Blood clotting substrate and medical device

1. A method of promoting blood clotting, comprising contacting blood with a blood clotting substrate comprising a plurality of oxygen plasma-treated polypropylene pillars extending from a surface of a oxygen plasma-treated polypropylene film, wherein the film and pillars demonstrate a normalized clotting time of 0.2, compared to an untreated film clot time of 0.9 when contacted with blood.

2. A method of promoting blood clotting, comprising contacting blood with a blood clotting medical device, comprising an oxygen plasma-treated polypropylene film having a plurality of oxygen plasma-treated polypropylene pillars extending from a surface thereof, wherein the oxygen plasma-treated polypropylene film and pillars demonstrate a normalized clotting time of 0.2, compared to an untreated film clot time of 0.9 when contacted with blood.

3. A method of forming a blood clotting substrate, comprising:

a) providing a mold dissolvable by a specific solvent including indentations;

b) providing a polypropylene film to the mold under conditions sufficient to permit filling the indentations of the mold by the polypropylene;

c) treating the mold and polypropylene of step b) to an extent sufficient to substantially solidify the polypropylene;

d) exposing the mold and polypropylene to the specific solvent selected to dissolve the mold but not the polypropylene under mold-dissolving conditions to provide a pillared substrate; and

e) oxygen plasma-treating the pillared substrate.

4. A blood clotting substrate, comprising a plurality of polypropylene pillars extending from a surface of a polypropylene film, wherein the polypropylene pillars and polypropylene film have been oxygen plasma-treated and demonstrate a normalized clotting time of 0.2, compared to an untreated film clot time of 0.9 when contacted with blood.

5. The blood clotting substrate of claim 4 , wherein the pillars are of a diameter from about 0.8 μm to about 3 μm and have aspect ratios from about 0.5 to about 40.

6. The blood clotting substrate of claim 5 , wherein the pillars have a diameter of about 1 μm and a height of about 20 μm.

7. The blood clotting substrate of claim 4 , which has a static water contact angle of less than about 15°.

8. The blood clotting substrate of claim 4 , wherein the polypropylene film and pillars have a higher oxygen content on surfaces thereof than non-oxygen plasma treated polypropylene film and pillars.

9. The blood clotting substrate of claim 4 , wherein the polypropylene film and pillars have an oxygen content of about 21%.

10. A blood clotting medical device, comprising an oxygen plasma-treated polypropylene film having a plurality of oxygen plasma-treated polypropylene pillars extending from a surface thereof, wherein the oxygen plasma-treated polypropylene film and pillars demonstrate a clotting time of 0.2, normalized to an untreated film clot time of 0.9 when contacted with blood.

11. The blood clotting medical device of claim 10 , wherein the pillars are of a diameter from about 0.8 μm to about 3 μm and have aspect ratios from about 0.5 to about 40.

12. The blood clotting medical device of claim 11 , wherein the pillars have a diameter of about 1 μm and a height of about 20 μm.

13. The blood clotting medical device of claim 10 , which has a static water contact angle of less than about 15°.

14. The blood clotting medical device of claim 10 , wherein the polypropylene film and pillars have a higher oxygen content on surfaces thereof than non-oxygen plasma treated polypropylene film and pillars.

15. The blood clotting medical device of claim 10 , wherein the polypropylene film and pillars have an oxygen content of about 21%.