MEDICAL DEVICES HAVING CARBON DRUG RELEASING LAYERS
According to various aspects of the invention, medical devices are provided, which comprise (a) a substrate, (b) a drug-containing layer disposed over the substrate, which contains one or more drugs and, optionally, one or more additional materials, and (c) a carbon layer disposed over the drug-containing layer.
1 . An implantable or insertable medical device comprising (a) a substrate, (b) a drug-containing layer over the substrate, said drug-containing layer comprising a drug and a rupturing element, and (c) a carbon layer disposed over said drug-containing layer, wherein said rupturing element acts to rupture the carbon layer during or after implantation or insertion of said device.
2 . The implantable or insertable medical device of claim 1 , wherein said rupturing element ruptures the carbon layer upon application of a compressive force to the drug-containing layer and the carbon layer during implantation or insertion of said device.
3 . The implantable or insertable medical device of claim 2 , wherein said rupturing element is a hard, sharp structural element which ruptures the carbon layer upon application of a compressive force to the drug-containing layer and the carbon layer.
4 . The implantable or insertable medical device of claim 3 , comprising a plurality of said hard, sharp structural elements.
5 . The implantable or insertable medical device of claim 4 , wherein said plurality of said structural elements comprise sharp metallic or non-metallic inorganic particles.
6 . The implantable or insertable medical device of claim 1 , wherein said rupturing element expands and ruptures the carbon layer upon exposure to bodily fluid.
7 . The implantable or insertable medical device of claim 6 , wherein said rupturing element is selected from a metallic element that expands upon corrosion and a hydrogel element that expands upon aqueous fluid uptake.
8 . The implantable or insertable medical device of claim 1 , wherein the substrate is a metallic substrate.
9 . The implantable or insertable medical device of claim 1 , wherein the device is a stent.
10 . The implantable or insertable medical device of claim 1 , wherein the carbon layer is a diamond-like carbon layer.
11 . The implantable or insertable medical device of claim 10 , wherein said diamond-like carbon layer comprises an sp 3 fraction of 50% or more.
12 . The implantable or insertable medical device of claim 10 , wherein said diamond-like carbon layer is either vapor deposited or formed from carbon atoms that were previously part of said drug-containing layer.
13 . A medical device comprising (a) a substrate, (b) a drug-containing layer over the substrate, said drug-containing layer comprising a drug and a reinforcing element, and (c) a carbon layer disposed over said drug-containing layer, wherein said reinforcing element protects said carbon layer by preventing compression of the drug-containing layer upon application of a compressive force to the drug-containing layer.
14 . The implantable or insertable medical device of claim 13 , wherein said reinforcing element is selected from a fiber mesh, a screen, and a porous membrane.
15 . The implantable or insertable medical device of claim 13 , comprising plurality of reinforcing elements.
16 . The implantable or insertable medical device of claim 15 , wherein the reinforcing elements are circular or oval in cross-section.
17 . The implantable or insertable medical device of claim 15 , wherein the reinforcing elements are spheroidal reinforcing elements.
18 . The implantable or insertable medical device of claim 13 , further comprising a rapidly dissolvable layer disposed over the carbon layer.
19 . An implantable or insertable medical device comprising (a) a substrate, (b) a drug-containing layer over the substrate, said drug-containing layer comprising a drug, (c) a carbon layer disposed over said drug-containing layer, and (d) a rapidly dissolvable organic layer disposed over the carbon layer.
20 . The implantable or insertable medical device of claim 19 , wherein the rapidly dissolvable organic layer comprises a material selected from a polysaccharide and a protein, a glycoprotein and a fatty acid alkyl ester.
21 . The implantable or insertable medical device of claim 19 , wherein the rapidly dissolvable organic layer comprises a plurality of sharp hard particles.