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Hamstring tendon autograft remains a popular graft choice for anterior cruciate ligament reconstruction. Although the technique of hamstring autograft harvest is relatively straightforward, it is critical to pay attention to several technical steps to avoid iatrogenic anatomic or neurovascular damage as well as to reduce the risk of premature amputation of the graft when using a tendon stripper. We describe a technique of hamstring autograft harvesting using only 2 anatomic references that makes it a simple and reproducible technique for surgeons, especially those in training.
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RESUMEN En el mundo actual, las llamadas "tecnologías de fabricación por adición" o impresión 3D también llamado prototipado rápido, han trascendido las fronteras de casi todos los campos de la ciencia, y su incursión en la medicina es cada vez mayor. Es justamente en el campo médico que esta tecnología de impresión por adición ha evolucionado a la bioimpresión, que incluye un proceso de cultivo celular en laboratorio haciendo posible la formación de órganos y/o tejidos personalizados. Para la impresión tridimensional de órganos en humanos se toman muestras de un tejido o células madre del paciente, para ser cultivadas y expandidas en laboratorio para su posterior diferenciación a una línea celular específica. Para este proceso se utiliza un material sólido como andamio a temperatura ambiente con un punto de fusión conocido. En la creación de un modelo para la fabricación de un órgano o tejido en impresión 3D, se utilizan los estudios de imágenes médicas de los pacientes intentando preservar al máximo la anatomía de las estructuras que se desean reproducir. En este artículo se abordan las bases y el potencial uso de esta tecnología en el área médica.
ABSTRACT In today's world, so-called "addition manufacturing technologies" or 3D printing also called rapid prototyping have transcended the borders of almost every field of science and medicine is no exception. It is not surprising that its exploration for practical uses is increasing. In medicine, this technology of printing by addition has evolved to bioprinting, which occurs by a special process, from cells grown in a laboratory, which makes possible its transformation into a type of organs tailored to the patient. The three-dimensional impression of human organs requires take samples of tissues or stem cells from the patient, which are grown in the laboratory waiting to multiply or differentiate to other cell lines; then, to create said object, a solid material at room temperature and with a known melting point is applied layer by layer. Currently the use of this technology uses the medical images of patients trying to preserve the anatomy of the structures that they want to reproduce. In this article the bases and the potential use of this technology in the medical area will be addressed.
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To compare the quality of the repair tissue in three-dimensional co-culture of human chondrocytes implanted in an in vivo model. Six cadaveric and five live human donors were included. Osteochondral biopsies from the donor knees were harvested for chondrocyte isolation. Fifty percent of cadaveric chondrocytes were expanded until passage-2 (P2) while the remaining cells were cryopreserved in passage-0 (P0). Fresh primary chondrocytes (P0f) obtained from live human donors were co-cultured. Three-dimensional constructs were prepared with a monolayer of passage-2 chondrocytes, collagen membrane (Geistlich Bio-Gide®), and pellet of non-co-cultured (P2) or co-cultured chondrocytes (P2 + P0c, P2 + P0f). Constructs were implanted in the subcutaneous tissue of athymic mice and left for 3 months growth. Safranin-O and Alcian blue staining were used to glycosaminoglycan content assessment. Aggrecan and type-II collagen were evaluated by immunohistochemistry. New-formed tissue quality was evaluated with an adaptation of the modified O'Driscoll score. Histological quality of non-co-cultured group was 4.37 (SD ±4.71), while co-cultured groups had a mean score of 8.71 (SD ±3.98) for the fresh primary chondrocytes and 9.57 (SD ±1.27) in the cryopreserved chondrocytes. In immunohistochemistry, Co-culture groups were strongly stained for type-II and aggrecan not seen in the non-co-cultured group. It is possible to isolate viable chondrocytes from cadaveric human donors in samples processed in the first 48-h of dead. There is non-significant difference between the numbers of chondrocytes isolated from live or cadaveric donors. Cryopreservation of cadaveric primary chondrocytes does not alter the capability to form cartilage like tissue. Co-culture of primary and passaged chondrocytes enhances the histological quality of new-formed tissue compared to non-co-cultured cells.
Assuntos
Desdiferenciação Celular , Condrócitos/citologia , Condrócitos/transplante , Técnicas de Cocultura/métodos , Animais , Cadáver , Cartilagem/citologia , Células Cultivadas , Glicosaminoglicanos/análise , Humanos , Doadores Vivos , Masculino , Camundongos Nus , Engenharia Tecidual/métodos , CicatrizaçãoRESUMO
Mobilized peripheral blood (MPB) bone marrow cells possess the potential to differentiate into a variety of mesenchymal tissue types and offer a source of easy access for obtaining stem cells for the development of experimental models with applications in tissue engineering. In the present work, we aimed to isolate by magnetic activated cell sorting CD90+ cells from MPB by means of the administration of Granulocyte-Colony Stimulating Factor and to evaluate cell proliferation capacity, after thawing of the in vitro culture of this population of mesenchymal stem cells (MSCs) in sheep. We obtained a median of 8.2 ± 0.6 million of CD90+ cells from the 20-mL MPB sample. After thawing, at day 15 under in vitro culture, the mean CD90+ cells determined by flow cytometry was 92.92 ± 1.29 % and cell duplication time determined by crystal violet staining was 47.59 h. This study describes for the first time the isolation, characterization, and post-in vitro culture thawing of CD90+ MSCs from mobilized peripheral blood in sheep. This population can be considered as a source of MSCs for experimental models in tissue engineering research.