U.S. patent application number 11/845683 was filed with the patent office on 2008-02-28 for high strength suture coated with rgd peptide.
Invention is credited to Augustus D. Mazzocca, Mary Beth McCarthy.
Application Number | 20080051835 11/845683 |
Document ID | / |
Family ID | 39197660 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080051835 |
Kind Code |
A1 |
Mazzocca; Augustus D. ; et
al. |
February 28, 2008 |
HIGH STRENGTH SUTURE COATED WITH RGD PEPTIDE
Abstract
A high strength surgical material with improved tie down
characteristics and tissue compliance formed of ultrahigh molecular
weight polyethylene (UHMWPE) yarns, the suture being coated with
arginine-glycine-aspartate (RGD) peptide. 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; Mary Beth; (Kensington,
CT) |
Correspondence
Address: |
DICKSTEIN SHAPIRO LLP
1825 EYE STREET NW
Washington
DC
20006-5403
US
|
Family ID: |
39197660 |
Appl. No.: |
11/845683 |
Filed: |
August 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60840467 |
Aug 28, 2006 |
|
|
|
Current U.S.
Class: |
606/222 ;
606/228; 606/232 |
Current CPC
Class: |
A61B 2017/0414 20130101;
A61L 2300/606 20130101; D06M 15/15 20130101; A61L 17/005 20130101;
D07B 2205/2014 20130101; D07B 2201/209 20130101; A61B 2017/06028
20130101; D07B 1/025 20130101; A61L 17/04 20130101; A61B 17/0401
20130101; A61B 2017/0409 20130101; D07B 2205/2014 20130101; D06M
2200/35 20130101; D07B 2801/22 20130101; D07B 2201/1096 20130101;
A61B 17/06166 20130101; A61L 2300/25 20130101; A61L 17/145
20130101 |
Class at
Publication: |
606/222 ;
606/228; 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 RGD peptide.
2. The suture of claim 1, further comprising a core comprising
yarns of a ultrahigh molecular weight polyethylene surrounded by
the jacket.
3. The suture of claim 2, wherein the yams of ultrahigh molecular
weight polyethylene coated with RGD peptide 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 is formed of yarns of
the ultrahigh molecular weight polyethylene braided with yarns of
polyester.
6. The suture of claim 2, wherein the jacket is braided with 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 is formed of yarns of
ultrahigh molecular weight polyethylene braided with yarns of a
bioabsorbable material comprising PLLA and collagen.
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; and a suture anchor, wherein the suture is threaded
through an eyelet of 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; 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. 60/840,467, filed on Aug. 28, 2006, the entire
disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to high strength surgical
suture materials, and more particularly to braided suture blends of
ultrahigh molecular weight polyethylene coated with RGD
peptide.
DESCRIPTION OF THE RELATED ART
[0003] 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
[0004] 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. The suture is coated with
arginine-glycine-aspartate (RGD) peptide. The ultrahigh molecular
weight polyethylene provides strength. Polyester fibers woven with
the high molecular weight polyethylene provide improved tie down
properties. RGD peptide promotes cell adhesion to substrates in
vivo by interacting with receptors, integrins, on cell surface
proteins. Further, RGD peptides also increase the permeability of
endothelial monolayers and therefore may aid in surgical
applications.
[0005] In a preferred embodiment, the suture includes a
multifilament jacket formed of ultrahigh molecular weight
polyethylene fibers 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.
[0006] The jacket preferably comprises eight strands of ultrahigh
molecular weight polyethylene braided with six strands of
polyester. The tinted strands can be included in black or some
other contrasting color.
[0007] 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.
[0008] 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.
[0009] The suture is coated with RGD peptide. RGD peptide suitable
for use in the present invention is marketed under PCI-36xx-PI by
Peptides International, and under GRADSP peptide and GRGDSP peptide
by Calbiochem. Other products suitable for use in the present
invention marketed by Pierce are: (i) Product #28390-BupH MES
Buffered Saline Packs to make a 500 ml of 0.1 M
2-[morpholino]ethanesulfonic acid, 0.9% NaCl, pH 4.7 when dissolved
in 500 ml deionized water (5 liters total); (ii) Product #
22980-1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride
(EDC or EDAC), a zero-length crosslinking agent used to couple
carboxyl groups to primary amines and a water-soluble carbodiimide
for rapid preparation of peptide conjugates; (iii) Product
#24510-N-hydroxysulfosuccinimide (Sulfo-NHS), a product useful in
improving the efficiency of EDC coupling.
[0010] 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.
[0011] 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
[0012] FIG. 1 is a copy of a scanning electron micrograph of a
length of suture according to the present invention.
[0013] FIG. 2 is a schematic cross section of a length of suture
according to the present invention.
[0014] FIG. 3 is an illustration of the suture of the present
invention attached to a suture anchor loaded onto a driver.
[0015] FIG. 4A and 4B show the suture of the present invention
attached to a half round, tapered needle.
DETAILED DESCRIPTION OF THE INVENTION
[0016] 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, yams are comprised of
fibers and/or filaments.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] Details of the present invention will be described further
below in connection with the following examples:
[0021] Example: USP Size 5 (EP size 7)
[0022] 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.
[0023] 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.
[0024] The suture is coated with RGD peptide (PCI-36xx-PI). The RGD
peptide-coating increases permeability of endothelial monolayers,
thereby resulting in a decrease in abrasion resistance to the
suture. RGD peptides promote cell adhesion to substrates in vivo by
interacting with receptors, integrins, on cell surface proteins and
thus, RGD peptide-coated sutures perform better than other sutures
in surgical applications.
[0025] Peptides may be coupled to or adsorbed to the suture.
Typically, about 500 ml of coupling buffer, e.g., about 0.1M MES
buffer, is prepared and a base, for example NaOH, is used to lower
the acidity of the coupling buffer to a pH value of about 6.0.
[0026] In one embodiment of the present invention, peptides are
coupled to a suture. For coupling peptides to a suture, the suture
is cut into 6 inch strips and soaked into an MES buffer for at
least 30 minutes. Later, acid hydrolysis is performed, i.e., the
suture is taken from the MES buffer and quickly dipped into an acid
medium, for example, about 15 ml of 6N HCl and about 200 ul of
H.sub.2O.sub.2. Thereafter, the suture is immediately put back into
the MES buffer and washed several times. EDC and sulfo-NHS buffers
are added to the MES buffer, for example, about 36 mg of EDC and
about 99 mg of sulfo-NHS is added to about 90 ml of MES buffer.
[0027] The suture is removed from the MES buffer and placed into
the EDC buffer for about 15 minutes. The suture is then washed
three times with the MES buffer. About 2 ml of peptide solution is
immediately prepared and the suture immersed in the peptide
solution. The peptide is allowed to react on the suture at
4.degree. C. The suture is then washed about five times with MES
buffer and then allowed to air dry under a hood.
[0028] In another embodiment of the present invention, peptides are
adsorbed to a suture. For adsorbing peptides to a suture, the
suture is cut into 6 inch strips and soaked in a MES buffer for at
least 30 minutes. Later, the suture is taken out and immediately
placed back into the MES buffer and washed about three times. About
2 ml of peptide solution is immediately prepared and the suture
immersed in the peptide solution. The peptide is allowed to react
on the suture at 4.degree. C. The suture is then washed about five
times with MES buffer and then allowed to air dry under the
hood.
[0029] 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 collagen, 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.
[0030] 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.
[0031] 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.
[0032] 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.
* * * * *