Surface treatments for vascular stents and methods thereof
Surface modified medical devices with nanotubes and polyelectrolyte multilayers, methods of promoting endothelialization, and methods of modifying a medical device surface are disclosed. Nanotubes may be formed on the surface of the medical device and may further be coated with polyelectrolyte multilayers of a polycation and a polyanion. The surface modification is characterized by a nanopattern on the surface of the medical device, with biomimetic properties.
1. A medical device for promoting endothelialization comprising:
a body having at least a first surface;
a plurality of nanotubes formed on the first surface of the body;
at least one polyelectrolyte layer deposited on the nanotubes comprising: a polycation layer; and
a polyanion layer,
wherein the nanotubes and the polyelectrolyte layers form a nanopatterned structure on the first surface of the body of the medical device to promote endothelialization and reduce platelet adhesion and activation.
2. The medical device of claim 1 , wherein the medical device is a vascular stent.
3. The medical device of claim 1 , wherein at least one of the polycation or polyanion comprises nitric oxide-releasing groups.
4. The medical device of claim 3 , wherein the device releases nitric oxide from the surface.
5. The medical device of claim 4 , wherein the device releases nitric oxide at a rate of about 5 nmol/s to about 500 nmol/s.
6. The medical device of claim 5 , wherein the device releases nitric oxide for a period of at least about 2 to about 3 weeks.
7. The medical device of claim 3 , wherein the polycation comprises nitric oxide-releasing groups.
8. The medical device of claim 3 , wherein the polyanion comprises nitric oxide-releasing groups.
9. The medical device of claim 1 , wherein the nanotubes comprise titanium, a titanium alloy, a titanium oxide, or stainless steel.
10. The medical device of claim 1 , wherein the polycation is chitosan.
11. The medical device of claim 1 , wherein the polyanion is a glycosaminoglycan.
12. The medical device of claim 11 , wherein the glycosaminoglycan is selected from heparin, heparan sulfate, chondroitin sulfate, keratan sulfate, dextran sulfate, a sulfated polysaccharide, and a sulfate-containing polylelectrolyte.
13. The medical device of claim 1 , further comprising a growth factor adsorbed on the at least one polyelectrolyte layer.
14. The medical device of claim 13 , wherein the growth factor is vascular endothelial growth factor (VEGF).
15. A method of promoting endothelialization and reducing platelet adhesion and activation in a tissue in a subject in need thereof, the method comprising:
implanting a medical device in the tissue, wherein the device comprises: a body having at least a first surface;
a plurality of nanotubes formed on the first surface of the body;
at least one polyelectrolyte layer deposited on the nanotubes comprising:
a polycation layer; and
a polyanion layer,
wherein the nanotubes and the polyelectrolyte layers form a nanopatterned structure on the first surface of the body of the medical device to promote endothelialization and reduce platelet adhesion and activation.
16. The method of claim 15 , wherein the medical device is a vascular stent.
17. The method of claim 15 , wherein at least one of the polycation or polyanion comprises nitric oxide-releasing groups.
18. The method of claim 17 , wherein the surface of the device releases nitric oxide over a period of time.
19. The medical device of claim 18 , wherein the device releases nitric oxide at a rate of about 5 nmol/s to about 500 nmol/s.
20. The medical device of claim 19 , wherein the device releases nitric oxide for a period of at least about 2 to about 3 weeks.
21. The method of claim 15 , wherein the polycation comprises nitric oxide-releasing groups.
22. The method of claim 15 , wherein the polyanion comprises nitric oxide-releasing groups.
23. The method of claim 15 , wherein the nanotubes comprise titanium, a titanium alloy, a titanium oxide, or stainless steel.
24. The method of claim 15 , wherein the polycation is chitosan.
25. The method of claim 15 , wherein the polyanion is a glycosaminoglycan.
26. The method of claim 25 , wherein the glycosaminoglycan is selected from heparin, heparan sulfate, chondroitin sulfate, keratan sulfate, dextran sulfate, a sulfated polysaccharide, and a sulfate-containing polylelectrolyte.
27. The method of claim 15 , wherein the medical device further comprises a growth factor adsorbed on to the at least one polyelectrolyte layer.
28. The method of claim 27 , wherein the growth factor is VEGF.
29. A method of modifying a surface of a medical device to promote (re)endothelialization and reduce platelet adhesion and activation, the method comprising:
forming nanotubes on at least a first surface of the medical device and depositing at least one polyelectrolyte layer on the nanotubes comprising:
depositing a polycation layer on the nanotubes;
rinsing the surface;
depositing a polyanion layer on the nanotubes; and
rinsing the surface,
wherein the nanotubes and the polyelectrolyte layers form a nanopatterned structure on the first surface of the medical device to promote (re)endothelialization and reduce platelet adhesion and activation.
30. The method of claim 29 , further comprising modifying at least one of the polycation or the polyanion with nitric oxide-releasing groups.
31. The method of claim 30 , wherein the surface of the device releases nitric oxide over a period of time.
32. The medical device of claim 31 , wherein the device releases nitric oxide at a rate of about 5 nmol/s to about 500 nmol/s.
33. The medical device of claim 32 , wherein the device releases nitric oxide for a period of at least about 2 to about 3 weeks.
34. The method of claim 29 , wherein forming the nanotubes comprises anodizing the first surface of the medical device.
35. The method of claim 29 , further comprising repeating the alternation of the polycation layer and polyanion layer until a desired thickness is reached.
36. The method of claim 29 , wherein the nanotubes comprise titanium, a titanium alloy, a titanium oxide, or stainless steel.
37. The method of claim 29 , wherein the polycation is chitosan.
38. The method of claim 29 , wherein the polyanion is selected from heparin, heparan sulfate, and chondroitin sulfate.
39. The method of claim 29 , further comprising adsorbing VEGF to the polyelectrolyte layers.