Formation of hybrid materials based on calcium phosphate deposit on carbon fiber scaffold

Abstract

Event Abstract Back to Event Formation of hybrid materials based on calcium phosphate deposit on carbon fiber scaffold Quentin Picard1, Lise Guichaoua1, Sandrine Delpeux-Ouldriane1, Nathalie Rochet2, Jérôme Chancolon1, Franck Fayon3, Fabienne Warmont1 and Sylvie Bonnamy1 1 CNRS / University of Orleans, ICMN, France 2 INSERM/BIPOA, IBV, France 3 CNRS, CEMHTI, France Introduction: Due to their breathability, specific mechanical properties and biocompatibility, activated carbon clothes (ACC) have previously been considered for hard and soft tissue implanting. However, their poor biological activity restricts their extensive use in medical applications and therefore needs to be enhanced[1]-[3]. Carbon fiber-reinforced calcium phosphate (CaP) composites, combining the highly biocompatible, osteoconductive and bioactive CaP matrix with the properties of carbon fibers, are promising bioceramic material, which could be particularly useful in the reconstruction of bone defects[3]. Experimental Methods: CaP coated ACC are obtained by sono-electrodeposition process using cathodic polarization. Ca(NO3)2, 4H2O and NH4H2PO4 are used as electrolyte. The influence of electrochemical parameters is connected to the amount, microtexture, structure and chemical composition of CaP phases. The materials biocompatibility was determined by culturing primary human osteoblast-cells (HOST) in contact with CaP/ACC hybrid materials. Results and Discussion: The mass uptake tends to a limit corresponding to the decrease of nucleation sites. The current density gouverns the CaP characteristics: amount, morphology and chemical composition. Indeed, the quantity of deposit is proportional to the applied current density (thickness ranging from 10 nm to 1 µm). During CaP deposition, water electrolysis regime gouverns the pH decrease at the carbon electrode surface and consequently leads to CaP precipitation. This process gives biomimetic and uniform CaP coated fibers. Their CaP chemical compositions can be modulated to get similar ones to natural bones. SEM, HRTEM and FTIR characterizations show that the coating consists in a mixture of octacalcium phosphate and plate-like carbonated HA phases at low current densities and needle-like carbonated HA with calcium carbonate phases at high current densities. 1H and 31P MAS NMR of deposits confirm the presence of carbonated HA with a minority of disordered CaP phase. First biological results through in vitro osteoblast culture have evidenced the cell viability on hybrid materials (Fig. 1). Figure 1: SEM image of human osteoblasts cultured at 7 days in the presence of CaP/ACC hybrid material obtained at low current density. Conclusion: The sono-electrodeposition process allows to tailor the thickness, morphology (platelets or needles), chemical composition and to get biomimetic CaP coatings consisting mainly in carbonated HA with minor disordered CaP phases. Close to natural bone chemical composition, the CaP/ACC hybrid materials show a good interaction with primary HOST and therefore could be used as bioactive scaffold for bone regeneration. European Program PF7_IRSES « ABREM »; Region Centre Val-de-Loire project: Hybrid bio-actives materials for bone reconstruction