U.S. patent application number 11/845670 was filed with the patent office on 2008-02-28 for high strength suture coated with collagen.
Invention is credited to Augustus D. Mazzocca, MaryBeth McCarthy.
Application Number | 20080051834 11/845670 |
Document ID | / |
Family ID | 38922763 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080051834 |
Kind Code |
A1 |
Mazzocca; Augustus D. ; et
al. |
February 28, 2008 |
HIGH STRENGTH SUTURE COATED WITH COLLAGEN
Abstract
A high strength surgical suture formed of ultrahigh molecular
weight polyethylene (UHMWPE) yarns, the suture being coated with
native or denatured collagen. The braided jacket surrounds a core
formed of twisted yarns of ultrahigh molecular weight polyethylene.
The suture has exceptional strength, is ideally suited for most
orthopedic procedures, and can be attached to a suture anchor or a
curved needle.
Inventors: |
Mazzocca; Augustus D.; (West
Hartford, CT) ; McCarthy; MaryBeth; (Kensington,
CT) |
Correspondence
Address: |
DICKSTEIN SHAPIRO LLP
1825 EYE STREET NW
Washington
DC
20006-5403
US
|
Family ID: |
38922763 |
Appl. No.: |
11/845670 |
Filed: |
August 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60840466 |
Aug 28, 2006 |
|
|
|
Current U.S.
Class: |
606/222 ;
606/229; 606/232 |
Current CPC
Class: |
B05D 1/18 20130101; D10B
2509/04 20130101; C08L 23/06 20130101; A61L 17/04 20130101; A61L
17/145 20130101; D04C 1/02 20130101; C08L 2203/12 20130101; C08L
23/06 20130101; A61L 17/04 20130101 |
Class at
Publication: |
606/222 ;
606/229; 606/232 |
International
Class: |
A61B 17/06 20060101
A61B017/06; A61B 17/04 20060101 A61B017/04 |
Claims
1. A suture comprising a jacket comprising a plurality of braided
yarns formed of ultrahigh molecular weight polyethylene, the suture
being coated with collagen.
2. The suture of claim 1, further comprising a core comprising
yarns of ultrahigh molecular weight polyethylene surrounded by the
jacket.
3. The suture of claim 2, wherein the yarns of ultrahigh molecular
weight polyethylene comprise at least 40% of the yarns in the
suture.
4. The suture of claim 2, wherein the core comprises about 18% or
greater of the total amount of yarns in the suture.
5. The suture of claim 2, wherein the jacket comprises yarns of the
ultrahigh molecular weight polyethylene braided with yarns of
polyester.
6. The suture of claim 2, wherein the jacket further comprises
trace yarns for suture identification.
7. The suture of claim 2, wherein the core is formed of at least
three yarns of the ultrahigh molecular weight polyethylene twisted
at three to six twists per inch.
8. The suture of claim 2, wherein the jacket comprises yarns of
ultrahigh molecular weight polyethylene braided with yarns of a
bioabsorbable material comprising PLLA.
9. The suture of claim 2, wherein the jacket comprises at least
eight yarns of the ultrahigh molecular weight polyethylene braided
with six yarns of polyester and two yarns of nylon.
10. A suture assembly comprising: a suture, the suture having a
longitudinal length and a multifilament jacket comprising a
plurality of braided yarns of ultrahigh molecular weight
polyethylene, the suture being coated with collagen; and a suture
anchor, wherein the suture is attached to the suture anchor.
11. A suture assembly comprising: a suture, the suture having a
longitudinal length and a multifilament jacket comprising a
plurality of braided yarns of ultrahigh molecular weight
polyethylene, the suture being coated with collagen; and a needle,
wherein the suture is attached to the needle.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application No. 60/840,466, filed on Aug. 28, 2006, the entire
disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to high strength surgical
suture materials, and more particularly to braided suture blends of
ultrahigh molecular weight polyethylene having bioabsorbable
coatings.
[0004] 2. Description of the Related Art
[0005] Suture strength is an important consideration in any
surgical suture material. One of the strongest materials currently
formed into elongated strands is an ultrahigh molecular weight long
chain polyethylene, typically used for fishing line and the like,
which is sold under the trade names Dyneema or Spectra. This
material is much stronger than ordinary surgical suture, however,
it does not have acceptable knot tie down characteristics for use
in surgical applications.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention advantageously provides a high
strength surgical suture material with improved tie down
characteristics. The suture features a braided jacket made of
ultrahigh molecular weight fibers coated with collagen. The
ultrahigh molecular weight polyethylene provides strength.
Polyester fibers woven with the high molecular weight polyethylene
provide improved tie down properties. Collagen coating is provided
to stimulate proliferation and protein synthesis more than standard
sutures, and therefore may aid in the tendon-to-bone incorporation
process. Moreover, collagen, in addition to providing structural
support, can interact with other matrix proteins and cellular
receptor affecting cell behavior and gene expression.
[0007] There are 19 recognized genetically distinct collagen types
and amongst them, the most abundant type is the collagen type I, a
heterotrimer. Integrins, a heterodimeric cell surface receptor
involved in cell-cell and cell-substrate adhesion, bind the
collagen. Typically, four different integrins, for example,
.alpha..sub.1.beta..sub.1, .alpha..sub.2.beta..sub.1,
.alpha..sub.10.beta..sub.1 and .alpha..sub.11.beta..sub.1, are
required to bind a collagen. The interactions of integrins with
collagen involve a von Willebrand factor A-like domain and require
triple helical collagen structures.
[0008] Many of the integrins can react with a specific amino acid
sequence. Certain integrins appear to bind to only one specific
ligand such as a fibronectin receptor, whereas other integrins such
as platelet IIb/IIIa and vitronectin receptor can interact with
numerous Arg-Gly-Asp (RGD)-containing proteins. Although collagens
contain RGD sequences in their primary sequences, the RGD sequences
are cryptic and generally inaccessible to cells in the native
proteins and therefore, collagens are considered as
non-RGD-dependent ligands.
[0009] In a preferred embodiment, the suture includes a
multifilament jacket formed of ultrahigh molecular weight
polyethylene fiber braided with polyester. The jacket surrounds a
fiber core made substantially or entirely of ultrahigh molecular
weight polyethylene. The core preferably includes three strands of
ultrahigh molecular weight polyethylene, twisted at about three to
six twists per inch.
[0010] The jacket preferably comprises eight strands of ultrahigh
molecular weight polyethylene braided with six strands of
polyester. Tinted strands can be included in black or some other
contrasting color.
[0011] Ultrahigh molecular weight polyethylene fibers suitable for
use in the present invention are marketed under the Dyneema
trademark by Toyo Boseki Kabushiki Kaisha, and are produced in the
U.S. by Honeywell under the trademark Spectra.
[0012] The suture of the present invention advantageously has the
strength of Ethibond No. 5 suture, yet has the diameter, feel and
tie-ability of No. 2 suture. As a result, the suture of the present
invention is ideal for most orthopedic procedures such as rotator
cuff repair, Achilles tendon repair, patellar tendon repair,
ACL/PCL reconstruction, hip and shoulder reconstruction procedures,
and replacement for suture used in or with suture anchors.
[0013] The suture is coated with collagen. Collagen suitable for
use in the present invention is marketed under the FIBRACOL
trademark by Johnson & Johnson, Medifil.RTM. by BioCore, and
hyCURE.RTM. by The Hymed Group.
[0014] A trace thread or two in the suture jacket aids surgeons in
identifying the travel direction of the suture during surgery,
particularly during operations viewed arthroscopically or remotely.
Providing the trace threads in a regularly repeating pattern is
particularly useful, allowing the surgeon to decode different ends
of a length of suture, and to determine the direction of travel of
a moving length of suture. The trace threads preferably are
provided uniquely on each half of a length of suture to allow for
tracing and identification of each end of the suture, such as when
the suture is threaded through an eyelet of a suture anchor.
[0015] Other features and advantages of the present invention will
become apparent from the following description of the invention
which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a copy of a scanning electron micrograph of a
length of suture according to the present invention.
[0017] FIG. 2 is a schematic cross section of a length of suture
according to the present invention.
[0018] FIG. 3 is an illustration of the suture of the present
invention attached to a suture anchor loaded onto a driver.
[0019] FIGS. 4A and 4B show the suture of the present invention
attached to a half round, tapered needle.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The term "yarn(s)," as used herein, is to be understood as
including fiber(s), filament(s), and the like used to make a suture
of the present invention. Typically, though, yarns are comprised of
fibers and/or filaments.
[0021] Referring to FIG. 1, a scanning electron micrograph of a
length of suture 2 according to the present invention is shown.
Suture 2 is made up of a jacket 4 and a core 6 surrounded by the
jacket 4. See FIG. 2. Strands of ultrahigh molecular weight
polyethylene (UHMWPE) 8, such as that sold under the tradenames
Spectra and Dyneema, strands of polyester 10, and tinted strands 12
are braided together to form the jacket 4. Core 6 is formed of
twisted strands of UHMWPE.
[0022] UHMWPE, used for strands 8, is substantially translucent or
colorless. The polyester strands 10 are white (undyed). Due to the
transparent nature of the UHMWPE, the suture takes on the color of
strands 10 and 12, and thus appears to be white with a trace in the
contrasting color.
[0023] In accordance with the present invention, trace strands 12
are preferably provided in black. The black trace assists surgeons
in distinguishing between suture lengths with the trace and suture
lengths without the trace. Traces also assist the surgeon in
identifying whether the suture is moving. The trace can extend the
entire length of the suture or only on half of a length of suture,
the other half of the suture length remaining plain (white).
Alternatively, the traces can form visibly distinct coding patterns
on each half of the suture length. As a result, when the suture is
threaded through the eyelet of a suture anchor, for example, the
two legs (halves) of the length of suture are easily distinguished,
and their direction of travel will be readily evident when the
suture is pulled during surgery.
[0024] Details of the present invention will be described further
below in connection with the following examples:
EXAMPLE
USP Size 5 (EP size 7)
[0025] Made on a 16 carrier Hobourns machine, the yarns used in the
braided jacket are Honeywell Spectra 2000, polyester type 712, and
nylon. The jacket is formed using eight strands of 144 decitex
Spectra per carrier, braided with six strands of 100 decitex
polyester, and two strands of tinted nylon. The core is formed of
three carriers of 144 decitex Spectra braided at three to six
twists per inch. A No. 5 suture is produced.
[0026] To make various sizes of the inventive suture, different
decitex values and different PPI settings can be used to achieve
the required size and strength needed. In addition, smaller sizes
may require manufacture on 12 carrier machines, for example. The
very smallest sizes can be made without a core. Overall, the suture
may range from 5% to 90% ultrahigh molecular weight polymer
(preferably at least 40% of the fibers are ultrahigh molecular
weight polymer), with the balance formed of polyester and/or nylon.
The core preferably comprises 18% or greater of the total amount of
filament.
[0027] The suture is coated with collagen (FIBRACOL, Medifil), a
bioabsorbable material. Collagen is a natural biomaterial that acts
as a hemostatic agent. Collagen coating, like all suture coatings,
also improves the pliability and handleability of the suture
without sacrificing the physical properties of the constituent
elements of the suture.
[0028] In one embodiment of the present invention, a suture may be
coated with native collagen. First, suitable amounts of collagen
are dissolved in acetic acid of about 0.1% concentration to derive
a stock solution having a final concentration of about 0.5 mg/ml.
The stock solution is further diluted with water to a final
concentration of about 0.5 mg/ml and the suture is soaked in the
stock solution at 4.degree. C. The suture is then dried for at
least 1 hour in a laminar flow hood free of dust and debris. About
30 mg of collagen can coat about 200 ft of the suture. A
collagen-coated suture may be stored at room temperature for future
use.
[0029] In yet another embodiment of the present invention, a suture
may be coated with denatured collagen. First, suitable amounts of
collagen are dissolved in acetic acid of about 0.1% concentration
to derive a stock solution having a final concentration of about
0.5 mg/ml. The stock solution is then heated in a water bath at
about 50.degree. C. for about 12 hours, later diluted with water to
about 0.5 mg/ml and the suture soaked at 4.degree. C. The suture is
then dried for at least 1 hour in a laminar flow hood free of dust
and debris. About 30 mg of collagen can coat about 200 ft of the
suture. A collagen-coated suture may be stored at room temperature
for future use.
[0030] In an alternative embodiment of the present invention, a
partially bioabsorbable suture is provided by blending a high
strength material, such as UHMWPE fibers, with a bioabsorbable
material, such as PLLA or one of the other peptides, for example.
Accordingly, a suture made with about 10% Spectra or Dyneema
blended with absorbable fibers would provide greater strength and
with less stretch. Over time, 90% or more of the suture would
absorb, leaving only a very small remnant of the knot. The
absorbable suture can include coatings, for example collagen.
[0031] The ultra high molecular weight (UHMW) polymer component of
the present invention provides strength, and the polyester
component is provided to improve tie ability and tie down
characteristics. However, it has been found that the UHMW polymer
provides an unexpected advantage of acting as a cushion for the
polyester fibers, which are relatively hard and tend to damage each
other. The UHMW polymer prevents breakage by reducing damage to the
polyester when the suture is subjected to stress.
[0032] In one method of using the suture of the present invention,
the suture 2 is attached to a suture anchor 14 as shown in FIG. 3
(prepackaged sterile with an inserter 16), or is attached at one or
both ends to a half round, tapered needle 18 as shown in FIGS. 4A
and 4B. FIG. 4A also illustrates a length of suture having
regularly repeating pattern of trace threads according to the
present invention. Sections of the length of suture 2 have tinted
tracing threads woven in. The alternating patterned and plain
sections aid the surgeon in determining the direction of suture
travel when pulling the suture, for example.
[0033] Although the present invention has been described in
relation to particular embodiments thereof, many other variations
and modifications and other uses will become apparent to those
skilled in the art.
* * * * *