Elaboration et caractérisations physico-chimiques et biologiques de biocéramiques utilisées comme substituts osseux

LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

Potentialities of ultrasounds for the nondestructive evaluation of cell adhesion

International audienc

Numerical and ex vivo studies of a bioprobe developed for laser-induced thermotherapy (LITT) in contact with liver tissue

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Calcite as a bone substitute. Comparison with hydroxyapatite and tricalcium phosphate with regard to the osteoblastic activity

International audienceClose to the bone mineral phase, the calcic bioceramics, such as hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), are commonly used as substitutes or filling materials in bone surgery. Besides, calcium carbonate (CaCO3) is also used for their excellent biocompatibility and bioactivity. However, the problem with the animal-origin aragonite demands the new technique to synthesize pure calcite capable of forming 3D bone implant. This study aims to manufacture and evaluate a highly-pure synthetic crystalline calcite with good cytocompatibility regarding to the osteoblasts, comparing to that of HA and β-TCP. After the manufacture of macroporous bioceramic scaffolds with the identical internal architecture, their cytocompatibility is studied through MC3T3-E1 osteoblasts with the tests of cell viability, proliferation, vitality, etc. The results confirmed that the studied process is able to form a macroporous material with a controlled internal architecture, and this synthesized calcite is non-cytotoxic and facilitate the cell proliferation. Indeed requiring further improvement, the studied calcite is definitely an interesting alternative not only to coralline aragonite but also to calcium phosphate ceramics, particularly in bone sites with the large bone remodelling

Numerical optimization of cell colonization modelling inside scaffold for perfusion bioreactor: A multiscale model

International audiencePart of clinically applicable bone graft substitutes are developed by using mechanical stimulation of flow-perfusion into cell-seeded scaffolds. The role of fluid flow is crucial in driving the nutrient to seeded cells and in stimulating cell colonization. A common numerical approach is to use a multiscale model to link some physical quantities (wall shear stress and inlet flow rate) that act at different scales. In this study, a multiscale model is developed in order to determine the optimal inlet flow rate to cultivate osteoblast-like cells seeded in a controlled macroporous biomaterial inside a perfusion bioreactor system. We focus particularly on the influence of Wall Shear Stress on cell colonization to predict cell colonization at the macroscale. Results obtained at the microscale are interpolated at the macroscale to determine the optimal flow rate. For a macroporous scaffold made of interconnected pores with pore diameters of above 350 and interconnection diameters of 150 the model predicts a cell colonization of 325% after a 7-day-cell culture with a constant inlet flow rate of 0.69 . Furthermore, the strength of this protocol is the possibility to adapt it to most porous biomaterials and dynamic cell culture systems