JP2005000683A - Closing system for flexible tissue - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device which can close a site of puncture and stanch it while faults and hazards in conventional methods are substantially avoided, a method for manufacturing implants, and the like. <P>SOLUTION: A closing system of a flexible tissue (10) closes a percutaneously punctured site or a void in the flexible tissue, and includes a transportation means (12) and an implant (13) which is set into the transportation means (12) with compression, is self-expansible and enables repeating absorption. In the system (10), the implant (13) expands itself by suiting to a shape of the void in the flexible tissue to close the void when the implant member (13) is released to the void of the flexible tissue. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Related Application The present invention is a continuation-in-part of US Patent Application No. 07 / 881,213 filed on May 11, 1992, the contents of which are hereby incorporated by reference.

TECHNICAL FIELD The present invention relates generally to closure of soft tissue sites with self-expanding and bioresorbable polymer implants, and more particularly to closure of percutaneous puncture sites. The present invention is also directed to transporting such implants using a tubular transport device that penetrates a soft tissue site to a predetermined depth for hemostasis or wound closure. A method of preparing an implant is also disclosed.

BACKGROUND OF THE INVENTION Inserting a catheter into a blood vessel through a puncture site is used to treat diseased blood vessels by a technique known in the art as percutaneous angioplasty (PTA) or apply chemical treatment It is routinely performed to transport systemic drugs into the bloodstream. In the case of the PTA technique, an outer tube for introduction is first inserted from the puncture site into the artery so that a balloon-type or other type of catheter can be inserted into the blood vessel for operation in the blood vessel. The size of the outer cylinder for introduction can be changed from 1 mm to 5 mm depending on the characteristics of the disease and the insertion site of the artery. One of the complications when these measures are taken is bleeding at the percutaneous puncture site after removal of the catheter and introducer tube. To stop this bleeding, pressure is applied to the puncture site until it stops. Because angiogenesis and related techniques often require the use of anticoagulants, this technique of applying pressure is not always effective, and it can be applied for long periods of time or with ancillary surgical treatment. You may need to be hospitalized again.

  Various commercially available hemostatic preparations such as those disclosed in US Pat. No. 2,465,357, US Pat. No. 3,742,955, and US Pat. No. 3,364,200 are used. US Pat. No. 4,066,083 discloses a felt or fleece-like collagen hemostatic forceps. US Pat. No. 4,891,359 discloses a collagen paste for hemostasis comprising a mixture of collagen powder and physiological saline. Many other collagen-based hemostatic materials are also disclosed in U.S. Pat. Nos. 4,412,947, 4,578,067, 4,515,637, 4,271,070, 4,891,359, 4,066,083, 4,016,877, and 4,215,200. None of these patents disclose hemostasis techniques at the puncture site of blood vessels.

The use of collagen-based devices to close arterial puncture sites is described in `` Ernst, S., Tjonjoegin, R, Schrader, R, et al. Immediate Sealing of Arterial Puncture Sites After Cardiac Catheterization and Coronary Angioplasty Using a Biodegradable Collagen Plug; Results of an International Registry , J. Am. Coll. Cardiology, 15: 851-855, 1993 ”. In order to transport the collagen material to the percutaneous puncture site, the puncture site must be sufficiently widened using an oversized dosing tube. Then, a transport cartridge is inserted into the spread puncture site to transport the collagen material. Collagen is transported twice to fill the void and ensure hemostasis. This elaborate approach, which would further expand the damaged site, can cause severe hematoma in patients treated with this device.

  Another device for closing an arterial puncture site is disclosed in US Pat. No. 4,744,364 to Kensey. The device includes means for inserting an inflatable and resorbable material into a blood vessel lumen through a tubular member fitted inside the introducer barrel. A shrink filament is secured to the resorbable material to draw the resorbable material to the puncture site such that the resorbable material plugs the intravascular surface around the puncture site. In order to hold the resorbable material in place, the filament is secured to the patient's skin with tape or other means while remaining taut.

  Kensey's device can pose several risks to the patient. With this device, an acute thrombus may be formed due to incomplete placement of the sealing material, or due to blood incompatibility of the material. If the filament breaks down quickly, the sealing material that has not been fixed is released, and there is a possibility of forming an embolus at a distance from the puncture site. Movement of the sealing material can cause thrombi that require surgical intervention as well as rebleeding. The risks that such devices carry may be more important than the benefits that they can provide. Therefore, a safe, effective and user friendly method that can block the puncture site and stop bleeding is still eager and welcomed.

  It has become apparent to the applicant that the key point in resolving complications associated with closure of the puncture site is the design of a resorbable matrix with the characteristics and properties unique to such applications. It was.

  Accordingly, a first object of the present invention is to provide an apparatus capable of closing a puncture site and stopping bleeding while substantially avoiding the disadvantages and dangers of the conventional methods.

  Another object of the present invention is to provide a self-expanding implant that can be used to fill voids or damage in tissues or organs using biocompatible and resorbable materials in vivo. .

  Yet another object of the present invention is to provide a method for transporting biocompatible and resorbable implant material to a target tissue or organ by means of a tubular transport device.

  Another object of the present invention is to provide a method for delivering drugs, antibodies, growth factors, or other biologically active molecules to selected tissues or organs.

  Yet another object of the present invention is to provide a method of manufacturing an implant.

[1] a) Self-expanding so that the average diameter of the pores is about 0.5 μm to about 50 μm and when compressed, the average diameter of the pores in the expanded state is about 100 μm to about 3,000 μm. An implant formed of a bioresorbable material and having a certain length, characterized in that
b) A means of transport having an outlet at the remote end and an insertion depth guide that can be inserted into the gap to a depth adjusted by the insertion depth guide, and that the implant is disposed internally in a compressed state C) a controlled distance of the compressed implant from the outlet to the soft tissue void so as to form an expanded water-containing matrix adapted to close the soft tissue void; Retractable, retractable release means comprising (i) an insertion depth guide, (ii) implant length, and (iii) a release means in which the position of the implant in the void is adjusted by a combination of the retractable release means A device for closing a void in a soft tissue of a living body.
[2] The device according to [1], wherein the self-expanding resorbable implant is formed from a biocompatible and bioresorbable material.
[3] The device according to [2], wherein the biocompatible and bioresorbable material is type I collagen.
[4] The compressed implant has a density of about 0.1 g / cm3 to about 1.30 g / cm3, an expansion capacity of about 3 cm3 / cm3 to about 100 cm3 / cm3, and a relaxation recovery time of about 1 second to about 60 seconds. The apparatus according to [1].
[5] The transport means is a long-axis tubular member, and the discharge means includes a pressurizing member positioned in the tubular member and arranged to move in the long-axis direction to push the implant from the outlet. [1] The apparatus.
[6] The apparatus according to [5], wherein the transportation means is formed from a biocompatible material.
[7] The apparatus according to [6], wherein the biocompatible material is a synthesized polymerizable material.
[8] The device of [1], wherein the implant self-expands to fit into the tissue void when in contact with bodily fluids.
[9] The device according to [1], wherein the implant has some geometric shape.
[10] The apparatus according to [1], wherein the insertion depth guide includes a protrusion extending outward from a long axis of the transportation means, and a distance between the protrusion and the outlet defines an insertion depth of the transportation means.
[11] The device according to [1], wherein the protrusion remains on the outermost layer of the living body's skin when the transport means is inserted to the insertion depth.
[12] The apparatus according to [1], wherein when the transportation means is inserted to the insertion depth, the protrusion remains at the end of the introduction outer cylinder.
[13] An incision site or a puncture site in a blood vessel wall where the soft tissue void extends to the surface of the skin, and the implant to be released is located adjacent to the outside of the blood vessel wall at the incision site or the puncture site The apparatus according to [1], wherein the insertion depth guides the insertion depth.
[14] a) producing an aqueous dispersion containing collagen;
b) pouring the aqueous dispersion into a mold,
c) freeze drying the aqueous dispersion to form a collagen matrix;
d) cross-linking the collagen matrix by treating with a cross-linking agent;
e) spraying the crosslinked collagen matrix with water vapor;
f) A method for producing a self-expanding resorbable collagen implant comprising compressing the steam treated collagen matrix.
[15] The dispersion further contains a drug containing an antibody, a growth factor, thrombin, glycosaminoglycan, prostaglandin, type II to XIV type collagen, glycoprotein, fibronectin, laminin, and a mixture thereof. [14] The method.
[16] The method according to [14], wherein the crosslinking agent is formaldehyde.
[17] The method of [16], wherein the degree of cross-linking is such that the collagen implant is resorbed in about 2 weeks to about 10 weeks.
[18] The resorbable collagen implant has a density of about 0.1 g / cm 3 to about 1.30 g / cm 3 in the compressed state and about 0.01 g / cm 3 to about 0.5 g / cm 3 in the expanded state. The method according to [14], having a density of:
[19] The method of [14], wherein the resorbable collagen implant has an expansion capacity of about 3 cm 3 / cm 3 to about 100 cm 3 / cm 3.
[20] The method of [14], wherein the resorbable collagen implant has a relaxation recovery time of about 1 second to about 60 seconds.
[21] The method of [14], wherein the resorbable collagen implant has a heat shrink temperature of about 50 ° C to about 75 ° C.
[22] a) Inserting a transport means having a long axis and having an outlet at a remote end into the space of the soft tissue to a depth adjusted by an insertion depth guide provided on the transport means,
b) discharging an implant having a constant length from the transport means into the void at an adjusted position by an adjusted distance (wherein the implant has an average pore diameter of about 0.5 μm to about Composed of a resorbable material in a living body that is in a compressed state that is 50 μm and is self-expandable so that when wet, the average diameter of the pores in the expanded state is from about 100 μm to about 3,000 μm, and (i The combination of the insertion depth guide and (ii) the length of the implant and (iii) the release means adjusts the positioning of the implant within the cavity)
c) A method for closing a void in soft tissue of a living body, comprising removing the means of transportation so that the implant is self-expanding and conforms to the void of the soft tissue to form a hydrous matrix that closes the void. .
[23] An incision site or puncture site in a blood vessel wall where the soft tissue void extends to the surface of the skin, and the released implant is located adjacent to the outside of the blood vessel wall at the incision site or puncture site The method according to [22], wherein the insertion depth guides the insertion depth of the transport device.
[24] The living body has a skin having an outermost layer and includes a protrusion extending outward from the major axis of the transporting means, and defines a distance between the protruding part and the outlet that defines the insertion depth of the transporting means [22] The method according to [22], wherein the insertion depth is adjusted by the insertion depth guide, and the protrusion remains on the outermost layer of the skin of the living body when the transportation means is inserted to the insertion depth.
[25] The method according to [22], wherein the implant is a biocompatible polymerizable material.
[26] The method according to [25], wherein the biocompatible polymerizable material is a material containing collagen.
[27] The method of [22], wherein the implant is self-expanding when it comes into contact with body fluid or blood.
[28] The compressed implant has a density of about 0.10 g / cm 3 to about 1.30 g / cm 3 in a compressed state, a density of about 0.01 g / cm 3 to about 0.50 g / cm 3 in an expanded state, about 3 cm 3 / [22] The method according to [22], having an expansion capacity of cm3 to about 100 cm3 / cm3, a heat shrink temperature of about 50 ° C to about 75 ° C, and a relaxation recovery time of about 1 second to about 60 seconds.
[29] The compressed implant further contains a drug comprising antibody, growth factor, thrombin, glycosaminoglycan, prostaglandin, type I to XIV type collagen, glycoprotein, fibronectin, laminin, and mixtures thereof The method of [22].
[30] A self-expanding resorbable collagen implant prepared by the method of [14].

SUMMARY OF THE INVENTION The present invention eliminates, or substantially eliminates, or substantially eliminates many of the disadvantages and problems associated with prior attempts to close a site that has been punctured and damaged by vascular catheterization or other soft tissue therapy. Self-expanding, resorbable hemostatic implants are disclosed that reduce. The present invention also provides a method for delivering a drug to a selected site of soft tissue. More particularly, the present invention can stop bleeding following angioplasty and related techniques by transporting a resorbable, self-expanding hemostatic implant to a specific vascular puncture site.

  The resorbable, self-expanding tissue closure implants of the present invention are generally dry, compressed, porous matrices containing biological fibers. As used herein, “biological fibers” include collagen, elastin, fibrin, polysaccharides, and the like. In a preferred form of the invention, the matrix comprises animal or human collagen fibers.

The implant of the present invention specifically comprises a compressed matrix having a density of about 0.10 g / cm ³ to about 1.30 g / cm ³ and an average pore diameter of about 0.5 μm to about 50 μm. The compressed matrix self-expands when contacted with an aqueous medium, and when fully expanded, the average pore diameter is from about 100 μm to about 3,000 μm, correspondingly from about 3 cm ³ / cm ³ to A volume that is about 100 cm ³ / cm ³ expands and a density that is 0.10 g / cm ³ to about 1.30 g / cm ³ in the compressed state is about 0.01 g / cm ³ to about 1 in the fully expanded state. It decreases to a density of 0.50 g / cm ³ .

The matrix may also contain drugs selected for topical therapeutic applications. Therapeutic agents include hemostatic agents such as thrombin, Ca ⁺⁺ , epidermal growth factor (EGF), acidic fibroblast growth factor (FGF), alkaline fibroblast growth factor (FGF), transforming growth factor alpha and Examples include, but are not limited to, injury repair agents such as beta (TGF alpha and beta), glycoproteins such as laminin and fibronectin, and various types of collagen.

A method of manufacturing a resorbable, self-expanding soft tissue closure implant, in its broadest aspect,
a) forming an aqueous dispersion containing biological fibers;
b) pouring the aqueous dispersion into a mold,
c) freeze drying the aqueous dispersion to form a collagen matrix;
d) cross-linking the lyophilized matrix by treating with a cross-linking agent;
e) spraying the crosslinked matrix with water vapor;
f) compressing the steam treated matrix.

The invention further includes a method for closing a soft tissue puncture site using a resorbable, self-expanding implant. In this method, a resorbable and self-expanding polymer implant is transported in a compressed state to a target site using a transport means, particularly a tubular transport device, and resorbable at a target soft tissue site. Release. At that site, the resorbable implant will self-expand to conform to the soft tissue site to close the lesion. In particular, the method
a) inserting a transport means having a major axis and having an outlet at a remote end into the soft tissue gap to a depth adjusted by an insertion depth guide provided on the transport means;
b) discharging an implant having a constant length from the transport means into the void at an adjusted position by an adjusted distance (wherein the implant has an average pore diameter of about 0.5 μm to about Composed of a resorbable material in a living body that is in a compressed state that is 50 μm and is self-expandable so that when wet, the average diameter of the pores in the expanded state is from about 100 μm to about 3,000 μm, and (i ) Insertion depth guide, (ii) the length of the implant, and (iii) the combination of release means adjusts the positioning of the implant in the cavity)
c) removing the means of transport so that the implant is self-expanding to form a hydrous matrix that fits into and closes the voids of the soft tissue.

The present invention also provides
a) It is in a compressed state where the average diameter of the pores is about 0.5 μm to about 50 μm, and is self-expandable so that when wet, the average diameter of the pores in the expanded state is about 100 μm to about 3,000 μm. An implant of a certain length, made of a material that can be resorbed in the body,
b) a vehicle having a remote end outlet and an insertion depth guide, adapted to be inserted into the cavity at a depth adjusted by the insertion depth guide, and wherein the implant is in a compressed state A means of transport such as disposed therein; and c) the compressed state from the outlet a controlled distance so as to form an expanded hydrous matrix adapted to close the soft tissue void. Retractable release means capable of releasing the implant into the soft tissue gap, where the combination of (i) insertion depth guide, (ii) length of implant, and (iii) retractable release means The position of the implant within the body is adjusted)
And a device for closing a void in a soft tissue of a living body.

The resorbable and self-expanding soft tissue closure implant of the present invention can provide maximum volume expansion capacity and surface area for liquid absorption, platelet adhesion, and hemostasis, while minimizing for insertion The matrix is configured to be highly compressed so that capacity can be maintained. A porous matrix by swelling provides maximum surface area for wetting and adhesion of cells to heal wounds. Accordingly, in a preferred embodiment of the present invention, the self-expanding implant of the present invention has the following physical and physicochemical properties. It should be understood that the features and properties shown for the “expanded” state self-expandable implant are generally the same as, and are illustrative of, the collagen matrix prior to being compressed during the formation of the implant.
Physical characteristics Cylinder diameter (cm)
Compressed state Normal: 0.1-0.6
When suitable: 0.2-0.4
Inflated state Normal: 1.0-10.0
When suitable: 3.0-7.0
Cylinder height (cm) Normal case: 0.2-10.0
When suitable: 0.5-5.0
Hole size (μm)
Compressed state Normal: 0.5-50
When suitable: 2.0-45.0
Optimal case: 5.0-40.0
Inflated state Normal case: 100-3,000
When suitable: 200-1,000
Best case: 250-700
Density (g / cm ³ )
Compressed state Normal case: 0.1-1.30
When suitable: 0.2-1.0
Optimal case: 0.3-0.8
Inflated state Normal: 0.01-0.50
When suitable: 0.02-0.25
Optimal case: 0.03-0.15
Physicochemical property expansion capacity (cm ³ / cm ³ ) Normal case: 3-100
When suitable: 10-50
Best case: 15-35
Heat shrink temperature (° C) Normal case: 50-75
When suitable: 55-65
Relaxation recovery time (seconds) Normal: 1-60
When suitable: 3-40
Best case: 5-30

The invention is described below in connection with the examples given as examples.
DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, like reference numerals refer to like elements, and FIG. 1 includes an implant transport means 12 and an implant member 13 disposed within the transport means 12 at 10. A flexible tissue closure system is shown in its entirety. The main function of the transport means 12 is to transport the implant member 13 effective for successfully filling and closing the void generated in the soft tissue of the living body to the target site in situ. In a preferred embodiment, the flexible tissue closure system of the present invention is used to effectively close a puncture or other opening created in a blood vessel, tubular section, or lumen. However, the closure system 10 can also be used to treat wounds arising from other voids formed in the soft tissue of a living body, typically voids made from surgical procedures. Such applications include filling voids after removing malignant tumors, necrotic tissue, collapsed tissue, deep bullet wounds, knife stabs, and the like. Gaps created by plastic surgery or cosmetic surgery can also be filled using the closure system of the present invention. Furthermore, the closure system of the present invention can be used to stop bleeding and fill voids in diagnostic applications such as tissue biopsy where a biopsy needle or other biopsy device is used.

  While the following description and drawings describe the closure of a percutaneous puncture site in an artery, it will be apparent from the foregoing that the present invention has broader applicability than this preferred embodiment.

  The transport means 12 can be biocompatible materials such as stainless steel, synthetic polymerizable materials (eg polyethylene, polypropylene, polyvinyl chloride, polystyrene, polytetrafluoroethylene, polyurethane, etc.), natural polymerizable materials (eg collagen). , Elastin, etc.), and other biocompatible materials well known to those skilled in the art. The means of transport is preferably made of a less expensive disposable material that can be easily discarded after use, for example. Synthetic polymers are desirable because of their ease of manufacture and disposable.

  The transport means shown in this figure includes a tubular member 11 having an outlet 20 at a distal end and a discharge means 22 slidably attached to a proximal end 28 of the tubular member 11. The tubular member 11 is provided with an insertion depth guide 15, an insertable tip portion 32, and a flange-like protrusion 30 on a long main body.

  The insertable tip portion 32 has a fixed length “y”, which is determined by the particular soft tissue site to be repaired and usually varies within the range of about 0.2 cm to about 10 cm. To do. Only the distal end portion 32 of the tubular member 11 which can be inserted is actually inserted into the patient's skin or the introduction cylinder. The depth of insertion can be easily adjusted by the insertion depth guide 15. The guide 15 is positioned at the length “y” of the tubular member 11 so that the tubular member cannot be inserted behind the guide. The guide 15 is a simple structure consisting of protrusions, i.e., bulges, provided at a part or all around the transportation means, and stops insertion of the transportation means when a tip portion into which this bulge can be inserted is inserted. At this time, the bulge of the guide is simply positioned on the outermost surface of the patient's skin (or not shown, but is positioned on the protrusion of the introduction cylinder in a manner well known to those skilled in the art). May be.) The shape or design of this guide is not critical as long as it has the ability to adjust the depth of insertion.

  The outer diameter of the insertable tip portion 32 is preferably a special intravascular introduction so that the insertable tip portion 32 can be easily inserted through the skin (or introducer tube) and is positioned just at the percutaneous puncture site. It is configured smaller than the introduction outer cylinder used in the law. Depending on the specific in-tube introduction method, the outer diameter of the tip can vary from about 1 mm to about 6 mm. The remaining portion of the tubular member 11 except for the insertable tip portion 32 may have any outer diameter as long as it does not enter the repair site. Desirably, however, a unitary tubular member having the same inner and outer diameters is typically formed for each component.

  The flange-like projection 30 is arranged so that it can be grasped by the user's hand when the implant member 13 is released by the releasing means 22. The flange-shaped protrusion 30 may be provided on the entire periphery around the end portion 28 on the near side of the main body of the tubular member 11, or may be provided on only a part around the end portion 28.

  The discharge means 22 includes a pressing plate 14 attached to a far end to be a flat plate perpendicular to the long axis, and a flat plate perpendicular to the long axis of the rod-shaped member 24 at a near end. It is comprised from the elongate cylindrical rod-shaped member 24 provided with the thumb rest 26 attached so that it might become. Since the pressing plate 14 is disposed at the position of the insertable tip portion 32 inside the tubular member 11 and has an outer diameter slightly smaller than the inner diameter of the insertable portion 32, the pressing plate 14 is inserted. It can be moved down in the longitudinal direction of the possible portion 32 and the implant member 13 can be pushed out of the outlet 20. The rod-shaped member 24 can be retracted by the distance “d” shown in FIG. This distance is only slightly longer than the length of the implant member 13 so that the implant can be fully released and, most importantly, it prevents an unnecessarily long implant from being extruded. ing. Thus, by adjusting the length “y” of the insertable tip portion 32, the length of the implant member 13, and the distance “d”, the implant member 13 can be accurately positioned at the repair site.

  In use, the closure system of the present invention is preferably used as soon as possible after removing the introducer outer cylinder or while the introducer outer cylinder is partially removed from the puncture site. As shown in FIG. 2, the insertable tip portion 32 is inserted into a repair site through the puncture site 42 of the skin 40. The insertion depth guide 15 adjusts the insertion depth by stopping the penetration of the insertable portion 32 when the guide 15 comes into contact with the surface of the skin 40. In order to successfully transport the implant member to the repair site, the user's hand grasps the protrusion 30 and places the finger on the thumb rest 26. By pushing the thumb rest 26, the discharge means slides a distance "d". As a result, the implant member 13 is released and transported so as to directly cover the punctured site 42 of the blood vessel 44.

  As is more clearly shown in FIG. 3, the implant member 13 is not positioned on the inner surface of the vessel lumen 44, and the adjustment of the insertion depth that can be achieved by the present invention causes the end surface 46 of the implant member to be at the vascular puncture site. Rather, it is transported out of the blood vessel so that it is located directly outside the top. The released implant member 13 expands rapidly in situ, completely closing the puncture site while the transport device is slowly removed.

  FIG. 3 is a schematic view of a closed puncture site. The implant member 13 is shown as being significantly expanded, and the blood around the implant member is absorbed and clots through a hemostatic mechanism induced by collagen to form a clot 50. The wound bandage is indicated at 52.

  The implantable and resorbable implant member 13 is primarily manufactured from biological polymers such as proteins, polysaccharides and the like. Preferably, a collagen-based material is used due to its nature as an endogenous hemostatic agent.

  Type I to XIV type collagen can be used alone or in combination to produce the implantable implant member 13. Preferably, type I collagen is used because it is available in large quantities, is easy to isolate and purify, and has a proven hemostatic effect. The main sources of type I collagen are tendons, skin, bones, and ligaments. Both human and animal tissues can be used to isolate collagen. In general, animal tissue is preferred because it is readily available fresh from local slaughterhouses.

  In preparing the implantable member 13, type I collagen is first isolated and purified. An overview of collagen preparation is described in “Methods in Enzymology”, vol. 82, pp. 33-64, 1982. In particular, the collagen of the present invention can be prepared by the following method.

  First, a natural source of type I collagen, such as skin, tendon, ligament, or bone, is first cleaned after removing fat, fascia, and other deposits. The clean, collagen-containing material that is not soiled is then cut or ground. The bone material is then subjected to a desalting process. This is done using an acid solution such as hydrochloric acid or a solution of a chelating agent such as ethylenediaminetetraacetic acid (EDTA).

  This material is then subjected to a defatting treatment using a fat solubilizer such as, for example, ethanol, propanols, ethers, or a mixture of ether and alcohol. The delipidated collagen-containing material is subsequently extracted with a neutral salt solution to remove neutral salt-dissolved material. Typically, a 1M NaCl solution is used to achieve this goal. This high ionic strength salt solution weakens the non-specific binding of non-collagenous material that is solubilized and removed. The salt-extracted collagen-containing material is then washed with deionized distilled water.

  The collagen-containing material extracted with the neutral salt is then subjected to acid extraction in the presence of a structure-stabilizing salt to further remove the acid-soluble non-collagenous material. Applicable acids are acetic acid, lactic acid, hydrochloric acid, sulfuric acid, phosphoric acid, and similar acids. Regardless of the acid used, the pH of the acid solution is adjusted to 3 or lower. Salts used include sodium chloride, ammonium sulfate, sodium sulfate, or similar salts. Acid extraction weakens the interaction between collagen and acidic non-collagenous impurities that are dissolved and removed.

  The acid extracted collagen is then neutralized by adjusting its isoelectric point to a pH of about 6 to about 7 by adding a base. Applicable bases include sodium hydroxide, potassium hydroxide, ammonium hydroxide, and similar bases. By adding a base, the collagen becomes coacervate. The coacervated collagen is then filtered by means well known to those skilled in the art, such as by vacuum filtration using a stainless steel mesh filter.

  Collagen extracted with acid and neutralized with base can subsequently be washed with deionized distilled water to remove salt residues produced in the neutralization step. The washed collagen is then extracted with a base in the presence of a structural stabilizing salt. Such bases include sodium hydroxide, potassium hydroxide, calcium hydroxide, and similar bases well known to those skilled in the art. Regardless of the base used, the pH of the solution is adjusted to 13 or higher. Base extraction weakens the interaction between collagen and basic non-collagenous impurities. By adding a base, the non-collagenous material is dissolved and removed. This base also lowers the isoelectric point due to partial deamidation of glutamine and asparagine contained in collagen to produce an additional carboxyl group. The base-extracted collagen is then isoelectrically adjusted to a pH of about 4.5-5.5 by adding acid to the collagen dispersant to sufficiently separate the fibers from the solution for easy filtration. The pH is adjusted to a point and coacervated. Such acids include hydrochloric acid, sulfuric acid, acetic acid, lactic acid, phosphoric acid, and similar acids. The coacervated collagen is then filtered. After discarding the extraction solution, the fibers are washed with deionized distilled water to remove the residual salt obtained by neutralization of the extraction solution. The collagen thus purified is stored in a freezer or lyophilized for the preparation of the member 13 into which collagen can be embedded.

  In order to produce a member 13 that can be implanted with collagen, a collagen dispersant is first prepared by methods well known in the art. One such preparation is disclosed in US Pat. No. 3,157,524, which is hereby fully incorporated by reference.

  In particular, the collagen dispersant of the present invention can be prepared by the following method.

The purified collagen material is first dispersed in a 1 × 10 ⁻⁴ M NaOH solution to swell the collagen fibers. This collagen material is then homogenized by conventional techniques such as using a blender or homogenizer so that the fibers are completely dispersed. The homogenized collagen is then filtered to remove unswelled aggregates by means well known to those skilled in the art, such as by passing the dispersant through a stainless steel mesh screen. The pH of the dispersant is adjusted to about 7.4 by adding 0.01M HCl. The initial dispersant contained in the base should be neutralized without passing through the isoelectric point so as not to cause coacervation of the collagen and to obtain a more uniform dispersant at pH 7.4. Can do. The dispersant is then evacuated to evacuate the air. The resulting collagen dispersant can then be used to prepare a self-expanding implantable soft tissue closure device.

  The amount of collagen included in the dispersant is typically about 0.5 to about 5.0 weight percent, and preferably in the range of about 0.75 to about 2.0 weight percent. A weight percent of collagen in a dispersant greater than 5.0 is obtained by centrifuging the dispersant in a centrifuge and discarding the supernatant. Generally, the greater the centrifugal force applied to the dispersant, the higher the weight percentage of collagen contained in the dispersant after discarding the supernatant.

  In one embodiment of the present invention, if the collagen soft tissue closure system functions as a drug transport container, a drug additive may be selectively included in the dispersant in addition to type I collagen. Examples of the drug additive include antibodies, thrombin, hyaluronic acid, chondroitin sulfates, polysaccharides such as alginic acid, chitosan, and the like, growth factors such as epidermal growth factor, transforming growth factor beta (TGF-β), and the like. , Glycoproteins such as fibronectin, laminin and the like, collagens of types II to XIV, and mixtures thereof.

  The collagen dispersant is then injected into the mold. The shape of the mold may be cylindrical, square, spherical, or any other shape as long as the size of the mold is larger than the inner diameter of the insertable tip portion 32. If the inner diameter (ID) of the insertable tip portion 32 is 2 mm and is a cylindrical implantable collagen member 13, the diameter of this mold is preferably between about 3 mm and about 15 mm. And the mold height is in the range of about 5 mm to about 25 mm.

  The mold containing the dispersant is then placed in a freezer maintained at a temperature of about −10 ° C. to about −50 ° C. for a sufficient time for the water contained in the dispersant to freeze, usually about 1 to about 24. Left for hours. The frozen dispersant is then lyophilized to remove frozen water. This lyophilization process is carried out under conditions well known to those skilled in the art, for example in a commercial lyophilizer such as that manufactured by Virtis, Stokes, or Hull. Typically, the vacuum space in the dryer chamber is maintained at a temperature of about −10 ° C. to about −50 ° C. for about 16 hours to about 96 hours at a pressure of about 50 μm Hg to about 300 μm Hg. This temperature is then raised to about 25 ° C. over about 3-24 hours.

  The freeze-dried highly porous collagen matrix is then subjected to a cross-linking treatment to form additional intermolecular cross-linked structures in order to stabilize the shape of the collagen matrix. Crosslinking is performed by methods well known to those skilled in the art. Reagents that can chemically react with amino groups, hydroxyl groups, guanidine groups, and carboxyl groups that can bind to the side chains of different collagen molecules can be used to crosslink the collagen matrix. This can be done using chromium sulfate, formaldehyde, glutaraldehyde, carbodiimide, adipyl chloride, hexamethylene diisocyanate, and similar materials. The rate at which collagen is reabsorbed in vivo depends on the degree of intermolecular crosslinking in the collagen matrix. Factors that control the degree of cross-linking include the type and concentration of the cross-linking agent, the pH, time, and temperature when incubating in the liquid phase, or the vapor pressure, time, temperature of the cross-linking agent if cross-linking occurs in the gas phase. , And relative humidity. The collagen matrix of the present invention is desirably crosslinked to such an extent that the collagen is completely resorbed in about 2 to 10 weeks.

  Proper cross-linking of the lyophilized matrix induces some very important properties of the present invention for special clinical applications as a soft tissue closure device. Effective cross-linking fixes the physical geometry of the matrix determined by the shape of the mold. The matrix therefore behaves elastically when pressure is applied to the matrix. This means that if the matrix is physically deformed or compressed, the external pressure is relieved or released to return to its original shape and size, or physical, such as the wall of the puncture site It spreads to the extent that it fits the obstacles. Such elastic behavior of a properly cross-linked lyophilized collagen matrix is particularly apparent when the collagen matrix becomes wet, for example when the collagen matrix absorbs blood at the puncture site. This is a result of the hydrophilicity and Donnan osmotic pressure of the collagen matrix. The time to recover from the deformed or compressed state in the wet state to the original shape is as short as about 1 second to about 60 seconds. This recovery time is desirably about 3 seconds to about 30 seconds.

  Another important property provided by cross-linking the collagen matrix is the ability of the volume to expand from a compressed state to an expanded state. The volume expansion capacity of the cross-linked collagen matrix of the present invention is limited by the mold size that determines the overall volume of the matrix of the present invention. The total volume of the matrix is determined by the geometry of the mold. Typically, if the mold is cylindrical, the volume is determined by the bottom area of the cylinder and the height of the cylinder. The desired volume of the matrix when used for puncture site closure depends on the specific size of the introducer cylinder used. In particular, when a 9F (about 3 mm) introducer outer cylinder is used, the desirable dimensions of the cylindrical matrix are from about 6 mm to about 15 mm in bottom dimension and from about 5 mm to about 25 mm in height. This means that the compressed matrix is transported and self-expanding to increase its volume from about 3 to 20 times.

Yet another property that can be controlled by crosslinking the collagen matrix is density. Depending on the specific puncture site to be repaired and the physical, chemical, and biological needs, the density of the compressed matrix is between about 0.1 g / cm ³ and about 1.30 g / cm ³ . Within that range, the density of the matrix when fully expanded will vary within the range of about 0.01 g / cm ³ to about 0.5 g / cm ³ . In order to close the puncture site created by the angioplasty method or related methods, the density of the matrix in the compressed state is usually in the range of about 0.25 g / cm ³ to about 1.0 g / cm ^3. The density in the varied and fully expanded state varies from about 0.02 g / cm ³ to about 0.15 g / cm ³ .

  Another property of the cross-linked collagen matrix is a porous structure. A fully swollen crosslinked collagen matrix has an average pore diameter of about 100 μm to about 3,000 μm. The average pore size decreases dramatically from about 0.5 μm to about 50 μm in the compressed state. The compression of the cross-linked matrix allows the matrix to be inserted into a small volume for transport, and is subsequently transported and the matrix self-expands so that the matrix fits well into the puncture hole. It is possible to expand to a size necessary for sealing. Of course, this compressed cross-linked collagen matrix material implant will conform to the wall of the puncture site and effectively close the puncture site by applying pressure to the wall of the puncture site when the implant is self-expanding. Is selected to have a specific physical dimension that takes into account the size of the puncture site to be closed, so as to expand to a range and size such that

The degree of cross-linking of the collagen matrix of the present invention can be measured by the heat shrink temperature (T ^S ) of the matrix, that is, the temperature at which the matrix begins to shrink in an aqueous environment as a result of the release of the triple helix structure of the collagen molecule. it can. Methods of measuring the heat shrink temperature of a material are well known to those skilled in the art, such as, for example, a differential scanning calorimeter method or a method of measuring dimensional changes using a categorometer.

  Usually, the degree of cross-linking is such that the shrinkage temperature of the collagen matrix is in the range of about 50 ° C to about 75 ° C, preferably about 55 ° C to about 65 ° C.

In one embodiment of the invention, the collagen matrix is crosslinked using formaldehyde vapor. Either commercially available formaldehyde vapor or formaldehyde vapor generated from a formaldehyde solution can be used. In particular, the crosslinking is carried out in a chamber having a relative humidity in the range of about 80% to about 100%, preferably in the range of about 85% to about 95%, and in an atmosphere of excess formaldehyde vapor. The process proceeds at about 25 ° C. for about 30 minutes to 8 hours. In particular, when crosslinked for 60 minutes at 95% humidity with formaldehyde vapor generated at 25 ° C. from a 1% formaldehyde solution, the density in a fully expanded state at a heat shrink temperature of about 55 ° C. to about 65 ° C. is 0.02 g. Collagen matrices from / cm ³ to about 0.15 g / cm ³ can be produced.

  The crosslinked collagen matrix is subsequently subjected to a steam treatment. A water vapor spray that can be purchased is suitable for this purpose. The collagen matrix is sprayed in about 10 seconds to about 60 seconds, during which time the collagen matrix disintegrates in the container at about 25 ° C. The water vapor that has treated the matrix is then equilibrated in a closed vessel for about 30 minutes to further soften the matrix for the subsequent compression step. As a result of this steam treatment, the collagen matrix has taken up about 10% to 40% by weight of water, based on the weight of the dry material. This steamed collagen matrix is then subjected to mechanical compression to reduce its size to fit into the insertable portion 32. In particular, when the matrix is cylindrical, the I.D. D. The mechanical compression is applied in a radial direction so that the magnitude decreases to approximately the same. Normally, a compressed collagen matrix is about 1/100 to 1/3 the volume of the uncompressed matrix. The compressed implantable member 13 is then inserted into the insertable tip portion 32. At this point, the filled soft tissue closure system is individually packaged for safety.

  Matrix crosslinking, steaming, and mechanical compression are important aspects of the present invention. More importantly, the sequence of operations as disclosed in the present invention is important in order to provide the desired properties of the collagen matrix. Density, porous structure, and expansion range of the compressed collagen implant member are directly related to whether this collagen matrix is obtained. For example, changing the order of steaming, mechanical compression, and matrix cross-linking from the present invention will not self-expand when the pressure is released, resulting in a matrix with no blood absorption capacity.

  Although only percutaneous puncture closure has been described as an example to illustrate the present invention, various changes, modifications, and applications can be made without departing from the scope and spirit of the invention. You can understand.

  The above and other objects, advantages and features of the present invention will be better understood from the following examples.

Preparation of Collagen Dispersant Fat and fascia were carefully removed from bovine flexor tendons, removed and washed with water. The cleaned tendon was frozen and reduced by slicing into 0.5 mm slices with a meat slicer. The tendon was first defatted with isopropanol (tendon: isopropanol = 1: 5 volume ratio) for 8 hours at 25 ° C. with constant agitation. The extraction solution was discarded, then an equal volume of isopropanol was added, and the tendon slices were extracted overnight at 25 ° C. with stirring. The tendon was then washed many times with deionized distilled water to remove any remaining isopropanol. The defatted tendon was then extracted with 10 volumes of 1.0 M NaCl for 24 hours at 4 ° C. with stirring. The tendon extracted with this salt was washed with deionized distilled water. The fiber was then extracted with 10 volumes of 1M NaOH for 24 hours at 25 ° C. with constant stirring in the presence of 1M Na 2 SO 4. The alkali extracted collagen was then collected by filtration, neutralized with 0.1 M HCl, and then the fibers were collected and washed to remove residual salts and frozen.

An aliquot of the fiber purified as described above is first suspended in 1 × 10 ⁻⁴ M NaOH solution. The amount of fiber and base used is such that a 1.5% (weight / volume) collagen suspension is obtained. The expanded fibers are then homogenized in a stainless steel mixer for 60 seconds. The reliable dispersed collagen material is filtered through a 40 μm stainless steel mesh. The dispersant pH is then adjusted to about 7.4 by adding 0.01 M HCl. The dispersed material is then evacuated and degassed and stored at 4 ° C. until use.

Preparation of collagen soft tissue closure implant The collagen dispersant prepared according to Example 1 is injected into a stainless steel mold having a diameter of 15 mm and a height of 10 mm. Next, the mold containing the collagen is subjected to a freeze-drying method using a freeze-dryer manufactured by Virtis. The lyophilization is performed by freezing at −40 ° C. for 6 hours, drying at −10 ° C. for 24 hours at a pressure of 150 μm Hg, followed by drying at 25 ° C. for 8 hours. The lyophilized collagen matrix is then placed in a crosslinking chamber containing an excess of formaldehyde vapor (generated from a 1% formaldehyde solution at 25 ° C.) for 60 minutes at 25 ° C. and 95% relative humidity. Perform formaldehyde vapor crosslinking. The cross-linked collagen material is sprayed with water vapor for 10 seconds and allowed to equilibrate in a closed container over the next 30 minutes. This steamed matrix can then be compressed by rotating between two glass plates with a gap of 2.5 mm to reduce the 15 mm diameter sponge-like matrix to about 2.5 mm. it can. The compressed collagen matrix is then D. Is 2.5 mm and O.D. D. Is inserted into a 3.0 mm prefabricated implant transport means (member 11 shown in FIG. 1).

Preparation of collagen soft tissue closing implant in the presence of thrombin The collagen dispersant obtained in Example 1 is mixed uniformly with thrombin (collagen: thrombin = 10: 1 weight ratio). This carefully mixed gel containing collagen / thrombin is then poured into a stainless steel mold as described in Example 2. This series of steps is the same as in Example 2.

Features of collagen soft tissue closure implants a) Density (g / cm ³ )
The apparent density of the soft tissue closure implant in the compressed and fully expanded state is measured by first weighing the collagen matrix to obtain a dry weight. Next, the volume of the matrix is determined by applying the following equation from the radius and height of the sponge. V = π × r ² × h: where r is the radius of the matrix and h is the height of the matrix. The density of the collagen soft tissue closure implant of the present invention, in a compressed matrix is from about 0.10 g / cm ³ ~ about 1.30 g / cm ^3, and about 0.01 g / cm ³ ~ about a fully expanded matrix It is in the range of 0.5 g / cm ³ .

b) Degree of expansion (cm ³ / cm ³ )
The degree of expansion is defined as the expansion volume of the matrix per unit volume of the soft tissue closure device. The volume of the compressed collagen matrix is first measured by measuring the dimensions of the matrix. The collagen matrix is then immersed in buffer at 25 ° C. for 5 minutes at pH 7.4. The volume of the expanded wet matrix is then measured. The degree of expansion of the collagen matrix (cm ³ / cm ³ ) is calculated by dividing the volume of the expanded matrix by the volume of the compressed matrix. The expansion capability of the collagen soft tissue closure implant according to the present invention is in the range of about 3 cm ³ / cm ³ to about 100 cm ³ / cm ³ .

c) Pore diameter (μm)
The pore size is obtained from a scanning electron micrograph (SEM) on the cross section of the collagen implant in the compressed state and in the fully expanded state. The pore size of the compressed matrix is defined as the distance between the compressed pore gaps. The pore size of the expanded matrix is defined as the average of the maximum and minimum distances of the hole openings. The pore size of the collagen matrix according to the present invention is in the range of about 0.5 μm to about 50 μm for a compressed implant, and in the range of about 100 μm to about 3,000 μm for a fully expanded implant.

d) Relaxation recovery time (seconds)
The collagen soft tissue closure implant of the present invention in a compressed state is extruded from a disposable transport means into a buffer solution adjusted to 25 ° C. having a pH of 7.4. The compressed matrix relaxes and hydrates and self-expands until fully expanded. The time taken to recover to this fully expanded state is recorded. The relaxation recovery time of the present invention is in the range of about 1 second to about 60 seconds.

e) Shrink temperature (° C)
A sample of 10 mg collagen matrix is first wetted in a buffer at pH 7.4. The sample is sealed in an aluminum sample pen and inserted into the sample holder of the differential scanning calorimeter. Buffer is used as a reference. The heating rate is 5 ° C./min. Shrink temperature is defined as an indication of an endothermic peak from heat capacity against a temperature plot. The thermal contraction temperature of the collagen soft tissue closure implant of the present invention is in the range of about 50 ° C to about 75 ° C.

Method for Using Collagen Soft Tissue Closure Implant Implant of an appropriate size for collagen soft tissue closure is inserted into the puncture site while gradually removing the introduction outer cylinder. The collagen implant is released to the puncture site and allowed to hydrate and self-expand for 5 minutes in situ. Subsequently, the dispersed transportation means is slowly pulled out. The wound is then closed completely by applying slight pressure to the wound for 5-10 minutes.

Method of Use for Closing a Soft Tissue Site An appropriately sized transport means is inserted through the puncture site into the target tissue. Subsequently, the collagen implant is pushed out of the tubular transport means to its tissue site by a piston while the transport means is slowly withdrawn. Collagen implants self-expand and fill the voids of soft tissue.

  The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Accordingly, all aspects are to be regarded as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description.

FIG. 1 is a cross-sectional view of the flexible tissue closure system of one embodiment of the present invention cut in the longitudinal direction. The soft tissue closure system includes an implant transport means and an implant disposed therein. FIG. 2 is a cross-sectional view illustrating the use of a system for delivering a resorbable implant at a percutaneous puncture site. FIG. 3 is a cross-sectional view showing a resorbable implant in place.

Claims (3)

a) producing an aqueous dispersion containing collagen;
b) pouring the aqueous dispersion into a mold,
c) freeze drying the aqueous dispersion to form a collagen matrix;
d) cross-linking the collagen matrix by treating with a cross-linking agent;
e) spraying the crosslinked collagen matrix with water vapor;
f) A method for producing a self-expanding resorbable collagen implant comprising compressing the steam treated collagen matrix.   The dispersion further comprises an agent comprising an antibody, a growth factor, thrombin, glycosaminoglycan, prostaglandin, type II-XIV collagen, glycoprotein, fibronectin, laminin, and mixtures thereof. 1 method.   The process of claim 1 wherein the cross-linking agent is formaldehyde.

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