Degradable biomedical magnesium alloy drug-eluting vascular stent and preparation method

A degradable biomedical magnesium alloy drug-eluting vascular stent, comprising a stent substrate, and a polymer intermediate layer, a polymer protective layer, and a drug coating layer arranged from inside to outside of the stent substrate, wherein the stent substrate comprises the following components in percentage by weight:

• 3.0-6.0% of Gd, 2.5-5.5% of Y, 0.3-1.0% of Zn, 0.2-1.0% of Zr and balance of Mg, with regard to a total weight of the stent substrate of 100%;
• wherein the polymer of the polymer protective layer is polyvinylidene fluoride and a copolymer thereof;
• and the polymer protective layer has a thickness of 2 μm-10 μm;
• wherein the vascular stent further comprises a drug coating layer provided on the outer surface of the polymer protective layer;
• the drug coating layer comprises a polymer carrier and an active drug;
• the active drug is a combination of tacrolimus and one selected from rapamycin and arsenic trioxide;
• wherein the weight ratio of arsenic trioxide or rapamycin to tacrolimus is 1:2-4:1.