A stent is formed of at least a cobalt-based alloy. The cobalt-based alloy may include 10-35 weight % metal member selected from the group consisting of platinum (Pt), gold (Au), iridium (Ir), osmium (Os), rhenium (Re), tungsten (W), palladium (Pd), tantalum (Ta), and combinations thereof； 16-21 weight % chromium (Cr)； 9-12 weight % molybdenum (Mo)； 0-25 weight % nickel (Ni)； and balance cobalt (Co). The cobalt-based alloy may be a thin outer shell of a hollow stent. The cobalt-based alloy may be used to form at least one of an inner core and an outer shell of a core-shell structure of a stent. The cobalt-based alloy may be used to form an end of a wire for forming a stent.
