Source: https://patents.google.com/patent/WO2011119742A2/en
Timestamp: 2019-08-17 17:23:15
Document Index: 605587889

Matched Legal Cases: ['application No. 2003021', 'Application No. 2010', 'Application No. 2009', 'Application No. 2008', 'Application No. 2009', 'art 5', 'art 5', 'art 5']

WO2011119742A2 - Coatings for the manufacture and application of polyhydroxyalkanoate medical devices - Google Patents
WO2011119742A2
WO2011119742A2 PCT/US2011/029638 US2011029638W WO2011119742A2 WO 2011119742 A2 WO2011119742 A2 WO 2011119742A2 US 2011029638 W US2011029638 W US 2011029638W WO 2011119742 A2 WO2011119742 A2 WO 2011119742A2
PCT/US2011/029638
WO2011119742A3 (en
2010-03-26 Priority to US31801410P priority Critical
2010-03-26 Priority to US61/318,014 priority
2010-04-19 Priority to US32568610P priority
2010-04-19 Priority to US61/325,686 priority
2010-07-12 Priority to US61/363,543 priority
2010-07-12 Priority to US36354310P priority
2010-11-09 Priority to US41162910P priority
2010-11-09 Priority to US61/411,629 priority
2011-03-23 Application filed by Tepha, Inc. filed Critical Tepha, Inc.
2011-09-29 Publication of WO2011119742A2 publication Critical patent/WO2011119742A2/en
2013-01-03 Publication of WO2011119742A3 publication Critical patent/WO2011119742A3/en
There is a need for absorbable braided sutures with improved performance. In particular, these sutures should have high initial tensile strength, prolonged strength retention in vivo, good knot security and tie down (with a small knot bundle), good handling characteristics, and be biocompatible. The braided sutures should also have a low tissue drag that minimizes trauma to the sutured tissues. Biocompatible braided
polyhydroxyalkanoate ("PHA") sutures, or those having a braided component, can be made with high tensile strength, prolonged strength retention in vivo, and good knot security; however, it would be advantageous if the tissue drag resulting from the braided structure of the suture could be reduced.
A number of different types of coatings have been applied to braided sutures to lower tissue drag. These coatings must: impart good lubricity to the fiber/braid, have a reasonable shelf life, be biocompatible, and be compatible with the physical and chemical structure of the fiber. For example, the coating must not react with the suture fiber, dissolve the fiber, or adversely alter the mechanical and thermal properties of the fiber. Thus, it is desirable to identify coatings that can be applied to PHA braided sutures to reduce tissue drag by imparting good lubricity to the braid and fill the braid interstices without adversely altering the inherent properties of the fiber/braid. Moreover, it is particularly desirable to identify coatings that can be applied to braided sutures, or sutures containing braided components, made from P4HB polymers and copolymers thereof. In addition to providing coatings for PHA fibers that reduce tissue drag, it is desirable to identify spin finishes that can be applied to PHA fibers to facilitate their manufacture and, optionally, their conversion to other products, including medical textiles. Spin finishes are applied during extrusion of multifilaments to keep the fiber bundle protected and intact, and to impart lubricity to the fiber bundle so that it may be manipulated in subsequent processing steps without damaging the fiber. Spin finishes are also applied to monofilament to facilitate textile processing without damaging the fiber. Spin finishes for medical applications must satisfy a number of conditions. These include compatibility with the fiber (similar to that described for suture coatings), and effectiveness under the process conditions, for example, in processes such as spinning and orienting of the fiber, and in knitting or weaving of the fiber. In addition, it must be easy to apply the spin finish, and easy to remove the spin finish without damaging the fiber or adversely impacting any component in the fiber such as dye, using conditions that are compatible with the fiber's subsequent use in a medical device. Residues of the spin finish should also be easily detectable, and any spin finish left on the device, even residues, needs to be
biocompatible. The spin finish should also be stable with a long shelf life, and any spin finish left on the final product should not adversely impact the properties or the shelf life of the final product.
It is also desirable to provide multifilament with a lower denier per filament (dpi) and improved tenacity compared to uncoated multifilament. Such fibers can be used to prepare higher strength medical devices as well as reduce the device profile.
The preferred coating weight for a spin finish will depend on the fiber being processed. Monofilaments require less spin finish than multifilaments, due to the smaller total surface area of a monofilament fiber. So a preferred coating weight on a monofilament may be less than 2 wt%, preferably less than 1 wt%, while for multifilament it may be less than 10 wt%, preferably less than 8 wt%. Spin finishes can be removed by a scouring process to prevent cytotoxicity. In preferred embodiments, the residual content of Tween® 20 after scouring is less than about 0.5 wt%, including less than about 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, or 0.03 wt%. In preferred embodiments, the residual content of PEG 400 after scouring is less than about 2 wt%, including less than about 1, 0.5, 0.4, 0.3, 0.2, or 0.1 wt%.
The polyhydroxyalkanoate of the braided fiber or yarn preferably has a molecular weight between 50,000 and 1,200,000. In preferred
embodiments, the polyhydroxyalkanoate is 4-hydroxybut rate.
In another embodiment, the coating is polyvinyl alcohol (PVOH). A particularly preferred embodiment is where the coating is polyvinyl alcohol applied to a poly-4-hydroxybut ate polymer or copolymer thereof or applied to devices, such as braided sutures, derived from poly-4-hydroxybutyrate or copolymers thereof.
In preferred embodiments, the biocompatible coating is present on the PHA polymers or the medical devices made from PHA polymers in a coating weight of about 0.1 wt% to 10 wt%, including about 0.1, 0.2, 0,3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 wt%. For example, PEG2000 is preferably present on the PHA polymers or the medical devices made from PHA polymers in a coating weight of less than 10 wt%, more preferably less than 7 wt%, even more preferably less than 5 wt%. For example, PVA is preferably present on the PHA polymers or the medical devices made from PHA polymers in a coating weight of less than 6 wt%, more preferably less than 4 wt%, even more preferably less than 3 wt%.
A method of reducing the tissue drag force of a braided suture formed from polyhydroxyalkanoate filaments is also provided. This method can involve coating the braided suture with polymers or oligomers of ethylene oxide, polymers or oligomers of propylene oxide, polyvinyl alcohol, or combinations thereof. Detailed Description of the Invention
"Polyhydroxyalkanoates" or "PHAs" are linear polyesters produced in nature by bacterial fermentation of sugar or lipids. Depending upon the microorganism and the cultivation conditions, homo- or copolyesters with different hydroxyalkanic acids are generated.
"Poly-4-hydroxybutyrate" as generally used herein means a homopolymer comprising 4-hydroxybutyrate units. It may be referred to herein as P4HB or TephaFLEX® biomaterial (manufactured by Tepha, Inc., Lexington, MA) .
"Copolymers of poIy-4-hydroxybutyrate" as generally used herein means any polymer comprising 4-hydroxybutyrate with one or more different hydroxyalkanic acid units.
"Breast reconstruction devices" means devices for (i) breast augmentation, including devices for use with breast implants (e.g. saline or silicone implants), (ii) mastopexy, (Hi) breast reduction (including removal, reshaping and reorienting of breast tissue), and (iv) breast reconstruction following mastectomy with or without breast implants.
"Elongation" or "extensibility" of a material means the amount of increase in length resulting from, as an example, the tension to break a specimen. It is expressed usually as a percentage of the original length. (Rosato's Plastics Encyclopedia and Dictionary, Oxford Univ. Press, 1993).
"Molecular weight" as used herein, unless otherwise specified, refers to the weight average molecular weight (Mw), not number average molecular TEPH 119 POT weight (Mn), and is measured by gel permeation chromatography (GPC) relative to polystyrene.
"Cytotoxicity" refers to the harmful affect of a medical device on cells as set forth in ISO 10993-5. Cytotoxicity can be measured using a rapid, standardized test that is very sensitive and inexpensive. These tests can determine if the materials in a medical device contain significant quantities of harmful extractables that negatively effect cellular components. Testing is required for all types of medical devices. An agar overlay media can be placed on top of a monolayer of L-929 cells, and a sample is placed on top of the agar media, then incubated. For MEM elution, an extract of the sample in Minimum Essential Medium (MEM) is placed in contact with the monolayer of L-929 cells and then incubated. In both methods the cells are scored for cytotoxic effect.
"Spin finishes" are lubricants and antistatic agents that are applied to textile fibers and yarns during production and processing.
"Denier" is a unit of weight of fiber or yarn. The weight in grams of 9,000 meters of fiber or yarn is its denier.
"Tenacity" is the strength of a yarn or fiber for its given size. It may be defined as the grams of breaking force per denier or breaking strength (grams force) divided by denier (i.e. grams per denier, or gpd).
"Pick count" is defined as the number of crossovers of sheath yarns per linear inch of suture or braid.
"PPI" stands for picks per inch.
«YPJ» stands for twists per inch.
"Lubricity" is the measure of the reduction in friction by a lubricant. Lubricity of a material cannot be directly measured, so tests are performed to quantify a lubricant's performance. This is done by determining how much wear is caused to a surface by a given friction-inducing object in a given amount of time. For sutures, lubricity can be determined by measuring tissue drag. A monofilament has low tissue drag, meaning it passes smoothly through tissue. Braided or twisted sutures have higher tissue drag, but are easier to knot and have greater knot strength. Braided sutures can be coated to increase lubricity and lower tissue drag.
Methods have been developed to produce iubricious compositions of PHA polymers that are suitable for the manufacture of PHA fibers and yarns, and for the manufacture of medical devices and medical device components, as well as to improve the lubricity of certain medical devices, such as sutures comprising PHA braided structures. These methods have been applied to P4HB multifilaments prepared by melt processing, and to P4HB
multifilaments and monofilaments braided, woven or knitted into medical device products, such as braided sutures and surgical meshes.
The processes described herein can typically be used to apply coatings or spin finishes to polyhydroxyalkanoate polymers, and more preferably to poly-4-hydroxybutyrate (P4HB) or a copolymer thereof.
Copolymers include P4HB with 3-hydroxybut ate, and P4HB with glycol ic acid monomer. P4HB and copolymers thereof can be obtained from Tepha, Inc. of Lexington, MA. Preferred PHA polymers have a weight average molecular weight (Mw) suitable for melt processing, and more preferably a Mw of 50,000 to 1,200,000, and even more preferably 100,000 to 800,000 based on gel permeation chromatography (GPC) relative to polystyrene standards. If desired, the PHA polymer may be blended with another PHA polymer prior to melt extrusion of the fibers, or blended with a non-PHA material, including other absorbable biocompatible polymers, dyes and active agents (such as drug molecules or other therapeutic, prophylactic or diagnostic agents).
Poly-4-hydroxybutyrate (P4HB) and copolymers thereof can be produced using transgenic fermentation methods, see, for example, U.S. Patent No. 6,548,569 to Williams et al, and are produced commercially, for example, by Tepha, Inc. (Lexington, MA). Poly-4-hydroxybutyrate (P4HB, TephaFLEX® biomaterial) is a strong, pliable thermoplastic polyester that, despite its biosynthetic route, has a relatively simple structure
microorganisms (see, for example, Steinbuchel A., et al. Diversity of Bacterial Polyhydroxyalkanoic Acids, FEMS Microbial Lett. 128:21 -228 (1995)). In nature these polyesters are produced as storage granules inside cells, and serve to regulate energy metabolism. They are also of commercial interest because of their thermoplastic properties, and relative ease of production. Several biosynthetic routes are currently known to produce P4HB:
Chemical synthesis of P4HB has been attempted, but it has been impossible to produce the polymer with a sufficiently high molecular weight that is necessary for most applications (Hori, Y., et al, Polymer 36:4703- 4705 (1995)).
U.S. Patent Nos. 6,245,537, 6,623,748 and 7,244,442 describe methods of making PHAs with little endotoxin, which is suitable for medical applications. U.S. Patent Nos. 6,548,569, 6,838,493, 6,867,247, 7,268,205, and 7,179,883 describe use of PHAs to make medical devices. Copolymers of P4HB include 4-hydroxybutyrate copolymerized with 3-hydroxybutyrate or glycolic acid (U.S. patent application No. 2003021 131 by Martin and Skraly, U.S. Patent No. 6,316,262 to Huisman, et al, and U.S. Patent No. 6,323,010 to Skraly, et al). Methods to control molecular weight of PHA polymers have been disclosed by U.S. Patent No. 5,811,272 to Snell, et al.
PHAs with controlled degradation and degradation in vivo of less than one year are disclosed in U.S. Patent No. 6,548,569, 6,610,764, 6,828,357, 6,867,248, and 6,878,758 to Williams, et al. and WO 99/32536 to Martin, et al. Applications of P4HB have been reviewed in Williams, S.F., et al, Polyesters, III, 4:91-127 (2002), and by Martin, D., et al Medical Applications of PoIy-4-hydroxybutyrate: A Strong Flexible Absorbable Biomaterial, Biochem. Eng. J. 16:97-105 (2003). The latter reference also describes monofilament fibers and textiles of P4HB. Medical devices and applications of P4HB have also been disclosed by WO 00/56376 to
Williams, et al. Several patents including U.S. Patent Nos. 6,555, 123, 6,585,994, and 7,025,980 to Williams, et al. describe the use of PHAs in tissue repair and engineering.
WO 06/015276 to Rizk, et al. discloses on-cur!ing P4HB fibers for use as sutures, and other medical devices including surgical meshes.
WO 07/003185 to Coleman, et al. discloses interposition and augmentation devices for tendon and ligament repair comprising P4HB fibers, and P4HB multifilament fiber with a filament denier of 4.4 and tenacity of 6.04 gram/denier. B. Coatings and Spin Finishes
The processes described herein typically use polymers or oligomers of ethylene oxide or propylene oxide as the spin finish and coating materials. The coating material can also be, for example, polyvinyl alcohol. For the textile processing of PHA monofilament fibers, the spin finish may be Tween® 20, a poly ox ethylene derivative of sorbttan monolaurate.
A preferred polymer of ethylene oxide is polyethylene glycol having an average molecular weight of approximately 400 to 10,000 daltons (e.g., PEG 400, PEG 2000, and PEG 10000), most preferably 1000 to 10,000, depending on whether the polymer is being used as a spin finish for textile processing or a coating to reduce tissue drag of a device, such as a suture. PEG 400 passed cytotoxicity testing at a coating weight of 4.8 wt%.
Polyethylene glycols manufactured by Spectrum Chemical Manufacturing Corporation are available under the tradename CARBOWAX. In addition, blends of the above-mentioned polymers and oligomers can be used as spin finish and coating materials.
Polyvinyl alcohol ("PVA") can also be used as a coating. Preferred coating weights for PVA range from 0.1 to 6%, preferably less than 3 wt%.
The PHA polymers and copolymers may contain other materials, including plasticizers, nucleants, other polymers (including absorbable polymers), additives, dyes, and compatibilizers. Examples of plasticizers are disclosed by U.S Patent No. 6,905,987 to Noda et al. Other components may be added to impart benefits such as, but not limited to, increased stability, including oxidative stability, brightness, color, flexibility, resiliency, workability, processibiHty (by addition of processing aids), and viscosity modifiers. Other absorbable polymers that may be included in the compositions include those comprising the following monomers: glycolic acid, lactic acid, trimethylene carbonate, p-dioxanone, and caprolactone.
ΙΠ. PHA Medical Devices a nd Methods of Man ufactu ring
A. Fibers and Textiles for Making PHA Medical Devices In a preferred embodiment, PHA multifilament can be prepared with a denier per filament (dpf) of less than 4, and even more preferably less than 3 dpf. It has been discovered that P4HB multifilament can be prepared with a dpf of approximately 2. It has also been discovered that P4HB multifilament can be prepared with a tenacity of greater than 6.5. Application of polymers and oligomers of ethylene and propylene oxide to the multifilament extrudate protects the extruded fiber bundle, and keeps the fiber bundle intact so that the individual fibers are not separated and damaged. The spin coating remains stable on the P4HB multifilament even as the yarn is moving. It has also been discovered that polymers and oligomers of ethylene or propylene oxide impart good lubricity to the PHA polymers, and can be pumped during the manufacture of the fibers under the conditions required for extrusion of the multifilament. In an even more preferred embodiment, P4HB
multifilament fibers are coated with PEG400.
It has also been found that polymers and oligomers of ethylene oxide can be left on the PHA polymers without adversely altering the properties of the polymer and the device. Long term exposure to these spin
finishes/coatings does not significantly alter the mechanical properties or molecular weight (Mw) of the fibers. This is important particularly if there is a significant time period between, for example, the manufacture of the multifilament and its subsequent processing into a textile construct. TEPH 1 19 PCX
In most cases it is necessary to remove substantially all the spin fmish from a medical device prior to its use. Spin finishes have a tendency to attract particulate to the surface they adhere to, and therefore removal of the spin fmish is desirable in most instances. High levels of certain spin finishes can also be too toxic for medical device use, and in these cases removal to a non-toxic level is essential (otherwise the spin finish cannot be used). It should be noted that some PHA polymers, including P4HB polymers and copolymers thereof, have relatively low melting points that significantly limit conditions under which spin finishes can be applied and removed. For example, exposure to high temperatures will melt the PHA fibers or cause changes in the physical (e.g. mechanical and morphological) properties of the polymers. Thus, spin finishes that are applied or removed at high temperatures cannot be used. Furthermore, the PHA polymers are also degradable, and therefore susceptible to hydrolysis under certain conditions, and are soluble in a range of solvents. These PHA properties also limit the choice of available spin finishes (e.g. some solvents used to apply or remove spin finish will dissolve the P4HB). As will be apparent to one skilled in the art, selection of a spin fmish for a PHA polymer or copolymer is a complicated task with the spin finish needing to satisfy a large number of performance requirements not just in processing but also in the removal process.
Fibers derived from PHA polymers and copolymers coated with polymers and oligomers of ethylene and propylene oxide as spin finish, and fibers derived from PHA monofilament coated with Tween® 20 as spin finish, possess properties that are desirable in preparing medical products, particularly implantable medical devices. For example, these fibers may be used to make partially or fully absorbable biocompatible medical devices, or components thereof. Such devices may include, but are not limited to: stent, stent graft, drug delivery device, device for temporary wound or tissue support, device for soft tissue repair, devices for cosmetic, neck and plastic surgery, replacement or regeneration (including facial surgery procedures such as blepharoplasty, facial scar revisions, forehead lifts (brow lifts), mentoplasty, malar augmentation, otoplasty, rhinoplasty, neck lift surgery, threadlifts (to lift and support sagging areas of the face, brow and neck), and rhytidectomy), repair patches including hybrid meshes, tissue engineering scaffolds, retention membranes (for example, to retain bone graft), anti- adhesion membrane, tissue separation membrane, hernia repair device, breast reconstruction device, device coating (including devices to improve fixation), cardiovascular patch, vascular closure device, vascular graft, sling, biocompatible coating, rotator cuff repair device, meniscus repair device, adhesion barrier, guided tissue repair/regeneration device, articular cartilage repair device, nerve guide, tendon repair device, ligament repair device, intracardiac septal defect repair device, including but not limited to atrial septal defect repair devices and PFO closure devices, left atrial appendage (LAA) closure device, pericardial patch, bulking and filling agent, vein valve, heart valve, bone marrow scaffold, meniscus regeneration device, ligament and tendon graft, ocular cell implant, spinal fusion device, imaging device, skin substitute, dural substitute, bone graft substitute, wound dressing, and hemostat.
In a preferred method, bulk PHA resin in pellet form is dried to under
300ppm of water using a rotary vane vacuum pump system. The dried resin is transferred to a feed hopper with a nitrogen purge to keep the pellets dry. The pellets are gravity fed into a chilled feeder section, and introduced into an extruder barrel, for example, 0.75 inches in diameter and 25.69 inches long via an extrusion screw with 30: 1 L/D ratio. A preferred extruder barrel contains four heating or extrusion zones and is manufactured by American Kuhne. The heated and softened resin from the extruder is fed into a heated metering pump (melt pump) and from the melt pump the extruded resin is fed into the heated block. The spin head houses a spin pack comprising filtering media (screens) and spinnerets containing the desired number of holes for forming the individual filaments of the yarn. (For example, 15, 30 and 60 or more holes.) The extruded filaments exit the spinneret, pass through a hot chimney, and are then air-cooled until they solidify inside a contained, clear tube. The resulting yarn is then passed through a spin finish applicator, over two rotating godets, and is collected on a precision winder as the yarn exits the second godet. The denier of the yarn at this point can range significantly depending on the number of holes and speed of the godets. A preferred range is 120-840 denier. The quantity of spin finish applied to the filaments during passage through the spin finish applicator may be controlled by varying the concentration of the spin finish while keeping all other parameters constant. This also allows direct comparison between spin finishes. In a preferred method, orientation of the yarn is accomplished offline, although it can also be done inline. In a preferred method, the extrudate is collected onto spools and then three sets of paired godets are used to orient the yarn from a payoff system holding the extrudate collection spool. The extruded yarn is rewet via a controlled pump speed spin finish applicator. In a preferred method, the yarn is hot stretched.
C. Method of Making Braided PHA Multifilament Sutures In a preferred method, drawn 60-fiIament yarn coated with spin finish is formed into braided sutures as follows. PHA yarn is twisted and/or plied and wound onto bobbins. These bobbins are then placed on 8, 12 or 16- carrier braiders and braided at various picks per inch. For some
constructions, cores are made and put in the center of the braid, for example, 60-filament yarn, multiple plied yarn strands, or monofilament fibers.
In the preferred method, braided sutures are manufactured from yarns comprising 4-hydroxybutyrate that are produced from P4HB polymers and copolymers with a weight average molecular weight between 100,000 and 800,000. The braided sutures have a tenacity from about 3-8 grams per denier, a percent elongation to break of less than 50 percent, and a denier per filament from 0.1 to 8.0. The braids are preferably made from yarns that are oriented to about 1.4 to 3.1 denier per filament (dpi). In one embodiment, yarns comprising 4-hydroxybutyrate can be braided into sutures using conventional or spiroid braid constructions as shown in Table 1.
Table 1. 4-hydroxybutyrate yarns
USP Diam. mm Approx USP Diam. mm Approx
Size Denier Size Denier
3.0 - > 0.600 > 3600 3/0 0.20-0.249 800
0 0.35-0.399 1700 6/0 0.070- 200
2/0 0.30-0.399 1200 7/0 0.050- <100
0.069 D. Scouring of PHA Devices and Fibers to Remove Spin
In a preferred method, spin finish is removed from PHA fibers and devices by scouring with water. The PHA material is washed in a water bath, using cold water - typically between 4°C and ambient temperature (i.e., water sufficiently cold that it does not adversely alter the properties of the PHA material, such as where the PHA has a low melting temperature). After washing for a pre-determined time, for example, five minutes or more, the PHA material is rinsed with fresh water. In the preferred method, a water- soluble detergent, such as Tween 20 or Tween 80, may also be added to the water at 1 to 10,000 ppm to facilitate scouring of the PHA material, and then the PHA material is carefully rinsed to remove the detergent. Placing the samples in an ultrasonic bath for a predefined period of time, for example, from 1 second up to 24 hours or 48 hours, can also be used to achieve enhanced scouring of the PHA material in water. As an alternative to adding detergent to the water, the PHA materials may also be scoured with aqueous solutions of alcohol, for example, ethanol or isopropylalcohol, and if desired, combining this treatment with ultrasonic cleaning. Alternatively, the PHA fibers and devices may be washed with alcohol solutions after scouring with water. Once the PHA fibers and devices have been scoured, the materials may be allowed to dry at ambient, or more preferably dried under vacuum to remove residual moisture/solvent. It will be apparent to those skilled in the art that various combinations of washing steps can be used to scour the PHA fibers and devices.
In a preferred method, PHA devices, particularly collagen sponges reinforced with PHA fabrics, can be prepared by immersing the PHA device in an acid-swollen collagen suspension that has been blended into a slurry. For example, the monofilament mesh of Example 8, may be coated with collagen in this manner. After immersion, the coated device may be air-dried or freeze-dried, and if necessary the process repeated multiple times to build up the thickness of the coating. In a preferred method, the process is repeated until the entire PHA device is encapsulated in a collagen sponge. Alkali and neutral slurries of collagen may also be used (as well as collagen
compositions that have been pre-digested with pepsin to remove the nonhelical terminal regions of the collagen molecule). Generally, freeze drying is preferred when it is desirable to obtain a porous collagen coating or sponge, and porosity can be tailored, for example, by altering the
concentration of the collagen in the slurry. In a particularly preferred method, the average porosity of the device is controlled to optimize the invasion of host fibroblasts in vivo, and is at least 5 μτη in diameter, and most preferably in the range of 5-150 μηι. In a preferred method, the coated device may be pressed, molded or cut to the desired device shape.
In certain cases it is desirable to crosslink the collagen after coating of a PHA device. Crosslinking can increase the tensile strength of the device, and improve the integrity of the coating and the handling of the device.
Crosslinking can also be used to control the rate of in vivo degradation, and tailor the rate to the application. For example, crosslinking can be used to slow down the degradation of a PHA reinforced collagen sponge in order to allow the implanted collagen to be replaced by host collagen. This can be particularly important where tissue reinforcement or regeneration is necessary, for example, in hernia repair and rotator cuff repair procedures, and where a strong repair is necessary.
A number of methods can be used to crosslink the collagen of a collagen coated PHA device. These include the formation of ionic bonds, covalent bonds, and hydrogen bonds. In a preferred method, the carboxyl groups of aspartic and glutamic residues or the epsilon-amino acid groups of lysine and hydroxylysine are crosslinked. The amino side-chain groups of asparagine and glutamine may also be crosslinked, and less preferably the hydroxyl groups of serine, threonine and hydroxy proline. In a preferred method, the collagen is covalently crosslinked with aldehydes most preferably formaldehyde, glutaraldehyde, glyceraldehyde, glyoxal, acetaldehyde, acrolein, and dialdehyde starch. The collagen may also be crosslinked with reagents such as carbodiimides, acyl azides, and isocyanates (e.g. 1,6-diisocyanatohexane). The degree of crosslinking can be altered, for example, by varying the concentration of crosslinking agent, and reaction time. In another preferred method, the collagen is ionically crosslinked with trivalent metals, preferably chromium or aluminum. In yet another method, the collagen may be crosslinked with borohydrtdes (e.g. sodium or potassmm borohydride). In yet still another method, the collagen may be crosslinked by exposure to UV or other sources of irradiation. In one preferred embodiment, the collagen is crosslinked by UV light at 120 μψ/cm2. In a less preferred method, the collagen may be crosslinked by heating preferably under vacuum. In the preferred method, the collagen is crosslinked after coating of the PHA device, however, the collagen may alternatively be crosslinked prior to coating.
The degree of crosslinking may also be controlled by derivatization of the collagen side groups prior to crosslinking, for example, by
methylation, acetylation or esterification. This method may also be used to further modify the device properties.
The collagen coated PHA devices may further comprise other materials. These materials may be added to control the device degradation rate, add or enhance other properties. For example, collagen sponges reinforced by PHA meshes can carry active agents such as antibiotics, or other materials such as hyaluronic acid and fibronectin. Such compounds could be used to increase fibroblast proliferation and improve organized tissue repair. A preferred method incorporates up to 5% hyaluronic acid (based on collagen weight). Another preferred method incorporates up to 20% chondroitin sulfate. The latter may enhance cellular attachment.
Plasticizers may also be added, for example, to improve flexibility and optimize porosity. Preferred plasticizers are biocompatible and absorbable, and include sorbitol, glycerine, and citrate.
PHA polymers and copolymers possess properties that are desirable for preparing devices for use in breast reconstruction, cosmetic surgery, facial and neck surgery. In a preferred method, PHA fibers are converted into breast reconstruction devices. In a particularly preferred method, PHA fibers are converted into meshes for breast reconstruction. Preferably, these meshes permit some fibrous tissue to grow into and around the mesh to reinforce it, have initial strength and stiffness to provide support, and yet are soft, supple, and barely palpable upon implantation. Importantly, the meshes are sufficiently soft to prevent rippling of the mesh during palpation of the breast. In an even more preferred method, PHA fibers are woven into three- dimensional shapes for use as breast reconstruction devices. Particularly preferred designs are the BREFORM™ internal bra systems used for mastopexy, and manufactured by Aspide Medical, La Talaudiere, France, and sling-shaped devices designed to support the breast or a breast implant, as described for example by US Patent No. 7,476,249 to Frank, US Patent Application No. 2010/0137679 to Lashinski et al., and US Patent No.
7,670,372 to Shfaram et al., and the mesh breast implant support device described by US Patent Application No. 2009/0082864 to Chen. The PHA meshes may be derived from PHA monofilament, PHA multifilament, or combinations of these constructs. The mesh devices may also be hybrid structures, for example, comprising PHA fibers and polypropylene and/or polyester fibers. In a further embodiment, the PHA fibers may be used as suspension members and support elements for breast reconstruction as described by US Patent Application No. 2008/0082113 to Bishop, and US Patent Application No. 2009/0248071 to Saint et al.
Braided or twisted sutures have higher tissue drag (i.e., force required to pull the suture through tissue), but are easier to knot and have greater knot strength. The disclosed coatings impart good lubricity to PHA polymers, particularly to fibers and braids made from these materials, making the coatings ideal for use on medical devices such as PHA braided sutures. Therefore, braided or twisted PHA sutures are preferably coated with polymers or oligomers of ethylene oxide, polymers or oligomers of propylene oxide, polyvinyl alcohol, or combinations thereof. These braided or twisted PHA sutures have an average tissue drag force at least 10% lower than the uncoated braid, including at least 20, 30, 40, 50, 60, 70, 80, 90, 100% lower than the uncoated braid. =
In preferred embodiments, the biocompatible coating is present on the twisted or braided PHA sutures in a coating weight of about 0.1 wt% to 10 wt%, including about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 wt%. For example, PEG2000 is preferably present on twisted or braided PHA sutures in a coating weight of less than 10 wt%, more preferably less than 7 wt%, even more preferably less than 5 wt%. For example, PVA is preferably present on the twisted or braided PHA sutures in a coating weight of less than 6 wt%, more preferably less than 4 wt%, even more preferably less than 3 wt%.
The present invention will be further understood by reference to the following non-limiting example. Example 1: Preparation of P4HB Multifilament Coated with Spin Finish
P4HB (Tepha, Inc., Lexington, MA) (Mw 200-600K) was extruded into P4HB multifilament as described in Section II. A (Method of Making PHA Multifilament Coated with Spin Finish) using the extruder operating conditions set forth in Table 2, and spinnerets with 15, 30 and 60 holes.
Table 2: Extruder Operating Conditions for P4HB Multifilaroe
180°C ±
15°C ± 10°C 75°C ± 40°C 50°C 215°C ± 40°C 250°C ± 40°C
230°C ± 110°C ±
230°C ± 30°C 30°C 230°C ± 30°C 60°C 1 ± 1
Gl MPM G2 MPM SF RPM In Out Pum RMP
The P4HB yarn extrudate was oriented offline using 3 sets of paired godets as described in Section II. A using the conditions for orientation set forth in Table 3.
Table 3: Orientation Conditions for P4HB Multifilament
Speed (MPM) Roll Temperature (°C)
10 60 ± 20 60 ± 20 Ambient 56 ±10 40 ± 10
Lurol was successfully applied to the P4HB yarn at concentrations of
10, 25 and 50%, however, the fiber bundle did not stay intact when paying off onto the orientation line, and many broken filaments were observed.
PEG400 was applied to the P4HB yarn at concentrations of 10, 25 and 50%, and at a 1% concentration for orientation. This spin finish displayed ideal properties by providing good lubricity, keeping the fiber bundle intact, and allowing easy payoff during orientation. Visual inspection under a microscope with a 10X magnification confirmed that the lubricant was spread throughout the fiber.
PEG40 Stearate was found to be too viscous at high concentrations, and therefore was evaluated at 10 and 15% concentrations for extrusion, and 1% for orientation. At these concentrations, the fiber bundle did not remain completely intact,
Propylene glycol was evaluated at concentrations of 25, 50 and 100%. It could be easily applied to the yarn, however, the fiber bundle tended to separate during orientation even at higher concentrations. TEPH 119 PCX
Table 4: Mechanical properties of 15 Filament Oriented P4HB
Specimen # Total filament Tenacity Elongation
# Filaments Denier (dpi) (gpd) (%)
Table 5: Mechanical properties of 30 Filament Oriented P4HB
# Filaments Denier (dpf) (gpd) (%)
I 30 68 2.27 7.232 20.4
Table 6: Mechanical properties of 60 Filament Oriented P4HB
Specimen # Total Denier per Tenacity Elongation
# Filaments Denier filament (dpf) ispd) (%)
Average 60 119 1.98 6.622 24.7 Example 2: Preparation of Multifilament P4HB braided sutures and knitted tubes
Oriented 60-filament yarns produced according to Example 1 with the following spin finishes were processed into P4HB braided sutures:
Tween® 20, PEG400, PEG Stearate, and Dacospin®. The mechanical properties of the braids produced are shown in Table 7.
Table 7: Mechanical properties of P4HB braided sutures
Lot # <gpd) (kfg/ mm2) Elong. (%)
Table 8: Mechanical properties of various P4HB braid configurations prepared using PEG400
16 2 30 3 multi 0.417
8 16 2 75 3 mu!ti 0.577
12 16 2 N/A 12 multi 0.712
13 16 2 70 16 multi 0.742
Example # Denier (kfe) (gpd) (%)
Example 3: Scouring of P4HB multifilament
P4HB knitted circular tubes prepared as described in Example 2 were scoured for 24 hours with 70% aqueous ethanol. All scouring was done at 37°C in a shaker (50 rpm) in 50 mL plastic Falcon® tubes containing 50 mL of wash solution. Following this treatment, the scoured P4HB knitted tubes (2 gram samples) were tested for cytotoxicity according to the protocol described in Example 4. Example 4: Cytotoxicity testing of P4HB multifilament after scouring
To test the cytotoxicity of the spin finishes, twice the amount of spin finish residue present on the circular knitted tube after 24 hour washing with 70% ethanoi {see Example 3) was determined (by GC for Dacospin®, Tween 20, and PEG20 Stearate, and by GPC-HPLC for PEG400) and supplied in a vial for testing (based on a 2 g sample mass of tube). The amounts used for preparing the cytotoxicity samples are shown in Table 9.
Cytotoxicity testing was undertaken using the ISO Elution Method (IX MEM Extract) following the guidelines of the International Organization for Standardization 10993: Biological Evaluation of Medical Devices, Part 5: Tests for Cytotoxicity: in vitro Methods.
Table 9: Results of cytotoxicity testing of Spin Finishes
Tween® 20 0.60 1.20 0.012 24 Fail
DacoSpin® 0.07 0.14 0.0014 2.8 Fail
Additionally, 2 g of the knitted tube itself after 10 minute ethanoi washing, was submitted for cytotoxicity testing. Results for the washed, knitted tubes are shown in Table 10.
Table 10. Results for cytotoxicity testing of 2 g of P4HB multifilament after 10 minute ethanoi wash*.
Residual Wt Residual Mass Cytotoxicity
Spin Finish Wt % Ratio (mg) Result
Tween® 20 L65 0.017 33 Fail
DacoSpin® 0.67 0.007 13.4 Fail
As shown in Table 10, only the PEG400 spin finish passed the cytotoxicity testing at twice the level present after 24 hours of ethanoi washing, and as a residue on an actual knitted sample of P4HB multifilament "i iiPH 1 ¾9 PCI" after a 10 minute ethanol wash. PEG40 Stearate passed cytotoxicity testing as a residue on the washed mesh, but both Tween® 20 and Dacospin® failed both of these cytotoxicity tests.
Example 5: Braided P4HB suture comprising an outer multifilament sheath and an inner P4HB monofilament core
Table 11: Properties of a braided P4HB suture with an outer
multifilament sheath and an inner P41IB monofilament core
Example Avg.
# Carriers TPI PI # Core
1 mono size
1 16 70 0.743
Example Load Tenacity
Denier Break Elong. (%) j is*!!
1 N/A 2 <6.654 N A 46.4
All multifilament used is 120 denier. Example 6: Braided P4HB suture comprising an outer multifilament and monofilament sheath and an inner P4HB monofilament core
P4HB multifilament fiber (120 denier), produced as described in Example 1, was placed on 8 of 16 carrier bobbins. The remaining 8 bobbins were filled with size 5/0 P4HB monofilament fiber (produced as described by the method in Example 7). A bundle of 3 ply size 5/0 P4HB
monofilament fiber was fed into the braider core eyelet, and run at 70 picks per inch to produce a P4HB braided suture comprising an outer multifilament and monofilament sheath of P4HB, and an inner P4HB monofilament 3-ply core with the properties described in Table 12. Table 12: Properties of a braided P4HB suture with an outer
multifilament sheath and an inner P4HB monofilament core
8 mono 3 ply size 5/0
1 size 5/0 8 multi 2 70 mono
Example 7: Preparation of P4HB Monofilament by melt extrusion
Bulk P4HB resin in pellet form was dried to under 300ppm water using a rotary vane vacuum pump system. The dried resin was transferred to an extruder feed hopper with nitrogen purge to keep the pellets dry. The pellets were gravity fed into a chilled feeder section and introduced into the extruder barrel, which was 1.50 inches in diameter and fitted with an extrusion screw with a 30:1 L/D ratio. The extruder barrel contained 5 heating zones (or extrusion zones)~zones 1, 2, 3, 4 and 5, and was manufactured by American Kuhne. The heated and softened resin from the extruder was fed into a heated metering pump (melt pump) and from the melt pump the extruded resin was fed into the heated block and an eight hole spinneret assembly. Processing profile ranges from 40°C to 260°C for temperatures, and 400psi to 2000 psi for pressures, were used. The molten filaments were water quenched and conveyed into a three-stage orientation, with inline relaxation, before winding of the monofilaments on spools. Test values for extruded monofilament fiber are shown in Table 13.
Table 13. Mechanical Test Data for P4HB Monofilament Fiber
Fiber USP Size Diameter, mm Breaking Strength, Break Elongation
Example 8: Preparation of a P4HB Monofilament mesh with Tween® 20
Spools with P4HB monofilament fiber prepared as described in Example 7 were converted into Tween® 20 coated P4HB monofilament mesh as follows: Monofilament fibers from 49 spools were pulled under uniform tension to the surface of a warp beam. A warp is a large wide spool onto which individual fibers are wound in parallel to provide a sheet of fibers ready for coating with a 10% solution of Tween® 20 lubricant Tween® 20 lubricant was added to the surface of the sheet of fiber by means of a 'kiss' roller that was spinning and was immersed in a bath filled with Tween® 20. The upper surface of the roller was brought into contact with the sheet of fiber, and the roller spun at a uniform speed to provide a consistent application of Tween® 20 finish. Following the application of Tween® 20, the sheet of fiber was placed onto a creel position such that each spooled fiber was aligned and wrapped side by side to the next spooled fiber on a warp beam. Next, warp beams were converted into a finished mesh fabric by means of interlocking knit loops. Eight warp beams were mounted in parallel onto a tricot machine let-offs and fed into the knitting elements at a constant rate determined by the 'runner length'. Each individual monofilament fiber from each beam was fed through a series of dynamic tension elements down into the knitting 'guides'. Each fiber was passed through a single guide, which was fixed to a guide bar. The guide bar directed the fibers around the needles forming the mesh fabric structure. The mesh fabric was then pulled off the needles by the take down rollers at a constant rate of speed determined by the fabric 'quality'. The mesh fabric was then taken up and wound onto a roll ready for finished product inspection.
Example 9: Scouring of P4HB monofilament mesh and cytotoxicity testing
The P4HB monofilament mesh produced according to the method of
Example 8 was scored ultrasonically with water, heat set in hot water, and then washed with a 70% aqueous ethanol solution. Cytotoxicity testing of two grams of the mesh was undertaken using the ISO Elution Method (IX MEM Extract) following the guidelines of the International Organization for Standardization 10993: Biological Evaluation of Medical Devices, Part 5: Tests for Cytotoxicity: in vitro Methods. The scoured P4HB monofilament mesh passed the cytotoxicity testing. The content of Tween 20 prior to scouring was approximately 0.3 wt%, and at this level the mesh failed the cytotoxicity testing. The residual content of Tween 20 after scouring was approximately 0.03 wt%, and at this level the mesh passed the cytotoxicity testing.
Example 10: Coating of P4HB Braided Sutures with Spin Finish
Braided P4HB sutures prepared according to Example 2, and scoured by the method of Example 3, can be recoated with PEG400. Cytotoxicity testing of a braided P4HB suture coated with approximately 6 wt% PEG400 was undertaken using the ISO Elution Method (IX MEM Extract) following the guidelines of the International Organization for Standardization 10993: Biological Evaluation of Medical Devices, Part 5: Tests for Cytotoxicity: in vitro Methods. The PEG400 braided suture passed the cytotoxicity testing at this coating weight.
Example 11: Preparation of Hybrid P4HB / Polypropylene Meshes
Spools with P4HB monofilament fiber prepared as described in Example 7 were converted into Tween® 20 coated P4HB monofilament mesh as follows. Monofilament fibers from 49 spools were pulled under uniform tension to the surface of a warp beam. A warp is a large wide spool onto which individual fibers are wound in parallel to provide a sheet of fibers ready for coating with a 10% solution of Tween® 20 lubricant. Tween® 20 lubricant was added to the surface of the sheet of fiber by means of a 'kiss' roller that was spinning and was immersed in a bath filled with Tween® 20. The upper surface of the roller was brought into contact with the sheet of fiber, and the roller spun at a uniform speed to provide a consistent application of Tween® 20 finish. Following the application of Tween® 20, the sheet of P4HB fibers was placed onto a creel position such that each spooled fiber was aligned and wrapped side by side to the next spooled fiber to form a set of P4HB warp beams. Similarly 49 spools of polypropylene monofilament, with diameter similar to P4HB monofilament, were processed to form a set of polypropylene warp beams. Next, warp beams were converted into a finished mesh fabric by means of interlocking knit loops. Each set of warp beams was mounted in parallel onto a tricot machine on two separate iet-offs and each set of beams was threaded into a separate guide bar for feeding into the knitting needles. The P4HB warp beam fiber was fed to the front guide bar and the polypropylene warp beam fiber was fed to the back guide bar. Each individual monofilament fiber from each beam was fed through a series of dynamic tension elements down into the knitting 'guides'. The guide bars directed the fibers around the needles forming the mesh fabric structure. Knitting patterns were selected so that intact polypropylene knits would remain once the absorbable P4HB monofilament was degraded from the construction in vivo. Both materials (P4HB and polypropylene) were knitted together to form one knitted construction. The mesh fabric was then pulled off the needles by the take down rollers at a constant rate of speed determined by the fabric 'quality'. The hybrid mesh fabric was then taken up and wound onto a roll.
Table 14. Hybrid Mesh Prepared from Polypropylene (PP) and P4HB
75% PP, 25% P4HB; Tepha Lot # 902001;
SN 3528
filament diameter - ΙΟΟμηι
75% PP, 25% P4HB; Tepha Lot # 902003;
SN 3566
filament diameter - 150μιη
50% PP, 50% P4HB; Tepha Lot # 902002; SN 3529
filament diameter - ΙΟΟμπι
50% PP, 50% P4HB; Tepha Lot # 902004;
SN 3567
To demonstrate that the hybrid meshes listed in Table 14 would progressively lose burst strength after implantation in vivo, samples of each mesh (n=5 for each time point, 2 inch x 2 inch squares) were placed in 3M HC1 at 37°C for 5, 24 and 48 hours prior to being subjected to mesh burst strength testing. Mesh Burst testing was performed at the required time points according to ASTM D6797-02 (Standard Test Method for Bursting Strength of Fabrics Constant-Rate-of-Extension (CRE) Bali Burst Test) at ambient conditions. The ball burst fixture had a 1,6 cm circular opening and a 1cm diameter half-rounded probe. Molecular weight measurements were made by placing hybrid mesh in chloroform to dissolve P4HB filament, and then determining molecular weights (Mw) by GPC. Over the course of the study, it became evident which filaments within the mesh were P4HB and which were polypropylene. By the 48 hr time point, the P4HB filaments were opaque white in color, and many were crumbling from the mesh. The polypropylene filaments did not appear to change over time. Test data for the samples shown in Table 14 at each time point, including time t=0, is shown in Tables 15-18.
Table 15. Burst Strength and Mw testing data for SN 3528 Hybrid Mesh samples - In Vitro testing
Time (hr) (mm) Std Dev ( gF) Std Dev
5 0.339 0.014 0.431
Extension at Peak %
Incubation at Peak Load Strength Mw % Mw
Time (hr) Load (mm) Std Dev Retention (Da) Retention
Table 16. Burst Strength and Mw testing data for SN 3566 Hybrid Mesh samples— In Vitro testing
48 10.516 0.501 81.3 73,388 23.7 Table 17. Burst Strength and Mw testing data for SN 3529 Hybrid Mesh samples - In Vitro testing
Time (hr) (mm) Std Dev (¾F) Std Dev
Example 12: Preparation of a Collagen Coated PHA Device
A monofilament P4HB mesh prepared as described in Example 8 can be coated with collagen by immersion into an aqueous slurry of 2% bovine skin collagen (prepared according to Example 1 of U.S. Patent No. 5,108,424 to Hoffman et αΐ). The slurry includes 8% glycerol and 17% ethanol. The coated mesh is removed from the slurry, and allowed to dry for
approximately 30 mins at room temperature. The coating and drying steps are repeated three more times to yield a collagen coated P4HB monofilament mesh.
Table 18. Burst Strength and Mw testing data for SN 3567 Hybrid Mesh samples -In Vi tro testing
Incubation Avg. thick Thickness Peak Load
Time (hr) (mm) Std Dev ( gF)
Incubation at Peak Mw % Mw at Peak Strength
Time (hr) Load (Da) Retention
Load (mm) Retention
24 7.484 0.297 48.2 120,880 39.9 48 8.194 0.487 50.9 77,384 25.6 Example 13: Crosslinking of a Collagen Coated PHA Monofilament Mesh
The coated mesh prepared in Example 12 can be crossHnked by exposure to formaldehyde vapor for five minutes. The resulting composite is then allowed to dry for approximately 15 mins in air at room temperature, and is then vacuum dried to remove residual crosslinking agent and any moisture.
Example 14: Tissue drag of scoured TephaFLEX braid
A 16-carrier, single-ply braided suture over a 6-ply core was prepared from 60-filament TephaFLEX yarn using PEG400 as a spin finish. The braid was then scoured in water for various lengths of time to remove the PEG400. The amount of force required to pull the suture through tissue was determined using a tissue drag test. In this test, the suture is passed through a simulated tissue multiple times, and one of the free ends is fixed to - the movable grip of a universal testing machine. The simulated tissue is held stationary in a frame below the movable cross member. The test is initiated and the kilograms of force ( gf) required to pull the suture through the simulated tissue is recorded. The suture may be tested dry or after wetting in water. Results for the 16-carrier over 6-ply core braided TephaFLEX suture are show in Table 19. Comparison is made to a Vicryl control suture. As can be seen in Table 1 , the 0-minute scoured TephaFLEX braid compares well to the Vicryl braid in that the drag forces are similar. However, as the time of scouring increases, and the amount of residual PEG400 decreases, the drag force increases.
Table 19. Drag force measurements for TephaFLEX braid.
(Kg!) (Kgf)
0.338 0.358
TephaFLEX Lot # 100136
0.323 0.373 Size 2, 10 min scoured sterile, wet
TephaFLEX Lot # 100198
0.415 0.475 Size 2, 2 hours scoured sterile, wet Example 15: Tissue drag of PEG2000 coated TephaFLEX braids
A 15-minute scoured TephaFLEX braid of Example 14 was coated with a PEG2000 coating to reduce the amount of tissue drag. PEG2000 was dissolved in ethanol (30% wt/vol.) and the braided suture was pulled through a bead of the solution to thoroughly wet the braid. The braid was allowed to dry to leave behind a residue of PEG2000 at a coating weight of approximately 7% by wt. The tissue drag of the coated suture after wetting in water was performed as described in Example 14, and the results are shown in Table 20.
Table 20. Drag force measurements for TephaFLEX braid coated with
TephaFLEX 0.284 0.299 89% 87% Control
PEG2000 Coated
TephaFLEX 0.242 0.288 76% 84% Braid
Example 16: Tissue drag of PVA coated TephaFLEX braids
Table 21. Drag force measurements for TephaFLEX braid coated with PVA compared to Vicryl and uncoated TephaFLEX controls.
Peak Relative to Vicryl
Avg Drag Load Avg Drag Peak Specimen Name Force (kgf) (kgf) Force (%) Load (%)
Control 0.316 0.337 N/A N/A
Scoured TephaFLEX
Control 0.305 0.346 97% 103%
TephaFLEX Braid 0.173 0.202 55% 60%
1. A multifilament yarn comprising polyhydroxyalkanoate polymer wherein the yarn has a denier per filament of less than 4.0.
2. The multifilament yarn of claim 1 wherein the yarn has a tenacity greater than 6.1 grams per denier.
3. The multifilament yarn of claim 1 or 2, wherein the
polyhydroxyalkanoate has a molecular weight between 50,000 and
4. The multifilament yarn of any one of claims 1 to 3, wherein the polyhydroxyalkanoate comprises 4-hydroxybutyrate.
5. A monofilament fiber or multifilament yarn comprising
polyhydroxyalkanoate polymer, wherein the polyhydroxyalkanoate polymer is coated with a spin finish comprising a coating material selected from the group consisting of polymers or oligomers of ethylene oxide, polymers or oligomers of propylene oxide, polyethylene glycol sorbitan monolaurate, and combinations thereof.
6. The monofilament fiber or multifilament yarn of claim 5, wherein the polyhydroxyalkanoate polymer comprises 4-hydroxybutyrate.
7. The monofilament fiber or multifilament yarn of claim 5, wherein the coating material is a polymer or oligomer of ethylene oxide.
8. The monofilament fiber or multifilament yarn of claim 7, wherein the polymer is polyethylene glycol having an average molecular weight of 100 to 1000 daltons in a spin finish or polyethylene glycol having an average molecular weight of 1000 to 10,000 in a coating.
9. The monofilament fiber or multifilament yarn of claim 5, wherein the coating material is polyethylene glycol sorbitan monolaurate.
10. A medical device formed from the monofilament fiber or multifilament yarn of any one of claims 1 to 9.
11. The device of claim 10 that has been scoured to remove substantially ail the spin finish.
12. The device of claim 10, wherein the device is selected from the group consisting of barbed sutures, braided sutures, monofilament sutures, ligatures, hybrid sutures of monofilament and multifilament fibers, braids, knitted or woven meshes, monofilament meshes, multifilament meshes, TEPH 119 PCX knitted tubes, stents, stent grafts, drug delivery devices, devices for temporary wound or tissue support, devices for soft tissue repair, devices for replacement or regeneration, repair patches, tissue engineering scaffolds, retention membranes, anti-adhesion membranes, tissue separation membranes, hernia repair devices, breast reconstruction devices, devices for blepharoplasty, devices for facial scar revisions, devices for forehead lifts, devices for mentoplasty, devices for malar augmentation, devices for otoplasty, devices for rhinoplasty, devices for neck lift surgery, devices for rhytidectomy, threadlift devices to lift and support sagging areas of the face, brow, and neck, fixation devices, cardiovascular patches, vascular closure devices, vascular grafts, slings, biocompatible coatings, rotator cuff repair devices, meniscus repair devices, adhesion barriers, guided tissue repair/regeneration devices, articular cartilage repair devices, nerve guides, tendon repair devices, ligament repair devices, intracardiac septal defect repair devices, left atrial appendage (LAA) closure devices, pericardial patches, bulking and filling agents, vein valves, heart valves, bone marrow scaffolds, meniscus regeneration devices, ligament and tendon graft, ocular cell implants, spinal fusion devices, imaging devices, skin substitutes, dural substitutes, bone graft substitutes, wound dressings, and hemostats.
13. The device of claim 12, wherein the breast reconstruction device is selected from the group consisting of devices for breast augmentation, devices for mastopexy, devices for breast reduction, devices for breast positioning and shaping, and devices for breast reconstruction following mastectomy.
14. The device of claim 12, comprising a braided suture wherein the suture comprises an outer polyhydroxyalkanoate multifilament sheath and an inner polyhydroxyalkanoate monofilament core.
15. The device of claim 14, comprising a suture wherein the suture comprises an outer polyhydroxyalkanoate multifilament and monofilament sheath, and an inner polyhydroxyalkanoate monofilament core.
16. The device of claim 14, wherein the polyhydroxyalkanoate comprises 4-hydroxybutyrate.
17. The device of claim 14, wherein the inner monofilament core is barbed, or is made from a non-degradable polymer.
18. The device of claim 10, wherein the device comprises one or more additional components selected from the group consisting of plasticizers, nucleants, collagen, crossl inked collagen, blends or copolymers of polyhydroxyalkanoates, blends or copolymers of lactic acid, glycol ic acid, caprolactone, p-dioxanone, or trimethylene carbonate, polymer additives, dyes, compatibilizers, fillers, therapeutic agents, diagnostic agents, and prophylactic agents,.
19. The device of claim 10, wherein the device is a suture and contains at least one or more Fibers with contrasting dye to provide an identifiable color trace in the suture strand.
20. The device of claim 10, wherein the device is a suture used for ligament and tendon repair.
21. The device of claim 10, wherein the device is a surgical mesh.
22. The device of claim 21, wherein the surgical mesh comprises polyhydroxyalkanoate fiber and a permanent fiber.
23. The device of claim 22, wherein the permanent fiber is
polypropylene, a polyester, or a combination thereof.
24. The device of claim 21, wherein the surgical mesh comprises monofilament fibers.
25. The device of claim 21 , wherein the surgical mesh has been coated or encapsulated with collagen.
26. The device of claim 25, wherein the porosity of the collagen is at least 5 μηι in diameter.
27. A method of producing the device of claim 25 or 26, wherein the polyhydroxyalkanoate component is, optionally treated with plasma gas, coated or encapsulated with collagen, the collagen is crosslinked, and the device is sterilized with ethylene oxide or by irradiation.
28. A method of using the device of claim 13, comprising implanting or administering the device at a site in or on a patient in need thereof.
29. A method of producing a multifilament yarn comprising
polyhydroxyalkanoate polymer wherein the yarn has a denier per filament of less than 4.0, comprising deriving the multifilament by melt-extrusion processing of the polymer between 40°C and 275°C, and air-cooling the extruded filaments.
30. The method of claim 29, wherein the yarn passes cytotoxicity testing using the ISO Elution Method (IX MEM Extract).
31. A method of producing a monofilament fiber or multifilament yarn comprising polyhydroxyalkanoate polymer wherein the
po yhydroxyalkanoate polymer is coated with polymers or oligomers of ethylene oxide or propylene oxide or polyethylene glycol sorbitan monolaurate, comprising deriving the monofilament fiber or multifilament yarn by melt-extrusion processing of the polymer between 40°C and 275 °C, allowing the polymer to cool and solidify and applying polymers or oligomers of ethylene oxide or propylene oxide polyethylene glycol sorbitan monolaurate to the fiber or yarn by passage through a spin finish applicator either inline or offline.
32. A braided monofilament fiber or multifilament yarn, comprising polyhydroxyalkanoate filaments coated with a coating material selected from the group consisting of polymers or oligomers of ethylene oxide, polymers or oligomers of propylene oxide, polyvinyl alcohol, and combinations thereof.
33. The braided monofilament fiber or multifilament yarn of claim 32, wherein the polyhydroxyalkanoate has a molecular weight between 50,000 and 1,200,000 measured by gel permeation chromatography.
34. The braided monofilament fiber or multifilament yarn of claim 32, wherein the polyhydroxyalkanoate comprises 4-hydroxybutyrate.
35. The braided monofilament fiber or multifilament yarn of any one of claims 32 to 34 wherein the coating material is polyethylene glycol, wherein the polyethylene glycol has an average molecular weight of 1000 to 10,000 daltons.
36. The braided monofilament fiber or multifilament yarn of any one of claims 32 to 35, wherein the coating material is polyvinyl alcohol.
37. The braided monofilament fiber or multifilament yarn of any one of claims 32 to 3 , wherein the average tissue drag force of the coated braid is reduced at least 10% relative to the uncoated braid.
38. A method of reducing the tissue draft force of a braided suture, comprising coating the braided suture with a coating material selected from the group consisting of polymers or oligomers of ethylene oxide, polymers or oligomers of propylene oxide, polyvinyl alcohol, and combinations thereof, wherein the braided suture is formed from polyhydroxyalkanoate filaments.
39. The method of claim 38, wherein the polyhydroxyalkanoate has a molecular weight between 50,000 and 1,200,000 as measured by gel permeation chromatography.
40. The method of claim 38, wherein the polyhydroxyalkanoate comprises 4-hydroxybutyrate.
41. The method of any one of claims 38 to 40, wherein the coating material is polyethylene glycol, wherein the polyethylene glycol has an average molecular weight of 400 to 10,000 daltons.
42. The method of any one of claims 38 to 41 , wherein the coating material is polyvinyl alcohol.
PCT/US2011/029638 2010-03-26 2011-03-23 Coatings for the manufacture and application of polyhydroxyalkanoate medical devices WO2011119742A2 (en)
US31801410P true 2010-03-26 2010-03-26
US61/318,014 2010-03-26
US32568610P true 2010-04-19 2010-04-19
US61/325,686 2010-04-19
US36354310P true 2010-07-12 2010-07-12
US61/363,543 2010-07-12
US41162910P true 2010-11-09 2010-11-09
US61/411,629 2010-11-09
EP11715324A EP2558133A2 (en) 2010-03-26 2011-03-23 Coatings for the manufacture and application of polyhydroxyalkanoate medical devices
WO2011119742A2 true WO2011119742A2 (en) 2011-09-29
WO2011119742A3 WO2011119742A3 (en) 2013-01-03
PCT/US2011/029638 WO2011119742A2 (en) 2010-03-26 2011-03-23 Coatings for the manufacture and application of polyhydroxyalkanoate medical devices
US (5) US8747468B2 (en)
WO (1) WO2011119742A2 (en)
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2011-03-23 EP EP11715324A patent/EP2558133A2/en active Pending
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