Biodegradable metallic scaffolds and implants constitute an important area of research in tissue engineering and regenerative medicine. In
contrast with other biomaterials used as scaffolds, such as hydrogels, they represent the only family of materials that can generate a
temporary platform to support and ideally induce the growth or healing of a biological tissue, while exhibiting sufficient mechanical
properties during the process in a number of applications, such as bone regeneration or cardiovascular stents. One of the main challenges
in this context is to synchronize the degradation of the scaffold with the healing process. An ideal biodegradable scaffold should degrade
first at the interface with the biological tissue and show a continuous degradation that is synchronized with the advance of the growing
tissue. However, the corrosion of metals under physiological conditions is a complex process, stochastic in nature, and this level of control
has never been achieved so far.

The project BIOFUN3D aims at overcoming this problem by the introduction of functional gradients into the scaffolds. In this context, sub-project 2 will focus on the effect of geometrical gradients in Zn lattices. Zn constitutes a very promising biodegradable metal, because it displays corrosion rates in between those of Fe and Mg, but it has not been widely studied for biomedical applications. So, the first objective will be the optimization of the composition of the Zn alloy to ensure biocompatibility and sufficient mechanical properties. Subsequently, with the best candidate alloys, lattices with gradients based on different geometries and material distribution will be produced using laser powder bed fusion (LPBF) additive manufacturing. Finally, the geometry and degradation mechanisms will be characterized by means of mechanical and corrosion tests and advanced, high-resolution imaging techniques such as tomography. The results obtained in zinc will be compared with those obtained in compositionally graded materials, combining both Zn and Mg alloys, manufactured in sub-project 1. The cytotoxicity and the biological evaluation of all the graded structures will be continuously evaluated during degradation to assess the biological effects in cells cultivated in vitro.