Advanced nanostructured medical device combining mesenchymal cells and VEGF nanoparticles for enhanced engineered tissue vascularization

AIM: Success of functional vascularized tissue repair depends on vascular support system supply and still remains challenging. Our objective was to develop a nanoactive implant enhancing endothelial cell activity, particularly for bone tissue engineering in the regenerative medicine field. MATERIALS & METHODS: We developed a new strategy of tridimensional implant based on cell-dependent sustained release of VEGF nanoparticles. These nanoparticles were homogeneously distributed within nanoreservoirs onto the porous scaffold, with quicker reorganization of endothelial cells. Moreover, the activity of this active smart implant on cells was also modulated by addition of osteoblastic cells. RESULTS & CONCLUSION: This sophisticated active strategy should potentiate efficiency of current therapeutic implants for bone repair, avoiding the need for bone substitutes

Multiple Scale Reorganization of Electrostatic Complexes of PolyStyrene Sulfonate and Lysozyme

We report on a SANS investigation into the potential for these structural reorganization of complexes composed of lysozyme and small PSS chains of opposite charge if the physicochemical conditions of the solutions are changed after their formation. Mixtures of solutions of lysozyme and PSS with high matter content and with an introduced charge ratio [-]/[+]intro close to the electrostatic stoichiometry, lead to suspensions that are macroscopically stable. They are composed at local scale of dense globular primary complexes of radius ~ 100 {\AA}; at a higher scale they are organized fractally with a dimension 2.1. We first show that the dilution of the solution of complexes, all other physicochemical parameters remaining constant, induces a macroscopic destabilization of the solutions but does not modify the structure of the complexes at submicronic scales. This suggests that the colloidal stability of the complexes can be explained by the interlocking of the fractal aggregates in a network at high concentration: dilution does not break the local aggregate structure but it does destroy the network. We show, secondly, that the addition of salt does not change the almost frozen inner structure of the cores of the primary complexes, although it does encourage growth of the complexes; these coalesce into larger complexes as salt has partially screened the electrostatic repulsions between two primary complexes. These larger primary complexes remain aggregated with a fractal dimension of 2.1. Thirdly, we show that the addition of PSS chains up to [-]/[+]intro ~ 20, after the formation of the primary complex with a [-]/[+]intro close to 1, only slightly changes the inner structure of the primary complexes. Moreover, in contrast to the synthesis achieved in the one-step mixing procedure where the proteins are unfolded for a range of [-]/[+]intro, the native conformation of the proteins is preserved inside the frozen core

Secondary structure of rhBMP-2 in a protective biopolymeric carrier material

Efficient delivery of growth factors is one of the great challenges of tissue engineering. Polyelectrolyte multilayer films (PEM) made of biopolymers have recently emerged as an interesting carrier for delivering recombinant human bone morphogenetic protein 2 (rhBMP-2 noted here BMP-2) to cells in a matrix-bound manner. We recently showed that PEM made of poly(l-lysine) and hyaluronan (PLL/HA) can retain high and tunable quantities of BMP-2 and can deliver it to cells to induce their differentiation in osteoblasts. Here, we investigate quantitatively by Fourier transform infrared spectroscopy (FTIR) the secondary structure of BMP-2 in solution as well as trapped in a biopolymeric thin film. We reveal that the major structural elements of BMP-2 in solution are intramolecular β-sheets and unordered structures as well as α-helices. Furthermore, we studied the secondary structure of rhBMP-2 trapped in hydrated films and in dry films since drying is an important step for future applications of these bioactive films onto orthopedic biomaterials. We demonstrate that the structural elements were preserved when BMP-2 was trapped in the biopolymeric film in hydrated conditions and, to a lesser extent, in dry state. Importantly, its bioactivity was maintained after drying of the film. Our results appear highly promising for future applications of these films as coatings of biomedical materials, to deliver bioactive proteins while preserving their bioactivity upon storage in dry state.This work was supported by the French Ministry of Research through an ANR-EmergenceBIO grant (ANR-09-EBIO-012-01), by the European Commission (FP7 program) via a European Research Council starting grant (BIOMIM, GA 259370), and by GRAVIT (081012_FIBIOS). C.P. is grafetul to IUF for financial support

Asesoría, capacitación y asistencia técnica para el sector añilero: creación de micro y pequeña empresas

38 páginasEl objetivo es iniciar fundamentos de diseño para el desarrollo de futuras líneas de productos artesanales en las que se aplique la técnica de teñido con añil, para qu el artesano, aplique a futuro, criterios sobre requerimientos básicos en la calidad y acabados al momento de elaborar un producto

New advanced therapy medicinal product for cartilage defect treatment with extemporaneous association of a scaffold and Wharton's jelly mesenchymal stromal cells

International audiencen the framework of an ANR project obtained in 2015, we propose to develop a new advancedtherapy medicinal product for cartilage defect treatment with extemporaneous association of ascaffold and Wharton’s jelly mesenchymal stromal cells (WJ-MSC).Due to their capacity of proliferation and differentiation, MSC appear to be currently one of themost promising ways of obtaining cartilage cells. The conjunctive tissue of the umbilical cordor Wharton’s jelly is an abundant and promising source of MSC for clinical applications. Theypresent immunomodulatory properties and have a higher proliferation potential than MSC fromadult tissues. All these advantages enable this source to represent a virtually inexhaustiblesource of stem cells especially for allogeneic tissue engineering therapies.The first part of this work made it possible to perform a technological transfer from researchtowards the clinic. The transfer consisted in adjusting MSC isolation, production andconservation methods developed by research lab in clinical grade conditions.Eight umbilical cords were obtained after the signing of an informed consent form by pregnantmothers. In parallel, for each umbilical cord collected, well identified obstetric factors wererecorded. We developed a fast, simple and efficient explant method for the isolation of MSCfrom human umbilical cords requiring minimal manipulation and thus reducing the risk ofcontamination. MSC isolation, production and conservation were performed in a controlledatmosphere zone. All reagents and materials were well-defined and controlled. Cell culture wasperformed in culture containers (CellSTACK®, Macopharma) in a closed system. MSC werecultivated in hypoxia until passage 2 and then frozen. Quality controls were carried out duringproduction: serological and microbiological controls, cell number, viability, clonogeniccapacity, immunophenotype, mesodermic differentiation potential and karyotype.This isolation method showed a 100% success rate. We were able to obtain a large number ofviable and secured cells with an average number of 50.106 cells per CellSTACK and a doublingtime of about 1.5 days. During the culture, WJ-MSC exhibited a sustained clonogenic capacityand a specific mesenchymal phenotype.These results made it possible to assess the feasibility and to validate the clinical gradeamplification technique as well as to obtain precisely characterized and secured WJ-MSC