pubmed; MEDLINE; LILACS; SciELO. Foram considerados artigos publicados no período de 1994 a 2014, nos idiomas inglês e português. Resultados A amostra final foi composta por nove artigos experimentais com modelos in vivo (animais e humanos) e in vitro (células humanas), que descrevem a utilização de diferentes doses de colágeno hidrolisado associadas à manutenção da composição e resistência óssea e proliferação e crescimento celular da cartilagem. Conclusão O colágeno hidrolisado tem função terapêutica positiva na osteoporose e osteoartrite com potencial aumento da densidade mineral óssea, efeito protetor da cartilagem articular e principalmente no alívio sintomático em quadros de dor.

Highlights • A 62 year old man without any history of trauma presented with progressive dysphonia, dyspnoea, without any dysphagia. • A fibreoptic laryngoscopic examination revealed nodular mass arising at the junction of posterior 1/3rd and middle 1/3rd of left vocal cord it was extending up to arytenoids. • A computed tomography scan of the neck region showed a rounded and circumscribed mass without infiltration of the surrounding tissues. Histological investigation of the lesion revealed the presence of fibroelastic cartilaginous tissue, surrounded by a thin rim of fibrous tissue, with rare hypercellular areas, occasional binucleated cells, slight hyperchromasia, and an irregular nuclear profile. Mitotic activity was absent. • Sub acute and progressive onset of clinical symptoms and histological and radiological findings helps to distinguish the chondrometaplastic nature of this nodule from true laryngeal cartilaginous tumours, such as chondroma and low grade chondrosarcoma. • The recognition of chondrometaplasia is important because of its occasionally troublesome differential diagnosis from true cartilaginous neoplasms of the larynx, such as chondroma and low grade chondrosarcoma., Introduction (Chondrometaplasia of the larynx is a rare disease. We report a case that presented at the otolaryngology department in our institute in 2015.) Presentation of case A 62 year old man without any history of trauma presented with progressive dysphonia, dyspnoea, without any dysphagia. A fibreoptic laryngoscopic examination revealed nodular mass arising at the junction of anterior 1/3rd and posterior 2/3rd of left vocal cord. Discussion A computed tomography scan of the neck region showed a rounded and circumscribed mass without infiltration of the surrounding tissues. Histological investigation of the lesion revealed the presence of fibroelastic cartilaginous tissue, surrounded by a thin rim of fibrous tissue, with rare hypercellular areas, occasional binucleated cells, slight hyperchromasia, and an irregular nuclear profile. Mitotic activity was absent. Conclusion The patient didn’t have history of laryngeal trauma. Subacute and progressive onset of clinical symptoms and histological and radiological findings helps to distinguish the chondrometaplastic nature from true laryngeal cartilaginous tumours, such as chondroma and low grade chondrosarcoma.

Cervical chondrocutaneous branchial remnants (CCBR) are rare benign masses of the neck that arise from anomalies in embryological branchial arch development. They present as a painless, flesh-toned exophytic nodule of the neck. They are most commonly seen on the lower third of the neck, anterior to the sternocleidomastoid muscle. CCBRs are harmless and asymptomatic, but the presence of these lesions in infants should prompt further evaluation for associated anomalies. Histopathologic examination of CCBRs show ectopic cartilaginous tissue with normal overlying epidermis. Treatment includes elective surgical excision. A case of an 18 year old male with a left-sided CCBR is reported.

Background Adult acquired flatfoot deformity (AAFD) is caused by impaired medial ligamentous structures and posterior tibialis tendon dysfunction (PTTD). Although degeneration and trauma could separately cause AAFD, how these factors interact in the pathomechanism of AAFD is unclear. The joint capsule in the medial ankle is considered an important structure, providing passive stability by limiting joint movement. Previous reports on the joint capsule suggest its involvement in pathological changes of the ankle, but because of the high priority placed on the ligaments, few reports address the ankle joint from the joint capsule standpoint. The current study aimed to anatomically examine the medial ankle joint, focusing on the deltoid and spring ligaments in perspective of the joint capsule. Methods We conducted a descriptive anatomical study of 19 embalmed cadavers (mean 82.7 years, range 58 to 99). We included 22 embalmed cadaveric ankles. We detached the joint capsule in 16 ankles from the anterior to posteromedial joint, analyzed the capsular attachments of the ankle and adjacent joints, and measured the widths of the bony attachments. We histologically analyzed the joint capsule using Masson’s trichrome staining in 6 ankles. Results The capsule could be separated as a continuous sheet, including 3 different tissues. The anterior capsule was composed of fatty tissue. Between the medial malleolus and talus, the capsule was strongly connected and was composed of fibrous tissue, normally referred to as the deep deltoid ligament. The tibial attachment formed a steric groove, and the talar side of the attachment formed an elliptical depressed area. On the medial part of the subtalar and talonavicular joints, the capsule covered the joints as cartilaginous tissue, normally referred to as the superomedial ligament of the spring ligament. The outer side of the cartilaginous and fibrous tissue formed the sheath floor of the posterior tibialis tendon. Histological analysis revealed three different tissue types. Conclusions The capsules of the ankle, subtalar, and talonavicular joints could be detached as a continuous sheet. The deltoid and the superomedial ligament of the spring ligaments could be interpreted as a part of the continuous capsule, which had different histological features. Level of evidence Descriptive Laboratory Study.

The aim of this study was to ascertain whether, like many cell types in cartilaginous tissues if type XI collagen was a pericellular component of annulus fibrosus (AF) cells and chondrocytes. Fine fibrillar networks were visualised which were perlecan, HS (MAb 10E4) and type XI collagen positive. Heparitinase-III pre-digestion abolished the type XI collagen and 10E4 localisation in these fibrillar assemblies demonstrating a putative HS mediated interaction which localised the type XI collagen. Type XI collagen was confirmed to be present in the Heparitinase III treated AF monolayer media samples by immunoblotting. Heparitinase-III generated ΔHS stub epitopes throughout these fibrillar networks strongly visualised by MAb 3-G-10. Monolayers of murine hip articular chondrocytes from C57BL/6 and Hspg2 exon 3 null mice also displayed pericellular perlecan localisations, however type XI collagen was only evident in the Wild type mice. Perlecan was also immunolocalised in control and murine knee articular cartilage from the two mouse genotypes subjected to a medial meniscal destabilisation procedure which induces OA. This resulted in a severe depletion of perlecan levels particularly in the perlecan exon 3 null mice and was consistent with OA representing a disease of the pericellular matrix. A model was prepared to explain these observations between the NPP type XI collagen domain and HS chains of perlecan domain-I in the pericellular matrix of AF cells which likely contributed to cellular communication, tissue stabilization and the regulation of extracellular matrix homeostasis.

Background To investigate the incidence of temporomandibular arthropathies diagnosed in a university center and to describe their histopathological characteristics. Material and Methods Temporomandibular arthropathy cases with corresponding slides were selected from an oral and maxillofacial surgical pathology service. Cases of exclusively articular disc disease were not included. Results The mean age was 31.3 years with a predominance of females (69.7%). Of these diagnoses, 53.6% were unilateral condylar hyperplasia, 17.8% were bony ankylosis, 14.3% were degenerative joint disease, 10.7% were osteochondroma, and 3.6% were synovial chondromatosis. Condylar hyperplasia presented as thick fibrocartilage and cartilage nests in the cancellous bone. Bony ankylosis exhibited lamellar bone and nests of chondrocytes. Degenerative joint disease presented as an irregular layer of fibrocartilage with areas of clustered chondrocytes and calcified cartilage. Osteochondroma of the condyle exhibited hyaline cartilage and areas of new bone formation. Synovial chondromatosis presented as immature cartilaginous tissue and randomly arranged chondrocytes. Conclusions The pathological alterations verified in these arthropathies involved diseases that were predominantly proliferative, i.e., unilateral condylar hyperplasia, osteochondroma and synovial chondromatosis of the tumor or pseudotumor type and bony ankylosis associated with callus formation of the reparative type, and less frequent degenerative changes for which the disease is so named. Key words:Temporomandibular joint, pathology, ankylosis, pathology, arthritis, degenerative, osteochondroma, chondromatosis, synovial.

[ES] El cartílago hialino es un tejido conectivo denso con poca capacidad de auto regeneración cuando es afectado por patologías degenerativas. Por lo tanto, la estimulación eléctrica se ha propuesto como una terapia alternativa no invasiva para mejorar la reparación del cartílago hialino. De acuerdo con esto, este trabajo presenta un enfoque computacional y experimental combinado para entender mejor la biología del cartílago hialino y su respuesta a la estimulación eléctrica usando diferentes modelos in vitro. En primer lugar, se ha desarrollado un modelo mecanobiológico para simular el proceso de osificación endocondral. Por otro lado, se ha evaluado el efecto de la estimulación eléctrica sobre el cartílago hialino en tres escenarios diferentes. Inicialmente se ha analizado la proliferación celular y la síntesis de glicosaminoglicanos de condrocitos cultivados en monocapa y estimulados con campos eléctricos. Luego, se ha realizado un análisis histomorfométrico a explantes de condroepífisis que fueron estimulados eléctricamente. Por último, se ha evaluado el efecto de los campos eléctricos sobre la diferenciación condrogénica de células madre mesenquimales cultivadas en hidrogeles. Los resultados indican que la estimulación eléctrica es un estímulo biofísico prometedor, ya que este tipo de estimulación mejora la viabilidad y la proliferación celular, induce cambios morfológicos en los condrocitos, y estimula la síntesis de las principales moléculas que componen el cartílago hialino, tales como SOX-9, glicosaminoglicanos y agrecan. Además, este proyecto es el primer paso hacia la implementación de un estímulo biofísico alternativo que modifica la dinámica celular de los condrocitos de la placa de crecimiento en condiciones ex vivo. Adicionalmente, este estudio resalta el efecto potencial de los campos eléctricos para inducir el proceso de condrogénesis de células madre mesenquimales cultivadas en condiciones basales. En general, la evaluación de la estimulación eléctrica sobre condrocitos, tejidos y andamios es una herramienta útil que puede contribuir al conocimiento actual de las terapias regenerativas enfocadas en la regeneración del cartílago hialino., [CA] El cartílag hialí és un teixit connectiu dens amb poca capacitat d'auto regeneració quan es veu afectat per patologies degeneratives. Per tant, l'estimulació elèctrica s'ha proposat com una teràpia alternativa no invasiva per millorar la reparació del cartílag articular. D'acord amb això, aquest treball presenta un enfoc computacional i experimental combinat per entendre millor la biologia del cartílag hialí i la seva resposta a l'estimulació elèctrica usant diferents models in vitro. En primer lloc, s'ha desenvolupat un model mecanobiològic per simular el procés d'ossificació endocondral. D'altra banda, s'ha avaluat l'efecte de l'estimulació elèctrica sobre el cartílag hialí en tres escenaris diferents. Inicialment s'ha analitzat la proliferació cel·lular i la síntesi de glicosaminoglicans de condròcits cultivats en monocapa i estimulats amb camps elèctrics. Després, s'ha realitzat una anàlisi histomorfomètrica a explants de condroepífisis que van ser estimulats elèctricament. Finalment, s'ha avaluat l'efecte dels camps elèctrics sobre la diferenciació condrogénica de cèl·lules mare mesenquimals cultivades en hidrogels. Els resultats indiquen que l'estimulació elèctrica és un estímul biofîsic prometedor, ja que aquest tipus d'estimulació millora la viabilitat i la proliferació cel·lular, indueix canvis morfològics en els condròcits, i estimula la síntesi de les principals molècules que componen el cartílag hialí, com ara SOX-9, glicosaminoglicans i agrecan. A més, aquest projecte és el primer pas cap a la implementació d'un estímul biofísic alternatiu que modifica la dinàmica cel·lular dels condròcits de la placa de creixement en condicions ex vivo. Addicionalment, aquest estudi ressalta l'efecte potencial dels camps elèctrics per induir el procés de condrogènesi de cèl·lules mare mesenquimals cultivades en condicions basals. En general, l'avaluació de l'estimulació elèctrica sobre condròcits, teixits i scaffolds és una eina útil que pot contribuir al coneixement actual de les teràpies regeneratives enfocades a la regeneració del cartílag hialí., [EN] Hyaline cartilage is a dense connective tissue with low self-healing capacity when is affected by degenerative pathologies. Therefore, electrical stimulation has been proposed as a possible non-invasive alternative therapy to enhance the restoration of the cartilaginous tissue. Accordingly, this work presents a combined computational and experimental approach to understand better the hyaline cartilage biology and its response to electrical stimulation using different in vitro models. On the one hand, a mechanobiological model was developed to simulate the endochondral ossification process. On the other hand, the electrical stimulation on hyaline cartilage was evaluated in three different scenarios. Initially, cell proliferation and glycosaminoglycans synthesis of chondrocytes, cultured in monolayer and stimulated with electric fields, was analyzed. Then, a histomorphometric analysis was performed to chondroepiphysis explants that were electrically stimulated. Finally, the effects of the electric fields on chondrogenic differentiation of mesenchymal stem cells cultured in hydrogels was assessed. The results indicated that electrical stimulation is a promising biophysical stimulus, due to the fact that this type of stimulation enhances the viability and the proliferation of cells, induces morphological changes in the chondrocytes, and stimulates the synthesis of the main molecules that compose the hyaline cartilage, such as SOX-9, glycosaminoglycans and aggrecan. Moreover, this project is the first step towards the implementation of an alternative biophysical stimulus that modifies the cellular dynamics of growth plate chondrocytes in ex vivo conditions. Additionally, this study highlights the potential effect of electric fields to induce the chondrogenesis process of mesenchymal stem cells cultured in basal conditions. Overall, the assessment of electrical stimulation on chondrocytes, tissues and scaffolds is a useful tool that may contribute to the current knowledge of regenerative therapies focused on hyaline cartilage healing., To the financial support from COLCIENCIAS – COLFUTURO through the fellowship No. 647 for national doctorates. To the financial support from COLCIENCIAS through the research grant 712-2015 No. 50457. To the financial support from the Spanish Ministry of Economy and Competitiveness through the MAT2016-76039-C4-1-R project.

Developing biomimetic cartilaginous tissues that support locomotion while maintaining chondrogenic behavior is a major challenge in the tissue engineering field. Specifically, while locomotive forces demand tissues with strong mechanical properties, chondrogenesis requires a soft microenvironment. To address this challenge, 3D cartilage-like tissue is bioprinted using two biomaterials with different mechanical properties: a hard biomaterial to reflect the macromechanical properties of native cartilage, and a soft biomaterial to create a chondrogenic microenvironment. To this end, a hard biomaterial (MPa order compressive modulus) composed of an interpenetrating polymer network (IPN) of polyethylene glycol (PEG) and alginate hydrogel is developed as an extracellular matrix (ECM) with self-healing properties, but low diffusive capacity. Within this bath supplemented with thrombin, fibrinogen containing human mesenchymal stem cell (hMSC) spheroids is bioprinted forming fibrin, as the soft biomaterial (kPa order compressive modulus) to simulate cartilage’s pericellular matrix and allow a fast diffusion of nutrients. The bioprinted hMSC spheroids improve viability and chondrogenic-like behavior without adversely affecting the macromechanical properties of the tissue. Therefore, the ability to print locally soft and cell stimulating microenvironments inside of a mechanically robust hydrogel is demonstrated, thereby uncoupling the micro- and macromechanical properties of the 3D printed tissues such as cartilage.

Recent advancement in cartilage tissue engineering has explored the potential of 3D culture to mimic the in vivo environment of human cartilaginous tissue. Three-dimensional culture using microspheres was described to play a role in driving the differentiation of mesenchymal stem cells to chondrocyte lineage. However, factors such as mechanical agitation on cell chondrogenesis during culture on the microspheres has yet to be elucidated. In this study, we compared the 2D and 3D culture of bone-marrow-derived mesenchymal stem cells (BMSCs) on gelatin microspheres (GMs) in terms of MSC stemness properties, immune-phenotype, multilineage differentiation properties, and proliferation rate. Then, to study the effect of mechanical agitation on chondrogenic differentiation in 3D culture, we cultured BMSCs on GM (BMSCs-GM) in either static or dynamic bioreactor system with two different mediums, i.e., F12: DMEM (1:1) + 10% FBS (FD) and chondrogenic induction medium (CIM). Our results show that BMSCs attached to the GM surface and remained viable in 3D culture. BMSCs-GM proliferated faster and displayed higher stemness properties than BMSCs on a tissue culture plate (BMSCs-TCP). GMs also enhanced the efficiency of in-vitro chondrogenesis of BMSCs, especially in a dynamic culture with higher cell proliferation, RNA expression, and protein expression compared to that in a static culture. To conclude, our results indicate that the 3D culture of BMSCs on gelatin microsphere was superior to 2D culture on a standard tissue culture plate. Furthermore, culturing BMSCs on GM in dynamic culture conditions enhanced their chondrogenic differentiation.

The article presents the results of conducted researches on osteoarthrosis modeling in dogs using the Pond-Nuki surgical method. The method of surgical operation and pereparing of histopreparations is described. The presence of expressive microscopic changes in tissue is described; and macroscopic changes in the joint. Its noted that osteoarthritis of the knee joint of dogs in the articular cartilage of the femur reveals the destruction of the surface layers of the articular cartilage, the disordered location of chondrocytes, the destruction and lysis of the part of chondrocytes, as well as the reduction of the content of glycoproteins in the intercellular substance. The knee osteoarthrosis modeling in dogs using the Pond-Nuki method was performed and the obtained macroscopic and microscopic changes were described. Experimental animals were dogs. Control was provided by dogs who did not receive treatment. The results of comparative histological evaluation of articular cartilage changes in operated and non-operated knee joints in the control group of dogs showed that the histological changes appear only one month after the operation (changes in articular cartilage of operated knee joints were 1.6 ± 0.11, p

978-1-5386-2471-5 ©2018 IEEEThis study aims to evaluate the cartilaginous extracellular matrix (ECM) production in in vitro poly(lacticco-glycolic acid) PLGA-based scaffolds seeded with rabbit chondrocytes. Scaffolds with the size of 7mm (diameter) × 3mm (height) using ratio of 65:35 were formed using solvent-casting and salt leaching method. The scaffolds were divided into four respective groups, 1) PLGA-atelocollagen-fibrin (PAF), 2) PLGA-atelocollagen (PA), 3) PLGA-fibrin (PF), and 4) PLGA (control). Gross morphology of the scaffold was observed for 3 weeks. Microscopy evaluation and histological staining was done using Haematoxylin and Eosin (H&E), Safranin O, Alcian Blue, Toluidine Blue for week 1, 2 and 3, respectively. The production of sulphated glycosaminoglycan (sGAG) was evaluated using Alcian Blue assay. The PAF group presented better cartilaginous appearance compared to other groups. The hybrid scaffold groups showed more ECM secretion indicated by the presence of web-like fibers network substance on the surface as visualized using scanning electron microscope (SEM). The presence of proteoglycan-rich matrix and glycosaminoglycan has been detected in both histological staining and sGAG assay. Based on the findings of this study, PLGA-based hybrid scaffold promoted better cartilaginous tissue formation in vitro.

Tissue engineered cartilage substitutes, which induce the process of endochondral ossification, represent a regenerative strategy for bone defect healing. Such constructs typically consist of multipotent mesenchymal stromal cells (MSCs) forming a cartilage template in vitro, which can be implanted to stimulate bone formation in vivo. The use of MSCs of allogeneic origin could potentially improve the clinical utility of the tissue engineered cartilage constructs in three ways. First, ready-to-use construct availability can speed up the treatment process. Second, MSCs derived and expanded from a single donor could be applied to treat several patients and thus the costs of the medical interventions would decrease. Finally, it would allow more control over the quality of the MSC chondrogenic differentiation. However, even though the envisaged clinical use of allogeneic cell sources for bone regeneration is advantageous, their immunogenicity poses a significant obstacle to their clinical application. The aim of this review is to increase the awareness of the role played by immune cells during endochondral ossification, and in particular during regenerative strategies when the immune response is altered by the presence of implanted biomaterials and/or cells. More specifically, we focus on how this balance between immune response and bone regeneration is affected by the implantation of a cartilaginous tissue engineered construct of allogeneic origin.

Determining the influence of tissue composition on the osmotic swelling stress of articular cartilage and meniscus fibrocartilage is important to enhance our understanding of physiology and disease. This osmotic swelling stress is critical for the load-bearing capability of both tissues and results in part due to the interactions between the negatively charged sulfated glycosaminoglycan (sGAG) chains and the ionic interstitial fluid. Changes in sGAG content, as those occurring during the progression of degenerative joint disease, alter such interactions. Here, we compare the time-varying effects of altered osmotic environments on the confined compression swelling behavior of bovine tissues spanning a range of sGAG concentrations: juvenile articular cartilage, juvenile and adult meniscus, and juvenile cartilage enzymatically degraded to reduce its sGAG content. The transient response to changes in bath conditions was evaluated for explants assigned to one of three compressive offsets (5%, 10%, or 15% strain) and one of three bath conditions (0.1X, 1X, or 10X phosphate-buffered saline). Our results show that relative responses to alterations to the osmotic environment are consistent across native tissues but differ for degraded juvenile cartilage, demonstrating that changes in sGAG do not completely recapitulate the native swelling behaviors. Further, we found a strong correlation between aggregate modulus and sGAG/collagen, as well as between sGAG and collagen contents across native tissue types, suggesting some conservation of composition-function relationships across a range of tissue types with varying sGAG concentrations. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:785-792, 2020.

A perda de tecidos devido a defeitos congênitos, processos patológicos ou traumas estimulou o desenvolvimento da engenharia tecidual com objetivo de reparo ou substituição de tecidos ou órgãos danificados. Devido às suas propriedades elásticas, o tecido cartilaginoso tem sido bastante utilizado em procedimentos reconstrutivos. A utilização deste tecido como biomaterial se dá principalmente pela manutenção das propriedades tridimensionais da matriz, priorizando sustentação estrutural, mecânica e biológica para as células e permitindo remodelamento adequado. O ideal é que se obtenha um biomaterial com características de biocompatibilidade, biofuncionalidade e resistência mecânica. Neste sentido, foram desenvolvidos tratamentos a fim de minimizar possíveis processos inflamatórios e rejeição da biomembrana no receptor. Objetivou-se comparar as alterações histológicas em cartilagens elásticas de orelha externa de bovinos submetidas a diferentes métodos de conservação com tratamento químico por solução alcalina. As amostras passaram por um processo de dissecação e higienização, sendo posteriormente divididas em grupo controle e grupos de tratamentos. Foram avaliados os métodos de conservação com solução supersaturada de sal, solução supersaturada de açúcar, glicerina, formalina e solução alcalina. As amostras foram mantidas em meios de conservação durante 60 dias e em solução alcalina durante 72 horas. Posteriormente passaram por preparação, análise e interpretação em lâminas histológicas. Em cada tratamento foram avaliados parâmetros microestruturais tais como a manutenção de fibras elásticas, substância fundamental amorfa e descelularização. Em comparação aos demais grupos, foi observado que o grupo do tratamento alcalino apresentou maior descelularização, remoção da substância fundamental amorfa e manutenção da estrutura tridimensional das fibras elásticas. Por isso, este grupo foi considerado o método mais efetivo neste estudo. The loss of tissue because of congenital defects, pathological processes or traumas stimulated the development of tissue engineering, with the aim of repairing or replacing damaged tissues or organs. Due to its elastic properties, cartilaginous tissue has been widely used in reconstructive procedures. The use of this tissue as biomaterial mainly aims at maintaining the three-dimensional properties of the matrix, prioritizing structural, mechanical and biological support for the cells and allowing adequate remodeling. The ideal is to obtain a biomaterial with characteristics of biocompatibility, biofunctionality and mechanical resistance. In this sense, treatments were developed in order to minimize possible inflammatory processes and rejection of the biomembrane at the receptor. The aim of this study was to compare the histological changes in elastic cartilages of the external ear of bovines, submitted to different treatments of conservation with chemical treatment by alkaline solution. The samples were cleaned, standardized and divided into control group and treatment groups. The conservation methods were evaluated with supersaturated salt solution, supersaturated sugar solution, glycerine, formalin and alkaline solution. The samples were maintained in storage media for 60 days and in alkaline solution for 72 hours. After, they underwent preparation, analysis and interpretation on histological slides. In each treatment were evaluated microstructureal parameters, as the maintenance of elastic fibers, fundamental amorphous substance and decellularization. When comparing to the other groups, we verified that the cartilages treated in alkaline solution had better decellularization rate, fundamental amorphous substance removal and mantainance of elastic fibers tridimensional structure. For this reason, this group was considered the most effective method in this study.

International audience; Osteogenesis imperfecta (OI) is a rare heritable skeletal dysplasia mainly caused by type I collagen abnormalities and characterized by bone fragility and susceptibility to fracture. Over 85% of the patients carry dominant mutations in the genes encoding for the collagen type I α1 and α2 chains. Failure of bone union and/or presence of hyperplastic callus formation after fracture were described in OI patients. Here we used the Col1a2+/G610C mouse, carrying in heterozygosis the α2(I)-G610C substitution, to investigate the healing process of an OI bone. Tibiae of 2-month-old Col1a2+/G610C and wild-type littermates were fractured and the healing process was followed at 2, 3, and 5 weeks after injury from fibrous cartilaginous tissue formation to its bone replacement by radiography, micro-computed tomography (µCT), histological and biochemical approaches. In presence of similar fracture types, in Col1a2+/G610C mice an impairment in the early phase of bone repair was detected compared to wild-type littermates. Smaller callus area, callus bone surface, and bone volume associated to higher percentage of cartilage and lower percentage of bone were evident in Col1a2+/G610C at 2 weeks post fracture (wpf) and no change by 3 wpf. Furthermore, the biochemical analysis of collagen extracted from callus 2 wpf revealed in mutants an increased amount of type II collagen, typical of cartilage, with respect to type I, characteristic of bone. This is the first report of a delay in OI bone fracture repair at the modeling phase.

A useful technique for culturing cells in a self-assembling nanofiber three-dimensional (3D) scaffold is described. This culture system recreates an environment that closely mimics the structural features of non-polarized tissue. Furthermore, the particular intrinsic nanofiber structure of the scaffold makes it transparent to visual light, which allows for easy visualization of the sample under microscopy. This advantage was largely used to study cell migration, organization, proliferation, and differentiation and thus any development of their particular cellular function by staining with specific dyes or probes. Furthermore, in this work, we describe the good performance of this system to easily study the redifferentiation of expanded human articular chondrocytes into cartilaginous tissue. Cells were encapsulated into self-assembling peptide scaffolds and cultured under specific conditions to promote chondrogenesis. Three-dimensional cultures showed good viability during the 4 weeks of the experiment. As expected, samples cultured with chondrogenic inducers (compared to non-induced controls) stained strongly positive for toluidine blue (which stains glycosaminoglycans (GAGs) that are highly present in cartilage extracellular matrix) and expressed specific molecular markers, including collagen type I, II and X, according to Western Blot analysis. This protocol is easy to perform and can be used at research laboratories, industries and for educational purposes in laboratory courses.

the photothermal effect of nanoparticles of oxide bronzes impregnated in the porcine cartilage rib tissue during laser heating was studied. A comparison of the magnitude of the photothermal effect showed that more high value of the effect of laser radiation on the cartilaginous tissue is demonstrated by the samples impregnated with molybdenum oxide bronzes nanoparticles.

Animal models commonly serve as a bridge between in vitro experiments and clinical applications; however, few physiological processes in adult animals are sufficient to serve as proof-of-concept models for cartilage regeneration. Intriguingly, some rodents, such as young adult mice, undergo physiological connective tissue modifications to birth canal elements such as the pubic symphysis during pregnancy; therefore, we investigated whether the differential expression of cartilage differentiation markers is associated with cartilaginous tissue morphological modifications during these changes. Our results showed that osteochondral progenitor cells expressing Runx2, Sox9, Col2a1 and Dcx at the non-pregnant pubic symphysis proliferated and differentiated throughout pregnancy, giving rise to a complex osteoligamentous junction that attached the interpubic ligament to the pubic bones until labour occurred. After delivery, the recovery of pubic symphysis cartilaginous tissues was improved by the time-dependent expression of these chondrocytic lineage markers at the osteoligamentous junction. This process potentially recapitulates embryologic chondrocytic differentiation to successfully recover hyaline cartilaginous pads at 10 days postpartum. Therefore, we propose that this physiological phenomenon represents a proof-of-concept model for investigating the mechanisms involved in cartilage restoration in adult animals.

To newly describe the clinical and histopathological characteristics of epibulbar complex cartilaginous choristoma incidentally observed in a series of pterygium excision patients. Noncomparative case series with chart review of 8 patients. During a 4-year period, we identified 8 cases of conventional unilateral nasal subpterygial cartilaginous choristoma in 1799 pterygium patients and analyzed their clinicopathological features. The incidence rate of this entity is 0.44% in pterygium patients. All of the cartilaginous choristomas were buried deep in the caruncle, covered by the pterygium, and embedded in tenon facia tissue. Its clinicopathological characteristics include hyaline cartilaginous tissue that is surrounded by fibrous connective tissue and smooth muscle bundles. S-100 protein-staining specifically revealed chondrocytes embedded within chondroid matrix. Epibulbar complex cartilaginous choristoma covered by pterygia and predominantly observed in the older population is rare. The lesions were buried deep in the caruncle, covered by the pterygium and embedded in tenon fascia tissue. These findings are inconsistent with those in previous reports.

Articular cartilage damage represents one of the most perplexing clinical problems of musculoskeletal therapeutics due to its limited self-repair and regenerative capabilities. In this study, 3D porous silk fibroin scaffolds derived from non-mulberry muga silkworm Antheraea assamensis were fabricated and examined for their ability to support cartilage tissue engineering. Additionally, Bombyx mori and Philosamia ricini silk fibroin scaffolds were utilized for comparative studies. Herein, the fabricated scaffolds were thoroughly characterized and compared for cartilaginous tissue formation within the silk fibroin scaffolds seeded with primary porcine chondrocytes and cultured in vitro for 2 weeks. Surface morphology and structural conformation studies revealed the highly interconnected porous structure (pore size 80–150 μm) with enhanced stability within their structure. The fabricated scaffolds demonstrated improved mechanical properties and were followed-up with sequential experiments to reveal improved thermal and degradation properties. Silk fibroin scaffolds of A. assamensis and P. ricini supported better chondrocyte attachment and proliferation as indicated by metabolic activities and fluorescence microscopic studies. Biochemical analysis demonstrated significantly higher production of sulphated glycosaminoglycans (sGAGs) and type II collagen in A. assamensis silk fibroin scaffolds followed by P. ricini and B. mori scaffolds (p < 0.001). Furthermore, histochemistry and immunohistochemical studies indicated enhanced accumulation of sGAGs and expression of collagen II. Moreover, the scaffolds in a subcutaneous model of rat demonstrated in vivo biocompatibility after 8 weeks of implantation. Taken together, these results demonstrate the positive attributes from the non-mulberry silk fibroin scaffold of A. assamensis and suggest its suitability as a promising scaffold for chondrocyte based cartilage repair.

There is a growing demand for the development of experimental strategies for efficient articular cartilage repair. Current tissue engineering-based regenerative strategies make use of human mesenchymal stromal cells (hMSCs). However, when implanted in a cartilage defect, control of hMSCs differentiation towards the chondrogenic lineage remains a significant challenge. We have recently demonstrated that silencing the anti-chondrogenic regulator microRNA-221 (miR-221) was highly effective in promoting in vitro chondrogenesis of monolayered hMSCs in the absence of the chondrogenic induction factor TGF-β. Here we investigated the feasibility of this approach first in conventional 3D pellet culture and then in an in vivo model. In pellet cultures, we observed that miR-221 silencing was sufficient to drive hMSCs towards chondrogenic differentiation in the absence of TGF-β. In vivo, the potential of miR-221 silenced hMSCs was investigated by first encapsulating the cells in alginate and then by filling a cartilage defect in an osteochondral biopsy. After implanting the biopsy subcutaneously in nude mice, we found that silencing of miR-221 strongly enhanced in vivo cartilage repair compared to the control conditions (untreated hMSCs or alginate-only). Notably, miR-221 silenced hMSCs generated in vivo a cartilaginous tissue with no sign of collagen type X deposition, a marker of undesired hypertrophic maturation. Altogether our data indicate that silencing miR-221 has a pro-chondrogenic role in vivo, opening new possibilities for the use of hMSCs in cartilage tissue engineering. This article is protected by copyright. All rights reserved.

Purpose The purpose of this study is to investigate whether healing potential of the femoral cartilage differs according to the site of injury in a rabbit, and whether poor potential of the cartilage repair correlates with the injured site which is not in contact with acetabulum. Furthermore, the efficacy of intraarticular injection of hyaluronic acid into the hip for the cartilage with lower healing potential was evaluated. Methods Male Japanese white rabbits were used in this study. Via the posterolateral approach, the articular capsule was incised and a 4 × 4 mm chondral defect was made at the load-bearing area (group A) or at head-neck junction (group B), and intraarticular injection of hyaluronic acid was performed to the group B model (group C). Results In group A, histological evaluation at 8 weeks revealed that the chondral defect was filled with cartilaginous tissue. However, in group B, the chondral defect was not filled with any tissue and subchondral bone was exposed. In group C, the defect was filled with synovial-like tissue, and smooth surface was reacquired macroscopically. According to the ICRS score, significant differences were detected between group A and group B, group A and group C, and group B and group C. There were no differences in the radiographic findings among the 3 groups. Conclusions The cartilage at head-neck junction of the femoral head had poorer healing potential than that at load-bearing area. Administration of HA could be promising for preventing progression of cartilage degeneration even at head-neck junction.

The keratocystic odontogenic tumor (KCOT), formerly known as odontogenic keratocyst, is a benign developmental odontogenic tumor with many distinguishing clinical and histologic features. Hard tissue deposits, which usually take the form of dystrophic calcifications, cartilaginous tissue, or dentinoid, are uncommon findings in the connective tissue capsule of the KCOT. We report a case of a 33-year-old female with KCOT showing osseous tissue and calcified deposits close to its epithelial lining, which is an extremely rare occurrence. A brief review on the reported prevalence of hard tissue deposits in KCOTs and possible mechanisms that has been implicated in mineralization and bone formation has been discussed.

Novel strategies are urgently required to facilitate regeneration of entire bones lost due to trauma or disease. In this study, we present a novel framework for the regeneration of whole bones by tissue engineering anatomically shaped hypertrophic cartilaginous grafts in vitro that subsequently drive endochondral bone formation in vivo. To realize this, we first fabricated molds from digitized images to generate mesenchymal stem cell-laden alginate hydrogels in the shape of different bones (the temporomandibular joint [TMJ] condyle and the distal phalanx). These constructs could be stimulated in vitro to generate anatomically shaped hypertrophic cartilaginous tissues that had begun to calcify around their periphery. Constructs were then formed into the shape of the distal phalanx to create the hypertrophic precursor of the osseous component of an engineered long bone. A layer of cartilage engineered through self-assembly of chondrocytes served as the articular surface of these constructs. Following chondrogenic priming and subcutaneous implantation, the hypertrophic phase of the engineered phalanx underwent endochondral ossification, leading to the generation of a vascularized bone integrated with a covering layer of stable articular cartilage. Furthermore, spatial bone deposition within the construct could be modulated by altering the architecture of the osseous component before implantation. These findings open up new horizons to whole limb regeneration by recapitulating key aspects of normal bone development.

Injury to the articular cartilage occurs commonly in the general population and undergoes minimal spontaneous healing. Traditional methods of cartilage repair provide no long-term cure and are significant causes of morbidity. For this reason, stem cell therapies have recently been investigated for their ability to regenerate cartilage, and the results have been promising. Since the discovery that adipose tissue is a major source of mesenchymal stem cells in 2001, scientists have been studying the use of adipose-derived stem cells (ASCs) for the treatment of various disorders including lesions of the articular cartilage. ASCs hold several advantages over autologous chondrocytes for cartilage repair, including but not limited to their anti-inflammatory effects, their multi-lineage differentiation potential, and their ability to form new cartilage in a defect. Whereas several investigations have been made in in vitro and animal models, there have been surprisingly little clinical studies on the intra-articular use of adipose-derived stem cells, despite their first isolation about a decade and a half ago. The few studies that have been conducted are encouraging. With approval for various stem cell therapies on the horizon, this review seeks to update the clinician and the researcher on the current state-of-the-art use of adipose-derived stem cells for the treatment of cartilage disorders and the regenerative engineering of cartilaginous tissue.

Regeneration of cartilaginous tissues is limited in mammals but it occurs with variable extension in lizards (reptiles), including in their vertebrae. The ability of lizard vertebrae to regenerate cartilaginous tissue that is later replaced with bone has been analyzed using tritiated thymidine autoradiography and 5BrdU immunocytochemistry after single pulse or prolonged-pulse and chase experiments. The massive cartilage regeneration that can restore broad vertebral regions and gives rise to a long cartilaginous tube in the regenerating tail, depends from the permanence of some chondrogenic cells within adult vertebrae. Few cells that retain tritiated thymidine or 5-bromodeoxy-uridine for over 35 days are mainly localized in the inter-vertebral cartilage and in sparse chondrogenic regions of the neural arch of the vertebrae, suggesting that they are putative resident stem/progenitor cells. The study supports previous hypothesis indicating that the massive regeneration of the cartilaginous tissue in damaged vertebrae and in the regenerating tail of lizards derive from resident stem cells mainly present in the cartilaginous areas of the vertebrae including in the perichondrium that are retained in adult lizards as growing centers for most of their lifetime.

Purpose: To review the literature on tubulointerstitial nephritis and uveitis (TINU) syndrome, and to report a case of a patient with relapsing polychondritis (RP) and TINU syndrome. Method: TINU syndrome is a rare oculorenal inflammatory disorder. It is more common in young women with autoimmune conditions, infections, systemic disease, and previous use of medications. We report the case of a 62-year-old woman with relapsing polychondritis and a 2-year history of acute, recurrent, asymmetric, bilateral, anterior, non-granulomatous uveitis accompanied by tubulointerstitial nephritis. Results: The patient was diagnosed with TINU syndrome associated with relapsing polychondritis. No cases of this association have been reported in the literature. The clinical features of TINU syndrome are discussed based on the published works. Conclusions: TINU is an uncommon syndrome; only about 200 cases have been reported in the literature related to infections, systemic disease, and previous use of medications such as antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs). We found that it can be associated with relapsing polychondritis; therefore, it is important to investigate symptoms of this disease since TINU syndrome can co-exist with it. © 2015 Taylor and Francis Group, LLC.

A novel tissue-engineered trachea was developed with appropriate mechanical behavior and substantial regeneration of tracheal cartilage. We designed hollow bellows scaffold as a framework of a tissue-engineered trachea and demonstrated a reliable method for three-dimensional (3D) printing of monolithic bellows scaffold. We also functionalized gelatin sponge to allow sustained release of TGF-β1 for stimulating tracheal cartilage regeneration and confirmed that functionalized gelatin sponge induces cartilaginous tissue formation in vitro. A tissue-engineered trachea was then created by assembling chondrocytes-seeded functionalized gelatin sponges into the grooves of bellows scaffold and it showed very similar mechanical behavior to that of native trachea along with substantial regeneration of tracheal cartilage in vivo. The tissue-engineered trachea developed here represents a novel concept of tracheal substitute with appropriate mechanical behavior similar to native trachea for use in reconstruction of tracheal stenosis.

During embryogenesis vertebral segmentation is initiated by sclerotomal cell migration and condensation around the notochord, forming anlagen of vertebral bodies and intervertebral discs. The factors that govern the segmentation are not clear. Previous research demonstrated that mutations in growth differentiation factor 6 resulted in congenital vertebral fusion, suggesting this factor plays a role in development of vertebral column. In this study, we detected expression and localization of growth differentiation factor 6 in human fetal spinal column, especially in the period of early ossification of vertebrae and the developing intervertebral discs. The extracellular matrix proteins were also examined. Results showed that high levels of growth differentiation factor 6 were expressed in the nucleus pulposus of intervertebral discs and the hypertrophic chondrocytes adjacent to the ossification centre in vertebral bodies, where strong expression of proteoglycan and collagens was also detected. As fetal age increased, the expression of growth differentiation factor 6 was decreased correspondingly with the progress of ossification in vertebral bodies and restricted to cartilaginous regions. This expression pattern and the genetic link to vertebral fusion suggest that growth differentiation factor 6 may play an important role in suppression of ossification to ensure proper vertebral segmentation during spinal development. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:279–289, 2016.

Near-infrared (NIR) Raman microprobe spectroscopy has been applied to the non-invasive characterization of the biochemical structure of extracellular matrix in articular cartilage, a step forward along the path of in vivo diagnostic application of chondropathy. In most studies handling ex vivo cartilage specimens, formalin fixation or freeze-thaw treatments have been applied in order to stabilize tissue and cell constituents prior to spectroscopic measurements. However, these pre-processing manipulations might significantly affect certain target bands of the cartilage spectra, thus introducing biases in the characterizations, and potentially leading to data misinterpretation. In this study, we evaluated how formalin fixing and freeze-thaw processes affect Raman spectra from human femur cartilage. Healthy cartilage specimens were fixed/stored either in a 10% neutral buffered formalin solution or in a deep freezer set at −80 °C. The results of this study show that formalin fixation significantly affects the NIR Raman spectra of cartilage specimens due to concurrent formalin absorption and water dehydration within both collagen and glycosaminoglycan macromolecules. Water dehydration was also confirmed in the amide I structure in the frozen-thawed specimen, but to a much lesser extent. Furthermore, soaking the tissues in phosphate-buffered saline solution minimized the storage-induced Raman artifacts, but its immersion had limited effectiveness in formalin-fixed specimens, predominantly due to an overlap of signals from the formalin liquid (i.e. emitting at 1046 and 1492 cm−1). Therefore, to provide a highly accurate biochemical evaluation of extracellular matrix using NIR Raman spectroscopy, freeze-thaw processes are more suitable for ex vivo samples of human cartilage than formalin fixation. Copyright © 2015 John Wiley & Sons, Ltd.

Aim To compare the incorporation, growth, and chondrogenic potential of bone marrow (BM) and adipose tissue (AT) mesenchymal stem cells (MSCs) in scaffolds used for cartilage repair. Methods Human BM and AT MSCs were isolated, culture expanded, and characterised using standard protocols, then seeded into 2 different scaffolds, Chondro-Gide or Alpha Chondro Shield. Cell adhesion, incorporation, and viable cell growth were assessed microscopically and following calcein AM/ethidium homodimer (Live/Dead) staining. Cell-seeded scaffolds were treated with chondrogenic inducers for 28 days. Extracellular matrix deposition and soluble glycosaminoglycan (GAG) release into the culture medium was measured at day 28 by histology/immunohistochemistry and dimethylmethylene blue assay, respectively. Results A greater number of viable MSCs from either source adhered and incorporated into Chondro-Gide than into Alpha Chondro Shield. In both cell scaffolds, this incorporation represented less than 2% of the cells that were seeded. There was a marked proliferation of BM MSCs, but not AT MSCs, in Chondro-Gide. MSCs from both sources underwent chondrogenic differentiation following induction. However, cartilaginous extracellular matrix deposition was most marked in Chondro-Gide seeded with BM MSCs. Soluble GAG secretion increased in chondrogenic versus control conditions. There was no marked difference in GAG secretion by MSCs from either cell source. Conclusion Chondro-Gide and Alpha Chondro Shield were permissive to the incorporation and chondrogenic differentiation of human BM and AT MSCs. Chondro-Gide seeded with BM MSCs demonstrated the greatest increase in MSC number and deposition of a cartilaginous tissue.

In the experiment on the 36 mature rats, the peculiarities of morphological disorders in the lower jaw of rats under the influence of salts of chromium, lead, zinc, iron, copper, and manganese are showed. Profound morphological changes in bone and cartilaginous tissues of lower jaw are followed by disorders of bone mineral content. The importance of the S100 protein in morphological changes in bone and cartilaginous tissues under the influence of heavy metal salts is shown.

During postnatal joint development, progenitor cells that reside in the superficial region of articular cartilage first drive the rapid growth of the tissue and later help direct the formation of mature hyaline cartilage. These developmental processes may provide directions for the optimal structuring of co-cultured chondrocytes (CCs) and multipotent stromal/stem cells (MSCs) required for engineering cartilaginous tissues. The objective of this study was to engineer cartilage grafts by recapitulating aspects of joint development where a population of superficial progenitor cells drives the development of the tissue. To this end, MSCs were either self-assembled on top of CC-laden agarose gels (structured co-culture) or were mixed with CCs before being embedded in an agarose hydrogel (mixed co-culture). Porcine infrapatellar fat pad-derived stem cells (FPSCs) and bone marrow-derived MSCs (BMSCs) were used as sources of progenitor cells. The DNA, sGAG and collagen content of a mixed co-culture of FPSCs and CCs was found to be lower than the combined content of two control hydrogels seeded with CCs and FPSCs only. In contrast, a mixed co-culture of BMSCs and CCs led to increased proliferation and sGAG and collagen accumulation. Of note was the finding that a structured co-culture, at the appropriate cell density, led to greater sGAG accumulation than a mixed co-culture for both MSC sources. In conclusion, assembling MSCs onto CC-laden hydrogels dramatically enhances the development of the engineered tissue, with the superficial layer of progenitor cells driving CC proliferation and cartilage ECM production, mimicking certain aspects of developing cartilage. Copyright © 2015 John Wiley & Sons, Ltd.

Angioedema, the rapid swelling of under-skin tissue, is typically triggered by complex biochemical processes that disrupt an original steady state filtration of liquid through the tissue. Swelling stabilizes once a new steady state is achieved in which the tissue has significantly increased liquid content. These processes are controlled by events at the molecular to the cellular length scale. For describing consequences at organ level length scales it is useful to invoke consolidated continuum mechanics treatments within a generalized hyperelastic framework. We describe the challenges associated with such modeling and demonstrate their use in the context of tracheal angioedema. The trachea is modeled as a two layered cylindrical tube. The inner layer and outer layer represent the soft mucosal tissue and the stiffer cartilaginous tissue respectively. Axially oriented fibers contribute anisotropy to the inner layer, and the swelling is largely confined to this layer. A boundary value problem is formulated; existence and uniqueness is verified. Numerical solutions track airway constriction as a function of mucosal swelling.

The micro-anatomical changes associated with lordotic and kyphotic vertebral curvatures (VC) in juvenile and adult Senegalese sole Solea senegalensis are described. In addition, it is demonstrated that the tissue and cellular structures of individual vertebrae can be severely affected. Two main conformations were found in deformed juvenile specimens: flattened vertebrae with dorso-ventral compression and trapezoidal vertebrae forming concave and convex sides under compressive and tensile stresses. Histological analyses revealed the occurrence of an ectopic cartilaginous tissue within the acellular bone, both in juveniles and adults, possibly to cope with altered mechanical stress in deformed vertebrae. The results suggest that the alteration in loading to which curved vertebral columns are subjected might trigger vertebral reshaping and differentiation of cells towards this ectopic tissue. In addition, mesenchymal cells appear to play an important role in its formation. It is here proposed that the acellular bone of S. senegalensis is capable of adaptively responding to altered loading regimes at the structural level by reshaping vertebrae and at the micro-anatomical level by recruiting chondrocyte-like cells to areas of altered mechanical stress.

The development of biologically and mechanically competent hydrogels is a prerequisite in cartilage engineering. We recently demonstrated that a marine exopolysaccharide, GY785, stimulates the in vitro chondrogenesis of adipose stromal cells. In the present study, we thus hypothesized that enriching our silated hydroxypropyl methylcellulose hydrogel (Si-HPMC) with GY785 might offer new prospects in the development of scaffolds for cartilage regeneration. The interaction properties of GY785 with growth factors was tested by surface plasmon resonance (SPR). The biocompatibility of Si-HPMC/GY785 towards rabbit articular chondrocytes (RACs) and its ability to maintain and recover a chondrocytic phenotype were then evaluated in vitro by MTS assay, cell counting and qRT-PCR. Finally, we evaluated the potential of Si-HPMC/GY785 associated with RACs to form cartilaginous tissue in vivo by transplantation into the subcutis of nude mice for 3 weeks. Our SPR data indicated that GY785 was able to physically interact with BMP-2 and TGFβ. Our analyses also showed that three-dimensionally (3D)-cultured RACs into Si-HPMC/GY785 strongly expressed type II collagen (COL2) and aggrecan transcripts when compared to Si-HPMC alone. In addition, RACs also produced large amounts of extracellular matrix (ECM) containing glycosaminoglycans (GAG) and COL2. When dedifferentiated RACs were replaced in 3D in Si-HPMC/GY785, the expressions of COL2 and aggrecan transcripts were recovered and that of type I collagen decreased. Immunohistological analyses of Si-HPMC/GY785 constructs transplanted into nude mice revealed the production of a cartilage-like extracellular matrix (ECM) containing high amounts of GAG and COL2. These results indicate that GY785-enriched Si-HPMC appears to be a promising hydrogel for cartilage tissue engineering. Copyright © 2015 John Wiley & Sons, Ltd.