Medical devices and methods of making the same
Medical devices, such as endoprostheses, and methods of making the devices are described. In some embodiments, the invention features a medical device including a generally tubular body including a biodisintegrable material, and a polyelectrolyte on the generally tubular body. The polyelectrolyte can be used to delay and/or slow the disintegration of the biodisintegrable material.
1 . A medical device, comprising:
a generally tubular body comprising a biodisintegrable material; and
a first polyelectrolyte on the generally tubular body.
2 . The medical device of claim 1 , wherein the first polyelectrolyte is biodisintegrable.
3 . The medical device of claim 1 , wherein the first polyelectrolyte comprises a polyacid.
4 . The medical device of claim 3 , wherein the polyacid is selected from the group consisting of polyphosphoric acids, polyvinylsulfuric acids, polyvinylsulfonic acids, polyvinylphosphonic acids, and polyacrylic acids.
5 . The medical device of claim 1 , wherein the first polyelectrolyte comprises a polybase.
6 . The medical device of claim 5 , wherein the polybase comprises polyallylamine, polyethylimine, polyvinylamine, and polyvinylpyridine.
7 . The medical device of claim 1 , wherein the first polyelectrolyte comprises a polycation.
8 . The medical device of claim 7 , wherein the polycation is selected from the group consisting of poly(allylamine)polycations, polyethyleneimine polycations, polydiallyldimethylammonium polycations, protamine sulfate polycations, chitosan polycations, gelatin polycations, spermidine polycations, poly(N-octyl-4-vinyl pyridinium iodide) polycations, and albumin polycations.
9 . The medical device of claim 1 , wherein the first polyelectrolyte comprises a polyanion.
10 . The medical device of claim 9 , wherein the polyanion is selected from the group consisting of poly(styrene sulfonate)polyanions, polyacrylic acid polyanions, sodium alginate polyanions, eudragit polyanions, gelatin polyanions, hyaluronic acid polyanions, carrageenan polyanions, chondroitin sulfate polyanions, and carboxymethylcellulose polyanions.
11 . The medical device of claim 1 , wherein the first polyelectrolyte comprises a polymer selected from the group consisting of heparin, proteins, polyglycolic acid, polylactic acid, polyamides, poly-2-hydroxy-butyrate, polycaprolactone, and poly(lactic-co-glycolic)acid.
12 . The medical device of claim 1 , wherein the biodisintegrable material comprises a metal.
13 . The medical device of claim 1 , wherein the biodisintegrable material comprises a metal selected from the group consisting of alkali metals, alkaline earth metals, iron, zinc, and aluminum.
14 . The medical device of claim 1 , wherein the biodisintegrable material comprises iron.
15 . The medical device of claim 1 , wherein the biodisintegrable material comprises magnesium.
16 . The medical device of claim 1 , wherein the biodisintegrable material comprises a metal alloy.
17 . The medical device of claim 1 , wherein the biodisintegrable material comprises an iron alloy.
18 . The medical device of claim 1 , wherein the biodisintegrable material comprises a magnesium alloy.
19 . The medical device of claim 1 , wherein the biodisintegrable material comprises a first component selected from the group consisting of magnesium, titanium, zirconium, niobium, tantalum, zinc, and silicon, and a second component selected from the group consisting of lithium, sodium, potassium, calcium, iron, and manganese.
20 . The medical device of claim 1 , wherein the biodisintegrable material comprises a non-metal.
21 . The medical device of claim 1 , wherein the biodisintegrable material comprises a polymer.
22 . The medical device of claim 1 , wherein the medical device comprises a first layer comprising the first polyelectrolyte, the first layer being supported by the generally tubular body.
23 . The medical device of claim 22 , wherein the first layer has a thickness of at most about 500 nanometers.
24 . The medical device of claim 23 , wherein the first layer has a thickness of at least about 0.2 nanometer.
25 . The medical device of claim 22 , wherein the first layer defines at least one opening.
26 . The medical device of claim 22 , wherein the first layer contacts the generally tubular body.
27 . The medical device of claim 22 , further comprising a second layer that is supported by the generally tubular body.
28 . The medical device of claim 27 , wherein the second layer contacts the first layer.
29 . The medical device of claim 27 , wherein the medical device comprises a plurality of first layers and a plurality of second layers.
30 . The medical device of claim 29 , wherein at least two of the first layers are spaced from each other by one or more second layers.
31 . The medical device of claim 27 , wherein the second layer comprises a second polyelectrolyte.
32 . The medical device of claim 31 , wherein the second polyelectrolyte is different from the first polyelectrolyte.
33 . The medical device of claim 31 , wherein the first polyelectrolyte is positively charged and the second polyelectrolyte is negatively charged.
34 . The medical device of claim 1 , wherein the medical device further comprises a second polyelectrolyte on the generally tubular body.
35 . The medical device of claim 34 , wherein the first polyelectrolyte and the second polyelectrolyte are cross-linked to each other.
36 . The medical device of claim 35 , wherein the first polyelectrolyte and the second polyelectrolyte are cross-linked to each other by at least one covalent bond.
37 . The medical device of claim 1 , wherein the medical device comprises a plurality of layers.
38 . The medical device of claim 37 , wherein a first portion of the medical device comprises a greater number of layers than a second portion of the medical device.
39 . The medical device of claim 38 , wherein the first portion includes at least 20 layers.
40 . The medical device of claim 39 , wherein the second portion includes at least 10 layers.
41 . The medical device of claim 37 , wherein the plurality of layers has a total thickness of at most 1500 nanometers.
42 . The medical device of claim 41 , wherein the plurality of layers has a total thickness of at least five nanometers.
43 . The medical device of claim 37 , wherein the medical device comprises at least 10 layers.
44 . The medical device of claim 43 , wherein the medical device comprises at most 300 layers.
45 . The medical device of claim 1 , wherein the medical device comprises an endoprosthesis.