Cerámica 55S como sustrato para la regeneración de defectos óseos, estudio in vitro / Ceramic 55S as a substrate for the regeneration of bone defects; an in vitro study

Introducción. El objetivo de nuestro trabajo es evaluar in vitro el comportamiento y la capacidad inductora de la diferenciación osteoblástica de una vitrocerámica 55S (Vc) sobre una población de células madre mesenquimales adultas (del inglés mesenchymal stem cells [MSCs]) de conejo. Material y métodos. El material se obtuvo mediante el método sol-gel. Las células se obtuvieron de aspirado de médula ósea de conejo y se sembraron sobre la Vc y sobre el plástico (control). Las MSCs se cultivaron en dos medios de cultivo, uno estándar DMEM (medio de crecimiento [Mc]) y otro inductor del fenotipo osteoblástico compuesto por DMEM complementado con dexametasona, ß-glicerofosfáto y ácido ascórbico-2P (medio osteogénico [Mo]). Se evaluó la morfología de las células que crecieron mediante microscopía electrónica de barrido. Se usó el ensayo de reducción de sales de tetrazolio (XTT) para la evaluación del crecimiento celular. Para determinar la diferenciación celular se cuantificó la producción de osteocalcina y la pérdida del antígeno de superficie CD90, característico de las MSCs. Resultados. Durante el tiempo en cultivo las MSCs se adhirieron, proliferaron y formaron matriz extracelular mineralizada sobre la Vc, mostrando finalmente un fenotipo osteoblástico, produciendo osteocalcina y disminuyendo la expresión del antigeno CD90, independientemente del medio de cultivo utilizado. Conclusión. En base a estos resultados podemos afirmar que la Vc 55S se comportó como un material capaz de soportar la adhesión y el crecimiento de las MSCs y de inducir por sí misma la diferenciación de las MSCs a células de estirpe osteoblástica, mostrando por tanto, propiedades osteoconductoras y osteoinductoras (AU)

Introduction. The purpose of this work is to evaluate the in vitro behaviour and the capacity to induce osteoblastic differentiation of a 55S vitro-ceramic (Vc) on a population of adult rabbit mesenchymal stem-cells (MSCs). Material and methods. The material was obtained using the sol-gel method. The cells were obtained from rabbit bone-marrow aspirate and seeded over the Vc, and over plastic (control). The MSCs were cultivated in two culture media; one a standard DMEM (growth medium), and the other an osteoblastic phenotype inducer, composed of DMEM complemented with dexamethasone, ß-glycerophosphate and ascorbic acid-2-phosphate (osteogenic medium). The morphology of the cells that grew was assessed using a scanning electronic microscope. The tetrazolium salt reduction test was used for evaluating the cell growth. For cell differentiation, osteocalcin production and loss of CD90 bone surface antigen, characteristic of MSCs, were quantified. Results. During the culture time the MSCs adhered, proliferated and formed a mineralised extracellular matrix over the Vc. An osteoblastic phenotype finally being shown, producing osteocalcin and decreasing the expression of the CD90 antigen, regardless of the culture medium used. Conclusion. Based on these results we can state that Vc 55S behaved like a material capable of supporting adhesion and growth of MSCs and, in turn, inducing the differentiation of the MSCs to osteoblastic cell lines, thus showing osteoconduction and osteoinduction properties (AU)

[Ceramic 55S as a substrate for the regeneration of bone defects; an in vitro study]. / Cerámica 55S como sustrato para la regeneración de defectos óseos, estudio in vitro.

INTRODUCTION: The purpose of this work is to evaluate the in vitro behaviour and the capacity to induce osteoblastic differentiation of a 55S vitro-ceramic (Vc) on a population of adult rabbit mesenchymal stem-cells (MSCs). MATERIAL AND METHODS: The material was obtained using the sol-gel method. The cells were obtained from rabbit bone-marrow aspirate and seeded over the Vc, and over plastic (control). The MSCs were cultivated in two culture media; one a standard DMEM (growth medium), and the other an osteoblastic phenotype inducer, composed of DMEM complemented with dexamethasone, ß-glycerophosphate and ascorbic acid-2-phosphate (osteogenic medium). The morphology of the cells that grew was assessed using a scanning electronic microscope. The tetrazolium salt reduction test was used for evaluating the cell growth. For cell differentiation, osteocalcin production and loss of CD90 bone surface antigen, characteristic of MSCs, were quantified. RESULTS: During the culture time the MSCs adhered, proliferated and formed a mineralised extracellular matrix over the Vc. An osteoblastic phenotype finally being shown, producing osteocalcin and decreasing the expression of the CD90 antigen, regardless of the culture medium used. CONCLUSION: Based on these results we can state that Vc 55S behaved like a material capable of supporting adhesion and growth of MSCs and, in turn, inducing the differentiation of the MSCs to osteoblastic cell lines, thus showing osteoconduction and osteoinduction properties.