KR20090028690A - A reinforced absorbable multilayered hemostatic wound dressing and method of making - Google Patents

Abstract

The present invention is directed to a reinforced absorbable multilayered hemostatic wound dressing comprising a first absorbable nonwoven fabric, a second absorbable woven or knitted fabric, thrombin and/or fibrinogen, and method of making.

Description

A reinforced absorbable multilayered hemostatic wound dressing and method of making}

The present invention relates to reinforced absorbent multilayer hemostatic wound dressings and methods of making the same.

Sealing air and various body fluids as well as controlling bleeding is essential and important for minimizing blood loss during surgical procedures, sealing tissue and organ systems, reducing postoperative complications, and reducing surgical time in the operating room. .

In an effort to provide dressings with improved hemostasis and tissue closure and adhesion properties, therapeutic agents, including but not limited to thrombin, fibrin and fibrinogen, may include gelatin-based carriers, polysaccharide-based carriers, glycolic acid, or lactic acid. Combined with a dressing carrier or substrate including a substrate carrier and collagen matrix. Examples of such dressings are described in US Pat. No. 6,762,336, US Pat. No. 6,733,774 and PCT Publication WO 2004/064878 A1.

Due to its biodegradability and its bactericidal properties, tissue closure, tissue repair, drug delivery and hemostatic properties, various surgeries including neurosurgery, abdominal surgery, cardiovascular surgery, thoracic surgery, head and neck surgery, pelvic surgery and skin and subcutaneous tissue procedures Preference is given to using cellulose containing oxidized carboxylic acid moieties represented by the following carboxylic-oxidized cellulose as a local dressing in the procedure.

However, when carboxylic-oxidized cellulose is used in combination with thrombin and / or fibrinogen, the acidic residues that may be present in the cellulose denature the activity of thrombin and / or fibrinogen. Thus, it is desirable to protect thrombin and / or fibrinogen from these acid residues to sustain their hemostatic activity.

As used herein, the term "nonwoven" includes, but is not limited to, bonded fabrics, manufactured fabrics, or engineered fabrics produced by processes other than weaving or knitting. More specifically, the term "nonwoven" refers to a porous textile-like material in the form of a generally flat sheet consisting predominantly or entirely of staple fibers assembled in the form of a web, sheet or batt. The structure of the nonwoven is based, for example, on an array of staple fibers, typically aligned somewhat randomly. Stretchable stress-strain and tactile properties of nonwovens typically result from frictional and / or adhesive bonding, chemical bonding, or physical bonding of fibers and fibers produced by, for example, reinforcing and entanglement of staple fibers. Nevertheless, the raw materials used to make the nonwovens may be yarns, scrims, meshes or filaments made by processes including weaving or knitting.

Summary of the Invention

The present invention relates to a reinforced absorbent multilayer hemostatic wound dressing comprising a first absorbent nonwoven fabric and one or more thrombin and / or fibrinogen reinforced with one or more second absorbent fabrics or knitted fabrics and methods for making the same. More particularly, the first absorbent nonwoven includes fibers comprising aliphatic polyester polymers, copolymers or mixtures thereof, and the second absorbent fabric or knitted fabric includes oxidized regenerated cellulose fibers.

1 shows the pressure required to break / rupture the seal formed between tissue and hemostatic wound dressing.

The multilayer dressings described herein provide and maintain effective hemostasis when attached to a wound that requires hemostasis. Effective hemostasis, as used herein, is the ability to control and / or alleviate capillary, venous or small arterial bleeding within an effective time recognized by a hemostatic artisan. Additional signs of effective hemostasis may be provided by government regulatory standards and the like.

In certain embodiments, the multilayer dressing of the present invention is effective to provide and maintain hemostasis in case of severe or drooling bleeding. Severe bleeding as used herein is meant to include the case of bleeding in which a relatively large amount of blood is lost at a relatively fast rate. Examples of severe bleeding include, but are not limited to, arterial puncture, hepatic resection, hepatic blunt trauma, splenic blunt trauma, bleeding from aortic aneurysm, bleeding in patients with coagulation disorders such as anticoagulant-hypertensive patients or hemophilia .

Reinforced absorbent multilayer dressings generally include a nonwoven fabric and one or more reinforcing fabrics. The reinforcing fabric provides a lining to which the nonwoven can be attached directly or indirectly, wherein the thrombin and / or fibrinogen are substantially homogeneously dispersed in the nonwoven and / or on the nonwoven surface. The reinforcing fabric provides sufficient strength to the dressing to allow the user of the dressing to place and manipulate the dressing on or in the wound, or directly on the tissue of the patient in need of hemostasis or on the tissue to be sealed and attached.

In addition to acting as a carrier for thrombin and / or fibrinogen, nonwovens also protect thrombin and / or fibrinogen from acidic residues that may be present in the reinforcement fabric, such as when carboxylic-oxidized cellulose is used as the reinforcement fabric. It works.

The nonwoven serves as the first absorbent nonwoven of the reinforced absorbent multilayer dressing described herein. The first absorbent nonwoven consists of fibers comprising aliphatic polyester polymers, copolymers or mixtures thereof. Aliphatic polyesters are typically lactic acid, lactide (including L-, D-, meso and D, L mixtures), glycolic acid, glycolide, ε-caprolactone, ρ-dioxanone (l, 4-dioxane- 2-one) and trimethylene carbonate (1,3-dioxan-2-one) are synthesized by ring-opening polymerization of monomers, including but not limited to.

Preferably, the first absorbent nonwoven fabric comprises a copolymer of glycolide and lactide, the copolymer comprising about 70 to 95% of the glycolide by molar basis and the remaining amount of lactide.

Preferably, the nonwoven is produced by a process other than weaving or knitting. For example, nonwovens can be made from yarns, scrims, meshes or filaments made by processes including weaving or knitting. The yarns, scrims, nets and / or filaments are crimped to enhance adhesion to each other and to the second absorbent fabric or knit. This crimped yarn, scrim, web and / or filament may then be cut to staple lengths sufficient to entangle. The staples may be about 0.1 to 2.5 inches long, preferably about 0.5 to 1.75 inches long and most preferably about 1.0 to 1.3 inches long. The staples may be carded to produce a nonwoven bat, which may then be needlepunched or calendered into the first absorbent nonwoven. In addition, staples may be kinked or piled.

Other known methods for the production of nonwovens can be used and include processes such as air lamination, wet forming and stitch bonding. Such procedures are described in Encyclopedia of Polymer Science and Engineering, Vol. 10, pp. 204-253 (1987) and Introduction to Nonwovens by Albin Turbank (Tappi Press, Atlanta GA 1999).

The thickness of the nonwoven may range from about 0.25 to 2 mm. The reference weight of the nonwoven fabric is about 0.01 to 0.2 g / in ² ; Preferably from about 0.03 to 0.1 g / in ² ; And most preferably in the range of about 0.04 to 0.08 g / in ² . The weight percent of the first absorbent nonwoven may range from about 5 to 50% based on the total weight of the reinforced absorbent multilayer dressing with thrombin and / or fibrinogen.

The second absorbent fabric or knitwear functions as a reinforcing fabric and includes oxidized polysaccharides, in particular oxidized cellulose and neutralized derivatives thereof. For example, the cellulose can be carboxylic oxidized or aldehyde-oxidized cellulose. More preferably, oxidized regenerated polysaccharides, including but not limited to oxidized regenerated cellulose, can be used to make the second absorbent fabric or knitted fabric. Regenerated cellulose is preferred because of its superior degree of homogeneity over unregenerated cellulose. Detailed descriptions of regenerated cellulose and methods for producing oxidized regenerated cellulose are provided in US Pat. No. 3,364,200, US Pat. No. 5,180,398, and US Pat. No. 4,626,253, each of which is herein incorporated by reference in its entirety. It is cited in the specification.

) 흡수성 부착 캐리어, 서지셀(Surgicel

)흡수성 지혈제; 서지셀 누-니트(Surgicel Nu-Knit

) 흡수성 지혈제; 및 서지셀(Surgicel

) 원섬유성 흡수성 지혈제가 포함되지만 이에 제한되는 것은 아니다.Examples of fabrics that can be used as reinforcing fabrics include Johnson & Johnson Wound Management Worldwide, a subsidiary of Ethicon, Inc. (Somerville, New Jersey), respectively. Interceed, available from Gynecare Worldwide

Absorbent Carrier, Surge Cell

) Absorbent hemostatics; Surgicel Nu-Knit

) Absorbent hemostatics; And Surgicel

Fibril-absorbing hemostatic agents include, but are not limited to.

The reinforcing fabrics used in the present invention can be woven or knitted, provided the fabric has the physical properties necessary for use in the intended application. For example, such fabrics are described in US Pat. No. 4,626,253, US Pat. No. 5,002,551, and US Pat. No. 5,007,916, the contents of which are incorporated herein by reference in their entirety. In a preferred embodiment, the reinforcing fabric is a warp knitted tricoat fabric consisting of bright rayon yarns that are subsequently oxidized to include an effective amount of carboxyl or aldehyde moiety that provides biodegradability to the fabric.

In an alternative embodiment, the reinforcing fabric comprises fibers composed of aliphatic polyester polymers, copolymers or mixtures thereof in combination with oxidized polysaccharide fibers.

The second absorbent fabric or knit preferably includes oxidized regenerated cellulose and ranges from about 0.001 to 0.2 g / in ² , preferably from about 0.01 to 0.1 g / in ² and most preferably from about 0.04 to 0.07 g It may have a reference weight in the range of / in ² .

The first absorbent nonwoven is attached directly or indirectly to the second absorbent fabric or knit. For example, the nonwoven can be incorporated into the second absorbent fabric or knit through needle punching, calendering, embossing or high hydro weaving, chemical or thermal bonding. Staples of the first absorbent nonwoven can be intertwined with each other and embedded into a second absorbent fabric or knitted fabric. More particularly, in methods other than chemical or thermal bonding, at least about 1% of staples, preferably about 10-20% and preferably up to about 50% of the staples of the first absorbent nonwoven fabric may be The first absorbent nonwoven can be attached to the second absorbent fabric or knitted fabric so as to be exposed to the other side. This allows the first absorbent nonwoven fabric and the second absorbent fabric or knit to stick together and prevent delamination in normal operating conditions. The reinforced absorbent multi-layer fabric is substantially uniform, without the portion of the second absorbent fabric or knitted fabric not visually covered by the first absorbent nonwoven fabric.

One method of making the multilayer fabric described herein is by the following process. Absorbent polymer fibers of about 1-4 denier / fiber are incorporated into about 80-120 denier multifilament yarns and then integrated into about 800-1200 denier yarns, thermally crimped, and then stapled to about 0.75 and 1.5 inches long. Can be cut Staples may be fed one or more times into a multiroller dry layer carding machine and carded to a uniform nonwoven bat, with humidity controlled at about 20-60% at room temperature of 15-24 ° C. For example, a uniform nonwoven bat can be made using a single cylinder roller-top card covered with rollers and stripper rolls where the main cylinders are replaced, where the bats are dope from the surface of the cylinder by a doffer roller. And placed on the collector roll. The bat may be further processed via any other method such as needle punching or calendering. The first absorbent nonwoven can then be attached to the second absorbent fabric or knitted fabric by various techniques such as needle punching. The reinforced absorbent multilayer fabric can then be refined by washing in a suitable solvent and dried for 10-30 minutes under mild conditions.

It is desirable to adjust process parameters such as staple length, staple opening, staple feed rate and relative humidity. For example, the integrated spinning may have about 5 to 50 crimps / in and preferably about 10 to 30 crimps / in. Effective cutting of crimped yarns is desirable because any long and incompletely cut staples tend to adhere onto the carding machine causing pilling. The preferred range of staple lengths is about 0.75 to 1.5 inches and preferably about 1.0 to 1.3 inches.

To optimize the uniformity and minimize the generation of static electricity, the relative humidity can be adjusted during the batting process, preferably during carding to form a uniform nonwoven bat. Preferably, the nonwoven bat is processed using a dry layer carding process at a relative humidity of at least about 20% at room temperature of about 15 to 24 ° C. More preferably, the nonwoven bat is processed at a relative humidity of about 40% to 60%.

Multilayer fabrics are refined using a solvent suitable for dissolving any spin finish. Solvents include, but are not limited to, isopropyl alcohol, hexane, ethyl acetate, and methylene chloride. The multilayer fabric is then dried under conditions that provide sufficient drying with minimal shrinkage.

The reinforced absorbent multilayer fabric has an average thickness of about 0.5 to 3.0 mm, preferably about 1.00 to 2.5 mm and most preferably about 1.2 to 2.0 mm. The reported thickness depends on the thickness measurement method. Preferred methods are generally ASTM methods (ASTM D5729-97 and ASTM D1777-64) commonly used in the textile industry and in particular nonwovens. This method may be slightly changed and may be suitably adopted in the case of the present invention described below. The reference weight of the reinforced absorbent multilayer fabric is about 0.05 to 0.25 g / in ² , preferably about 0.08 to 0.2 g / in ² and most preferably about 0.1 to 0.18 g / in ² . Reinforced absorbent multilayer fabrics are uniform such that they are below a rate of change (relative standard deviation of the mean) of about 10% in the reference weight or thickness over each in ² .

Thrombin and / or fibrinogen may be animal derived, preferably human derived or recombinant. Thrombin activity on multilayer dressings may range from about 20 to 500 IU / cm ² , preferably from about 20 to 200 IU / cm ² and most preferably from about 50 to 200 IU / cm ² . Fibrinogen activity on the multilayer dressing may range from about 2 to 15 mg / cm ² , preferably from about 3 to 10 mg / cm ² and most preferably from about 4 to 7 mg / cm ² .

The reference weight of the multilayer dressing with thrombin and / or fibrinogen powder is 0.1 to 1.0 g / in ² , preferably 0.1 to 0.5 g / in ² and most preferably 0.1 to 0.3 g / in ² . Multilayer dressings with thrombin and / or fibrinogen may be sterilized, for example by radiation, preferably electron beam radiation.

The air porosity of the multilayer dressing with thrombin and / or fibrinogen powder is about 50 to 250 cm ³ / sec / cm ² , preferably 50 to 150 cm ³ / sec / cm ² and most preferably 50 to 100 cm ³ / sec / cm ^It is in the range of ² .

If a reinforced absorbent multilayer dressing is used therein, about 50 to 75% of its mass is absorbed after about two weeks. % Mass loss can be measured using a rat feed model. Here, the dressing is first inserted into the rat by a median incision (approximately 4 cm) in the skin above the rat's lumbar spinal column. The skin is then separated from the underlying connective tissue to both left and right and exposed to the gluteus muscle on the surface. The posterolateral fascia is then incised and placed directly on the gluteal muscle and adjacent to the spinal column. Using blunt exfoliation, a small pocket is created between the gluteus and fascia of the incision side. The multilayer dressing is placed in the gluteal pocket. The fascia is then sutured as appropriate. After 2 weeks, the rats are euthanized and the multilayer dressing is eaten out to determine the percent mass loss over a 2 week period.

The first absorbent nonwoven has solid thrombin and / or solid fibrinogen powder with no separation from its surface and with minimal powder loss. Thrombin and / or fibrinogen containing solutions are individually lyophilized. The lyophilized material is then ground into powder using an ultrafine or cold blade mill. The powders are weighed and suspended together in a carrier fluid in which the protein does not dissolve. Preferred carrier fluids are perfluorinated hydrocarbons, including but not limited to HFE-7000, HFE-7100, HFE-7300 and PF-5060 (available from 3M, Minnesota). Any other carrier fluid that does not dissolve the protein may be used, for example alcohols, ethers or other organic fluids. The suspension is thoroughly mixed and the first method is carried out by conventional methods such as wet, dry or electrostatic spray, dip coating, painting or spraying while maintaining a room temperature of about 60 to 75 degrees Fahrenheit and a relative humidity of about 10 to 45%. It is applied to an absorbent nonwoven fabric. The multilayer dressing is then dried at ambient room temperature and packaged in a suitable moisture barrier container. Multilayer dressings with thrombin and / or fibrinogen contain up to 25% moisture, preferably up to 15% moisture and most preferably up to 5% moisture.

The amount of thrombin and / or fibrinogen powder applied to the nonwoven is sufficient to cover the surface of the nonwoven so that there are no visually uncovered areas. The powder can generally be placed on top of the nonwoven or penetrated into the nonwoven up to the surface of the second absorbent fabric or knit. However, most of the powder is not in contact with the second absorbent fabric or knit, and very little powder penetrates below the second absorbent fabric or knit.

As surgical dressings, the multilayer dressings described herein can be used as an aid to primary wound closure devices, such as arterial closure devices, staples and sutures, which not only seal potential leaks of gases, liquids or solids, but also provide hemostasis. Can be. For example, multilayer dressings can be used to seal air from tissues or body fluids of organs and tissues, including but not limited to bile, lymph, cerebrospinal fluid, gastrointestinal fluid, interstitial fluid, and urine.

The multilayer dressings described herein have additional medical applications, i.e. include tissue reinforcement and support for gastrointestinal tract or vascular anastomosis, ie access and tension release that connect the anastomosis that is difficult to perform (ie, under tension). It can be used for various clinical functions, but not limited to this. The dressing can in all cases additionally promote and possibly enhance the natural tissue healing process. Such dressings can be used internally in various types of surgery, including but not limited to cardiovascular, peripheral blood, cardio-thoracic, gynecological, neurosurgery, and general surgery. In addition, dressings may be used to attach medical devices (eg, meshes, clips, and films) with tissue, tissues with tissues, or medical devices with medical devices.

Example 1

Poly (glycolide-co-lactide) (PGL, 90/10 mol / mol) was melt spun into fibers. 80 denier dafilament yarns were consolidated to 800 denier integrated yarns. The consolidated yarns were crimped at approximately 110 ° C. The crimped yarn was cut into staples having a length of about 1.25 ". 20 g of crimped staples were accurately weighed and placed uniformly on the feed conveyor belt of the multiroller carding machine. Environmental conditions (temperature: 21 ° C./55%) RH), then staples were carded to produce nonwoven bats.The bats were removed from the pickup roller and cut into four equal parts, which were fed back to the carding machine perpendicular to the harvesting direction. After the pass, the batt was weighed (19.8 g: 99% fabric yield) and then compacted to felt The compact felt was placed exactly on the ORC fabric and firmly attached by two passes in a needle punching device. Trimmed and refined in three separate isopropyl alcohol baths to remove the spin finish and all the machine oil. And a fabric layer and dried at 70 ℃ oven for 30 minutes, followed by measurement by cooling.

18.93 g of BAC-2 [Omrix Biopharmaceuticals, Inc.); 0.3 g / g of specific activity (by Clauss) and 1.89 g of thrombin-containing powder (which is also Omrix Biopharmaceuticals, Inc.) was thoroughly mixed with about 420 ml of HFE-7000. The slurry was sprayed through a nozzle onto a multilayer fabric weighing about 12 g and measuring 8 "x 12". The multilayer hemostatic wound dressings were air dried for about 30 minutes. Environmental conditions were maintained at 24 ° C./45% RH throughout the process. The multilayer hemostatic wound dressing was cut to a suitable size and packaged in a tray. The clearance between the top and bottom of the tray is thinner than the overall thickness of the dressing so that it is specifically designed to minimize the movement of the dressing during shipping and handling and to prevent the coated powder from moving during transportation. The tray is further packed in a foil bag and heat sealed with a desiccant if necessary. The dressing was stored at 2-8 ° C. until needed.

The "thickness" of the multilayer fabric / dressing was measured as described herein. The measurement tool was as follows:

(1) Mitutoyo Absolute Gauge Model No. ID-C125EB [Code No.-543-452B]. A 1 "diameter foot was used on the gauge.

(2) Locked in place using a magnet holder, and a caliper was placed on a die platen.

(3) a metal plate with a weight of two 40.8 g to 41.5 g [total ~ 82.18 g] to 2.75 "x 2" x 0.60 ".

The multilayer fabric / dressing was placed on the plate surface, which was a smooth and machined surface. Two metal plates were placed on top of each other for multilayer fabrics / dressings and gently pressed at their corners to ensure that the multilayer fabrics / dressings were flat. The gauge foot was placed on top of the metal plates, then lifted up and back down, and the time was recorded.

Example 2

In general, anesthetized pigs are dissected to expose the abdominal aorta. A 4 mm aortic incision was removed using a biopsy punch. The blood was allowed to flow freely, and the dressing to be tested was quickly applied to the wound site to aspirate any excess accumulated blood. Hand compression was applied to the wound to maintain the dressing for 3 minutes. At the end of the 3 minute period, the pressure was removed. The test was considered "pass" if the dressing adhered well to the wound and hemostasis was achieved completely without any bleeding.

^* Failure was caused by improper aspiration of deceased blood in the punctured area

^{** The} failure was caused by improper suction of blood accumulated in the punctured portion as a result of the suction hose failure.

^*** Scope targeted during generation

All animals were euthanized after test trials, with the exception of Sample IDs 46 and 47, which survived for at least 2 weeks after surgery.

Example 3

Nonwoven PGL fabric with ORC reinforcement fabric.

로 입수가능한 편성된 카복실릭-산화된 재생 셀룰로오스 직물내로 니들펀칭하여, 부직포를 ORC 직물에 고정시켰다. 최종 구조물은 약 60중량%의 부직포 섬유를 포함하였다.Poly (glycolide-co-lactide) (PGL, 90/10 mol / mol) was melt spun into the fiber. The fibers were cut into small staples and then carded to produce a fairly fine nonwoven fabric having a thickness of about 1.25 mm and a density of about 98.1 mg / cc. Subsequently, the nonwoven fabric was traded under the trade name Interceed from Ethicon, Inc.

The needles were fixed to the ORC fabric by needle punching into a knitted carboxylic-oxidized regenerated cellulose fabric available as a. The final structure contained about 60% by weight nonwoven fibers.

Example 4

Analysis of adhesion / closure properties of samples coated with fibrinogen and thrombin

The material described in Example 3 was coated with anhydrous particles consisting mainly of fibrinogen (7-8 mg / cm ² ) and thrombin (50 IU / cm ² ), followed by the Hydraulic Burst Leak test (HBLT). Was tested. Samples were cut into 3/4 inch diameter circular pieces. The sample was placed on a tissue substrate derived from the bovine pericardium with a hole in the center of the tissue. The perforated tissue substrate was placed over an airtight chamber into which saline was pumped in. The pressure required to break up / rupture the seal formed between the tissue and the sample was measured (see FIG. 1). Samples without protein coating do not adhere to the tissue.

Example 5

Poly (glycolide-co-lactide) (PGL, 90/10 mol / mol) was melt spun into fibers. 80 denier dafilament yarns were consolidated to 800 denier integrated yarns. The consolidated yarns were crimped at approximately 110 ° C. The crimped yarn was cut into staples having a length of about 1.25 ". After the yarn was conditioned for about 30 minutes in a high humidity environment (> 55% RH), 44 g of crimped staples were accurately weighed. It was placed evenly on the feed conveyor belt of the roller carding machine The feed time (5 minutes) was accurately controlled within 30 to 45 seconds The environmental conditions (temperature: 21 ° C./25% RH) were recorded. a, 2 ^nd Randomiser roller near well was used to close steel pick-up roller was operated for progression to minimize the harmful effects of static generation (static generation) for gender yield and uniformity of the resulting batt. then, the nonwoven fabric by carding the staple Bats were created: two vacuum inlets were strategically placed near the two edges of the 2 ^nd Randomizer rollers and the resulting bat width was determined. The bat was removed from the pickup roller and weighed (41 g: 91% yield) The uniform bat was correctly placed on the ORC fabric and firmly attached by a single pass in a needle punching device. The multilayer fabric was trimmed and refined (along with other similarly prepared sheets) on a rack suspended in a tank containing isopropyl alcohol to remove the spin finish and all mechanical oil. The fabric (matrix sheet) was calendered to remove excess solvent, dried in a 70 ° C. oven for approximately 30 minutes, cooled and weighed.

Example 6

The matrix sheets described have gray / beige colors on both sides. One side may be on the nonwoven side and the other side may be on the knitted fabric side. For accurate application, it may be important to identify the nonwoven surface versus the knitted surface of the matrix. Under difficult environmental conditions, (some degree of) similarity in color and texture makes it difficult to distinguish between one and the other. Several methods can be used to impose bilaterality on the matrix sheet, which allows the observer to separate the two sides separately. These methods include physical (stitch / knitting, braiding, pleating, etc.), thermo-mechanical (heating, heat embossing; laser etching, etc.) and chromic acid (using dyes) methods that can be used to achieve double sidedness. The following example illustrates some methods:

6a) The matrix sheet was modified on knitted fabric side by attaching a 1 mm wide 4 inch long braided tape of polyglactin 910 fibers. Although successful in imposing bilaterality, the tape increased the amount of polyglycotin 910 that reabsorbed for longer.

6b) A web made of dyed nylon fibers was placed under knitted fabric and nonwoven during the needlepunching step. The web is fixed to the knitted fabric side due to the needle process. The webs could be used to produce matrix sheets that provide good bilaterality and, where possible, are completely reabsorbable and implantable in absorbent materials. The web (mesh) can be similarly fixed on the nonwoven side. Another method of securing the web may be thermo-mechanical in nature. The inclusion of such webs may also be for reasons of mechanical reinforcement. In this case, the web may be secured to one or both sides between the two layers. This reinforced structure can have various applications.

6c) A small amount of polyglactin 910 present on the knitted fabric side (due to the needle punching step) of the matrix sheet can be thermally modified to create double sidedness. This may include heating under pressure such that a gloss film of polyglactin 910 is formed. Another option includes a heating embossing recognizability pattern. Both approaches achieve double sided but can lead to thermal decomposition of the polymer / structure.

6d) Pleat the knitted ORC fabric prior to the needle punching step (vertical or horizontal pleat). The pleats are stabilized using heating and pressure. The pleated fabric is then used in the case of ordinary fabrics for the remaining processes described in Example 5. The resulting matrix sheet has distinct stripes that achieve double sidedness.

6e) Stained polyglactin 910 produces a matrix sheet colored on the nonwoven side and gray / beige colored on the other side. This structure achieves double sidedness. Dyes can be similarly used by using sutures or the like dyed on the knitted side. Sutures (braided into tape or used as such) may be sewn in or thermally bonded.

The examples illustrate certain aspects of the invention, but they are not to be construed as limiting the scope of the invention, but rather serve to complete the description of the invention. All reinforcing fabrics described in the examples below are non-sterile materials of corresponding commercially available products referred to in their trade names.

Claims (32)

A multilayer wound dressing comprising a first absorbent nonwoven, one or more second absorbent fabrics or knits, thrombin and / or fibrinogen. The method of claim 1 wherein the first absorbent nonwoven fabric is an aliphatic polyester polymer or lactic acid, lactide (including L-, D-, meso and D, L mixtures), glycolic acid, glycolide, ε-caprolactone, p-di A multilayer wound dressing comprising fibers comprised of a copolymer of one or more monomers selected from the group consisting of oxanone and trimethylene carbonate. 3. The multilayer wound dressing of claim 2, wherein the first absorbent nonwoven comprises a glycolide / lactide copolymer. The multi-layer wound dressing of claim 2, wherein the second absorbent fabric or knitted fabric comprises oxidized polysaccharides. The multi-layered wound dressing of claim 4, wherein the second absorbent fabric or knitted fabric comprises oxidized cellulose. 6. The multilayer wound dressing of claim 5, wherein the second absorbent fabric or knitwear comprises oxidized regenerated cellulose. 6. The multilayer wound dressing of claim 5, wherein the second absorbent fabric or knitwear is an absorbent knitted fabric comprising oxidized regenerated cellulose. The multilayer wound dressing as claimed in claim 1, wherein the first absorbent nonwoven fabric comprises a glycolide / lactide copolymer and the second absorbent fabric or knitted fabric comprises oxidized regenerated cellulose. The multi-layer wound dressing of claim 8, wherein the first absorbent nonwoven fabric comprises staples about 0.75 to 1.5 inches long. The multi-layer wound dressing according to claim 9, wherein the staples are crimped. 10. The wound dressing of claim 8, wherein the first absorbent nonwoven comprises staples of about 1.0 to 1.3 inches in length. The multi-layer wound dressing according to claim 11, wherein the staples are crimped. 10. The multilayer of claim 8, wherein the first absorbent nonwoven fabric comprises from about 70 to 95% polyglycolide by mol, the remaining amount of polylactide, and the second absorbent fabric or knitted fabric comprises oxidized regenerated cellulose. Wound dressing. The wound dressing of claim 11, wherein the staples are derived from about 0.001 to 4 denier / filament of fibers. The method of claim 14, wherein the first absorbent nonwoven has a reference weight of about 0.01 to 0.2 g / in ² ; The second absorbent fabric or knitwear has a reference weight of about 0.001 to 0.2 g / in ² ; The multilayer wound dressing, wherein the multilayer dressing with thrombin and / or fibrinogen has a reference weight of about 0.1 and 1.0 g / in ² . The multilayer wound dressing according to claim 8, wherein the thrombin activity on the multilayer dressing is in the range of about 20 to 500 IU / cm ² and the fibrinogen activity on the multilayer dressing is in the range of about 2 to 15 mg / cm ² . A multi-layer dressing comprising a first absorbent nonwoven comprising a glycolide / lactide copolymer staple of about 0.75 to 1.5 inches long, a second absorbent fabric or knitted fabric comprising oxidized regenerated cellulose, thrombin and / or fibrinogen , Glycolide / lactide copolymer comprises from about 70 to 95% polyglycolide in mol, polylactide in residual amount, thrombin activity on multilayer dressings ranges from about 20 to 500 IU / cm ² , multilayer Fibrinogen activity on the dressing ranges from about 2 to 15 mg / cm ² , wherein about 50 to 75 mass% of the dressing can be absorbed after about 14 days. A method of treating a wound, comprising applying the multilayer wound dressing according to claim 17 to achieve hemostasis and / or to seal fluid leakage. (a) crimping the absorbent polymer fiber or yarn in the range of about 10 to 30 crimps / in; (b) cutting the crimped fibers or yarns to staple about 0.1 to 2.5 inches in length; (c) carding staples while adjusting the humidity to about 20 to 60% and the ambient temperature to about 15 to 24 ° C. to prepare a first absorbent nonwoven fabric; (d) attaching the first absorbent nonwoven to the second absorbent fabric or knitwear; (e) applying a thrombin and / or fibrinogen to the first absorbent nonwoven fabric, wherein the first absorbent nonwoven fabric, the second absorbent fabric or knitted fabric, thrombin and / or fibrinogen is made. 20. The method of claim 19, wherein the first absorbent nonwoven is an aliphatic polyester polymer or lactic acid, lactide (L-, D-, meso and D, L mixture), glycolic acid, glycolide, ε-caprolactone, p-dioxa A method of making a multilayer wound dressing comprising a fiber consisting of a copolymer of at least one monomer selected from the group consisting of paddy and trimethylene carbonate. 21. The method of claim 20, wherein the first absorbent nonwoven comprises a glycolide / lactide copolymer. 21. The method of claim 20, wherein the second absorbent fabric or knitted fabric comprises oxidized polysaccharides. The method of claim 22, wherein the second absorbent fabric or knitted fabric comprises oxidized cellulose. 24. The method of claim 23, wherein the second absorbent fabric or knitted fabric comprises oxidized regenerated cellulose. 24. The method of claim 23, wherein the second absorbent fabric or knitted fabric is an absorbent knitted fabric comprising oxidized regenerated cellulose. 20. The method of claim 19, wherein the first absorbent nonwoven fabric comprises a glycolide / lactide copolymer and the second absorbent fabric or knitted fabric comprises oxidized regenerated cellulose. 27. The method of claim 26, wherein the first absorbent nonwoven comprises staples of about 0.75 to 1.5 inches in length. 27. The method of claim 26, wherein the first absorbent nonwoven comprises staples of about 1.0 to 1.3 inches in length. 27. The absorbent fabric of claim 26, wherein the first absorbent nonwoven comprises a copolymer of glycolide and lactide, comprising about 70 to 95% by weight of glycolide, the remaining amount of lactide, and a second absorbent fabric or A method of making a multilayer wound dressing, wherein the knitted fabric comprises oxidized regenerated cellulose. The method of claim 29, wherein the staples are derived from a fiber of about 0.001 to 4 denier / filament. 27. The method of claim 26, wherein the first absorbent nonwoven has a reference weight of about 0.01 to 0.2 g / in ² ; The second absorbent fabric or knitwear has a reference weight of about 0.001 to 0.2 g / in ² ; A method of making a multilayer wound dressing, wherein the multilayer dressing with thrombin and / or fibrinogen on the multilayer dressing has a reference weight of about 0.1 and 1.0 g / in ² . The method of claim 26, wherein the thrombin activity on the multilayer dressing is in the range of about 20 to 500 IU / cm ² and the fibrinogen activity on the multilayer dressing is in the range of about 2 to 15 mg / cm ² .

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