Biocompatibility of vascular stents manufactured using metal injection molding in animal experiments

This study aimed to evaluate the feasibility and safety of a novel stent manufactured by metal injection molding (MIM) in clinical practice through animal experiments. Vessel stents were prepared using powder injection molding technology to considerably improve material utilization. The influence of MIM carbon impurity variation on the mechanical properties and corrosion resistance of 316L stainless steel was studied. In vitro cytotoxicity and animal transplantation tests were also carried out to evaluate the safety of MIM stents. The results showed that the performance of 316L stainless steel was very sensitive to the carbon content. Carbon fluctuations should be precisely controlled during MIM. All MIM stents were successfully implanted into the aortas of the dogs, and the MIM 316L stents had no significant cytotoxicity. The novel intravascular stent manufactured using MIM can maintain a stable form and structure with fast endothelialization of the luminal surface of the stent and ensure long-term patency in an animal model. The novel intravascular stent manufactured using MIM demonstrates favorable structural, physical, and chemical stability, as well as biocompatibility, offering promising application in clinical practice.