U.S. patent application number 10/100765 was filed with the patent office on 2002-08-01 for monolayer modification to gold coated stents to reduce adsorption.
Invention is credited to You, Chuanting.
Application Number | 20020103530 10/100765 |
Document ID | / |
Family ID | 24733725 |
Filed Date | 2002-08-01 |
United States Patent
Application |
20020103530 |
Kind Code |
A1 |
You, Chuanting |
August 1, 2002 |
Monolayer modification to gold coated stents to reduce
adsorption
Abstract
A stent has a body and a surface with at least a portion of the
surface comprising metal with a coating thereon. The coating is
selected from the group consisting of thiols and disulfides and
combinations thereof. The thiols are of the form R--SH and the
disulfide of the form R--S--S--R" where R is an alkyl group and R"
is an alkyl group. The metal is selected from the group consisting
of noble metals, silver and copper.
Inventors: |
You, Chuanting; (Brooklyn
Park, MN) |
Correspondence
Address: |
VIDAS, ARRETT & STEINKRAUS, P.A.
6109 BLUE CIRCLE DRIVE
SUITE 2000
MINNETONKA
MN
55343-9185
US
|
Family ID: |
24733725 |
Appl. No.: |
10/100765 |
Filed: |
March 18, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10100765 |
Mar 18, 2002 |
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09681080 |
Dec 26, 2000 |
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6398806 |
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Current U.S.
Class: |
623/1.15 |
Current CPC
Class: |
A61L 31/088 20130101;
A61L 31/022 20130101; A61F 2/91 20130101; A61L 31/08 20130101 |
Class at
Publication: |
623/1.15 |
International
Class: |
A61F 002/06 |
Claims
1. A stent having a body and a surface, at least a portion of the
surface comprising a metal with a coating thereon, the metal
selected from the group consisting of noble metals, copper and
silver and combinations thereof, the coating selected from the
group consisting of thiols and disulfides and combinations thereof,
the thiols of the form R--SH and the disulfide of the form
R--S--S--R" where R is an alkyl group and R" is an alkyl group.
2. The stent of claim 1 wherein R has from 12 to 32 carbons.
3. The stent of claim 2 wherein the entire surface is metal and the
coating is on the entirety of the surface.
4. The stent of claim 3 wherein the metal is selected from the
group consisting of noble metals, copper and silver.
5. The stent of claim 4 wherein the metal is gold.
6. The stent of claim 3 wherein the coating is substantially one
monolayer thick.
7. The stent of claim 5 wherein the coating is substantially one
monolayer thick.
8. The stent of claim 3 wherein the coating comprises one or more
thiols.
9. The stent of claim 8 wherein the one or more thiols includes a
thiol where R=16.
10. The stent of claim 8 wherein R is a straight chain alkyl
group.
11. The stent of claim 3 wherein the stent has a body portion and
the metal surface is coated on the body portion.
12. The stent of claim 11 wherein the metal is gold and the gold
surface is plated on the body portion.
13. A method of preparing a stent comprising the steps of:
providing a stent having a surface at least a portion of which
comprises metal; and coating the metal with a coating moiety
selected from the group consisting of thiols and disulfides and
combinations thereof, the thiols of the form R--SH and the
disulfides of the form R--S--S--R" where R is an alkyl group and R"
is an alkyl group.
14. The method of claim 13 wherein R has from 12 to 32 carbons and
R" has from 12 to 32 carbons.
15. The method of claim 14 wherein the entire surface of the stent
is coated in the coating step.
16. The method of claim 15 wherein the metal is selected from the
group consisting of noble metals, copper and silver.
17. The method of claim 16 wherein the metal is gold.
18. The method of claim 17 wherein the coating moiety is disposed
in a solvent.
19. The method of claim 18 wherein the solvent is selected from the
group consisting of methanol, ethanol, isopropanol and combinations
thereof.
20. The method of claim 18 wherein the solvent is methanol.
21. The method of claim 20 wherein the coating moiety comprises a
thiol.
22. The method of claim 21 wherein R=16.
23. The method of claim 18 wherein the coating step comprises
placing the stent in the solvent.
24. A stent prepared in accordance with the method of claim 14.
25. The stent of claim 24 wherein the coating is substantially one
monolayer thick.
26. A stent prepared in accordance with the method of claim 21.
27. A stent prepared in accordance with the method of claim 23.
28. The stent of claim 26 wherein the coating is substantially one
monolayer thick.
29. A stent at least a portion of which has a substantially
monolayer thick coating of one or more members selected from the
group consisting of thiols, disulfides, and combinations
thereof.
30. The stent of claim 29 wherein at least a portion of the stent
includes a layer of gold thereon, the monolayer coating disposed on
the layer of gold.
31. The stent of claim 29 wherein the stent has a body portion and
the gold layer and monolayer coating extend over the entirety of
the surface of the body portion of the stent.
Description
BACKGROUND OF INVENTION
[0001] The use of gold plated stents is known in the art and is
disclosed in a number of patents and patent applications including
U.S. Pat. Nos. 5,824,045, 6,099,561 and copending and commonly
assigned U.S. application Ser. No. 09/697,634 filed Oct. 26, 2000.
Gold plating increases the radiopacity of the stent, a feature that
has proven useful for imaging purposes.
[0002] Over time, stents that have been implanted in the body tend,
whether gold plated or otherwise, to have proteins adsorbed thereto
which increases the likelihood of restenosis. While numerous
surface modification treatments to achieve desired surface
properties are known for stents, there remains a need for treatment
processes for modifying the surface properties of stents having a
surface of gold or other noble metals.
[0003] For the purposes of this disclosure, the term noble metal
shall refer to a metal of the group Ruthenium (Ru), Rhodium (Rd),
Palladium (Pd), Osmium (Os), Iridium (Ir), Platinum (Pt), Silver
(Ag), and Gold (Au).
[0004] All US patents and applications all other published
documents mentioned anywhere in this application are incorporated
herein by reference in their entirety.
[0005] The abstract provided herewith is intended to comply with 37
CFR 1.72 and is not intended to be used in determining the scope of
the claimed invention.
[0006] Without limiting the scope of the invention in any way, the
invention is briefly summarized in some of its aspects below.
SUMMARY OF INVENTION
[0007] The instant invention is directed in at least some of its
embodiments to coated stents. Other embodiments of the invention
include methods of coating stents.
[0008] In one embodiment, the invention is directed to a stent
having a body and a surface, at least a portion of the surface
comprising a metal with a coating on the metal. The coating is
selected from the group consisting of thiols and disulfides and
combinations thereof. The thiols are of the form R--SH and the
disulfides are of the form R--S--S--R" where R and R" are alkyl
groups. Suitably, R has at least 4 carbons. Desirably, R has from
12 carbons to 32 carbons. More desirably R has from 12 to 24
carbons.
[0009] Suitably, R" has at least 4 carbons. Desirably, R" has from
12 carbons to 32 carbons.
[0010] More desirably R" has from 12 to 24 carbons. Only a portion
of the surface may be metal or, more desirably, the entirety of the
surface may comprise the metal. The metal desirably is selected
from the group consisting of noble metals, copper and silver and
combinations thereof. Where the metal is gold, the gold may be
coated on the body of the stent via plating or any other technique.
Desirably, the thiol and/or disulfide coating is substantially one
monolayer thick.
[0011] The invention is also directed to a method of preparing a
stent comprising the steps of providing a stent having a surface at
least a portion of which is metal and coating the metal surface
with a coating moiety selected from the group consisting of thiols
and disulfides and combinations thereof. The thiols are of the form
R-SH and the disulfides are of the form R--S--S--R" where R is an
alkyl group and R" is an alkyl group.
[0012] Suitably, R has at least 4 carbons. Desirably, R has from 12
carbons to 32 carbons.
[0013] More desirably R has from 12 to 24 carbons. Suitably, R" has
at least 4 carbons.
[0014] Desirably, R" has from 12 carbons to 32 carbons. More
desirably R" has from 12 to 24 carbons. Desirably, the entire
surface of the stent is coated in the coating step. Also desirably,
the metal is selected from the group consisting of noble metals,
copper and silver. More desirably, the metal is gold. In accordance
with the inventive method, the coating moiety may be disposed in a
solvent such as methanol, ethanol, isopropanol and combinations
thereof and the stent placed in the solvent. The coating may be
provided via other techniques as well including spraying the
coating on the metal surface of the stent. Desirably, the coating
is substantially one monolayer thick.
[0015] The invention is also directed to a stent at least a portion
of which has a substantially monolayer thick coating of one or more
members selected from the group consisting of thiols, disulfides,
and combinations thereof. Desirably, at least a portion of the
stent includes a layer of gold thereon, the monolayer coating
disposed on the layer of gold. More desirably, the gold layer and
monolayer coating extend over the entirety of the surface of the
body portion of the stent.
[0016] A detailed description of the invention in its various
embodiments is provided below.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 shows a perspective view of an inventive stent;
[0018] FIG. 2 shows a cross-sectional view of the stent of FIG. 1
taken along line 22;
[0019] FIG. 3 shows a perspective view of another inventive stent;
and
[0020] FIG. 4 shows a perspective view of another inventive
stent.
DETAILED DESCRIPTION
[0021] For the purposes of this disclosure, unless otherwise
indicated, like reference numerals in the figures refer to the same
component.
[0022] The instant invention is directed in at least some of its
embodiments to coated stents. Other embodiments of the invention
include methods of coating stents.
[0023] The inventive stent may be any suitable stent having a
surface at least a portion of which comprises metal with an
inventive coating thereon. An example of a stent is shown in FIG. 1
at 100. Stent 100 comprises a plurality of serpentine segments 104,
each of which comprises a plurality of interconnected struts 107.
Segments 104, which are adjacent one another are connected together
via connectors 108. As shown in FIG. 1, connectors 108 have at one
bend therein. The connectors may also be provided with a plurality
of bends or may substantially linear or rectilinear. The instant
invention may be practiced using a stent such as that shown in FIG.
1 or using any other stent geometry. Stent 100 is shown in
transverse cross-section in FIG. 2.
[0024] The stent includes body 112 and surface 116 as shown in FIG.
2. At least a portion and desirably, the entirety, of surface 116
comprises a metal such as a noble metal, copper, silver or another
radiopaque metal. Desirably, the metal is gold. The body of the
stent may also comprise the metal or may comprise one or more
different metals or polymeric materials. Other suitable metals for
the body of the stent include 316L stainless steel, chromium,
nickel, titanium, or iridium, or nitinol. Where the body of the
stent is of a different metal or other material from the surface
metal, the gold or other surface metal may be coated on the body of
the stent by plating, painting, swaging, vapor deposition or may be
otherwise deposited on the body of the stent.
[0025] Coating of stents with metals such as gold is discussed in
commonly assigned U.S. application Ser. No. 09/659,571 as well as
in U.S. Pat. No. 5,824,045. As shown in FIGS. 1 and 2, the metal
surface of the inventive stents has a coating 120 thereon selected
from the group consisting of thiols and disulfides and combinations
thereof. The coating is indicated by hatching in FIG. 1. The thiols
are of the form R--SH and the disulfides are of the form RS--S--R"
where R is an alkyl group and R" is an alkyl group. Suitably, R has
at least 4 carbons. Desirably, R has from 12 carbons to 32 carbons.
More desirably R has from 12 to 24 carbons. Suitably, R" has at
least 4 carbons. Desirably, R" has from 12 carbons to 32 carbons.
More desirably R" has from 12 to 24 carbons. Most desirably, the
alkyl group R and/or R" is a 16 carbon alkyl group. Suitably, the
alkyl group is a straight chain alkyl group. Desirably, the thiol
and/or disulfide coating is substantially one monolayer thick and
in the form of a self-arranging monolayer.
[0026] The invention is also directed to a stent at least a portion
of which has a substantially monolayer thick coating of one or more
members selected from the group consisting of thiols, disulfides,
and combinations thereof. Desirably, at least a portion of the
stent includes a layer of gold thereon, the monolayer coating
disposed on the layer of gold. More desirably, the gold layer and
monolayer coating extend over the entirety of the surface of the
body portion of the stent.
[0027] An example of such a stent is shown in FIG. 3. Stent 100 of
FIG. 3 includes a plurality of serpentine segments 104. Each
serpentine segment comprises a plurality of interconnected struts
107. Adjacent serpentine segments 104 are connected by
substantially linear connectors 108 extending therebetween.
Proximal end 101 and distal end 102 include a surface layer of
metal such as gold. The surface layer is coated with a coating
comprising a thiol, disulfide, or both as discussed above. The
coating is indicated by hatching in the figure.
[0028] Yet another example of such a stent is shown generally at
100 in FIG. 4. Stent 100 includes bands of metals such as noble
metals, or silver which are coated with a coating 120 comprising a
thiol, disulfide, or both as discussed above.
[0029] It is also within the scope of the invention to coat stents
having any other pattern of noble metals, copper and/or silver on
the surface of the stent. The coating is desirably limited to the
patterned metal. Examples of other specific patterns are shown in
U.S. application Ser. No. 09/697,634.
[0030] The invention is also directed to methods of preparing a
stent comprising the steps of providing a stent having a surface at
least a portion of which comprises metal and coating at least a
portion of the metal with a coating moiety selected from the group
consisting of thiols and disulfides and combinations thereof. The
metal is desirably a radiopaque metal. Suitable metals include
noble metals, copper and silver.
[0031] The body of the stent may be formed of the same metal as
that on the surface of the stent or may be made of a different
metal or material. As an example, where the surface metal is a
layer of gold, the gold may be providing by plating, painting,
swaging, vapor deposition or otherwise depositing it.
[0032] As discussed above, the thiols are of the form R--SH and the
disulfides are of the form R--S--S--R" where R is an alkyl group
and R" is an alkyl group. Suitably, R has at least 4 carbons.
Desirably, R has from 12 carbons to 32 carbons. More desirably R
has from 12 to 24 carbons. Suitably, R" has at least 4 carbons.
Desirably, R" has from 12 carbons to 32 carbons. More desirably R"
has from 12 to 24 carbons. Most desirably, the alkyl group R and/or
R" is a 16 carbon alkyl group. Suitably, the alkyl group is a
straight chain alkyl group.
[0033] In accordance with the invention, the coating moiety may be
applied to the surface metal through any suitable technique. One
suitable method involves providing the coating moiety in a solvent.
Suitable solvents include methanol, ethanol and isopropanol.
Desirably, the concentration of the coating moiety in the solvent
is between about 0.1 mM (millimolar) and 10 mM. The stent may be
dipped in the solvent or the solvent sprayed on the stent. In the
former case, using the concentrations disclosed above, the stent is
desirably dipped in the solvent for a period of from about 0.5 hour
to about 24 hours. During this time, the coating moiety desirably
forms a self-arranging monolayer on the metal surface. Where the
solvent is sprayed on the metal surface of the stent, the
concentration of the coating moiety is desirably significantly
greater than the above-mentioned values to facilitate the formation
of a self-arranging monolayer on the stent.
[0034] After the coating moiety is applied to the stent, the stent
may be removed from the solvent or spraying of the stent ceased and
the stent allowed to dry.
[0035] Where only portions of the stent have a noble metal, silver
or copper thereon, the noble metal, silver or copper may
selectively be coated by masking those portions of the stent which
do not have the metal thereon so that only the relevant portions of
the stent are exposed for coating.
[0036] The invention is also directed to stents made using any of
the inventive techniques disclosed herein.
[0037] The inventive stents may be used for coronary arteries,
peripheral arteries, arteries of the neck and intracranial
arteries. More generally, the inventive stents may be used for any
vessel of the human body including but not limited to arteries,
veins, biliary ducts, urethras, fallopian tubes, bronchial tubes,
the trachea and the esophagus.
[0038] Suitable stent delivery devices including those disclosed in
U.S. Pat. No. 6,123,712, No. 6,120,522 and No. 5,957,930 may be
used to deliver the inventive stents to the desired bodily
location. The choice of delivery device will depend on whether a
self-expanding or balloon expandable stent is used.
[0039] In addition to the specific embodiments claimed below, the
invention is also directed to other embodiments having any other
possible combination of the dependent features claimed below in
combination with the independent claims from which they depend.
[0040] The above disclosure is intended to be illustrative and not
exhaustive. The description will suggest many variations and
alternatives to one of ordinary skill in this art. All these
alternatives and variations are intended to be included within the
scope of the attached claims. Those familiar with the art may
recognize other equivalents to the specific embodiments described
herein which equivalents are also intended to be encompassed by the
claims attached hereto.
* * * * *