Additive manufacturing (AM) has a high potential for manufacturing patient-specific implants. Hence, the processing of biodegradable metallic materials to fabricate new temporary implants with complex geometry and with adjusted mechanical and (bio)chemical properties is currently drawing increasing attention. Thereby, laser powder bed fusion (LPBF) – as a dominating metal AM process – presents an attractive technology. Regarding biodegradable materials, Fe-Mn-based alloys show a high potential as implant materials, besides Mg- or Zn-based systems, due to the broad range of mechanical properties, the high mechanical integrity during degradation as well as an excellent processability, [1]. Especially, the processing of Fe-Mn-C-based alloys via LPBF is very attractive because very filigree structures can be realized due to their high strength. Such filigree structures are needed for e.g. stents to open up clogged vessels. Furthermore, owing to the LPBF processing a relatively homogenous microstructure can will be achieved leading to the desired uniform degradation.

First stent prototypes were successfully processed via LPBF using our developed Fe-30Mn-1C-0,02S alloy [2-6]. The stents with a generic structure could be expanded manually with a balloon catheter [5]. In 3-point-bending tests, those stents revealed superior mechanical properties in comparison to LPBFprocessed stent structures made of clinically applied 316L SS [6]. Further on, generic stent structures were seeded with endothelial cells and cultivated for up to 14 days. Thereby, the influence of different degradation stages due to pre-incubation in cell culture medium on adhesion, viability and morphology of the endothelial cells was analyzed [6]. After 1 day of cultivation of endothelial cells on different degraded samples, no difference of the degradation stages was obvious. Only after longer cultivation of 7 to 14 days, the influence of the degradation layer became visible. Overall, biocompatibility of the alloy was confirmed and Fe-Mn-C systems are promising candidates for potential application as temporary implant material.

Funding of this project by the DFG under project number HU 2371/1-1 is gratefully acknowledged.