Coated medical device and method of coating such a device
A medical device such as a stent ( 10 ) or medical balloon ( 40 ) is at least partially coated with a carboxylic acid layer in order to enhance biocompatibility, reduce thrombogenesis and increase endothelialisation. The coating is preferably of citric acid in non-crosslinked form and preferably non-porous so as to mask the underlying structure of the medical device. The acid coating forms an outer surface of at least a part of the medical device, that is has no other layer or material overlying it, save for in some embodiments a partial coating of a bioactive material.
1. A medical device including:
a structure for implantation or disposition inside a patient, the structure including at least one surface;
wherein the at least surface is at least partially covered by a layer of a carboxylic acid or a derivative of carboxylic acid;
said layer being an outermost layer of the structure; and
wherein the outermost layer is at least 90% carboxylic acid or a derivative thereof.
2. A medical device according to claim 1 , wherein the outermost layer is a non-porous layer.
3. A medical device according to claim 1 , wherein the outermost layer is carrier free.
4. A medical device according to claim 1 , wherein the outermost layer has a thickness of less than 100 nanometres.
5. A medical device according to claim 1 ,
wherein the outermost layer is formed of non-crosslinked molecules.
6. A medical device according to claim 1 , wherein the outermost layer is dispersed over at least 80% of the at least one surface.
7. A medical device according to claim 1 , including an interstitial layer between the at least one surface and the outermost layer.
8. A medical device according to claim 1 , wherein the medical device includes an abluminal and a luminal surface, wherein at least one of the abluminal and luminal surfaces is covered by a layer of a carboxylic acid or a derivative of a carboxylic acid as an outermost layer of the at least one surface.
9. A medical device including:
a structure for implantation or disposition inside a patient, the structure including at least one surface;
wherein the at least surface is at least partially covered by a layer of a carboxylic acid or a derivative of carboxylic acid;
said layer being an outermost layer of the structure, and
wherein the outermost layer includes in the region of 100 micrograms of carboxylic acid or a derivative thereof.
10. A medical device including:
a structure for implantation or disposition inside a patient, the structure including at least one surface;
wherein the at least surface is at least partially covered by a layer of a carboxylic acid or a derivative of carboxylic acid;
said layer being an outermost layer of the structure, and
wherein the outermost layer is a layer of citric acid.
11. A medical device including:
a structure for implantation or disposition inside a patient, the structure including at least one surface;
wherein the at least surface is at least partially covered by a layer of a carboxylic acid or a derivative of carboxylic acid;
said layer being an outermost layer of the structure, and
wherein the outermost layer is a layer of citric acid mixed with citrate.
12. A medical device including:
a structure for implantation or disposition inside a patient, the structure including at least one surface;
wherein the at least surface is at least partially covered by a layer of a carboxylic acid or a derivative of carboxylic acid;
said layer being an outermost layer of the structure, and
wherein the outermost layer is formed of amorphous carboxylic acid or a derivative thereof.
13. A medical device including:
a structure for implantation or disposition inside a patient, the structure including at least one surface;
wherein the at least surface is at least partially covered by a layer of a carboxylic acid or a derivative of carboxylic acid;
said layer being an outermost layer of the structure,
wherein the medical device includes an abluminal and a luminal surface, wherein at least one of the abluminal and luminal surfaces is covered by a layer of a carboxylic acid or a derivative of a carboxylic acid as an outermost layer of the at least one surface, and
wherein one of the abluminal and luminal surfaces is covered by a layer of a carboxylic acid or a derivative thereof as an outermost layer of the at least one surface and the other of the abluminal and luminal surfaces is covered by a layer of a carboxylic acid or a derivative thereof underlying a layer of bioactive agent.
14. A medical device according to claim 13 , wherein the bioactive agent layer consists of or is principally of bioactive material.
15. A medical device according to claim 13 , wherein the bioactive agent layer is or includes a therapeutic substance.
16. A medical device according to claim 13 , wherein the bioactive agent layer is or includes paclitaxel.
17. A medical device including:
a structure for implantation or disposition inside a patient, the structure including at least one surface;
wherein the at least surface is at least partially covered by a layer of a carboxylic acid or a derivative of carboxylic acid;
said layer being an outermost layer of the structure, and
wherein the outermost layer is a non-porous layer of at least 90% amorphous carboxylic acid or a derivative thereof, citric acid or citric acid mixed with citrate;
wherein the outermost layer is formed of non-crosslinked molecules, has a thickness of less than 100 nanometers and includes in the region of 100 micrograms of carboxylic acid or a derivative thereof, wherein the device further includes an interstitial layer between the at least one surface and the outermost layer, and wherein the device further includes a layer of bioactive agent including paclitaxel of which the outermost layer underlies the layer of bioactive agent.
18. Use of a medical device including a structure for implantation or disposition inside a patient, the structure including at least one surface, wherein the at least surface is covered by a layer of a carboxylic acid or a derivative of carboxylic acid, said layer being an outermost layer of the structure and is one of a layer of citric acid, a layer of citric acid mixed with citrate, and a layer of at least 90% carboxylic acid or a derivative thereof, in the reduction or prevention of thrombogenesis.
19. Use of a medical device including a structure for implantation or disposition inside a patient, the structure including at least one surface, wherein the at least surface is covered by a layer of a carboxylic acid or a derivative of carboxylic acid, said layer being an outermost layer of the structure and is a layer of citric acid, a layer of citric acid mixed with citrate, and a layer of at least 90% carboxylic acid or a derivative thereof, in the enhancement of endothelialisation.