CA1203137B - Elastomeric surgical sutures-comprising segmented copolyether/esters - Google Patents
Elastomeric surgical sutures-comprising segmented copolyether/estersInfo
- Publication number
- CA1203137B CA1203137B CA000485231A CA485231A CA1203137B CA 1203137 B CA1203137 B CA 1203137B CA 000485231 A CA000485231 A CA 000485231A CA 485231 A CA485231 A CA 485231A CA 1203137 B CA1203137 B CA 1203137B
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- CA
- Canada
- Prior art keywords
- percent
- derived
- suture
- units
- glycol
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/78—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products
- D01F6/86—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products from polyetheresters
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- 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
- A61L17/00—Materials for surgical sutures or for ligaturing blood vessels ; Materials for prostheses or catheters
- A61L17/04—Non-resorbable materials
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/66—Polyesters containing oxygen in the form of ether groups
- C08G63/668—Polyesters containing oxygen in the form of ether groups derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/672—Dicarboxylic acids and dihydroxy compounds
Abstract
A B S T R A C T
The present invention relates to surgical sutures and more particularly to soft elastomeric sutures having unique handling and knot tying characteristics.
These objects are achieved by providing an elastomeric non-absorbable surgical suture in a sterile condition with a needle attached to at least one end comprising a monofilament containing intra-polymerized butylenephthalate hard segments and polytetramethylene ether soft segments having the structure more fully described in the disclosure.
Fibers used as surgical sutures have been formed from such polymers having the physical properties described in the specification.
The present invention relates to surgical sutures and more particularly to soft elastomeric sutures having unique handling and knot tying characteristics.
These objects are achieved by providing an elastomeric non-absorbable surgical suture in a sterile condition with a needle attached to at least one end comprising a monofilament containing intra-polymerized butylenephthalate hard segments and polytetramethylene ether soft segments having the structure more fully described in the disclosure.
Fibers used as surgical sutures have been formed from such polymers having the physical properties described in the specification.
Description
~ ~a ~ Y
~ 1 --BACKGROUND` `OF `THE `INVENTION
The present invention relates to surgical sutures, and more particularly, to soft, elastomeric sutures having unique handling and knGt tying characteristics. The sutures may be prepared from segmented copolyether/esters or other 5 elastomeric polymers.
Many natural and synthetic materials are presently used as surgical sutures. These materials may be used as single filament strands, i.e, monofilament sutures, or as multifilament strands in a braided, twisted or other multi-ln filament construction. ~atural materials such as silk, cotton,linen and the like, of course do not lend themselves to the fabrication of monofilament sutures and are accordingly generally used in one of the multifilament constructions.
Synthetic materials which are extruded in continuous 15 lengths can be used in monorilament form. Common synthetic monofilament sutures include polyethylene terephthalate, polypropylene, polyethylene, and nylon. Such monofilament sutures are preferred by surgeons for many surgical applications due to their inherent smoothness and noncapillarity to body 20 fluids.
The presently available synthetic monofilament sutures all sufer to a greater or lesser degree from one particular disadvantage, that is inherent stiffness. Besides making the material more difficult to handle and use, suture 25 stiffness can adversely affect knot tying ability and knot security. It is because of the inherent stiffness of available monofilament sutures that most larger suture sizes are braided or have other multifilament constructions with better handling flexibility.
Monofilament sutures of the prior art are also characterized by a low degree of elasticity, the most elastic of the above-mentioned synthetics being nylon which has a yield elongation of about 1.7 percent and a visco-elastic elongation of about 8.5 percent. The inelasticity of these 35 sutures also makes knot tying more difficult and reduces knot~~~
'~
lZ~3~3`~
security. In addition, the inelasticity prevents the suture from "giving" as a newly sutured wound swells, with the result that the suture may place the wound tissue under greater tension than is desirable, and may even cause some tearing, 5 cutting or necrosis of the tissue.
The problems associated with the use of inelastic sutures in certain applications were recognized in U.S. Patent No. 3,454,011, where it was proposed to fabricate a surgical suture composed of Spandex* polyurethane. Such sutures, however, were highly elastic with "rubbery" characteristics and did not find general acceptance in the medical profession.
It is accordingly an object o~ the present invention to provide a novel soft, limp, monofilament suture material.
It is a further object of this invention to provide a mono-filament suture with a controlled degree of elasticity toaccommodate changing wound conditions. It is another object of this invention to provide a new, nonabsorbable suture having a diameter of from about 0.01 to 1.0 mm and possessing unique and desirable physical properties. These and other objects will be made apparent from the ensuing description and claims.
SUMMARY
Monofilament sutures of the present invention are characterized by the following combination of physical properties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - preferably from about 30,000 to 320,000 psi Tensile strength - at least about 40,000 psi Knot s-trength - at least about 30,000 psi.
Sutures possessin~ the above characteristics may be prepared by melt extruding certain elastomeric polymers such as copolyether/ester polymers to form a continuous filamentary strand, and thereafter drawing the extruded filament to obtain the desired suture properties. Certain copolyether/
ester polymers available commercially from E.I. du Pont de *Trade mark 3~37 Nemours & Co. under the trademark "HYTREL" have been discovered to be suitable starting materials for the preparation of sutures in accordance with the present invention.
This invention is therefore further characterized 5 by the use of such polymers which comprise intrapolymerized butylenephthalate hard segments and polytetramethylene ether soft segments and having the following general structure (o - (CH2)4 ~ - Cta (o(cH2cH2cH2cH2o)x C ~ -~
(hard segment) (soft segment) The monofilament non-absorbable sutures of this invention are in a sterile condition with a needle attached to at least one end thereof.
Monofilament sutures having physical properties in accordance with the present invention are particularly useful in many surgical procedures where the suture is used to close a wound which may be subject to later swelling or change in position. The combination of low Young's modulus and signif-icant yield elongation provides the suture w.ith an appreciable degree of controlled elasticity under low applied force. As a result, the suture is able to "give" to accommodate swelliny in the wound area. The relatively high visco-elastic yield elongation and high tensile strength of the suture allows the suture to stretch during knot tie-down so that the knot "snugs down" for improved tying ability and knot security with a more predictable and consistent knot geometry regardless of variations in suture tying technique or tension.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a representive stress-strain curve characteristic of the surgical filaments of the present invention.
Figure 2 is a representative stress-strain curve comparing filaments of the present invention with monofilament sutures of the prior art.
`` ~ ;Z1~3:~3'7 DEs(~ o~ OF PR~ ;~K~;L~ EMBO~ IENTS
.
The sutures of the present in~ention are character~
ized by a combination of~ physical properties which are unique for monofilament sutures, and which provide the sutures of the 5 present invention with unique and desirable functional proper-ties.
The characteristic propertïes of the inventive sutures are readily determined by conventional test procedures.
Figure 1 illustrates a typical stress-strain or load-elongation 10 diagram for the sutures of this invention. In Figure 1, yield elongation (Ey) is the point at which permanent deformation of the suture begins to ta~e place. So long as the filament is - not elongated beyond Ey, elastic recovery is essentially complete.
The sutures of the present invention have an Ey with the range 15 of 2 to 9 percent.
Young's modulus is a measure of the slope of the stress-strain curve over the initial portion of the curve ex-tending from the origin. In Figure 1, line a is a drawn tangent to the curve at the origin, and Young's modulus is equal to 20 tan ~. The slope of the curve, and Young's modulus, are seen to be a measure of the resistance to elongation in the initial elastic portion of the curve. The sutures of the present invention are designed to have a significant, but relatively lo~ modulus of 30,000 to 320,000 psi and preferably 200,000 psi, 25 and more preferably within the range of 50,000 to 150,000 psi.
A modulus within the claimed range provides the correct amount of increasing tension on the suture as the suture is extended towards its yield point (Ey). At lower values of Young's modulus the suture readily elongates under very low tension to its yield 30 point and the advantages of having a significant yield elonga-tion are lost. At higher values of Young's modulus, filament stiffness becomes the controlling consideration, and the softness and good handling properties of the suture ~;m;n;sh ~ The portion of the stress-strain cur~e extending 35 between Ey and Ev on Figure 1 i5 the visco-elastic region during which there is considerable elongation and permanent deformation of the suture with only slightly increasing tension. The visco-3~3~
elastic elongation (E~) o~ the sutures of the present in~ention is controlled to be within the xange of from about 10 to 30 percent. This property of the suture allows the suture to draw down during knotting to assure good knot security.
As the suture is elongated beyond Ev, the ioad increases rapidly as indicated in Figure l. This rapid increase in load imparts a positive feel to the suture which, in the hands of a skilled surgeon, signals when Ev and maximum knot security are achieved. Preferably, the value of Ev is at least 2.5 times the value of Ey in order to provide the surgeon witha broad visco-elastic region in which to work during suture tie-down.
As seen in Figure l, the load from 0 to Ev elongation is relatively low compared to the breaking load (Sb). Preferably, the breaking load or straight tensile strength is at least 40,000 psi, and the load Sv corresponding to visco-elastic elongation is less than one-third of the breaking load, with the result that the suture may be easily knotted under relatively low forces and without risk of unintentionally breaking the suture. Knot strength of the suture is preferably at least 30,000 psi.
The breaking elongation (Eb~ of the sutures of the present invention are generally within the range of 30 to 100 percent. ~lthough this property is not critical to the perform-ance of the suture since suture elongation in use does not generally exceed Ev, it is preferabIe that Eb be at least 1.5 x Ev in order to reduce the possibility of inadvertantly over elongating and breaking the suture during tie-down.
The unique mechanical properties of the sutures of the present invention will be more readily appreciated from Figure 2 where such sutures are compared to nylon and polypro-pylene sutures of the prior art. Representative physical properties of these three suture materials are given in Table I.
Each of these prior art sutures has a considerably higher Young's modulus which results in the characteristic stiffness of these materials. In addition, neither suture has a noticeable Ey or an extended visco-elastic region which characterïze the sutures of the invention and impart the desirable properties discussed 3L2q33~1L3~
above.
The mechanical properties of the sutures of the present invention reflected in the relative values of Ev and Ey in combination with the low Youn~ls moduius and high tensile 5 strength are unique in the field of surgical sutures and dis-tinguish the monofilament sutures of the present invention from all prior art material~.
TABLE I
Suture property Suture material Polypropylene Nylon This invention Diameter, mils 12.5 12.8 12.9 (mm~ (0.32~ (0.33) (0.33t Tensile strength, psi 58,900 75,200 64,700 (Kg/cm2~ ~4,100) (5,300)(4,500) Elongation to break, ~ 32.2 40.1 39.5 Visco-elastic elongation (E~), % 9.0 8.5 14.8 Yield elongation (Ey), % 1.1 1.7 2.2 S~ress at Ey (Sy), psi 5,100 3,600 2,500 ~ e (Kg/cm2) (360) (250) (180) Stress at Ev (Sv), psi 25,700 13,200 9,200 (Kg/cm2) (1,800) (930) (650) Young's modulus, psi 425,000 221,000112,000 (Kg/cm2) (29,900j (15,500)(7~900) 33~3~9 Sutu.res ha~ing mecha.~ic.a~ properties in accordance with the present invention.~ay be p~epared from the segmen.ted copolyether/ester compositions disclosed in U.S. Patent ~o.
~ 1 --BACKGROUND` `OF `THE `INVENTION
The present invention relates to surgical sutures, and more particularly, to soft, elastomeric sutures having unique handling and knGt tying characteristics. The sutures may be prepared from segmented copolyether/esters or other 5 elastomeric polymers.
Many natural and synthetic materials are presently used as surgical sutures. These materials may be used as single filament strands, i.e, monofilament sutures, or as multifilament strands in a braided, twisted or other multi-ln filament construction. ~atural materials such as silk, cotton,linen and the like, of course do not lend themselves to the fabrication of monofilament sutures and are accordingly generally used in one of the multifilament constructions.
Synthetic materials which are extruded in continuous 15 lengths can be used in monorilament form. Common synthetic monofilament sutures include polyethylene terephthalate, polypropylene, polyethylene, and nylon. Such monofilament sutures are preferred by surgeons for many surgical applications due to their inherent smoothness and noncapillarity to body 20 fluids.
The presently available synthetic monofilament sutures all sufer to a greater or lesser degree from one particular disadvantage, that is inherent stiffness. Besides making the material more difficult to handle and use, suture 25 stiffness can adversely affect knot tying ability and knot security. It is because of the inherent stiffness of available monofilament sutures that most larger suture sizes are braided or have other multifilament constructions with better handling flexibility.
Monofilament sutures of the prior art are also characterized by a low degree of elasticity, the most elastic of the above-mentioned synthetics being nylon which has a yield elongation of about 1.7 percent and a visco-elastic elongation of about 8.5 percent. The inelasticity of these 35 sutures also makes knot tying more difficult and reduces knot~~~
'~
lZ~3~3`~
security. In addition, the inelasticity prevents the suture from "giving" as a newly sutured wound swells, with the result that the suture may place the wound tissue under greater tension than is desirable, and may even cause some tearing, 5 cutting or necrosis of the tissue.
The problems associated with the use of inelastic sutures in certain applications were recognized in U.S. Patent No. 3,454,011, where it was proposed to fabricate a surgical suture composed of Spandex* polyurethane. Such sutures, however, were highly elastic with "rubbery" characteristics and did not find general acceptance in the medical profession.
It is accordingly an object o~ the present invention to provide a novel soft, limp, monofilament suture material.
It is a further object of this invention to provide a mono-filament suture with a controlled degree of elasticity toaccommodate changing wound conditions. It is another object of this invention to provide a new, nonabsorbable suture having a diameter of from about 0.01 to 1.0 mm and possessing unique and desirable physical properties. These and other objects will be made apparent from the ensuing description and claims.
SUMMARY
Monofilament sutures of the present invention are characterized by the following combination of physical properties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - preferably from about 30,000 to 320,000 psi Tensile strength - at least about 40,000 psi Knot s-trength - at least about 30,000 psi.
Sutures possessin~ the above characteristics may be prepared by melt extruding certain elastomeric polymers such as copolyether/ester polymers to form a continuous filamentary strand, and thereafter drawing the extruded filament to obtain the desired suture properties. Certain copolyether/
ester polymers available commercially from E.I. du Pont de *Trade mark 3~37 Nemours & Co. under the trademark "HYTREL" have been discovered to be suitable starting materials for the preparation of sutures in accordance with the present invention.
This invention is therefore further characterized 5 by the use of such polymers which comprise intrapolymerized butylenephthalate hard segments and polytetramethylene ether soft segments and having the following general structure (o - (CH2)4 ~ - Cta (o(cH2cH2cH2cH2o)x C ~ -~
(hard segment) (soft segment) The monofilament non-absorbable sutures of this invention are in a sterile condition with a needle attached to at least one end thereof.
Monofilament sutures having physical properties in accordance with the present invention are particularly useful in many surgical procedures where the suture is used to close a wound which may be subject to later swelling or change in position. The combination of low Young's modulus and signif-icant yield elongation provides the suture w.ith an appreciable degree of controlled elasticity under low applied force. As a result, the suture is able to "give" to accommodate swelliny in the wound area. The relatively high visco-elastic yield elongation and high tensile strength of the suture allows the suture to stretch during knot tie-down so that the knot "snugs down" for improved tying ability and knot security with a more predictable and consistent knot geometry regardless of variations in suture tying technique or tension.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a representive stress-strain curve characteristic of the surgical filaments of the present invention.
Figure 2 is a representative stress-strain curve comparing filaments of the present invention with monofilament sutures of the prior art.
`` ~ ;Z1~3:~3'7 DEs(~ o~ OF PR~ ;~K~;L~ EMBO~ IENTS
.
The sutures of the present in~ention are character~
ized by a combination of~ physical properties which are unique for monofilament sutures, and which provide the sutures of the 5 present invention with unique and desirable functional proper-ties.
The characteristic propertïes of the inventive sutures are readily determined by conventional test procedures.
Figure 1 illustrates a typical stress-strain or load-elongation 10 diagram for the sutures of this invention. In Figure 1, yield elongation (Ey) is the point at which permanent deformation of the suture begins to ta~e place. So long as the filament is - not elongated beyond Ey, elastic recovery is essentially complete.
The sutures of the present invention have an Ey with the range 15 of 2 to 9 percent.
Young's modulus is a measure of the slope of the stress-strain curve over the initial portion of the curve ex-tending from the origin. In Figure 1, line a is a drawn tangent to the curve at the origin, and Young's modulus is equal to 20 tan ~. The slope of the curve, and Young's modulus, are seen to be a measure of the resistance to elongation in the initial elastic portion of the curve. The sutures of the present invention are designed to have a significant, but relatively lo~ modulus of 30,000 to 320,000 psi and preferably 200,000 psi, 25 and more preferably within the range of 50,000 to 150,000 psi.
A modulus within the claimed range provides the correct amount of increasing tension on the suture as the suture is extended towards its yield point (Ey). At lower values of Young's modulus the suture readily elongates under very low tension to its yield 30 point and the advantages of having a significant yield elonga-tion are lost. At higher values of Young's modulus, filament stiffness becomes the controlling consideration, and the softness and good handling properties of the suture ~;m;n;sh ~ The portion of the stress-strain cur~e extending 35 between Ey and Ev on Figure 1 i5 the visco-elastic region during which there is considerable elongation and permanent deformation of the suture with only slightly increasing tension. The visco-3~3~
elastic elongation (E~) o~ the sutures of the present in~ention is controlled to be within the xange of from about 10 to 30 percent. This property of the suture allows the suture to draw down during knotting to assure good knot security.
As the suture is elongated beyond Ev, the ioad increases rapidly as indicated in Figure l. This rapid increase in load imparts a positive feel to the suture which, in the hands of a skilled surgeon, signals when Ev and maximum knot security are achieved. Preferably, the value of Ev is at least 2.5 times the value of Ey in order to provide the surgeon witha broad visco-elastic region in which to work during suture tie-down.
As seen in Figure l, the load from 0 to Ev elongation is relatively low compared to the breaking load (Sb). Preferably, the breaking load or straight tensile strength is at least 40,000 psi, and the load Sv corresponding to visco-elastic elongation is less than one-third of the breaking load, with the result that the suture may be easily knotted under relatively low forces and without risk of unintentionally breaking the suture. Knot strength of the suture is preferably at least 30,000 psi.
The breaking elongation (Eb~ of the sutures of the present invention are generally within the range of 30 to 100 percent. ~lthough this property is not critical to the perform-ance of the suture since suture elongation in use does not generally exceed Ev, it is preferabIe that Eb be at least 1.5 x Ev in order to reduce the possibility of inadvertantly over elongating and breaking the suture during tie-down.
The unique mechanical properties of the sutures of the present invention will be more readily appreciated from Figure 2 where such sutures are compared to nylon and polypro-pylene sutures of the prior art. Representative physical properties of these three suture materials are given in Table I.
Each of these prior art sutures has a considerably higher Young's modulus which results in the characteristic stiffness of these materials. In addition, neither suture has a noticeable Ey or an extended visco-elastic region which characterïze the sutures of the invention and impart the desirable properties discussed 3L2q33~1L3~
above.
The mechanical properties of the sutures of the present invention reflected in the relative values of Ev and Ey in combination with the low Youn~ls moduius and high tensile 5 strength are unique in the field of surgical sutures and dis-tinguish the monofilament sutures of the present invention from all prior art material~.
TABLE I
Suture property Suture material Polypropylene Nylon This invention Diameter, mils 12.5 12.8 12.9 (mm~ (0.32~ (0.33) (0.33t Tensile strength, psi 58,900 75,200 64,700 (Kg/cm2~ ~4,100) (5,300)(4,500) Elongation to break, ~ 32.2 40.1 39.5 Visco-elastic elongation (E~), % 9.0 8.5 14.8 Yield elongation (Ey), % 1.1 1.7 2.2 S~ress at Ey (Sy), psi 5,100 3,600 2,500 ~ e (Kg/cm2) (360) (250) (180) Stress at Ev (Sv), psi 25,700 13,200 9,200 (Kg/cm2) (1,800) (930) (650) Young's modulus, psi 425,000 221,000112,000 (Kg/cm2) (29,900j (15,500)(7~900) 33~3~9 Sutu.res ha~ing mecha.~ic.a~ properties in accordance with the present invention.~ay be p~epared from the segmen.ted copolyether/ester compositions disclosed in U.S. Patent ~o.
3,023,192, which states in part at Column 2, line 20 et seq.:.
"The copolyetheresters of thïs invention are prepared by rea.cting one or more boxylic acids or their ester-forming derivatives, one or more difunctional polyethers with the formula:
HO(RO)pH
(in which R is one or more divalent organic radicals and p is an integer of a value to provide a glycol with a molecular weight of between about 350 and about 6,00Q~, and one or more dihydroxy-compounds selected from the class consisting of bis-phenols and lower ali-phatic glycols with the formula:
HO(CH2)~OH
(in which q is 2-10, with the proviso that the reactants be selected so that substantially all of the repeating units of the polyester contain at least one aromatic ring. The resulting ester is then polymerized."
The preparation of other related segmented thermo-plastic copolymers are described in the following additional references: U.S. Patents Nos. 3,651,014; 3,763,109; 3,766,1~6;
and 3,78~,520.
According to the above references, the disclosed segmented thermoplastic copolymers may be cast as films, injection molded to form objects, or melt extruded to form filaments. The products obtained in accordance with these references, however, are characterized by physical proper~ies which are not desirable for surgical sutures.
In particular, the filaments o the references are rubbery with a very high de~ree o~ elasticity as indicated by break elongations in excess of 500 percent. Tensïle strengths, on the other hand, are ~ery low, generally less than 8,000 psi.
The ~ilaments prepared from.copolyether/esters in accordance '~2~:)3:13~
with the teachings of these referen.ces therefore do not possess the mechanical properties of the sutures of the invention, and, in fact, are obviously not at all suitable for use as surgical.
sutures.
The disadvantages of the prior art references are overcome by means of the present invention wherein filaments extruded from certain copolyether/esters are quenched and drawn with the result that the mechanical properties of the filaments are controlled to be within the specific limits discovered to be particularly desirable for surgical sutures.
The segmented copolyether/esters useful in the present invention comprise a multiplicity of recurring long chain ether/
ester units and short chain ester units joined head to tail through ester linkages according to the following general formula:
O O O O
[(O - D - O - C - R - C)a(O - G - O - C - R - C ~ )b3n (I) The long chain ether/ester units of the polymer are represented by the general formula:
O O
,. ..
- O - G - O - C - R - C - (II) wherein G is a divalent radical remaining after the xemoval of terminal hydroxyl groups from à poly (C2 10 alkylene oxide) glycol having a molecular weight within the range of about 350 to 6,000, and R is a divalent radical remaining after the removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight of less than about 300.
The short chain ester units are represented by the general formula:
O O
ll ll - O - D - O - C - R - C - (III) wherein D is a divalent radical remaining after remoual of hydroxyl groups from an alkyldiol having a molecular weight of less than about 250, and R is as defined above.
In the above Formula I, a is an integer such that the short chain copolymer segments represented by a comprise from 50 to 90 percent by weight of the total copolymer composi-3~ 7 - 1.0 tion; _ is an integer such that the long chain copolymer seg-ments represented by b comprise from 10 to 50 percent of the total copolymer composition; and n is the degree of polymeriza-tion resulting in a f:iber-orming copolymer.
The copolyether/esters represented by Formula I may be melt extruded, quenched and drawn to obtain filaments having physical properties desirable for surgical sutures as above defined. Polymer to be extruded is dried at about 200-220F in a circulating hot air oven and/or under vacuum in order to remove all traces of moisture and other volatile materials.
The polymer is then melt extruded and water quenched in accor-dance with the conventional melt spinning techniques forsynthetic fibers. The fiber is finally drawn at least about 5X, and usually ~rom about 7X to 9X to achieve molecular orien-tation.
The preparation of fibers useful as surgical suturesfrom copolyether/esters in accordance with the present invention is demonstrated by the following examples which are presented by way of illustration and are not limiting of the present invention. The polymers utilized in these examples are copoly-ether/esters prepared from 1,4-butanediol, dimethyl phthalate, and polytetramethylene ether glycol (M/W/ of about 1,000), and are ~ ~L~ially available from E.I. du Pont de Nemours & Co.
under the trademark "HYTREL". The polymer contains intrapo]y-merized butylenephthalate hard segments (short chain ester units)and polytetramethylene ether terephthalate soft segments (long chain ester units) and has the following general structure as reported in the Journal of Elastomers and Plastics 9, 416-38 (Oct., 1977):
O O O O
Il ~ 11 11 30 ( ~ (CH2)4 ~ C ~ ~ ~a ((CH2CH ~ 2cH20)x _ C ~ -C~b (IV) thard segment) (soft segment) wherein a and b are as defined above a~d x is an integer xeflecting the molecular weight of the ethex ~lycol reactant (x = 14 for M~Wo of about 1,000).
f~L2~3~3'7 In the following exa~les, physical properties of individual monofilaments were determined on an Instron*
tensile tester under the following conditions~
Crosshead speed (XH)~ 5 in/min Chart speed (CS) : 10 in/min Sample length (GL) . 5 in Scale load (SL) ~ 2 lbs~in With reference to Figure 1, Young's modulus is calculated from the slope a of the stress-strain curve in the initial linear~ elastic region as follows-, tan ~ x GL x ~'S x SL
Young s modulus ~pSl) = XH x XS
wherein ~ = the angle indicated in Figure 1XS = the cross-sectional area of the fiber, in2 SL, XH, CS, and GL are as identified above.
Yield stress (Sy) is the load at the point of inter-section of lines a and b drawn tangent to the initial elastic region and the visco-elastic region, respectively, of the curve as illustrated in Figure 1. Yield elongation (Ey) is the elong-ation corresponding to Sy and is read directly off the stress-strain curve.
Visco~elastic stress (Sv) is the load at the point of intersection of line b with line c drawn tangent to the curve as illustrated in Figurè 1. Visco-elastic elongation (Ev) is the elongation corresponding to Sv and is read directly off the curve.
~reak elongation ~Eb) and breaking tensile strength (Sb) are read directly off the stress-strain curve as illus-trated in Figure 1.
EXAMPLE I
A sample of copolyether/ester of Formula IV having approximately 40 wt percent soft segments and comprising ap-proximately 51 percent terephthaloyl units, 16 percent units derived from polytetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol was dried four hours at 200F
in a circulating hot air oven and then further dried under vacuum at 100 microns (no heat) fGr 16 hours. The dry polymer was placed in a one-inch horizontal extruder and extruded through *Trade ~ark ~`.33~3~
a J/50/1 die at an extrusion te~pe~ature of 380F.
The extrudate was quenched in water at ambient temperature and drawn to a si~e 2-0 monofilament suture using a 8.8X draw ratio at a temperature of 530F and with a take-up speed of 485 ft/min. Physical properties of the resultingfilaments are given in Table II.
EXAMP~E II
.
A sample of copolyether/ester of Formula IV having approximately 23 wt percent soft segments and comprising ap-proximately 45 percent terephthaloyl units~ 4 percent ortho-phthaloyl units, 20 percent units derived from polytetramethylene ether glycol and 31 percent units derived from 1,4-butanediol was dried and extruded at 400F as described in Example I. The extrudate was quenched and drawn into a size 2-0 monofilament using a 7.5~ draw ratio at a temperature of 450F and with a take-up speed of 412 ft/min. Physical properties of the result-ing filaments are given in Table II.
EXAMPLE III
A sample of copolyether/ester of Formula IV having approximately 18 wt percent soft segments and comprising ap-proximately 41 percent terephthaloyl units, 35 percent units derived from polytetramethylene ether glycol and 24 percent units derived from l,4-butanediol was dried and extruded at ~05F as described in Example I. The extrudate was quenched and drawn into a size 2-n monofilament suture using a 6.5 draw ratio at a temperature of 560F. The take-up speed was 75 ft/min.
Physical properties of the resulting filaments are given in Table II. It is noted that the Young's modulus of these fila-ments exceeded the preferred maximum desirable limit for sutures of the present invention.
EX~PLE IU
Three parts of a copolyether/ester of Example I and two parts of a copolyether/ester of Exa~ple III were dry blended to provide a polymer having a total of 30.2 perce~t soft seg-ments. The blended material was dried in a vacuum o~en fortwo hours at 1-2 mm Hg (no heat~ and then heated at 50C for three hours at 1-2 mm Hg.
~13~3~7 The dried mixture was me~t blended in a 3/~-inch Brabe~der extruder with a 25-inch barrel with a 20/1 screw and extruded at 430F through a 5~32-inch die in a vertical monofilament assembly. The extrudate was water quenched at ambient temperature~ pelletized, and again dried as described above for the dry-blended material before extruding into mono-filament sutures. A size 2-0 monGfilament suture of this material was extruded at 400F using a 7.9X draw ratio at a temperature of 460F and a ~ake-up speed of 435 ft/min.
Physical properties of the resulting filaments are given in Table II.
EXAMPLE ~
3.5 parts of a copolyether/ester of Example I and 1.5 parts of a copolyether/ester of Example III were dry-blended for a total of 33.4 percent soft segments and extruded follow-ing the general procedure of Example IV, and using a final draw ratio of 7.5X with a draw temperature of 485F and a take-up speed of 412 ft/min to obtain a size 2-0 monofilament suture.
The physical properties of the resulting filaments are given in Table II.
EXAMPLE ~I
The procedure of Example IV was repeated using `various blends of copolyether/ester polymers of Examples I, II
and III having the compositions and blended in ratios as shown in Table II. The physical properties of the resulting filaments are also given in Table III.
EXAMPLE VII
A copolyether/ester of Example I with 40 wt percent soft segments was dried and extruded in accordance with the general procedure o Example I using a 20 mil spinnerette to obtain a size 5-0 suture, and a 50 mil spinnerette to obtain-a size 0 suture. Drawing condition~ and physical properties of the resulting suture are compared in Table IV with a size 2-0 suture of the same composition prepared according to Example I.
TABLE II
Examples I II III IV V
Suture size 2-0 2-0 2-0 2-0 2-0 Diameter, mils 11.1 13.1 12.2 13.2 13.2 ~mm) (0.28)(0.33) ~0.31) (0.343 (0.34~
Knot strength, psi 37,20039,700 44,900 40,100 41,000 (Kg/cmZ) (2,600)(2,780)(3,140) (2,800) (2,870) Tensile strength, psi 64,1bO 71,300 72,300 65,500 60,500 (Kg/cm2) (4 (5,060) (4,580) (4,200) Break elongation, % -31.8 27.8 18.3 25.2 31.4 Visco-elastic elongation, % 18.6 13.3 7.25 10.35 11.6 Yield elongation, ~ 3.2 2.9 2~6 4.2 4.7 Young's modulus, psi50,000172,000 320,000 140,000 120,000 (Kg/cm2) (3,500)~12,000) (22,400) (9,800) (8,400) TABLE III
Polymer compositions Wt % Young's Break Visco- Yield Wt ~ soft Wt ratio soft modulus elonga- elastic elonga-segments of of segments psi tion elonga tion components components in blend (Kg/cm2~ Eb, ~ tion Ey, %
Ev, %
40/23 65/35 34.0584,000 34.8 14.3 9.2 ( 5,850) 40/18 75/25 34.50107,000 33.4 13.3 3.2 ( 7,470) 40/23 50/50 31.50105,000 33.7 14.7 1.9 40/18 70/30 33.40120,000 31.4 11.6 4.7 ~ 8,390) ~3 4~/18 65/35 32.30134,000 27.5 12.1 4.6 ~ 9,400) 40/18 60/40 31.20140,000 26.5 10.2 4.8 ~ 9,790) 40/18 55/45 30.10170,000 24.5 10.8 2.6 (11,920) 40/18/23 30/30/40 26.60173,000 18.9 10.3 3.5 (12,080) 40/23/18 3~/30/40 26.10201,000 22.4 10.3 2.8 ~14,060) ~(33~
~ 16 -~T~BLE~IV~`
Suture size Draw ratio 7.5 8.8 7~3*
Draw temperature, F 340 530 370 ~5 Take-up ft/min 205 485 110 Diameter, mils 7.08 11.10 14.03 Knot strength, psi48,600 37,200 34,200 (Kg/cm2) (3,400) (2,600) (2,400) Tensile strength, psi67,50064,10068,600 (Kg/cm2) (4,700) (4,400) (4,800) Break elongation, ~ 43.5 31.8 36.7 Visco-elastic elongation, ~ 10.8 18.6 17.6 Yield elongation, ~ 3.0 3.2 6.3 Young's modulus, psi49,00050,000 51,000 (Kg/cm2) (3,400) (3,500) (3,600) *Two stage draw EXAMPLE VIII
Monofilament sutures prepared from a copolyether/
ester of Example II with 23 wt percent soft segments were sterilized by cobalt-60 irradiation and with ethylene oxide in accordance with conventional procedures for sterilizing 20 surgical sutures. The physical properties of th~ sutures were affected only slightly by ethylene oxide sterilization, and even less by cobalt-60, as shown by the data in Table V.
3.~
TABLE V
5uture Nonsterile Sterilized control 60 Co E.O.
Diameter, mils 12.5 12.6 13.2 Knot strength, psi35,30033,400 29,900 (Kg/cm2) (2,500) (2,300~ ~2,100) Tensile strength, psi 70,300 70,000 67,700 (Kg/cm2) (4,900~ (~,900)`(4,800) Break elongation, %28.2 31.6 45.2 Visco-elastic elongation, %13.2 15.0 23.5 Yield elongation, %2.9 2.3 2.2 Young's modulus, psi185,000165,000138,000 (Kg/cm2) (13,000) (11,600) (9,600) The important physical properties of the sutures prepared from copolyether/esters are responsive to changes in polymer composition and processing conditions. For example, visco-elastic elongation and yield elongation increase as the proportion of soft segments in polymer are increased, and conversely, Young's modulus decreases with an increasing propor-tion of soft segments. The break elongation may be decreased and tensile strength increased by employing higher draw ratios during the manufacture of the suture. By regulation of the composition and processing variables therefor, it is possible to obtain specific mechanical properties for individual sutures with a great degree of latitudeO
While the preceding examples have been directed to the preparation of monofilament sutures of copolyether/esters, this was for the sake of convenience in describing one polym~r system and the effect of various polymer compositions and spinning condition~ on fiber properties. The copolyether/ester polymers 30 may also be used in the manufacture of braided or other multi-filament suture constructions, and sinyle filaments and braids may be used in the preparation of surgical fabrics and knitted ~3~
or woven prosthetic devices such as ~ein and arterial grafts.
In addition, elastomeric filaments having a ~ombination of physical properties in accordance with the present invention may be prepared from other polymer systems such as polyurethane 5 or silicone elastomers or polyether copolymers of urethane or silicone elastomers. ~urthermore, elastomeric filaments of the present invention may be blended with each other, with other elastomeric or non-elastomeric filaments, and with either absorbable or non-absorbable filaments in order to provide 10 yarns and fabrics with special properties, all of which is deemed to be included within the scope of the present invention.
"The copolyetheresters of thïs invention are prepared by rea.cting one or more boxylic acids or their ester-forming derivatives, one or more difunctional polyethers with the formula:
HO(RO)pH
(in which R is one or more divalent organic radicals and p is an integer of a value to provide a glycol with a molecular weight of between about 350 and about 6,00Q~, and one or more dihydroxy-compounds selected from the class consisting of bis-phenols and lower ali-phatic glycols with the formula:
HO(CH2)~OH
(in which q is 2-10, with the proviso that the reactants be selected so that substantially all of the repeating units of the polyester contain at least one aromatic ring. The resulting ester is then polymerized."
The preparation of other related segmented thermo-plastic copolymers are described in the following additional references: U.S. Patents Nos. 3,651,014; 3,763,109; 3,766,1~6;
and 3,78~,520.
According to the above references, the disclosed segmented thermoplastic copolymers may be cast as films, injection molded to form objects, or melt extruded to form filaments. The products obtained in accordance with these references, however, are characterized by physical proper~ies which are not desirable for surgical sutures.
In particular, the filaments o the references are rubbery with a very high de~ree o~ elasticity as indicated by break elongations in excess of 500 percent. Tensïle strengths, on the other hand, are ~ery low, generally less than 8,000 psi.
The ~ilaments prepared from.copolyether/esters in accordance '~2~:)3:13~
with the teachings of these referen.ces therefore do not possess the mechanical properties of the sutures of the invention, and, in fact, are obviously not at all suitable for use as surgical.
sutures.
The disadvantages of the prior art references are overcome by means of the present invention wherein filaments extruded from certain copolyether/esters are quenched and drawn with the result that the mechanical properties of the filaments are controlled to be within the specific limits discovered to be particularly desirable for surgical sutures.
The segmented copolyether/esters useful in the present invention comprise a multiplicity of recurring long chain ether/
ester units and short chain ester units joined head to tail through ester linkages according to the following general formula:
O O O O
[(O - D - O - C - R - C)a(O - G - O - C - R - C ~ )b3n (I) The long chain ether/ester units of the polymer are represented by the general formula:
O O
,. ..
- O - G - O - C - R - C - (II) wherein G is a divalent radical remaining after the xemoval of terminal hydroxyl groups from à poly (C2 10 alkylene oxide) glycol having a molecular weight within the range of about 350 to 6,000, and R is a divalent radical remaining after the removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight of less than about 300.
The short chain ester units are represented by the general formula:
O O
ll ll - O - D - O - C - R - C - (III) wherein D is a divalent radical remaining after remoual of hydroxyl groups from an alkyldiol having a molecular weight of less than about 250, and R is as defined above.
In the above Formula I, a is an integer such that the short chain copolymer segments represented by a comprise from 50 to 90 percent by weight of the total copolymer composi-3~ 7 - 1.0 tion; _ is an integer such that the long chain copolymer seg-ments represented by b comprise from 10 to 50 percent of the total copolymer composition; and n is the degree of polymeriza-tion resulting in a f:iber-orming copolymer.
The copolyether/esters represented by Formula I may be melt extruded, quenched and drawn to obtain filaments having physical properties desirable for surgical sutures as above defined. Polymer to be extruded is dried at about 200-220F in a circulating hot air oven and/or under vacuum in order to remove all traces of moisture and other volatile materials.
The polymer is then melt extruded and water quenched in accor-dance with the conventional melt spinning techniques forsynthetic fibers. The fiber is finally drawn at least about 5X, and usually ~rom about 7X to 9X to achieve molecular orien-tation.
The preparation of fibers useful as surgical suturesfrom copolyether/esters in accordance with the present invention is demonstrated by the following examples which are presented by way of illustration and are not limiting of the present invention. The polymers utilized in these examples are copoly-ether/esters prepared from 1,4-butanediol, dimethyl phthalate, and polytetramethylene ether glycol (M/W/ of about 1,000), and are ~ ~L~ially available from E.I. du Pont de Nemours & Co.
under the trademark "HYTREL". The polymer contains intrapo]y-merized butylenephthalate hard segments (short chain ester units)and polytetramethylene ether terephthalate soft segments (long chain ester units) and has the following general structure as reported in the Journal of Elastomers and Plastics 9, 416-38 (Oct., 1977):
O O O O
Il ~ 11 11 30 ( ~ (CH2)4 ~ C ~ ~ ~a ((CH2CH ~ 2cH20)x _ C ~ -C~b (IV) thard segment) (soft segment) wherein a and b are as defined above a~d x is an integer xeflecting the molecular weight of the ethex ~lycol reactant (x = 14 for M~Wo of about 1,000).
f~L2~3~3'7 In the following exa~les, physical properties of individual monofilaments were determined on an Instron*
tensile tester under the following conditions~
Crosshead speed (XH)~ 5 in/min Chart speed (CS) : 10 in/min Sample length (GL) . 5 in Scale load (SL) ~ 2 lbs~in With reference to Figure 1, Young's modulus is calculated from the slope a of the stress-strain curve in the initial linear~ elastic region as follows-, tan ~ x GL x ~'S x SL
Young s modulus ~pSl) = XH x XS
wherein ~ = the angle indicated in Figure 1XS = the cross-sectional area of the fiber, in2 SL, XH, CS, and GL are as identified above.
Yield stress (Sy) is the load at the point of inter-section of lines a and b drawn tangent to the initial elastic region and the visco-elastic region, respectively, of the curve as illustrated in Figure 1. Yield elongation (Ey) is the elong-ation corresponding to Sy and is read directly off the stress-strain curve.
Visco~elastic stress (Sv) is the load at the point of intersection of line b with line c drawn tangent to the curve as illustrated in Figurè 1. Visco-elastic elongation (Ev) is the elongation corresponding to Sv and is read directly off the curve.
~reak elongation ~Eb) and breaking tensile strength (Sb) are read directly off the stress-strain curve as illus-trated in Figure 1.
EXAMPLE I
A sample of copolyether/ester of Formula IV having approximately 40 wt percent soft segments and comprising ap-proximately 51 percent terephthaloyl units, 16 percent units derived from polytetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol was dried four hours at 200F
in a circulating hot air oven and then further dried under vacuum at 100 microns (no heat) fGr 16 hours. The dry polymer was placed in a one-inch horizontal extruder and extruded through *Trade ~ark ~`.33~3~
a J/50/1 die at an extrusion te~pe~ature of 380F.
The extrudate was quenched in water at ambient temperature and drawn to a si~e 2-0 monofilament suture using a 8.8X draw ratio at a temperature of 530F and with a take-up speed of 485 ft/min. Physical properties of the resultingfilaments are given in Table II.
EXAMP~E II
.
A sample of copolyether/ester of Formula IV having approximately 23 wt percent soft segments and comprising ap-proximately 45 percent terephthaloyl units~ 4 percent ortho-phthaloyl units, 20 percent units derived from polytetramethylene ether glycol and 31 percent units derived from 1,4-butanediol was dried and extruded at 400F as described in Example I. The extrudate was quenched and drawn into a size 2-0 monofilament using a 7.5~ draw ratio at a temperature of 450F and with a take-up speed of 412 ft/min. Physical properties of the result-ing filaments are given in Table II.
EXAMPLE III
A sample of copolyether/ester of Formula IV having approximately 18 wt percent soft segments and comprising ap-proximately 41 percent terephthaloyl units, 35 percent units derived from polytetramethylene ether glycol and 24 percent units derived from l,4-butanediol was dried and extruded at ~05F as described in Example I. The extrudate was quenched and drawn into a size 2-n monofilament suture using a 6.5 draw ratio at a temperature of 560F. The take-up speed was 75 ft/min.
Physical properties of the resulting filaments are given in Table II. It is noted that the Young's modulus of these fila-ments exceeded the preferred maximum desirable limit for sutures of the present invention.
EX~PLE IU
Three parts of a copolyether/ester of Example I and two parts of a copolyether/ester of Exa~ple III were dry blended to provide a polymer having a total of 30.2 perce~t soft seg-ments. The blended material was dried in a vacuum o~en fortwo hours at 1-2 mm Hg (no heat~ and then heated at 50C for three hours at 1-2 mm Hg.
~13~3~7 The dried mixture was me~t blended in a 3/~-inch Brabe~der extruder with a 25-inch barrel with a 20/1 screw and extruded at 430F through a 5~32-inch die in a vertical monofilament assembly. The extrudate was water quenched at ambient temperature~ pelletized, and again dried as described above for the dry-blended material before extruding into mono-filament sutures. A size 2-0 monGfilament suture of this material was extruded at 400F using a 7.9X draw ratio at a temperature of 460F and a ~ake-up speed of 435 ft/min.
Physical properties of the resulting filaments are given in Table II.
EXAMPLE ~
3.5 parts of a copolyether/ester of Example I and 1.5 parts of a copolyether/ester of Example III were dry-blended for a total of 33.4 percent soft segments and extruded follow-ing the general procedure of Example IV, and using a final draw ratio of 7.5X with a draw temperature of 485F and a take-up speed of 412 ft/min to obtain a size 2-0 monofilament suture.
The physical properties of the resulting filaments are given in Table II.
EXAMPLE ~I
The procedure of Example IV was repeated using `various blends of copolyether/ester polymers of Examples I, II
and III having the compositions and blended in ratios as shown in Table II. The physical properties of the resulting filaments are also given in Table III.
EXAMPLE VII
A copolyether/ester of Example I with 40 wt percent soft segments was dried and extruded in accordance with the general procedure o Example I using a 20 mil spinnerette to obtain a size 5-0 suture, and a 50 mil spinnerette to obtain-a size 0 suture. Drawing condition~ and physical properties of the resulting suture are compared in Table IV with a size 2-0 suture of the same composition prepared according to Example I.
TABLE II
Examples I II III IV V
Suture size 2-0 2-0 2-0 2-0 2-0 Diameter, mils 11.1 13.1 12.2 13.2 13.2 ~mm) (0.28)(0.33) ~0.31) (0.343 (0.34~
Knot strength, psi 37,20039,700 44,900 40,100 41,000 (Kg/cmZ) (2,600)(2,780)(3,140) (2,800) (2,870) Tensile strength, psi 64,1bO 71,300 72,300 65,500 60,500 (Kg/cm2) (4 (5,060) (4,580) (4,200) Break elongation, % -31.8 27.8 18.3 25.2 31.4 Visco-elastic elongation, % 18.6 13.3 7.25 10.35 11.6 Yield elongation, ~ 3.2 2.9 2~6 4.2 4.7 Young's modulus, psi50,000172,000 320,000 140,000 120,000 (Kg/cm2) (3,500)~12,000) (22,400) (9,800) (8,400) TABLE III
Polymer compositions Wt % Young's Break Visco- Yield Wt ~ soft Wt ratio soft modulus elonga- elastic elonga-segments of of segments psi tion elonga tion components components in blend (Kg/cm2~ Eb, ~ tion Ey, %
Ev, %
40/23 65/35 34.0584,000 34.8 14.3 9.2 ( 5,850) 40/18 75/25 34.50107,000 33.4 13.3 3.2 ( 7,470) 40/23 50/50 31.50105,000 33.7 14.7 1.9 40/18 70/30 33.40120,000 31.4 11.6 4.7 ~ 8,390) ~3 4~/18 65/35 32.30134,000 27.5 12.1 4.6 ~ 9,400) 40/18 60/40 31.20140,000 26.5 10.2 4.8 ~ 9,790) 40/18 55/45 30.10170,000 24.5 10.8 2.6 (11,920) 40/18/23 30/30/40 26.60173,000 18.9 10.3 3.5 (12,080) 40/23/18 3~/30/40 26.10201,000 22.4 10.3 2.8 ~14,060) ~(33~
~ 16 -~T~BLE~IV~`
Suture size Draw ratio 7.5 8.8 7~3*
Draw temperature, F 340 530 370 ~5 Take-up ft/min 205 485 110 Diameter, mils 7.08 11.10 14.03 Knot strength, psi48,600 37,200 34,200 (Kg/cm2) (3,400) (2,600) (2,400) Tensile strength, psi67,50064,10068,600 (Kg/cm2) (4,700) (4,400) (4,800) Break elongation, ~ 43.5 31.8 36.7 Visco-elastic elongation, ~ 10.8 18.6 17.6 Yield elongation, ~ 3.0 3.2 6.3 Young's modulus, psi49,00050,000 51,000 (Kg/cm2) (3,400) (3,500) (3,600) *Two stage draw EXAMPLE VIII
Monofilament sutures prepared from a copolyether/
ester of Example II with 23 wt percent soft segments were sterilized by cobalt-60 irradiation and with ethylene oxide in accordance with conventional procedures for sterilizing 20 surgical sutures. The physical properties of th~ sutures were affected only slightly by ethylene oxide sterilization, and even less by cobalt-60, as shown by the data in Table V.
3.~
TABLE V
5uture Nonsterile Sterilized control 60 Co E.O.
Diameter, mils 12.5 12.6 13.2 Knot strength, psi35,30033,400 29,900 (Kg/cm2) (2,500) (2,300~ ~2,100) Tensile strength, psi 70,300 70,000 67,700 (Kg/cm2) (4,900~ (~,900)`(4,800) Break elongation, %28.2 31.6 45.2 Visco-elastic elongation, %13.2 15.0 23.5 Yield elongation, %2.9 2.3 2.2 Young's modulus, psi185,000165,000138,000 (Kg/cm2) (13,000) (11,600) (9,600) The important physical properties of the sutures prepared from copolyether/esters are responsive to changes in polymer composition and processing conditions. For example, visco-elastic elongation and yield elongation increase as the proportion of soft segments in polymer are increased, and conversely, Young's modulus decreases with an increasing propor-tion of soft segments. The break elongation may be decreased and tensile strength increased by employing higher draw ratios during the manufacture of the suture. By regulation of the composition and processing variables therefor, it is possible to obtain specific mechanical properties for individual sutures with a great degree of latitudeO
While the preceding examples have been directed to the preparation of monofilament sutures of copolyether/esters, this was for the sake of convenience in describing one polym~r system and the effect of various polymer compositions and spinning condition~ on fiber properties. The copolyether/ester polymers 30 may also be used in the manufacture of braided or other multi-filament suture constructions, and sinyle filaments and braids may be used in the preparation of surgical fabrics and knitted ~3~
or woven prosthetic devices such as ~ein and arterial grafts.
In addition, elastomeric filaments having a ~ombination of physical properties in accordance with the present invention may be prepared from other polymer systems such as polyurethane 5 or silicone elastomers or polyether copolymers of urethane or silicone elastomers. ~urthermore, elastomeric filaments of the present invention may be blended with each other, with other elastomeric or non-elastomeric filaments, and with either absorbable or non-absorbable filaments in order to provide 10 yarns and fabrics with special properties, all of which is deemed to be included within the scope of the present invention.
Claims (23)
1. An elastomeric non-absorbable surgical suture in a sterile condition with a needle attached to at least one end thereof comprising a monofilament containing an intrapolymerized butylenephthalate hard segments and polytetramethylene ether soft segments and having the following general structure:
(hard segment) (soft segment) and having the following combination of mechanical properties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent.
Young's modulus - from about 30,000 to 320,000 psi Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi.
(hard segment) (soft segment) and having the following combination of mechanical properties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent.
Young's modulus - from about 30,000 to 320,000 psi Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi.
2. A suture of claim 1 having a diameter of from about 0.01 to 1.0 mm.
3. A suture of claim 1 wherein the Young's modulus is 50,000 to 150,000.
4. A suture of claim 1 wherein the tensile stress at the visco-elastic elongation yield point is less than about one-third the suture tensile strength.
5. A suture of claim 1 having an elongation to break of about 30 to 100 percent.
6. A suture of claim 5 wherein the elongation to break is at least 1.5 times the visco-elastic elongation.
7. A suture of claim 1 wherein the visco-elastic elongation is at least about 2.5 times the yield elongation.
8. A suture of claim 1 comprising a drawn and oriented monofilament of a segmented copolyether/ester polymer.
9. A drawn and oriented elastomeric non-absorbable surgical suture in a sterile condition with a needle attached to at least one end thereof comprising a segmented copolyether/ester polymer consisting essentially of a multiplicity of recurring long chain ether/ester units and long chain ester units joined head to tail through ester linkages and having the following general formula:
wherein G is a divalent radical remaining after the removal of terminal hydroxyl groups from a poly(C2-10 alkylene oxide) glycol having a molecular weight of about 350 to 6,000; R is a divalent radical remaining after removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight less than about 300; and D is a divalent radical remaining after removal of hydroxyl groups from an alkyldiol having a molecular weight less than about 250; a and b are integers such that the long chain units represented by a comprise from 50 to 90 percent by weight of the composition; and n is the degree of polymerization resulting in a fiber-forming polymer, said drawn sutures being characterized by being soft, limp and having controlled elasticity under low applied force to accommodate swelling in a wound area and to allow the suture to draw down during knotting and by the following physical properties:
Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent.
wherein G is a divalent radical remaining after the removal of terminal hydroxyl groups from a poly(C2-10 alkylene oxide) glycol having a molecular weight of about 350 to 6,000; R is a divalent radical remaining after removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight less than about 300; and D is a divalent radical remaining after removal of hydroxyl groups from an alkyldiol having a molecular weight less than about 250; a and b are integers such that the long chain units represented by a comprise from 50 to 90 percent by weight of the composition; and n is the degree of polymerization resulting in a fiber-forming polymer, said drawn sutures being characterized by being soft, limp and having controlled elasticity under low applied force to accommodate swelling in a wound area and to allow the suture to draw down during knotting and by the following physical properties:
Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent.
10. The suture of claim 9 having a Young's modulus of about 30,000 to 320,000 psi.
11. The suture of claim 9 having a Young's modulus from about 30,000 to 200,000 psi.
12. A suture of claims 9, 10 or 11, wherein G
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid.
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid.
13. A suture of claims 9, 10 or 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, wherein R is selected from the group consisting of terphthaloyl isophthaloyl, orthophthaloyl, and mixtures thereof.
14. A suture of claims 9, 10 or 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid, and wherein said poly(tetramethylene-oxide) glycol has a molecular weight of about 1,000.
15. A suture of claims 9, 10 and 11 wherein G
is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid wherein the long chain units represented by b comprise about 40 wt. percent of the copolyether/
ester.
is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid wherein the long chain units represented by b comprise about 40 wt. percent of the copolyether/
ester.
16. A suture of claims 9, 10 or 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid wherein the long chain units represented by b comprise about 40 wt percent of the copolyether/
ester, and comprising approximately 51 percent tere-phthaloyl units, 16 percent units derived from poly-tetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol.
ester, and comprising approximately 51 percent tere-phthaloyl units, 16 percent units derived from poly-tetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol.
17. A suture of claims 9, 10 or 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein the long chain units represented by b comprise about 40 wt percent of the copolyether/
ester, and comprising approximately 51 percent tere-phthaloyl units, 16 percent units derived from poly-tetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol, and characterized by a visco-elastic elongation of about 19 percent and a Young's modulus of about 50,000 psi.
ester, and comprising approximately 51 percent tere-phthaloyl units, 16 percent units derived from poly-tetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol, and characterized by a visco-elastic elongation of about 19 percent and a Young's modulus of about 50,000 psi.
18. A suture of claims 9, 10 or 11, wherein G
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein the long chain units represented by b comprise about 23 wt percent of the copolyether/
ester.
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein the long chain units represented by b comprise about 23 wt percent of the copolyether/
ester.
19. A suture of claims 9, 10 or 11, wherein G
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein the long chain units represented by b comprise about 23 wt percent of the copolyether/ester and comprising approximately 45 percent terephthaloyl units, 4 percent orthophthaloyl units, 20 percent units derived from polytetramethylene ether glycol and 31 percent units derived from 1,4-butanediol.
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein the long chain units represented by b comprise about 23 wt percent of the copolyether/ester and comprising approximately 45 percent terephthaloyl units, 4 percent orthophthaloyl units, 20 percent units derived from polytetramethylene ether glycol and 31 percent units derived from 1,4-butanediol.
20. A suture of claims 9, 10 or 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein the long chain units represented by b comprise about 23 wt percent of the copolyether/
ester, comprising approximately 45 percent terephthaloyl units, 4 percent orthophthaloyl units, 20 percent units derived from polytetramethylene ether glycol and 31 percent units derived from l,4-butanediol, and character-ized by a visco-elastic elongation of about 13 percent and a Young's modulus of about 170,000 psi.
ester, comprising approximately 45 percent terephthaloyl units, 4 percent orthophthaloyl units, 20 percent units derived from polytetramethylene ether glycol and 31 percent units derived from l,4-butanediol, and character-ized by a visco-elastic elongation of about 13 percent and a Young's modulus of about 170,000 psi.
21. A suture of claims 9, 10 or 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein said poly(tetramethyleneoxide) glycol has a molecular weight of about 1,000, and comprising a mixture of individual segmented copoly-ether/ester polymers, each of said polymers having from about 18 to 40 percent by weight long chain ester units, the mixture of said individual polymers con-taining an average of from about 26 to 35 percent long chain ester units.
22. A suture of claims 9, 10 or 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein said poly(tetramethyleneoxide) glycol has a molecular weight of about 1,000, com-prising a mixture of individual segmented copolyether/
ester polymers, each of said polymers having from about 18 to 40 percent by weight long chain ester units, the mixture of said individual polymers containing an average of from about 26 to 35 percent long chain ester units, and wherein said polymer mixture comprises from about 55 to 75 percent by weight of polymer having about 40 percent long chain ester units, and from about 25 to 45 percent by weight of polymer having about 18 percent long chain ester units.
ester polymers, each of said polymers having from about 18 to 40 percent by weight long chain ester units, the mixture of said individual polymers containing an average of from about 26 to 35 percent long chain ester units, and wherein said polymer mixture comprises from about 55 to 75 percent by weight of polymer having about 40 percent long chain ester units, and from about 25 to 45 percent by weight of polymer having about 18 percent long chain ester units.
23. A suture of claims 9, 10 or 11, wherein G
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein said poly(tetramethylene-oxide)glycol has a molecular weight of about 1,000, comprising a mixture of individual segmented copoly-ether/ester polymers, each of said polymers having from about 18 to 40 by weight long chain ester units, the mixture of said individual polymers containing an average of from about 26 to 35 percent long chain ester units, and wherein said polymer mixture comprises approximately 40 percent by weight of a polymer having about 40 percent long chain ester units, from about 30 to 40 percent by weight of a polymer having about 23 percent long chain ester units, and from about 30 to 40 percent by weight of a polymer having about 18 percent long chain ester units.
is derived from poly(tetramethyleneoxide)glycol, D
is derived from 1,4-butanediol, and R is derived from a phthalic acid, wherein said poly(tetramethylene-oxide)glycol has a molecular weight of about 1,000, comprising a mixture of individual segmented copoly-ether/ester polymers, each of said polymers having from about 18 to 40 by weight long chain ester units, the mixture of said individual polymers containing an average of from about 26 to 35 percent long chain ester units, and wherein said polymer mixture comprises approximately 40 percent by weight of a polymer having about 40 percent long chain ester units, from about 30 to 40 percent by weight of a polymer having about 23 percent long chain ester units, and from about 30 to 40 percent by weight of a polymer having about 18 percent long chain ester units.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96765678A | 1978-12-08 | 1978-12-08 | |
| US967,656 | 1978-12-08 | ||
| US7705579A | 1979-09-26 | 1979-09-26 | |
| US77,055 | 1979-09-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1203137B true CA1203137B (en) | 1986-04-15 |
Family
ID=26758834
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000341398A Expired CA1141915A (en) | 1978-12-08 | 1979-12-06 | Elastomeric surgical sutures-comprising segmented copolyether/esters |
| CA000485231A Expired CA1203137B (en) | 1978-12-08 | 1985-06-25 | Elastomeric surgical sutures-comprising segmented copolyether/esters |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000341398A Expired CA1141915A (en) | 1978-12-08 | 1979-12-06 | Elastomeric surgical sutures-comprising segmented copolyether/esters |
Country Status (23)
| Country | Link |
|---|---|
| AR (1) | AR222361A1 (en) |
| AT (1) | AT370999B (en) |
| AU (1) | AU530057B2 (en) |
| BR (1) | BR7907998A (en) |
| CA (2) | CA1141915A (en) |
| CH (1) | CH643460A5 (en) |
| DE (1) | DE2949181A1 (en) |
| ES (1) | ES8101387A1 (en) |
| FR (1) | FR2473316B1 (en) |
| GB (1) | GB2038704B (en) |
| HK (1) | HK30083A (en) |
| IL (1) | IL58897A (en) |
| IN (1) | IN151798B (en) |
| IT (1) | IT1164078B (en) |
| MX (1) | MX152227A (en) |
| MY (1) | MY8400142A (en) |
| NL (1) | NL7908845A (en) |
| NZ (1) | NZ192138A (en) |
| PH (1) | PH22728A (en) |
| PL (1) | PL141223B1 (en) |
| PT (1) | PT70564A (en) |
| SE (1) | SE7910106L (en) |
| SG (1) | SG10283G (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4388926A (en) * | 1980-12-22 | 1983-06-21 | Ethicon, Inc. | High compliance monofilament surgical sutures comprising poly[alkylene terephthalate-co-(2-alkenyl or alkyl)succinate] |
| US4689424A (en) * | 1981-08-06 | 1987-08-25 | Ethicon, Inc. | Radiation sterilizable absorbable polymeric materials and methods for manufacturing the same |
| NL8202893A (en) * | 1982-07-16 | 1984-02-16 | Rijksuniversiteit | ORGANIC Tolerant, ANTHITHROMBOGENIC MATERIAL, SUITABLE FOR RECOVERY SURGERY. |
| US4906729A (en) * | 1988-08-05 | 1990-03-06 | E. I. Du Pont De Nemours And Company | Thermoplastic copolyetherester elastomers |
| US5009955A (en) * | 1989-03-06 | 1991-04-23 | General Motors Corporation | Dual modulus oriented elastomeric filaments |
| AU694983B2 (en) * | 1994-06-06 | 1998-08-06 | Johnson & Johnson Consumer Companies, Inc. | Novel compositions for dental floss |
| AU2007201213A1 (en) * | 2006-04-06 | 2007-10-25 | Tyco Healthcare Group Lp | Yarns containing thermoplastic elastomer copolymer and polyolefin filaments |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3454011A (en) * | 1966-12-28 | 1969-07-08 | Marvin Wagner | Sutures and prosthetic patches |
| CA933319A (en) * | 1968-12-04 | 1973-09-11 | Sumoto Misao | Melt spinning elastic polyester polyether block copolymer |
| US4127127A (en) * | 1977-05-23 | 1978-11-28 | Alza Corporation | Therapeutic systems made from certain segmented copolyesters |
| US4224946A (en) * | 1978-08-14 | 1980-09-30 | American Cyanamid Company | Surgical sutures derived from segmented polyether-ester block copolymers |
-
1979
- 1979-10-30 IN IN1132/CAL/79A patent/IN151798B/en unknown
- 1979-11-15 NZ NZ192138A patent/NZ192138A/en unknown
- 1979-11-27 AU AU53197/79A patent/AU530057B2/en not_active Ceased
- 1979-12-05 IT IT50997/79A patent/IT1164078B/en active
- 1979-12-06 CA CA000341398A patent/CA1141915A/en not_active Expired
- 1979-12-06 PL PL1979220182A patent/PL141223B1/en unknown
- 1979-12-06 FR FR7929946A patent/FR2473316B1/en not_active Expired
- 1979-12-06 DE DE19792949181 patent/DE2949181A1/en active Granted
- 1979-12-07 MX MX180381A patent/MX152227A/en unknown
- 1979-12-07 AR AR279206A patent/AR222361A1/en active
- 1979-12-07 BR BR7907998A patent/BR7907998A/en unknown
- 1979-12-07 NL NL7908845A patent/NL7908845A/en not_active Application Discontinuation
- 1979-12-07 PT PT70564A patent/PT70564A/en unknown
- 1979-12-07 PH PH23379A patent/PH22728A/en unknown
- 1979-12-07 CH CH1089979A patent/CH643460A5/en not_active IP Right Cessation
- 1979-12-07 GB GB7942325A patent/GB2038704B/en not_active Expired
- 1979-12-07 AT AT0776179A patent/AT370999B/en not_active IP Right Cessation
- 1979-12-07 ES ES486698A patent/ES8101387A1/en not_active Expired
- 1979-12-07 IL IL58897A patent/IL58897A/en unknown
- 1979-12-07 SE SE7910106A patent/SE7910106L/en unknown
-
1983
- 1983-03-11 SG SG102/83A patent/SG10283G/en unknown
- 1983-08-18 HK HK300/83A patent/HK30083A/en unknown
-
1984
- 1984-12-30 MY MY142/84A patent/MY8400142A/en unknown
-
1985
- 1985-06-25 CA CA000485231A patent/CA1203137B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| BR7907998A (en) | 1980-07-22 |
| PL220182A1 (en) | 1980-12-01 |
| FR2473316A1 (en) | 1981-07-17 |
| ES486698A0 (en) | 1980-12-16 |
| CA1141915A (en) | 1983-03-01 |
| IL58897A (en) | 1982-09-30 |
| NL7908845A (en) | 1980-06-10 |
| PL141223B1 (en) | 1987-07-31 |
| DE2949181A1 (en) | 1980-06-26 |
| ES8101387A1 (en) | 1980-12-16 |
| ATA776179A (en) | 1982-10-15 |
| PT70564A (en) | 1980-01-01 |
| CH643460A5 (en) | 1984-06-15 |
| IL58897A0 (en) | 1980-03-31 |
| IT7950997A0 (en) | 1979-12-05 |
| NZ192138A (en) | 1984-05-31 |
| AU530057B2 (en) | 1983-06-30 |
| MY8400142A (en) | 1984-12-31 |
| SG10283G (en) | 1983-12-16 |
| FR2473316B1 (en) | 1986-05-23 |
| PH22728A (en) | 1988-11-28 |
| MX152227A (en) | 1985-06-12 |
| AR222361A1 (en) | 1981-05-15 |
| HK30083A (en) | 1983-08-26 |
| GB2038704A (en) | 1980-07-30 |
| IT1164078B (en) | 1987-04-08 |
| AU5319779A (en) | 1980-06-19 |
| DE2949181C2 (en) | 1990-01-18 |
| GB2038704B (en) | 1983-01-12 |
| IN151798B (en) | 1983-07-30 |
| AT370999B (en) | 1983-05-25 |
| SE7910106L (en) | 1980-06-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| NARE | Reissued | ||
| MKEX | Expiry |