# US 10,441,686 B2 · Stent having functional material coated on cell space thereof

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- Number: US 10,441,686 B2
- Document ID: US10441686B2
- Status: Granted
- Kind: B2
- Application number: 15/545,058
- Filed: 2016-03-09
- Published: 2018-01-11
- Granted: 2019-10-15
- Earliest claimed: 2015-03-12
- Assignees: Utah-Inha Dds & Advanced Therapeutics Research Center; Nextbiomedical Co., Ltd.
- Applicants: Utah-Inha Dds & Advanced Therapeutics Research Center; Nextbiomedical Co., Ltd.
- Inventors: Don Haeng Lee; Jong Chae Park; Dong Gon Kim; Choong Ryeol Choi
- Web page: https://patentgrep.com/patent/US10441686B2

## CPC

- A61L 31/08: Materials for coatings
- A61L 31/022: {Metals or alloys}
- A61L 31/10: Macromolecular materials
- A61L 31/148: {Materials at least partially resorbable by the body}
- A61L 31/16: Biologically active materials, e.g. therapeutic substances {(A61L31/047 takes precedence)}
- A61L 31/18: Materials at least partially X-ray or laser opaque
- A61L 2300/416: Anti-neoplastic or anti-proliferative or anti-restenosis or anti-angiogenic agents, e.g. paclitaxel, sirolimus
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)

## Abstract

The present invention relates to a stent having a functional material coated on a cell space (safe coating space) thereof. The stent of the present invention, as a stent having a space for mounting and coating drugs and other materials for expanding the functions of the stent, is highly feasible as an actual product in consideration of the structure, transfer device, and manufacturing process of the stent as a whole, and secures a coating space (safe coating space) of a functional material in a cell of the stent through quantitative and qualitative modelling. Since an additional increase in volume does not occur even when the stent is press-mounted in a transfer device as a result of mounting a radio marker or a drug in the coating space, the stent of the present invention has excellent radio opacity without obstructing the loading and deployment of the stent, and may stably mount a great amount of a functional drug.

## Claims

### Claim 1

A stent having a cell area coated with a functional material wherein the cell area has a volume defined by equation 1 below:
Vsa=Asa×Iscx Equation 1
wherein in equation 1, Vsa represents the average coating volume per node and Asa represents the average coating area per node, the node meaning a hook or cross; and Iscx represents the axial length of cell.

### Claim 2 (depends on 1)

The stent of claim 1, wherein the stent is a wire stent having a cell area comprising a hook, a cross, or a hook and a cross.

### Claim 3 (depends on 1)

The stent of claim 1, wherein the axial length of cell (Iscx) is defined by equation 2:
I
scx
=
{
I
cx
/
(
1
-
r
short
)
-
L
hook
:
I
scx
⁢
⁢
is
⁢
⁢
between
⁢
⁢
hook
⁢
⁢
and
⁢
⁢
hook
I
cx
/
(
1
-
r
short
)
-
(
L
hook
+
L
cross
)
/
2
:
I
scx
⁢
⁢
is
⁢
⁢
between
⁢
⁢
hook
⁢
⁢
and
⁢
⁢
cross
I
cx
/
(
1
-
r
short
)
-
L
cross
:
I
scx
⁢
⁢
is
⁢
⁢
between
⁢
⁢
cross
⁢
⁢
and
⁢
⁢
cross
Equation
⁢
⁢
2
wherein in equation 2, Icx represents the axial length of cell, rshort represents the shortening ratio and is defined by equation 3 below, Lhook represents the length of hook node and is defined by equation 4 below, and Lcross represents the length of hook node and is defined by equation 5 below; wherein in equation 3 below, Lstent.load represents the length of stent when the stent is loaded in a delivery device, Lstent represents the length of stent before the stent is loaded in the delivery device, and the rshort has a value of 0.2-0.6; wherein in equations 4 and 5 below, ϕw represents the diameter of a wire; wherein in equation 4 below, SFlh represents the length scale factor of hook node and has a value of 4; and wherein in equation 5 below, SFlc represents the length scale factor of cross node and has a value of 5:
rshort=(Lstent.load−Lstent)/Lstent.load Equation 3
Lhook=ϕw×SFlh Equation 4
Lcross=ϕw×SFlc. Equation 5

### Claim 4 (depends on 1)

The stent of claim 1, wherein the average coating area per node (Asa) is defined by equation 6 below; and wherein in equation 6, Asx represents the maximum coating area and is defined by equation 7 below, and Nt represents the total number of nodes per section of stent and is defined by equation 8 below:
Asa=Asx/Nt Equation 6
Asx=π(R2ob−R2ib)−And Equation 7
Nt=Nh+Nc Equation 8
wherein in equation 7 above, Rob represents the radius of outmost boundary, Rib represents the radius of inmost boundary, and And represents the node area per section of stent; and wherein in equation 8 above, Nh represents the number of hook nodes per section of stent, and Nc represents the number of cross nodes per section of stent.

### Claim 5 (depends on 4)

The stent of claim 4, wherein the radius of outmost boundary (Rob) is defined by equation 9; the radius of inmost boundary (Rib) is defined by equation 10; and And is defined by equation 11:
R
ob
=
R
tb
cos
⁡
(
180
/
N
x
)
Equation
⁢
⁢
9
R
ib
=
W
avg
2
·
tan
⁡
(
180
/
N
t
)
Equation
⁢
⁢
10
A
nd
=
(
W
hook
×
H
hook
×
N
h
)
+
(
W
cross
×
H
cross
×
N
c
)
Equation
⁢
⁢
11
wherein in equation 9 above, Rtb represents the inradius of outmost boundary, and Nx represents the number of virtual hook nodes tangential on the outmost boundary; wherein in equation 10 above, Wavg represents the average width of node per section of stent, equation 10 above satisfying conditions of π/(Nt tan(180/Nt))≤1; and wherein in equation 11 above, Whook represents the width of hook node, Hhook represents the height of hook node, Wcross represents the width of cross node, and Hcross represents the height of cross node.

### Claim 6 (depends on 5)

The stent of claim 5, wherein the average width of node per section of stent (Wavg) is defined by equation 12 below; the number of virtual hook nodes tangential on the outmost boundary (Nx) is defined by equation 13 below; the height of hook node (Hhook) is defined by equation 14 below; and the height of cross node (Hcross) is defined by equation 15 below:
W
avg
=
W
total
/
N
t
Equation
⁢
⁢
12
N
x
=

180
tan
-
1
⁡
(
W
avg
/
(
2
⁢
⁢
R
tb
)
)

Equation
⁢
⁢
13
H
hook
=
Φ
w
×
SF
hh
Equation
⁢
⁢
14
H
cross
=
Φ
w
×
SF
hc
Equation
⁢
⁢
15
wherein in equation 12 above, Wtotal represents the sum total of width of all nodes per section of stent; wherein in equation 13 above, Rtb represents the inradius of outmost boundary; wherein in equations 14 and 15 above, ϕw represents the diameter of wire; wherein in equation 14 above, SFhh represents the height scale factor of hook node and has a value of 3; and wherein in equation 15 above, SFhc represents the length scale factor of cross node and has a value of 2.

### Claim 7 (depends on 6)

The stent of claim 6, wherein the sum total of width of all nodes per section of stent (Wtotal) is defined by equation 16 below; and the inradius of outmost boundary (Rtb) is defined by equation 17 below:
Wtotal=(Whook×Nh+Wcross×Nc) Equation 16
Rtb=Rib+Hhook Equation 17
wherein in equation 16 above, Whook represents the width of hook node, and Wcross represents the width of cross node.

### Claim 8 (depends on 6)

The stent of claim 6, wherein the width of hook node (Whook) is defined by equation 18 below; and the width of cross node (Wcross) is defined by equation 19 below:
Whook=ϕw×SFwh Equation 18
Wcross=ϕw×SFwc Equation 19
wherein in equations 18 and 19 above, ϕw represents the diameter of wire; wherein in equation 18 above, SFwh represents the width scale factor of hook node and has a value of 3.3; and wherein in equation 19 above, SFwc represents the width scale factor of cross node and has a value of 2.

### Claim 9

A stent having a cell area coated with a functional material, wherein the cell area has a volume defined by equation 20 below:
V=2R×(Icx−2R)×h Equation 20
wherein in equation 20 above, R represents the radius of cell axial end, Icx represents the axial length of cell, and h represents the thickness or height of cell, and wherein the stent is a tube stent having a cell area formed by a strut.

### Claim 10 (depends on 1)

The stent of claim 1, wherein the stent is formed of a material selected from the group consisting of a nitinol alloy, stainless steel, tantalum, a tantalum alloy, platinum, a platinum alloy, gold, a gold alloy, a cobalt alloy, a cobalt-chromium alloy, a titanium alloy, and a niobium alloy.

### Claim 11 (depends on 1)

The stent of claim 1, wherein the functional material includes biodegradable and non-biodegradable polymers.

### Claim 12 (depends on 11)

The stent of claim 11, wherein the functional material further includes at least one selected from the group consisting of a radiation marker, an anticancer agent, an antiinflammatory agent, and an antithrombotic agent.

### Claim 13 (depends on 11)

The stent of claim 11, wherein the biodegradable and non-biodegradable polymers are selected from the group consisting of gelatin, polyglycolic acid/polylactic acid (PGLA), polycaprolactone (PCL), polyhydroxybutyrate valerate (PHBV), polyorthoester (POE), polyethyleneoxide/polybutylene terephthalate (PEO/PBTP), polyurethane (PUR), polydimethylsiloxane (PDMS), silicone (SIL), polyethylene terephthalate (PETP), polytetrafluoroethylene (PTFE), and expanded polytetrafluoroethylene (ePTFE).

### Claim 14 (depends on 12)

The stent of claim 12, wherein the radiation marker is selected from the group consisting of gold (Au), platinum (Pt), silver (Ag), titanium (Ti), tantalum (Ti), niobium (Nb), molybdenum (Mo), rhodium (Rh), palladium (Pd), hafnium (Hf), tungsten (W), iridium (Ir), platinum-iridium (Pt—Ir), barium (Ba), barium sulfate (BaSO4), cobalt (Co), and a mixture thereof.

### Claim 15 (depends on 12)

The stent of claim 12, wherein the anticancer agent is selected from the group consisting of cisplatin, carboplatin, oxalyplatin, procarbazine, mechlorethamine, cyclophosphamide, ifosfamide, melphalan, chlorambucil, bisulfan, nitrosourea, camptothecin, irinotecan, dactinomycin, carmustine, rapamycin, daunorubicin, doxorubicin, doxorubicin HCl, idarubicin HCl, bleomycin, plicomycin, mitomycin-C, etoposide, tamoxifen, paclitaxel, docetaxel, transplatinum, 5-fluorouracil, adriamycin, acvicin, aclarubicin, acodazole, ormaplatin, vincristin, vincristin sulfate, vinblastin, vinblastin sulfate, cytarabine, methotrexate, gemcitabine, gemcitabine HCl, capecitabine, and a mixture thereof.

### Claim 16 (depends on 12)

The stent of claim 12, wherein the antiinflammatory agent is selected from the group consisting of aspirin, diclofenac, indomethacin, sulindac, ketoprofen, flurbiprofen, iborprofen, naproxen, piroxicam, tenoxicam, tolmetin, ketorolac, oxaprosin, mefenamic acid, fenprofen, nambumetone (Relafen), acetaminophen (Tylenol), and a mixture thereof.

### Claim 17 (depends on 12)

The stent of claim 12, wherein the antithrombotic agent is selected from the group consisting of aspirin, clopidogrel, indobufen, cilostazol, ticlopidine, beraprost, heparin, and a mixture thereof.