Endoprosthesis with three-dimensional disintegration control
The present invention comprises a medical device having a support structure made from alternating layers. One or more layers may be made by direct metal laser sintering. One or more layers may be made by introducing nitrogen into a previously formed layer via excimer laser nitriding.
1. A method of making a biodisintegrable endoprosthesis, the method comprising:
forming a first layer of biodisintegrable metal on a support structure by direct metal laser sintering a metal powder, wherein the first layer is biodisintegrable; and
introducing a first nitrogen content into a first part of the first layer by excimer laser nitriding.
2. The method of claim 1 , wherein the endoprosthesis is a stent.
3. The method of claim 1 , further comprising:
constructing a second layer of a second material, upon the first layer, by direct metal laser sintering.
4. The method of claim 3 , further comprising:
introducing a second nitrogen content into a second part of the second layer by excimer laser nitriding.
5. The method of claim 3 , further comprising:
constructing a third layer of a third material, upon the second layer, by direct metal laser sintering.
6. The method of claim 5 , further comprising:
introducing a third nitrogen content into a third part of the third layer by excimer laser nitriding.
7. The method of claim 5 , further comprising:
constructing further alternating layers on the third layer, wherein the alternating layers comprise, in sequence, a direct metal laser sintered layer, and a direct metal laser sintered layer having a nitrogen content introduced by excimer nitriding.
8. The method of claim 1 wherein the biodisintegrable metal is a metal selected from the group consisting of: alkali metals, alkaline earth metals, iron, zinc, and aluminum.
9. The method of claim 8 wherein the biodisintegrable metal is magnesium.
10. The method of claim 3 wherein the biodisintegrable metal is iron.
11. The method of claim 1 , wherein the biodisintegrable metal is a metal alloy.
12. The method of claim 1 wherein the endoprosthesis has a shape, and wherein the shape is generally tubular.
13. The method of claim 1 wherein the first part of the first layer is the entirety of the first layer.
14. The method of claim 1 wherein the first material comprises platinum nanoparticles within a matrix of the biodisintegrable metal.
15. The method of claim 10 wherein the second material is magnesium.
16. A method of making a support structure for a medical device, the method comprising:
constructing, on the support structure, a first layer of iron by direct metal laser sintering;
introducing a first nitrogen content into a first part of the first layer by excimer laser nitriding;
constructing a second layer of magnesium, upon the first layer, by direct metal laser sintering, wherein, after excimer nitriding, the second layer has a ratio of nitrogen to magnesium of less than 0.45.
17. A method of making a support structure for a medical device, the method comprising:
constructing, on the support structure, a first layer of iron by direct metal laser sintering;
introducing a first nitrogen content into a first part of the first layer by excimer laser nitriding;
constructing a second layer of magnesium, upon the first layer, by direct metal laser sintering, wherein, after excimer nitriding, the second layer has a ratio of nitrogen to magnesium of greater than 0.45.
18. The method of claim 1 wherein the direct metal laser sintering is laser-engineered net shaping.