The Effect of the Overexpression or Addition of IGF1 and FGF2 in Human Chondrocytes Included in a Fibrin Matrix and Cultivated in a Dynamic Environment.

Hyaline cartilage is a highly specialized tissue. When injured, its repair capacity is low, which results in the massive destruction of the articular surface. Using tissue engineering and genetic engineering techniques, it is possible to provide a suitable microenvironment providing chondrocyte growth factors involved in the development of hyaline cartilage proteins, as well as cell proliferation and differentiation. Our aim was to stimulate the synthesis of an extracellular matrix via the chondrocytes included in a fibrin matrix through the addition or overexpression of IGF1 and/or FGF2, while maintaining a constant agitation of the culture medium. Collagen type II and glycosaminoglycans increased during the entire incubation time. In contrast, collagen type I decreased its expression under the same culture conditions, transfecting or supplementing growth factors to chondrocytes. However, chondrocytes that were not transfected or supplemented showed a general increase in the proteins analyzed in this study. The presence of IGF1 and FGF2 increased the protein synthesis of the hyaline cartilage, regardless of which one was the source of growth factors. Continuous agitation using the spinner flask allows for the adequate nutrition of chondrocytes included in the fibrin matrix. However, they require growth factors to up-regulate or down-regulate collagenous proteins.

Down-regulation of long noncoding RNA HOXA11-AS nullifies the impact of microRNA-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis.

OBJECTIVES: This study was directed towards exploring the impacts of lncRNA HOXA11-AS-mediated microRNA (miR)-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis (OA). METHODS: The articular cartilages were provided by OA patients who received total knee arthroplasty, and Human Chondrocyte (HC)-OA (HCOA) was also attained. The miR-506-3p and HOXA11-AS expressions in articular cartilages from OA patients and HCOA cells were analyzed via qPCR. After gain- and loss-of-function assays in HCOA cells, MTT assay and flow cytometry (FC) were used for assessing cell viability and apoptosis, accordingly. The levels of PIK3CA, AKT, and mTOR as well as AKT and mTOR phosphorylation levels assessed using western blotting (WB). The targeting correlation of HOXA11-AS and miR-506-3p as well as miR-506-3p and PIK3CA was assessed through Dual-Luciferase Reporter gene Assay (DLRA). RESULT: The articular cartilages from OA patients and Human Chondrocyte (HC)-OA (HCOA) cells showed increased HOXA11-AS and decreased miR-506-3p. Mechanistically, HOXA11-AS was capable of binding to miR-506-3p to increase PIK3CA, the target gene of miR-506-3p. miR-506-3p suppression facilitated HCOA cell proliferation and reduced their apoptosis, which was nullified by further silencing HOXA11-AS or silencing PIK3CA. The down-regulation of HOXA11-AS disrupted the PI3K/AKT/mTOR pathway, which was counteracted by further miR-506-3p inhibition. CONCLUSION: The silencing of HOXA11-AS might block the PI3K/AKT/mTOR pathway through miR-506-3p up-regulation, thereby restricting HCOA cell proliferation and provoking apoptosis.

Tanshinone IIA alleviates IL-1ß-induced chondrocyte apoptosis and inflammation by regulating FBXO11 expression.

OBJECTIVE: This study explored the pharmacological mechanism of Tanshinone IIA (TAN IIA) in the treatment of Osteoarthritis (OA), which provided a certain reference for further research and clinical application of Tan IIA in OA. METHODS: CHON-001 cells were stimulated with 10 µg/mL IL-1ß for 48 h and treated with 10 µM TAN IIA for 48 h. Cellular viability and apoptosis were evaluated by CCK-8 assay and flow cytometry, and Cleaved caspase-3 was measured by Immunoblot assay and RT-qPCR. TNF-α, IL-6, and iNOS in CHON-001 cells were determined by RT-qPCR and ELISA. To further verify the effect of TAN IIA on OA, a rat model of OA in vivo was established by right anterior cruciate ligament transection. TAN IIA was administered at 50 mg/kg or 150 mg/kg for 7 weeks. The degree of cartilage destruction in OA rats was observed by TUNEL and HE staining. Cleaved caspase-3 and FBXO11 were measured by immunohistochemical staining, RT-qPCR, and Immunoblot. TNF-α, IL-6, and iNOS in chondrocytes of OA rats were detected by ELISA. RESULTS: IL-1ß stimulated CHON-001 cell apoptosis and inflammation, and TAN IIA had anti-apoptosis and anti-inflammatory effects on IL-1ß-regulated CHON-001 cells. TAN IIA down-regulated FBXO11 and inhibited PI3K/AKT and NF-κB pathways, thereby alleviating apoptotic and inflammatory reactions in CHON-001 cells under IL-1ß treatment. Moreover, TAN IIA treatment improved chondrocyte apoptosis and inflammations in OA rats. CONCLUSION: TAN IIA inhibits PI3K/Akt and NF-κB pathways by down-regulating FBXO11 expression, alleviates chondrocyte apoptosis and inflammation, and delays the progression of OA.

Hydrogel Based on Chitosan/Gelatin/Poly(Vinyl Alcohol) for In Vitro Human Auricular Chondrocyte Culture.

Three-dimensional (3D) hydrogels provide tissue-like complexities and allow for the spatial orientation of cells, leading to more realistic cellular responses in pathophysiological environments. There is a growing interest in developing multifunctional hydrogels using ternary mixtures for biomedical applications. This study examined the biocompatibility and suitability of human auricular chondrocytes from microtia cultured onto steam-sterilized 3D Chitosan/Gelatin/Poly(Vinyl Alcohol) (CS/Gel/PVA) hydrogels as scaffolds for tissue engineering applications. Hydrogels were prepared in a polymer ratio (1:1:1) through freezing/thawing and freeze-drying and were sterilized by autoclaving. The macrostructure of the resulting hydrogels was investigated by scanning electron microscopy (SEM), showing a heterogeneous macroporous structure with a pore size between 50 and 500 µm. Fourier-transform infrared (FTIR) spectra showed that the three polymers interacted through hydrogen bonding between the amino and hydroxyl moieties. The profile of amino acids present in the gelatin and the hydrogel was determined by ultra-performance liquid chromatography (UPLC), suggesting that the majority of amino acids interacted during the formation of the hydrogel. The cytocompatibility, viability, cell growth and formation of extracellular matrix (ECM) proteins were evaluated to demonstrate the suitability and functionality of the 3D hydrogels for the culture of auricular chondrocytes. The cytocompatibility of the 3D hydrogels was confirmed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reaching 100% viability after 72 h. Chondrocyte viability showed a high affinity of chondrocytes for the hydrogel after 14 days, using the Live/Dead assay. The chondrocyte attachment onto the 3D hydrogels and the formation of an ECM were observed using SEM. Immunofluorescence confirmed the expression of elastin, aggrecan and type II collagen, three of the main components found in an elastic cartilage extracellular matrix. These results demonstrate the suitability and functionality of a CS/Gel/PVA hydrogel as a 3D support for the auricular chondrocytes culture, suggesting that these hydrogels are a potential biomaterial for cartilage tissue engineering applications, aimed at the regeneration of elastic cartilage.

Down-regulation of long noncoding RNA HOXA11-AS nullifies the impact of microRNA-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis

Abstract Objectives This study was directed towards exploring the impacts of lncRNA HOXA11-AS-mediated microRNA (miR)-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis (OA). Methods The articular cartilages were provided by OA patients who received total knee arthroplasty, and Human Chondrocyte (HC)-OA (HC-OA) was also attained. The miR-506-3p and HOXA11-AS expressions in articular cartilages from OA patients and HC-OA cells were analyzed via qPCR. After gain- and loss-of-function assays in HC-OA cells, MTT assay and flow cytometry (FC) were used for assessing cell viability and apoptosis, accordingly. The levels of PIK3CA, AKT, and mTOR as well as AKT and mTOR phosphorylation levels assessed using western blotting (WB). The targeting correlation of HOXA11-AS and miR-506-3p as well as miR-506-3p and PIK3CA was assessed through Dual-Luciferase Reporter gene Assay (DLRA). Result The articular cartilages from OA patients and Human Chondrocyte (HC)-OA (HC-OA) cells showed increased HOXA11-AS and decreased miR-506-3p. Mechanistically, HOXA11-AS was capable of binding to miR-506-3p to increase PIK3CA, the target gene of miR-506-3p. miR-506-3p suppression facilitated HC-OA cell proliferation and reduced their apoptosis, which was nullified by further silencing HOXA11-AS or silencing PIK3CA. The down-regulation of HOXA11-AS disrupted the PI3K/AKT/mTOR pathway, which was counteracted by further miR-506-3p inhibition. Conclusion The silencing of HOXA11-AS might block the PI3K/AKT/mTOR pathway through miR-506-3p up-regulation, thereby restricting HC-OA cell proliferation and provoking apoptosis.

Tanshinone IIA alleviates IL-1β-induced chondrocyte apoptosis and inflammation by regulating FBXO11 expression

Abstract Objective This study explored the pharmacological mechanism of Tanshinone IIA (TAN IIA) in the treatment of Osteoarthritis (OA), which provided a certain reference for further research and clinical application of Tan IIA in OA. Methods CHON-001 cells were stimulated with 10 μg/mL IL-1β for 48 h and treated with 10 μM TAN IIA for 48 h. Cellular viability and apoptosis were evaluated by CCK-8 assay and flow cytometry, and Cleaved caspase-3 was measured by Immunoblot assay and RT-qPCR. TNF-α, IL-6, and iNOS in CHON-001 cells were determined by RT-qPCR and ELISA. To further verify the effect of TAN IIA on OA, a rat model of OA in vivo was established by right anterior cruciate ligament transection. TAN IIA was administered at 50 mg/kg or 150 mg/kg for 7 weeks. The degree of cartilage destruction in OA rats was observed by TUNEL and HE staining. Cleaved caspase-3 and FBXO11 were measured by immunohistochemical staining, RT-qPCR, and Immunoblot. TNF-α, IL-6, and iNOS in chondrocytes of OA rats were detected by ELISA. Results IL-1β stimulated CHON-001 cell apoptosis and inflammation, and TAN IIA had anti-apoptosis and anti-inflammatory effects on IL-1β-regulated CHON-001 cells. TAN IIA down-regulated FBXO11 and inhibited PI3K/AKT and NF-κB pathways, thereby alleviating apoptotic and inflammatory reactions in CHON-001 cells under IL-1β treatment. Moreover, TAN IIA treatment improved chondrocyte apoptosis and inflammations in OA rats. Conclusion TAN IIA inhibits PI3K/Akt and NF-κB pathways by down-regulating FBXO11 expression, alleviates chondrocyte apoptosis and inflammation, and delays the progression of OA.

Humeral chondrosarcoma associated with lung metastases in a young dog - case report / [Condrossarcoma em úmero associado a metástases pulmonares em cão jovem - relato de caso]

ABSTRACT Chondrosarcoma, an unusual malignant neoplasm, develops in cartilaginous tissue and presents low rate of metastasis, mainly affecting the axial skeleton from the adult to senile dogs. In the face of unusual occurrence of chondrosarcoma in the long bones of young dogs, the present report aimed to describe it in the right humerus of a two-and-a-half-year-old Siberian Husky, attended at the Veterinary Hospital of the University of Franca, with limping of the right thoracic limb, for 20 days. The radiographic examination of the humerus showed bone lysis and periosteal proliferation. In the incisional biopsy, proliferation of atypical chondrocytes with diffuse distribution, interspersed with compact bone matrix, was observed. The amputation of the limb was performed, and the fragment histopathological analysis showed grade I chondrosarcoma. Periodic returns were made for neoplastic staging, and at 240 days after surgery lung metastases were detected, however, the tutor did not authorize chemotherapy and radiotherapy for financial reasons and due to the absence of respiratory symptoms so far (410 days after surgery). Although uncommon, chondrosarcoma can affect the long bones of young dogs, with clinical signs similar to other bone neoplasms, and, even with the radical limb amputation, can demonstrate systemic metastasis.

RESUMO O condrossarcoma, neoplasia maligna incomum, desenvolve-se em tecido cartilaginoso e apresenta baixo índice de metástases, acometendo principalmente o esqueleto axial de cães adultos a senis. Diante da ocorrência incomum de condrossarcoma em ossos longos de cães jovens, o presente relato teve como objetivo descrevê-lo no úmero direito de um Husky Siberiano de dois anos e meio de idade, atendido no Hospital Veterinário da Universidade de Franca, com claudicação do membro torácico direito, há 20 dias. O exame radiográfico do úmero mostrou lise óssea e proliferação periosteal. Na biópsia incisional, observou-se proliferação de condrócitos atípicos com distribuição difusa, intercalados com matriz óssea compacta. Foi realizada a amputação do membro, e a análise histopatológica do fragmento evidenciou condrossarcoma grau I. Foram feitos retornos periódicos para estadiamento neoplásico e, aos 240 dias após a cirurgia, foram detectadas metástases pulmonares. O tutor não autorizou quimioterapia e radioterapia por motivos financeiros e por ausência de sintomas respiratórios até o momento (410 dias após a cirurgia). Apesar de incomum, o condrossarcoma pode acometer os ossos longos de cães jovens, com sinais clínicos semelhantes a outras neoplasias ósseas, e, mesmo com a amputação radical do membro, pode demonstrar metástase sistêmica.

Treatment of Chondral Lesions in the Knee.

Articular cartilage injuries are common and lead to early joint deterioration and osteoarthritis. Articular cartilage repair techniques aim at forming a cartilaginous neo-tissue to support the articular load and prevent progressive degeneration. Several techniques are available for this purpose, such as microfracture and chondrocyte transplantation. However, the procedural outcome is often fibrocartilage, which does not have the same mechanical resistance as cartilaginous tissue. Procedures with autologous osteochondral graft have a morbidity risk, and tissue availability limits their use. As such, larger lesions undergo osteochondral transplantation using fresh or frozen grafts. New techniques using minced or particulate cartilage fragments or mesenchymal stem cells are promising. This paper aims to update the procedures for treating chondral lesions of the knee.

The Effects of the Combination of Rhein and Platelet-Rich Plasma on Human Articular Chondrocytes.

BACKGROUND: The presence of side effects and low bioavailability of rhein has limited its use in the treatment of osteoarthritis. We aimed to evaluate the in vitro response of human articular chondrocytes to the presence of the combination of platelet-rich plasma (PRP) and rhein. METHODS: Solutions of rhein were prepared to assess solubility and select a working concentration. A stimulus with interleukin-1ß (IL-ß, 10 ng/mL) was induced for 24 h on human chondrocytes. Five treatment groups were established: control, IL-ß control, PRP, rhein, and PRP + rhein. Cell viability, cell migration, nitric oxide (NO) production, tumor necrosis factor-α (TNF-α), and gene expression analyses were carried out. RESULTS: A concentration of 50 mg/L was selected after a dose-response curve assay. Both NO and tumor TNF-α production significantly decreased after PRP and PRP + rhein treatments at 24 and 48 h. The wound healing assay revealed a significant stimulation of migration after 72 h with the PRP and PRP + rhein treatments. Expression of IL-1ß, IL-6, MMP-13, and ADAMTS-5 was significantly downregulated, particularly after treatment with the combination of PRP + rhein. CONCLUSIONS: Much of the determinations denoted a better performance of the combination of PRP and rhein in decreasing the levels of the different targets evaluated; however, this was not great enough to detect a significant difference in comparison with the PRP treatment alone.

Study of the Early Effects of Chitosan Nanoparticles with Glutathione in Rats with Osteoarthrosis.

Due to cartilage's limited capacity for regeneration, numerous studies have been conducted to find new drugs that modify osteoarthrosis's progression. Some evidence showed the capability of chitosan nanoparticles with glutathione (Np-GSH) to regulate the oxide-redox status in vitro in human chondrocytes. This work aimed to evaluate the capacity of Np-GSH in vivo, using Wistar rats with induced surgical osteoarthritis. Radiographic, biochemical (GSH and TBARS quantification), histopathological, and immunohistochemical (Col-2 and MMP-13) analyses were performed to evaluate the progress of the osteoarthritic lesions after the administration of a single dose of Np-GSH. According to the results obtained, the GSH contained in the NPs could be vectored to chondrocytes and used by the cell to modulate the oxidative state reduction, decreasing the production of ROS and free radicals induced by agents oxidizing xenobiotics, increasing GSH levels, as well as the activity of GPx, and decreasing lipid peroxidation. These results are significant since the synthesis of GSH develops exclusively in the cell cytoplasm, and its quantity under an oxidation-reduction imbalance may be defective. Therefore, the results allow us to consider these nanostructures as a helpful study tool to reduce the damage associated with oxidative stress in various diseases such as osteoarthritis.

Treatment of Chondral Lesions in the Knee / Tratamento das lesões condrais no joelho

Abstract Articular cartilage injuries are common and lead to early joint deterioration and osteoarthritis. Articular cartilage repair techniques aim at forming a cartilaginous neo-tissue to support the articular load and prevent progressive degeneration. Several techniques are available for this purpose, such as microfracture and chondrocyte transplantation. However, the procedural outcome is often fibrocartilage, which does not have the same mechanical resistance as cartilaginous tissue. Procedures with autologous osteochondral graft have a morbidity risk, and tissue availability limits their use. As such, larger lesions undergo osteochondral transplantation using fresh or frozen grafts. New techniques using minced or particulate cartilage fragments or mesenchymal stem cells are promising. This paper aims to update the procedures for treating chondral lesions of the knee.

Resumo As lesões da cartilagem articular são comuns e levam à deterioração precoce da articulação e ao desenvolvimento da osteoartrite. As técnicas de reparo da cartilagem articular visam a formação de um neo-tecido cartilaginoso capaz de suportar carga articular e evitar a progressão da degeneração. Há várias técnicas disponíveis para esse fim, como a microfratura e o transplante de condrócitos. Entretanto muitas vezes o desfecho do procedimento é a formação de fibrocartilagem, que não possui a mesma resistência mecânica do tecido cartilaginoso. Em outros procedimentos, nos quais é realizado enxerto osteocondral autólogo, há risco de morbidade associada ao procedimento, além da disponibilidade limitada de tecido. Por esse motivo, o transplante osteocondral, utilizando enxertos a fresco ou congelados tem sido utilizado para lesões de maior volume. Por fim, novas técnicas utilizando fragmentos de cartilagem picada ou particulada, assim como o uso de células tronco mesenquimais se apresentam como promissores. O objetivo desse artigo é realizar uma atualização dos procedimentos para tratamento das lesões condrais do joelho.

Effect of glycosaminoglycans on the structure and composition of articular cartilage and bone of broilers.

This study aimed to assess the influence of glycosaminoglycan (chondroitin and glucosamine sulfates) supplementation in the diet of broilers on the expression of matrix metallopeptidase 9 (MMP-9) and metallopeptidase inhibitor 2 (TIMP-2) genes, the synthesis of proteoglycans, collagen type II and chondrocytes, bone and cartilage macroscopy, bone mineral densitometry, bone breaking strength and mineral profile. A completely randomized design was carried out in a 3 × 3 factorial scheme (3 levels of chondroitin sulfate: 0.00, 0.05, and 0.10%; and 3 levels of glucosamine sulfate: 0.00, 0.15, and 0.30%), totaling 9 treatments. At 21 and 42 d of age, broilers were slaughtered, and tibias and femurs were collected for evaluation. There was an interaction (P < 0.05) of sulfates for the expression of MMP-9 and its inhibitor TIMP-2 in femur articular cartilage, as well as for the number of chondrocytes, collagen type II and proteoglycans in tibia articular cartilage, bone and cartilage macroscopy and mineral profile (P < 0.05), with better results obtained with the inclusion of chondroitin and/or glucosamine sulfates in the feed. In conclusion, chondroitin and glucosamine sulfates can be used in broiler diets in order to favor the development of the structure of the locomotor system (bones and joints), thus preventing locomotion problems.

Effect of the addition of different concentrations of Solanum glaucophyllum desf. extract on chondrocyte cultures from the growth cartilage of newborn rats.

Solanum glaucophyllum Desf. is a calcinogenic plant responsible for enzootic calcinosis that affects ruminants and causes alterations in bone and cartilaginous tissues, among others. It is believed that changes in cartilage tissue, with reduced bone growth, are due to hypercalcitoninism, caused by excess vitamin D. However, we hypothesized that S. glaucophyllum Desf. can act directly on chondrocytes and therefore, chondrocyte cultures from the epiphysis of the long bones of newborn rats were used as a model to elucidate the direct effects of S. glaucophyllum Desf. on bone growth. Plant samples were collected from Cañuelas, Argentina. An aliquot of the plant extract was used to quantify vitamin D (1,25(OH)2D3). The effects of the three concentrations of the plant extract were tested in cultures of chondrocytes extracted from the epiphyses of the long bones of 32 three-day-old Wistar rats. A control group (without extract), and three groups treated with different concentrations of plant extract were formed: group 1 (100 µL/L); group 2 (1 mL/L), and group 3 (5 mL/L), containing respectively 1 × 10-9 M, 1 × 10-8 M, and 5 × 10-8 M of 1,25(OH)2D3. After 7, 14, and 21 days of culture, MTT assay for cell viability, alkaline phosphatase activity, and quantification of the percentage of areas with glycosaminoglycans (GAG) stained with periodic acid-Schiff (PAS) were performed. On day 7, all chondrocytes in group 3, that is, those with the highest concentration of plant extract, died. On days 14 and 21, groups 1 and 2 showed a significant reduction in chondrocyte viability compared to the control. At 7, 14, and 21 days, groups 1 and 2 showed significantly lower alkaline phosphatase activity than the control. On day 21, group 2 showed a significant reduction in areas with PAS + GAGs. There were no significant differences between the groups in the expression of gene transcripts for Sox9, Col2, ColX, and aggrecan. The S. glaucophyllum Desf. extract directly affected growing rat chondrocytes by reducing viability, alkaline phosphatase activity, and GAG synthesis without altering the expression of gene transcripts for Sox9, Col2, ColX, and aggrecan, which may be one of the mechanisms by which there is a reduction in bone growth in animals intoxicated by the plant.

Suitable characteristics in the selection of human allogeneic chondrocytes donors to increase the number of viable cells for cartilage repair.

Autologous chondrocyte implantation has shown optimal long-term outcomes in the treatment of cartilage lesions. The challenge for a single-stage approach lies in obtaining sufficient number of cells with high viability. The answer could lie in supplementing or replacing them with allogenic chondrocytes coming from cadaveric donors. In the present work, we aimed to compare the number of viable cells isolated from cartilage of live and cadaveric donors and to determine the suitable characteristics of the best donors. A total of 65 samples from donors aged from 17 to 55 years, either women or men, were enrolled in this study (33 living vs. 32 cadaveric). The mean time of hours from death to processing samples in cadaveric donors was higher compared to live donors (64.3 ± 17.7 vs. 4.6±6.4). The number of isolated chondrocytes per gram of cartilage was higher in cadaveric donors (5.389 × 106 compared to 3.067 × 106 in living donors), whereas the average of cell viability was comparable in both groups (84.16% cadaveric, 87.8% alive). It is possible to obtain viable chondrocytes from cartilage harvested from cadaveric donors, reaching a similar cell number and viability to that obtained from the cartilage of living donors.

Fracturas osteocondrales de la rodilla

Introducción: Las fracturas osteocondrales que afectan la articulación de la rodilla se presenta de forma aislada o asociada a otras afecciones traumáticas. El diagnóstico inicial es en ocasiones difícil de realizar por la convergencia de signos clínicos e imagenológicos. Objetivo: Brindar información actualizada sobre los elementos más importantes de esta enfermedad traumática. Métodos: La búsqueda y el análisis de la información se realizó en un periodo de 31 días (del primero al 31 de agosto de 2021) y se emplearon las siguientes palabras del idioma ingles: osteochondral lesions, osteochondral fractures, osteochondral injuries a partir de la información obtenida se realizó una revisión bibliográfica de un total de 315 artículos publicados en las bases de datos PubMed, Hinari, SciELO y Medline mediante el gestor de búsqueda y administrador de referencias EndNote. Resultados: Se hace referencia al mecanismo de producción, aspecto artroscópico, localización, características en cuanto a extensión, profundidad, clasificación y desplazamiento. Se describen las modalidades imagenológicas empleadas en el diagnóstico y su utilidad. Con relación al diagnóstico diferencial se describen un grupo de enfermedades con características similares. Se mencionan las modalidades de tratamiento basadas en el tamaño y tiempo de evolución. Conclusiones: Las fracturas osteocondrales son lesiones frecuentes, para su diagnóstico se necesita de un alto índice de sospecha, ya que el diagnóstico clínico e imagenológico inicial no son concluyentes en la mayoría de los pacientes por estar combinada con otras afecciones.

Introduction: Osteochondral fractures that affect the knee joint occur in isolation or associated with other traumatic conditions. The initial diagnosis is sometimes difficult to make due to the convergence of clinical and imaging signs. Objective: To provide updated information on the most important elements of this traumatic entity. Methods: The search and analysis of the information was carried out in a period of 31 days (from August the first to the 31st, 2021) and the following words of the English language were used: osteochondral lesions, osteochondral fractures, osteochondral injuries from the Information obtained, a bibliographic review of a total of 315 articles published in the PubMed, Hinari, SciELO and Medline databases was carried out using the EndNote search manager and reference manager. Results: Reference is made to the mechanism of production, arthroscopic appearance, location, characteristics in terms of extension, depth, classification and displacement. The imaging modalities used in diagnosis and their usefulness are described. Regarding the differential diagnosis, a group of entities with similar characteristics are described. Treatment modalities based on size and time of evolution are mentioned. Conclusions: Osteochondral fractures are frequent injuries, for their diagnosis a high index of suspicion is needed, since the initial clinical and imaging diagnosis are not conclusive in most patients because they are combined with other conditions.

Postembryonic development and aging of the appendicular skeleton in Ambystoma mexicanum.

BACKGROUND: The axolotl is a key model to study appendicular regeneration. The limb complexity resembles that of humans in structure and tissue components; however, axolotl limbs develop postembryonically. In this work, we evaluated the postembryonic development of the appendicular skeleton and its changes with aging. RESULTS: The juvenile limb skeleton is formed mostly by Sox9/Col1a2 cartilage cells. Ossification of the appendicular skeleton starts when animals reach a length of 10 cm, and cartilage cells are replaced by a primary ossification center, consisting of cortical bone and an adipocyte-filled marrow cavity. Vascularization is associated with the ossification center and the marrow cavity formation. We identified the contribution of Col1a2-descendants to bone and adipocytes. Moreover, ossification progresses with age toward the epiphyses of long bones. Axolotls are neotenic salamanders, and still ossification remains responsive to l-thyroxine, increasing the rate of bone formation. CONCLUSIONS: In axolotls, bone maturation is a continuous process that extends throughout their life. Ossification of the appendicular bones is slow and continues until the complete element is ossified. The cellular components of the appendicular skeleton change accordingly during ossification, creating a heterogenous landscape in each element. The continuous maturation of the bone is accompanied by a continuous body growth.

Matrix-assisted autologous chondrocyte transplantation for treatment of focal chondral lesions in the knee: the Hospital Israelita Albert Einstein experience

ABSTRACT Objective Phase 1 clinical trial to determine feasibility, safety, and efficacy of a new advanced cell therapy product for treatment of knee articular cartilage injuries. Methods Three participants with knee focal chondral lesions were included, with no signs of osteoarthritis. Chondrocytes were obtained through knee arthroscopy, cultured in collagen membrane for 3 weeks at the laboratory, subjected to tests to release the cell therapy product, and implanted. All patients underwent a specific 3-month rehabilitation protocol, followed by assessments using functional and imaging scales. The main outcome was the incidence of severe adverse events. Results Three participants were included and completed the 2-year follow-up. There was one severe adverse event, venous thrombosis of distal leg veins, which was no associated with therapy, was treated and left no sequelae. The clinical and radiological scales showed improvement in the three cases. Conclusion The preliminary results, obtained with the described methodology, allow concluding that this product of advanced cell therapy is safe and feasible. ReBEC platform registration number: RBR-6fgy76

Report of a clinical and laboratory management of cell therapy for knee cartilage in the face of mycoplasma contamination

ABSTRACT To describe a case of autologous chondrocyte implantation after cell culture contamination by Mycoplasma pneumoniae and the measures taken to successfully complete cell therapy in a patient with focal chondral lesion. A 45-year-old male patient, complaining of chronic pain on the knee and no history of trauma. He had a chondral lesion in the trochlear region of the femur and clinical tests compatible with pain in the anterior compartment of the knee. Conservative treatment failed to alleviate symptoms. Surgical treatment was indicated, but due to the size of the lesion, membrane-assisted autologous chondrocyte implantation was the technique of choice. Cartilage biopsies were collected from the intercondylar region of the distal femur. After isolation, chondrocytes were expanded ex vivo in a trained laboratory, for three weeks, and seeded onto a commercially available collagen membrane prior to implantation in the knee. Two days before surgery, a cell culture sample tested positive for Mycoplasma pneumoniae. The source of contamination was found to be autologous blood serum, extracted from the patient´s peripheral vein, and used to supplement the cell culture medium. After treating the patient with antibiotics, all procedures were repeated and the new final cell product, free from contaminants, was successfully implanted. We discuss the strategies available to deal with this situation, and describe the results of this particular case, which led to modifications in the autologous chondrocyte implant protocol.

Phenotype and synthesis activity of joint chondrocytes extracted from newborn rats with prenatal ethanol exposure.

Thirteen female Wistar rats were divided into two groups: one treated with ethanol and the other of untreated. Four newborns from each mother were selected and weighed, measured, and evaluated for physical characteristics. From these neonates, chondrocytes were extracted from the articular cartilages of the femur and tibia, and cultivated in a chondrogenic medium at 37oC and 5% CO2. At 7, 14, and 21 days of cultivation, alkaline phosphatase activity tests, MTT conversion to formazan, and percentage area covered by cells per field were performed. At 21 days, the percentage of PAS+ areas in 3D cultures was performed, as well as the evaluation of gene transcript expression for aggrecan, SOX-9, collagen type II, collagen X, Runx-2, and VEGF by real-time RT-PCR. The means were compared by Student's t-test. The weight of the ethanol group neonates was significantly lower than that of the controls. Chondrocyte cultures from the ethanol group showed significantly higher AP activity, MTT conversion, and cell percentage. There was higher expression of collagen type II and lower expression of SOX-9 in the ethanol group. There was no difference in the percentage of PAS+ areas in pellets and in expression of aggrecan, collagen X, Runx-2, or VEGF between groups. In conclusion, prenatal exposure to ethanol alters the phenotype and activity of offspring chondrocytes, which may be mechanisms by which endochondral bone formation is compromised by maternal ethanol consumption.

Tracheal Repair with Human Umbilical Cord Mesenchymal Stem Cells Differentiated in Chondrocytes Grown on an Acellular Amniotic Membrane: A Pre-Clinical Approach.

Acellular amniotic membrane (AM) has been studied, with promising results on the reconstruction of lesioned tissues, and has become an attractive approach for tracheal repair. This study aimed to evaluate the repair of the trachea with human umbilical cord mesenchymal stem cells (hucMSCs) differentiated in chondrocytes, grown on an experimental model. Tracheal defects were induced by surgical tracheostomy in 30 New Zealand rabbits, and the acellular amniotic membrane, with or without cells, was covering the defect. The hucMSCs were isolated and cultivated with chondrogenic differentiation over the culture of 14 days, and then grown on the AM. In this study, the AM was biocompatible and hucMSCs differentiated into chondrocytes. Our results demonstrated an important role for AM with cultured cells in the promotion of immature collagen, known to produce tissue regeneration. In addition, cartilaginous tissue was found at the tracheal defects, demonstrated by immunohistology results. This study suggests that this biomaterial implantation can be an effective future therapeutic alternative for patients with tracheal injury.