US4613517A — Heparinization of plasma treated surfaces

Claim 1

Independent Claim 46 words

In the method of reducing thrombogenicity by attaching heparin to the surface of a polymeric substrate, the improvement comprising subjecting said substrate to a plasma treatment and steeping the plasma-treated substrate with an aqueous dispersion of a cationic surface active agent before attaching said heparin thereto.

Claim 2

Dependent Claim 46 words

In the method of reducing thrombogenicity by attaching heparin to the surface of a polymeric substrate, the improvement comprising subjecting said substrate to a plasma treatment and steeping the plasma-treated substrate with an aqueous dispersion of a cationic surface active agent before attaching said heparin thereto.

Claim 3

Dependent Claim 36 words

The improved method in accordance with claim 1 in which said polymeric substrate is selected from the group consisting of silicone, polyethylene, polypropylene, polyurethane, polyacrylics, polyamide, polyester, polyvinyl pyrrolidone, polyvinyl alcohol, cellulose acetate, polyvinylchloride and polytetrafluoroethylene.

Claim 4

Dependent Claim 34 words

The improved method in accordance with claim 1 wherein said plasma is generated from a gas selected from the group consisting of oxygen, ammonia, hydrogen, helium, neon, argon, krypton, xenon, nitrogen or mixtures thereof.

Claim 5

Dependent Claim 18 words

The improved method in accordance with claim 1 wherein said plasma is generated using a radio frequency discharge.

Claim 6

Dependent Claim 24 words

The improved method in accordance with claim 1 wherein said plasma is generated with a power of from about 10 to about 200 watts.

Claim 7

Dependent Claim 29 words

The improved method in accordance with claim 1 wherein said polymeric substrate is subjected to said plasma for a period of from about for 0.1 to about 30 minutes.

Claim 8

Dependent Claim 14 words

The improved method in accordance with claim 2 wherein said polymeric surface is polytetrafluoroethylene.

Claim 9

Dependent Claim 14 words

The improved method in accordance with claim 2 wherein said polymeric surface if polyethylene.

Claim 10

Dependent Claim 31 words

The improved method in accordance with claim 3 wherein said gas is maintained at a Chamber pressure of from about 10 to about 300μ of mercury during generation of said plasma.

Claim 11

Dependent Claim 21 words

The improved method in accordance with claim 4 wherein said radio frequency is maintained from about 1 to about 50 megahertz.

Claim 12

Dependent Claim 57 words

The improved method in accordance with claim 1 wherein a polytetrafluoroethylene substrate is subjected to an oxygen plasma wherein said plasma is generated by a discharge of about 50 watts at a radio frequency of about 13.56 megahertz, said discharge being maintained for about 10 minutes with said oxygen at a pressure of about 180μ of Hg.

Claim 13

Independent Claim 62 words

A method for binding heparin to a polymeric substrate comprising the sequential steps of (1) subjecting said polymeric substrate to a plasma treatment, (2) steeping said plasma treated substrate in an aqueous dispersion of a cationic surface active agent, (3) immersing said substrate in an aqueous solution of sodium heparin, and (4) treating said substrate with an aqueous solution of a dialdehyde.

Claim 14

Independent Claim 62 words

A method for binding heparin to a polymeric substrate comprising the sequential steps of (1) subjecting said polymeric substrate to a plasma treatment, (2) steeping said plasma treated substrate in an aqueous dispersion of a cationic surface active agent, (3) immersing said substrate in an aqueous solution of sodium heparin, and (4) treating said substrate with an aqueous solution of a dialdehyde.

Claim 15

Dependent Claim 66 words

The method in accordance with claim 12 in which said cationic surface active agent is a compound of the formula ##STR3## wherein R 1 is an alkyl group of 12-18 carbon atoms, R 2 , R 3 and R 4 are each independently selected from the group consisting of hydrogen and lower alkyl of 1 to 6 carbon atoms and X is a negative monovalent ion.

Claim 16

Dependent Claim 32 words

The method in accordance with claim 13 wherein R 2 is a lower alkyl of 1 to 6 carbon atoms, R 3 and R 4 are each hydrogen and X is halogen.

Claim 17

Dependent Claim 11 words

The method in accordance with claim 14 wherein X is chloride.

Claim 18

Dependent Claim 28 words

The method in accordance with claim 15 wherein said compound is selected from the group consisting of dodecylmethylammonium chloride, tetradecylmethylammonium chloride, hexadecylmethylammonium chloride, octadecylmethylammonium chloride and dodecylhexylammonium chloride.

Claim 19

Dependent Claim 13 words

The method in accordance with claim 16 wherein said compound is dodecylmethylammonium chloride.

Claim 20

Dependent Claim 24 words

The method in accordance with claim 12 wherein the aqueous concentration of said cationic surface active agent is from about 0.01 to about 2.0%.

Claim 21

Dependent Claim 33 words

The method in accordance with claim 12 wherein the steeping of said substrate in the aqueous dispersion of said surface active agent is carried out for from about 1 to about 24 hours.

Claim 22

Dependent Claim 44 words

The method in accordance with claim 12 wherein the steeping of said substrate in the aqueous dispersion of said surface active agent is carried out at ambient temperature or at an elevated temperature up to or slightly above the softening temperature of said substrate.

Claim 23

Dependent Claim 27 words

The method in accordance with claim 12 wherein said substrate is immersed in an aqueous solution of from about 1 to about 15 percent of sodium heparin.

Claim 24

Dependent Claim 24 words

The method in accordance with claim 12 wherein said immersion is carried out at a temperature from about ambient temperature to about 80° C.

Claim 25

Dependent Claim 28 words

The method in accordance with claim 12 wherein said substrate is immersed in said aqueous solution of sodium heparin for from about 1 hour to about 24 hours.

Claim 26

Dependent Claim 17 words

The method in accordance with claim 12 wherein said dialdehyde contains from 2 to 6 carbon atoms.

Claim 27

Dependent Claim 12 words

The method in accordance with claim 24 wherein said dialdehyde is glutaraldehyde.

Claim 28

Dependent Claim 23 words

The method in accordance with claim 12 wherein said dialdehyde is used in an aqueous solution of from about 0.01 to about 5%.

Claim 29

Dependent Claim 25 words

The method in accordance with claim 12 wherein said substrate is contacted with said dialdehyde aqueous solution for from about 1 to about 6 hours.

Claim 30

Dependent Claim 24 words

The method in accordance with claim 12 wherein the temperature of said dialdehyde aqueous solution is from about ambient temperature to about 80° C.

Claim 31

Independent Claim 146 words

A method for reducing thrombogenicity comprising the sequential steps of: (1) subjecting a polytetrafluoroethylene substrate to an oxygen plasma wherein said plasma is generated by a discharge of about 50 watts at a radiofrequency of about 13.56 megahertz, said discharge being maintained for about 10 minutes with said oxygen at a pressure of about 180μ of Hg; (2) steeping said substrate in an aqueous solution of dodecylmethyl ammonium chloride of about 15% concentration for about 16 hours at 65° C.; (3) washing said substrate thoroughly in distilled water; (4) immersing said substrate in an aqueous solution of sodium heparin of about 9% concentration for 16 hours at 65° C.; (5) washing said substrate thoroughly in distilled water; (6) digesting said substrate in an aqueous solution of glutaraldehyde of about 1% concentration for about 2 hours at about 60° C.; (7) washing said substrate in distilled water.

Claim 32

Independent Claim 146 words

A method for reducing thrombogenicity comprising the sequential steps of: (1) subjecting a polytetrafluoroethylene substrate to an oxygen plasma wherein said plasma is generated by a discharge of about 50 watts at a radiofrequency of about 13.56 megahertz, said discharge being maintained for about 10 minutes with said oxygen at a pressure of about 180μ of Hg; (2) steeping said substrate in an aqueous solution of dodecylmethyl ammonium chloride of about 15% concentration for about 16 hours at 65° C.; (3) washing said substrate thoroughly in distilled water; (4) immersing said substrate in an aqueous solution of sodium heparin of about 9% concentration for 16 hours at 65° C.; (5) washing said substrate thoroughly in distilled water; (6) digesting said substrate in an aqueous solution of glutaraldehyde of about 1% concentration for about 2 hours at about 60° C.; (7) washing said substrate in distilled water.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-09-22	1990-03-24	1990-09-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-09-22	1994-03-24	1994-09-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-09-22	1998-03-24	1998-09-23	$7700.00	Window Closed / Lapsed

Heparinization of plasma treated surfaces

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