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A new generation of bio-derived ceramics can be developed as a base material for medical implants. Specific plant species are used as templates on which innovative transformation processes can modify the chemical composition maintaining the original biostructure. Building on the outstanding mechanical properties of the starting lignocellulosic templates, it is possible to develop lightweight and high-strength scaffolds for bone substitution. In vitro and in vivo experiments demonstrate the excellent biocompatibility of this new silicon carbide material (bioSiC) and how it gets colonized by the hosting bone tissue because of its unique interconnected hierarchic porosity, which opens the door to new biomedical applications.

Spinel ferrites (iron cobalt oxide) were prepared by the microemulsion method at different temperatures and sodium dodecyl sulphate (SDS) surfactant concentrations. Subsequently, a quantity of the different samples were coated with an intrinsically conducting polymer (ICP) shell of polypyrrole. The polymer shell was synthesized by a chemical route after the ferrites particle production. By combining in a single material the electrical conductivity of ICPs and the magnetic properties of nanopowder ferrites, new multifunctional materials have been developed. Different CoFe2O4 grain size particles were obtained ranging from 3 to 30 nm, as determined by x-ray diffraction (XRD). Particles with grain size below a critical size exhibit a superparamagnetic behaviour. These superparamagnetic particles, without and with a conducting polymer shell, were analysed by transmission electron microscopy (TEM) to find the grains’ morphology and the growth evolution of the polypyrrole shell in the ferrites grains. The electrical conductivity of the nanocomposite was measured by the four points probe method, showing values of 120 ± 4 S cm−1 at ambient temperature. The behaviour of the magnetization and the coercivity with temperature, from nearly 0 K to the ambient, were measured in a vibrating sample magnetometer (VSM).

Abstract. Biomorphic silicon carbide ceramics are light, tough and high-strength materials with interesting biomedical applications. The fabrication method of the biomorphic SiC is based in the infiltration of molten-Si in carbon preforms with open porosity. The final product is a biostructure formed by a tangle of SiC fibers. This innovative process allows the fabrication of complex shapes and the tailoring of SiC ceramics with optimised properties and controllable microstructures that will match the biomechanical requirements of the natural host tissue. An interdisciplinary approach of the biomorphic SiC fabricated from beech, sapelly and eucalyptus is presented. Their mechanical properties, microstructure and chemical composition were evaluated. The biocompatible behaviour of these materials has been tested in vitro.

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