Additively manufactured WE43 for biodegradable urinary devices: Exploring the corrosion profile under in vitro urinary tract conditions

• Thin-walled tubes and wires of a Mg WE43 alloy were successfully produced via PBF-LB and tested under dynamic urinary tract conditions, representing a first step towards an additively manufactured Mg-based biodegradable ureteral stent. • The corrosion behaviour was strongly influenced by printing parameters and geometry as a result of a changing microstructure as well as morphology. • Thin-walled tubes produced at the smallest evaluated hatch distance of 40 µm showed the most promising results, while for wires it was the samples manufactured at the largest hatch distance of 60 µm giving the best results, highlighting hatch distance and structure-specific optimization as key factors in achieving controlled corrosion performance . Urinary stents are widely used medical devices, however, the necessity of a second surgery for the stent removal is a significant drawback. Hence, using biodegradable materials for stent development has been considered a promising approach. Biodegradable Mg alloys have been gaining popularity for biodegradable medical devices due to the recognized biocompatibility and mechanical characteristics. This work explored the suitability of a WE43 alloy for urinary stent applications using additive manufacturing (AM). This manufacturing technique allows the creation of intricate geometries with high resolution, thus presenting a significant potential for stent design development. The corrosion behaviour of WE43-printed tubes and wires, potential precursors for ureteral stents, were investigated under simulated dynamic urinary tract conditions. While the corrosion pattern was found to be greatly influenced by the different designs and process parameters, where the corrosion rates varied considerably among the samples over time, the resulting corrosion layer exhibited similarities, all presenting a non-homogeneous coverage and the same chemical elements. This work highlighted the challenge of obtaining homogeneous corrosion but suggested that this type of design exploration could be a useful approach to optimize and tune the stents' corrosion pattern, given the considerable influence of the design on the corrosion pattern. AM is hence a promising research strategy for the exploration of ureteral stent designs given the possibility to easily print a high number of samples with different printing parameters.