Protected magnesium alloys for bioresorbable stents
AssigneeMedtronic Vascular, Inc.
InventorsSyamala Rani Pulugurtha, Jeffrey Allen, James Mitchell, Christopher Storment, Jill Mendelson
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Abstract
Biodegradable magnesium alloy implantable medical devices are protected to delay onset of corrosion, and thus biodegradability, or to corrode more uniformly. The protection allows for extended effective use of the devices while maintaining biodegradability. Examples of protective coatings include conversion coatings that at least partially remove exposed second phases from a surface of the magnesium alloy and coatings that provide a barrier between water and the surface of the magnesium alloy.
Claims13
A biodegradable frame for an implantable medical stent, the frame comprising:
- a magnesium (Mg) alloy core;
- a conversion coating that removes exposed secondary phases from a surface of the Mg alloy;
- and
- a layer of pure magnesium over the conversion coating.
A biodegradable tubular frame for an implantable medical stent, comprising:
- a magnesium (Mg) alloy layer;
- a first layer of pure magnesium;
- a second layer of pure magnesium, and
- a first conversion coating layer on the Mg alloy layer;
- wherein the Mg alloy layer is between the first and the second layers of pure magnesium, and
- wherein the first conversion coating layer is between the Mg alloy layer and the first layer of pure magnesium, and wherein the first conversion coating layer removes exposed secondary phases from a surface of the Mg alloy layer.
A biodegradable tubular frame, for an implantable medical stent, comprising:
- a magnesium (Mg) alloy layer;
- a conversion coating layer on the Mg alloy layer;
- a first layer of pure magnesium;
- and
- a second layer of pure magnesium;
- wherein the Mg alloy layer is between the first and the second layers of pure magnesium, and
- wherein the conversion coating layer is between the Mg alloy layer and the second layer of pure magnesium, and wherein the conversion coating layer removes exposed secondary phases from a surface of the Mg alloy layer.
Dependencies are inferred from the claim text.