A Biodegradable Metal‐Polymer Composite Stent Safe and Effective on Physiological and Serum‐Containing Biomimetic Conditions

The new‐generation coronary stents are expected to be biodegradable, and then the biocompatibility along with biodegradation becomes more challenging. It is a critical issue to choose appropriate biomimetic conditions to evaluate biocompatibility. Compared with other candidates for biodegradable stents, iron‐based materials are of high mechanical strength, yet have raised more concerns about biodegradability and biocompatibility. Herein, a metal‐polymer composite strategy is applied to accelerate the degradation of iron‐based stents in vitro and in a porcine model. Furthermore, it is found that serum, the main environment of vascular stents, ensured the safety of iron corrosion through its antioxidants. This work highlights the importance of serum, particularly albumin, for an in vitro condition mimicking blood‐related physiological condition, when reactive oxygen species, inflammatory response, and neointimal hyperplasia are concerned. The resultant metal‐polymer composite stent is implanted into a patient in clinical research via interventional treatment, and the follow‐up confirms its safety, efficacy, and appropriate biodegradability. A metal‐polymer composite strategy is applied to control the degradation of iron‐based materials. The stents fabricated with this strategy exhibit a balance between accelerated biodegradation and adequate radial strength to match the arterial remodeling. This work highlights the ability of serum, especially the albumin in it, to scavenge ROS and thus enhance the biosafety of iron‐based materials.