Bioabsorbable encapsulating powder

Abstract

The present invention provides a bioabsorbable encapsulating powder, comprising: (a) a water-soluble electrophilic polymer having at least three reactive electrophilic groups capable of reacting with amine groups under the formation of covalent bonds; (b) a water-soluble nucleophilic crosslinker having at least two reactive nucleophilic groups capable of reacting in the presence of water with a reactive electrophilic group of the electrophilic polymer under formation of a covalent bond between the electrophilic polymer and the nucleophilic crosslinker; (c) water-absorbing particles comprising at least 50% by weight of the water-absorbing particles of a water-insoluble polymer comprising reactive nucleophilic groups; (d) a water-soluble dispersing agent that is solid at 20° C. and is selected from monosaccharides, disaccharides, oligosaccharides, sugar alcohols, and combinations thereof. Components (a), (b), (c) and (d) relate to a bioabsorbable encapsulating powder which may be contained in the same particle or in different particles. The present invention also provides a method for preparing the bioabsorbable encapsulating powder. Further provided are (i) an apparatus for applying a powder comprising a bioabsorbable sealant powder, (ii) a biocompatible, flexible hemostatic sheet comprising a bioabsorbable sealant powder, and (iii) a kit of parts for preparing a sealant suspension, the kit comprising a bioabsorbable powder, and (iv) a sealant suspension containing the bioabsorbable sealant powder.

Description

[Technical Field]

[0001] The present invention (a) A water-soluble electrophilic polymer having at least three reactive electrophilic groups that can react with an amine group under the formation of a covalent bond, (b) A water-soluble nucleophilic crosslinker having at least two reactive nucleophilic groups that can react with the reactive electrophilic groups of the electrophilic polymer in the presence of water, under the formation of a covalent bond between the electrophilic polymer and the nucleophilic crosslinker, (c) Water-absorbing particles comprising a water-insoluble polymer containing at least 50% by weight of a reactive nucleophilic group selected from amine groups and thiol groups, (d) A water-soluble dispersant that is solid at 20°C, and is selected from monosaccharides, disaccharides, oligosaccharides, sugar alcohols and combinations thereof, comprising: This invention relates to a bioabsorbable encapsulated powder in which components (a), (b), (c), and (d) may be contained in the same particle or in different particles.

[0002] When the sealing powder of the present invention is applied to moist tissue, the reactive components in the powder rapidly react in the form of a tissue-adhesive hydrogel that seals the underlying tissue. The adhesive hydrogel provides a sufficiently strong seal to give an effective seal against air leaks in the lungs. [Background technology]

[0003] Hemostasis is a highly regulated process that maintains blood flow through the vascular system while simultaneously involving a thrombotic response to tissue damage. Maintaining hemostasis requires complex interactions between the blood vessel walls, platelets, and the coagulation and fibrinolytic systems. Hemostasis has two main stages: primary (i.e., the cellular stage) and secondary (i.e., the fluid stage).

[0004] Primary hemostasis begins immediately after endothelial damage and is characterized by vasoconstriction, platelet adhesion, and the formation of soft aggregate plugs. After injury, transient local contraction of vascular smooth muscle occurs, slowing blood flow and promoting platelet adhesion and activation. Within 20 seconds of injury, circulating von Willebrand factor adheres to the subendothelial layer at the injury site and attaches to glycoproteins on the surface of platelets. Once attached to the injury surface, platelets are activated by contact with collagen-exposed receptors that bind to circulating fibrinogen. A soft plug of aggregated platelets and fibrinogen is formed. This stage of hemostasis is brief, and the soft plug can be easily sheared away from the injury surface.

[0005] The soft platelet plug is stabilized during secondary hemostasis to form a blood clot. Vasoconstriction and the resulting decrease in blood flow are maintained by platelet secretion of serotonin, prostaglandins, and thromboxanes while the coagulation cascade is initiated. The coagulation cascade is a series of dependent reactions involving several plasma proteins, calcium ions, and platelets, resulting in the conversion of fibrinogen to fibrin. Coagulation factors are produced by the liver and circulate in an inactive form until the coagulation cascade is initiated. Then, each step of the cascade is initiated and completed via a series of sequential and dependent coagulation factor activation reactions. In the final step, thrombin converts fibrinogen, a soluble plasma protein, to the insoluble protein fibrin, and simultaneously converts factor XIII to factor XIIIa. This factor conversion stabilizes fibrin, resulting in crosslinking of fibrin monomers and the formation of a stable blood clot.

[0006] During surgery, maintaining a delicate balance between bleeding and clotting is crucial to optimizing surgical success and patient outcomes, ensuring that blood continues to flow to the surgical site tissue without excessive loss. Persistent bleeding from diffusing capillaries or small veins during surgery can obscure the surgical field, prolong surgery time, increase the risk of physiological complications, and expose the patient to transfusion-related risks.

[0007] Surgeons have many options for controlling bleeding, including mechanical and thermal techniques and devices, as well as drug therapy and topical medications.

[0008] One of the earliest topical hemostatic agents was cotton in the form of gauze sponge. These materials concentrate blood and coagulation products through physical adsorption, but are not absorbed by the body. If removed, the blood clot may detach, potentially leading to further bleeding. Since then, absorbable topical hemostatic agents have been developed, providing useful adjunctive therapy when conventional hemostatic methods are ineffective or impractical. Topical hemostatic agents can be applied directly to the bleeding site and can prevent persistent, uncontrollable bleeding. Hemostasis using topical agents can also avoid the adverse effects of systemic hemostatic agents, such as "undesirable" blood coagulation. Furthermore, in surgical procedures where blood loss is unpredictable, topical hemostatic agents can be used in small amounts for minor blood loss and in larger amounts during severe bleeding.

[0009] Currently, there are many topical hemostatic agents for use in surgery. These topical hemostatic agents can be divided into two categories: those that exert their mechanisms of action on the coagulation cascade in a biologically active manner, and those that act passively through contact activation and promotion of platelet aggregation. Examples of passive topical hemostatic agents include collagen, cellulose, and gelatin, while examples of active agents include thrombin and products in which thrombin is combined with a passive agent to provide an active overall product.

[0010] U.S. Patent Application Publication No. 2003 / 0064109 describes a method that includes providing an aqueous solution containing gelatin combined with at least one rehydration aid, drying the solution to produce a solid, pulverizing the solid to produce a powder, crosslinking the powder, removing at least 50% (w / w) of the rehydration aid, and drying the crosslinked gelatin to produce a powder. The rehydration aid may include at least one material selected from the group consisting of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and dextran.

[0011] U.S. Patent Application Publication No. 2012 / 0021058 describes a process for making a hemostatic composition, which includes: a) providing a dry granular preparation of a biocompatible polymer; and b) coating the granules in the dry granular preparation with a preparation of a coagulation inducer such as a thrombin solution. The biocompatible polymer may be selected from gelatin, soluble collagen, albumin, hemoglobin, fibrinogen, fibrin, casein, fibronectin, elastin, keratin, laminin, and derivatives or combinations thereof.

[0012] U.S. Patent Application Publication No. 2013 / 0316974 describes a hemostatic material comprising a consolidated ORC powder containing particles having an average aspect ratio of about 1 to about 18. The hemostatic material may further include an additive selected from polysaccharides, calcium salts, anti-infective agents, hemostasis promoters, gelatin, and collagen.

[0013] U.S. Patent Application Publication No. 2016 / 0271228 describes a hemostatic composition, · a particulate form hemostatic biocompatible polymer selected from the group consisting of proteins, polysaccharides, biopolymers, non-biopolymers, and derivatives and combinations thereof, which exists as granular particles having a median diameter range of 50 to 700 μm, ·A hydrophilic crosslinking agent containing an electrophilic reactive group, wherein the electrophilic reactive group retains its reactivity until the composition is exposed to the patient's blood, and the electrophilic reactive group is configured to crosslink with blood proteins in the patient to form a gel having sealing and hemostatic properties, and the hydrophilic crosslinking agent, ·A binder that does not react with the electrophilic reactive group of one hydrophilic crosslinking agent, The hemostatic composition is described as being in paste form.

[0014] International Publication No. WO 2012 / 057628 describes a kit for producing a biocompatible crosslinked polymer, the kit comprising an electrophilic activated polyoxazoline (EL-POx), the EL-POx comprising m electrophilic groups, the nucleophilic crosslinking agent comprising n nucleophilic groups, the m electrophilic groups being capable of reacting with the n nucleophilic groups to form a covalent bond, m > 2, n > 2 and m + n > 5, and at least one of the m electrophilic groups being a pendant electrophilic group.

[0015] International Publication No. WO 2016 / 056901 describes an adhesive hemostatic product selected from a coated mesh, a coated foam, or a coated powder, the adhesive hemostatic product comprising: ·A porous solid substrate having an outer surface and comprising a nucleophilic polymer having a porosity of at least 5% by volume and containing reactive nucleophilic groups, ·An adhesive coating covering at least a portion of the solid substrate, the coating comprising an electrophilic activated polyoxazoline (EL-POX), the EL-POX comprising on average at least one reactive electrophilic group, and the adhesive coating.

[0016] U.S. Patent Application Publication No. US 2016 / 0375202 describes an apparatus for extruding a hemostatic powder, a) An elongated hollow reservoir having a manual air pump attached to the reservoir and an extrusion port at the distal end of the reservoir, and the reservoir, b) A porous filter slidably disposed within the reservoir between the air pump and the compression port, c) comprising a spring positioned in the reservoir between the air pump and the filter, The present invention describes an apparatus in which powder is placed in a reservoir between a filter and an extrusion port, and a pump is in fluid communication with the extrusion port via the porous filter and powder. [Overview of the project] [Means for solving the problem]

[0017] The inventors have developed a bioabsorbable sealing powder that can be conveniently used to control bleeding during surgery and / or to provide a protective seal.

[0018] The sealing powder of the present invention is (a) A water-soluble electrophilic polymer comprising at least 5% by weight, having at least 3 reactive electrophilic groups that can react with amine groups under the formation of covalent bonds, (b) A water-soluble nucleophilic crosslinking agent in an amount of 1 to 50% by weight, having at least two reactive nucleophilic groups that can react with the reactive electrophilic groups of the electrophilic polymer in the presence of water, forming a covalent bond between the electrophilic polymer and the nucleophilic crosslinking agent, (c) Absorbent particles comprising a water-insoluble polymer containing 1 to 60% by weight of absorbent particles, wherein at least 50% by weight of the absorbent particles contains reactive nucleophilic groups selected from amine groups, thiol groups, and combinations thereof, (d) A water-soluble dispersant comprising 10 to 75% by weight, which is solid at 20°C, and is selected from monosaccharides, disaccharides, oligosaccharides, sugar alcohols and combinations thereof, The combination of components (a), (b), (c), and (d) constitutes at least 60% by weight of the sealing powder. The sealing powder has a tap density in the range of 0.3 to 0.9 g / ml. At least 90% by weight of the powder has a diameter of less than 600 μm, and 10% by weight or less of the powder has a diameter of less than 10 μm. This invention relates to a bioabsorbable encapsulated powder in which components (a), (b), (c), and (d) may be contained in the same particle or in different particles.

[0019] The sealing powder of the present invention, when applied to moist tissue, rapidly forms a sealing portion in the form of a hydrogel that adheres to the tissue. The sealing powder can be suitably used to provide an effective sealing portion for, for example, air leaks in the lungs. In addition, the sealing powder has excellent hemostatic ability due to the fact that it can absorb large amounts of blood in the form of a strongly gelled blood clot that seals the bleeding site.

[0020] The sealing powder of the present invention can be easily distributed across tissue. If necessary, additional sealing powder can be applied to form an additional sealing layer that adheres to the underlying hydrogel layer.

[0021] While the inventors do not wish to be bound by theory, it is assumed that when a layer of hemostatic powder is applied to moist tissue, the water-soluble electrophilic polymer and water-soluble nucleophilic polymer will dissolve rapidly. The dissolved electrophilic polymer reacts with the reactive nucleophilic groups of the dissolved water-soluble nucleophilic polymer to form a hydrogel incorporating water-absorbing particles. These water-absorbing particles provide water absorption capacity due to their swelling ability. The dissolved electrophilic polymer also reacts with proteins in the tissue, thereby fixing the hydrogel to the tissue. Furthermore, the dissolved electrophilic polymer reacts with proteins in the blood, thereby forming a gelled blood clot.

[0022] The water-soluble dispersant in the sealing powder of the present invention ensures that the other components of the sealing powder are rapidly and uniformly dispersed when the sealing powder comes into contact with moisture. Furthermore, the inclusion of a water-soluble dispersant makes it possible to prepare a sealing powder composed of particles with a density high enough to allow for precise application of the powder to the tissue by an airflow, such as an airflow generated by a bellows.

[0023] Remarkably, after the sealing powder is applied to moist tissue, the gauze pad does not stick to the sealing powder after or during gelation, allowing for suitable compression with a moist gauze pad soaked in saline solution.

[0024] Another aspect of the present invention is a method for preparing the bioabsorbable encapsulating powder of the present invention, (a) A step of providing particles A containing an electrophilic polymer and a water-soluble dispersant, (b) A step of providing particles B comprising a nucleophilic crosslinking agent, water-absorbing particles, and a water-soluble dispersant, (c) The present invention relates to a method comprising the step of combining particle A and particle B.

[0025] A further aspect of the present invention is an apparatus for applying powder, A reservoir containing the bioabsorbable encapsulating powder of the present invention, A long, slender hollow tubular structure having a proximal end and a distal end, wherein the distal end has a powder outlet and the proximal end is connected to a reservoir, The present invention relates to an apparatus comprising a manual air pump, preferably a valve or bellows, disposed to generate an airflow that carries powder from a reservoir through an elongated hollow tubular structure to a powder outlet.

[0026] Another aspect of the present invention is a biocompatible and flexible hemostatic sheet, • A three-dimensional, interconnected interstitial space is included in this adhesive fibrous carrier structure, The present invention comprises a bioabsorbable encapsulating powder, The present invention relates to a hemostatic sheet in which sealing powder is distributed within the interstitial space and / or fixed on a fibrous carrier structure.

[0027] The present invention also provides a kit of parts for preparing a bioabsorbable encapsulated suspension, • A first container or compartment containing a biocompatible liquid, The present invention also relates to a kit comprising a second container or compartment containing the bioabsorbable encapsulating powder of the present invention.

[0028] Another aspect of the present invention is a bioabsorbable encapsulated suspension, • A biocompatible continuous liquid non-aqueous phase, The present invention relates to a bioabsorbable encapsulation suspension comprising a dispersed phase containing the bioabsorbable encapsulation powder of the present invention. [Modes for carrying out the invention]

[0029] Therefore, a first aspect of the present invention is a bioabsorbable encapsulating powder, (a) A water-soluble electrophilic polymer comprising at least 5% by weight, having at least 3 reactive electrophilic groups that can react with amine groups under the formation of covalent bonds, (b) A water-soluble nucleophilic crosslinking agent in an amount of 1 to 50% by weight, having at least two reactive nucleophilic groups that can react with the reactive electrophilic groups of the electrophilic polymer in the presence of water, forming a covalent bond between the electrophilic polymer and the nucleophilic crosslinking agent, (c) Absorbent particles comprising a water-insoluble polymer containing 1 to 60% by weight of absorbent particles, wherein at least 50% by weight of the absorbent particles contains reactive nucleophilic groups selected from amine groups, thiol groups, and combinations thereof, (d) A water-soluble dispersant comprising 10 to 75% by weight, which is solid at 20°C, and is selected from monosaccharides, disaccharides, oligosaccharides, sugar alcohols and combinations thereof, The combination of components (a), (b), (c), and (d) constitutes at least 60% by weight of the sealing powder. The sealing powder has a tap density in the range of 0.3 to 0.9 g / ml. At least 90% by weight of the powder has a diameter of less than 600 μm, and 10% by weight or less of the powder has a diameter of less than 10 μm. This invention relates to a bioabsorbable encapsulated powder in which components (a), (b), (c), and (d) may be contained in the same particle or in different particles.

[0030] As used herein, the term “bioabsorbable encapsulating powder” means that all components of the encapsulating powder are absorbed by the body. Some components of the encapsulating powder, particularly polymer components, are gradually broken down in the body before being absorbed.

[0031] As used herein, the term "water-soluble electrophilic polymer" refers to an electrophilic polymer having a solubility of at least 50 g / L in desalinated water at 20°C and pH 7. To determine the water solubility of nucleophilic polymers at different pH levels, the pH of the desalinated water is adjusted using hydrochloric acid.

[0032] As used herein, the term "polyoxazoline" refers to poly(N-acylalkyleneimine) or poly(aloylalkyleneimine), and is further referred to as POx. An example of POx is poly(2-ethyl-2-oxazoline). The term "polyoxazoline" also encompasses POx copolymers.

[0033] As used herein, the term "water-soluble nucleophilic crosslinking agent" refers to a nucleophilic crosslinking agent having a solubility of at least 50 g / L in desalinated water at 20°C and pH 7. To determine the water solubility of the nucleophilic crosslinking agent at different pH levels, the pH of the desalinated water is adjusted using hydrochloric acid.

[0034] As used herein, the term "protein" includes cross-linked and hydrolyzed proteins unless otherwise specified. Similarly, unless otherwise specified, when referring to a specific protein species such as gelatin or collagen, the hydrolyzed and cross-linked forms of that protein species are also included.

[0035] As used herein, the term “collagen” refers to the major structural protein in the extracellular space of various connective tissues in animal bodies. Collagen forms a characteristic triple helix of three polypeptide chains. Depending on the degree of mineralization, collagenous tissue can be either rigid (bone) or extensible (tendon), or it may have a gradient from rigid to extensible (cartilage). Unless otherwise specified, the term “collagen” also includes modified collagen other than gelatin (e.g., cross-linked collagen).

[0036] As used herein, the term “gelatin” refers to a mixture of peptides and proteins produced by the partial hydrolysis of collagen extracted from the skin, bones, and connective tissues of animals such as livestock, chickens, pigs, and fish. During hydrolysis, the natural molecular bonds between individual collagen chains are broken down into forms that are more readily rearranged. As used herein, the term “gelatin” also includes modified gelatins such as cross-linked gelatin and reduced cross-linked gelatin.

[0037] As used herein, the term "reduced cross-linked gelatin" refers to partially hydrolyzed cross-linked gelatin. Partial hydrolysis of peptide bonds in cross-linked gelatin can be carried out, for example, by alkaline treatment. Hydrolysis of cross-linked gelatin results in an increase in the density of free carboxyl groups and free amine groups.

[0038] As used herein, the term "gel foam" refers to a cross-linked gelatin material having a sponge-like structure, unless otherwise specified.

[0039] The term "water-insoluble polymer containing reactive nucleophilic groups" refers to polymers containing reactive nucleophilic groups that have a solubility of less than 5 g / L in desalinated water at 20°C and pH 7. To determine the water solubility of water-soluble polymers at different pH levels, the pH of the desalinated water is adjusted using hydrochloric acid.

[0040] As used herein, the term "hemostatic sheet" refers to a sheet having the ability to stop bleeding from damaged tissue unless otherwise specified. The hemostatic sheets of the present invention can achieve hemostasis by converting blood into a gel and / or by forming a sealing portion that closes the wound site.

[0041] As used herein in relation to fibrous carrier structures, the term "water-resistant" means that, under neutral pH conditions (pH 7) and a temperature of 37°C, the structure is not water-soluble and does not disintegrate in water to form a colloidal dispersion.

[0042] As used herein, the term “interstitial space” refers to the void ("empty") space within the fibrous carrier structure. The interstitial space within the fibrous carrier structure allows for the introduction of hemostatic powder into the structure. Blood and other bodily fluids can also enter the interstitial space, thereby allowing the hemostatic powder to exert its hemostatic effect and / or to provide tissue adhesion to the hemostatic sheet.

[0043] As used herein, the term "tap density" refers to the density obtained by carefully filling a graduated cylinder (250 mL, 37 mm inner diameter) with 250 mL of powder and then mechanically tapping the cylinder until no further volume reduction is observed. The tap density is calculated as the mass of the powder divided by its final volume.

[0044] As used herein, the term "particle" encompasses both particles consisting of a single homogeneous particle and aggregates of subparticles, unless otherwise specified. Aggregates can be prepared by granulation techniques known in the art, such as wet granulation.

[0045] As used herein, the term "liquid" means a liquid at a temperature of 20°C and a pressure of 1 atmosphere unless otherwise specified.

[0046] The diameter distribution of the sealing powder and its particle components can be suitably determined by laser diffraction using a Malvern Mastersizer 2000 in combination with a stainless steel sample dispersion unit. The sample dispersion unit is filled with approximately 120 ml of cyclohexane / diethyl ether (1:1 v / v), stabilized at a stirring speed of 1800 rpm for 5-10 minutes, and then a background measurement (blank measurement) is performed. The sample tube is shaken and rotated horizontally 20 times. Next, approximately 50 mg is dispersed in the sample dispersion unit containing cyclohexane. After introducing the sample into the dispersion unit, the sample is stirred at 1800 rpm for 1.5 minutes to ensure that all particles are properly dispersed before measurement. The dispersed particles are not subjected to sonication. The average particle size is D[4,3], and the volume-weighted average diameter (ΣniDi) is ΣniDi 4 ) / (ΣniDi 3 It is represented as ).

[0047] In addition to components (a), (b), (c), and (d), the sealing powder of the present invention may suitably contain one or more other components such as surfactants, buffers, and / or polysaccharides. Preferably, the combination of components (a), (b), (c), and (d) constitutes at least 80% by weight, most preferably at least 90% by weight, of the sealing powder.

[0048] The sealing powder preferably has a tap density in the range of 0.25 to 0.8 g / ml, more preferably 0.3 to 0.6 g / ml.

[0049] In another preferred embodiment, at least 90% by weight of the sealing powder has a diameter of less than 500 μm, and 10% by weight or less of the sealing powder has a diameter of less than 20 μm. More preferably, at least 90% by weight of the sealing powder has a diameter of less than 400 μm, and 10% by weight or less of the sealing powder has a diameter of less than 40 μm.

[0050] Preferably, at least 50% by weight of the sealing powder has a diameter in the range of 65 to 300 μm, more preferably in the range of 80 to 280 μm, and most preferably in the range of 100 to 200 μm.

[0051] The sealing powder has a volume-weighted average diameter (D[4,3]) preferably in the range of 65 to 300 μm, more preferably 80 to 250 μm, and most preferably 125 to 180 μm.

[0052] The water-soluble electrophilic polymer contained in the sealing powder of the present invention is preferably selected from electrophilic polyoxazoline, electrophilic polyethylene glycol, and combinations thereof.

[0053] Preferably, the sealing powder contains 10 to 50% by weight, more preferably 20 to 30% by weight, of a water-soluble electrophilic polymer.

[0054] The water-soluble electrophilic polymer preferably has a solubility of at least 100 g / L, more preferably at least 200 g / L, in desalted water at 20°C with a pH in the range of 3 to 7.

[0055] The water-soluble electrophilic polymer has a solubility of preferably less than 10 mg / L, more preferably less than 5 mg / L, and most preferably less than 1 mg / L in acetone at 20°C.

[0056] The water-soluble electrophilic polymer preferably has a molecular weight of at least 2 kDa. More preferably, the electrophilic polymer has a molecular weight of 5 to 200 kDa, most preferably 10 to 100 kDa.

[0057] The water-soluble electrophilic polymer and the water-soluble nucleophilic crosslinking agent are preferably combined in the encapsulation powder of the present invention, with minimal crosslinking reactions between the electrophilic polymers and minimal decomposition of the electrophilic polymers. Therefore, in a very preferred embodiment of the present invention, the water-soluble electrophilic polymer in the encapsulation powder has a polydispersity index (PDI) of less than 2.0, more preferably less than 1.8, and most preferably less than 1.5.

[0058] The water-soluble electrophilic polymer preferably contains at least 4 reactive electrophilic groups, more preferably at least 8 reactive electrophilic groups, even more preferably at least 16 reactive electrophilic groups, and most preferably at least 32 reactive electrophilic groups.

[0059] The water-soluble electrophilic polymer generally has, on average, at least 10, more preferably at least 20 reactive electrophilic groups.

[0060] According to a particularly preferred embodiment, the electrophilic polymer is an electrophilic polyoxazoline.

[0061] The electrophilic polyoxazoline is preferably derived from a polyoxazoline whose repeating unit is represented by the following formula (I). (CHR 1 ) m NCOR 2 In the formula, each of R 2 , and R 1 is independently selected from H, optionally substituted C 1~22 alkyl, optionally substituted cycloalkyl, optionally substituted aralkyl, and optionally substituted aryl, and m is 2 or 3.

[0062] Preferably, R 1 and R 2 in formula (I) are selected from H and C 1~8 alkyl, and even more preferably selected from H and C 1~4 alkyl. R 1 is most preferably H. The integer m in formula (I) is preferably equal to 2.

[0063] According to preferred embodiments, the polyoxazoline is a polymer of 2-alkyl-2-oxazoline, more preferably a homopolymer, where the 2-alkyl-2-oxazoline is selected from 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-butyl-2-oxazoline, and combinations thereof. Preferably, the polyoxazoline is a homopolymer of 2-propyl-2-oxazoline or 2-ethyl-oxazoline. Most preferably, the polyoxazoline is a homopolymer of 2-ethyl-oxazoline.

[0064] In a particularly preferred embodiment, the electrophilic polyoxazoline comprises at least 20 oxazoline units, more preferably at least 30 oxazoline units, and most preferably at least 80 oxazoline units.

[0065] Electrophilic polyoxazolines preferably contain at least 0.05 reactive electrophilic groups on average per oxazoline residue. More preferably, electrophilic polyoxazolines contain at least 0.1 reactive electrophilic groups on average per oxazoline residue. Most preferably, electrophilic polyoxazolines contain at least 0.12 to 0.5 reactive electrophilic groups on average per oxazoline residue.

[0066] Polyoxazolines may have reactive electrophilic groups in their side chains (pendant-reactive electrophilic groups), their terminals, or both. An advantage of the electrophilic polyoxazolines used in this invention is that they contain one or more pendant-reactive electrophilic groups.

[0067] Generally, electrophilic polyoxazolines contain 0.03 to 0.5 pendant-reactive electrophilic groups per monomer, more preferably 0.04 to 0.35 pendant-reactive electrophilic groups per monomer, and even more preferably 0.05 to 0.25 pendant-reactive electrophilic groups per monomer.

[0068] According to a preferred embodiment, the reactive electrophilic group of the electrophilic polyoxazoline is selected from carboxylic acid esters, sulfonic acid esters, phosphonic acid esters, pentafluorophenyl esters, p-nitrophenyl esters, p-nitrothiophenyl esters, acid halide groups, anhydrides, ketones, aldehydes, isocyanates, thioisocyanates, isocyanos, epoxides, activated hydroxyl groups, olefins, glycidyl ethers, carboxyls, succinimidyl esters, sulfosuccinimidyl esters, maleimide (maleimidyl), ethensulfonyl, imide esters, acetacetates, haloacetals, orthopyridyl disulfide, dihydroxyphenyl derivatives, vinyls, acrylates, acrylamides, iodoacetamides, and combinations thereof. More preferably, the reactive electrophilic group is selected from carboxylic acid esters, sulfonic acid esters, phosphonic acid esters, pentafluorophenyl esters, p-nitrophenyl esters, p-nitrothiophenyl esters, acid halide groups, anhydrides, ketones, aldehydes, isocyanates, thioisocyanates, isocyanos, epoxides, activated hydroxyl groups, glycidyl ethers, carboxyls, succinimidyl esters, sulfosuccinimidyl esters, imide esters, dihydroxyphenyl derivatives, and combinations thereof. Even more preferably, the reactive electrophilic group is selected from haloacetals, orthopyridyl disulfide, maleimide, vinyl sulfone, dihydroxyphenyl derivatives, vinyl, acrylate, acrylamide, iodoacetamide, succinimidyl ester, and combinations thereof. Most preferably, the reactive electrophilic group is selected from maleimide, vinyl, acrylate, acrylamide, succinimidyl ester, sulfosuccinimidyl ester, and combinations thereof.

[0069] Examples of succinimidyl esters that can be used include succinimidyl glutarate, succinimidylpropionate, succinimidylsuccinaamide, succinimidyl carbonate, disuccinimidyl sverate, bis(sulfosuccinimidyl)sverate, dithiobis(succinimidylpropionate), bis(2-succinimodoxycarbonyloxy)ethylsulfone, 3,3'-dithiobis(sulfosuccinimidyl-propionate), succinimidylcarbamate, and sulfosuccinimidyl Examples include zyl(4-iodoacetyl)aminobenzoate, bis(sulfosuccinimidyl)sverate, sulfosuccinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carboxylate, dithiobis-sulfosuccinimidylpropionate, disulfo-succinimidyl tartarate; bis[2-(sulfosuccinimidyloxycarbonyloxyethylsulfone)], ethylene glycol bis(sulfosuccinimicrylsuccinate), and dithiobis-(succinimidylpropionate).

[0070] Examples of dihydroxyphenyl derivatives that can be used include dihydroxyphenylalanine, 3,4-dihydroxyphenylalanine (DOPA), dopamine, 3,4-dihydroxyhydroccinamic acid (DOHA), norepinephrine, epinephrine, and catechol.

[0071] The water-soluble nucleophilic crosslinking agent used in the sealing powder of the present invention is preferably selected from nucleophilic polyoxazolines, nucleophilic polyethylene glycol, polyethyleneimines, proteins, and combinations thereof. More preferably, the nucleophilic crosslinking agent is selected from nucleophilic polyoxazolines, nucleophilic polyethylene glycol, and combinations thereof. Most preferably, the nucleophilic crosslinking agent is a nucleophilic polyoxazoline.

[0072] The water-soluble nucleophilic crosslinking agent preferably contains at least 3 reactive nucleophilic groups, more preferably at least 4 reactive nucleophilic groups, even more preferably at least 8 reactive nucleophilic groups, and most preferably at least 10 reactive nucleophilic groups. Most preferably, these reactive nucleophilic groups are amine groups, and most preferably primary amine groups.

[0073] According to one embodiment of the present invention, the water-soluble nucleophilic crosslinking agent is nucleophilic polyethylene glycol (PEG). Preferably, the nucleophilic PEG contains at least 3, more preferably at least 5, and most preferably 8 reactive nucleophilic groups.

[0074] In a particularly preferred embodiment, the nucleophilic crosslinking agent is a nucleophilic polyoxazoline. Preferably, the nucleophilic polyoxazoline contains at least 3, more preferably at least 5, and most preferably 8 to 20 reactive nucleophilic groups.

[0075] Preferably, the nucleophilic polyoxazoline contains at least 0.1 reactive nucleophilic groups on average per oxazoline residue. Most preferably, the nucleophilic polyoxazoline contains an average of 0.12 to 0.5 reactive nucleophilic groups per oxazoline residue.

[0076] Preferably, the sealing powder contains 1.5 to 35% by weight, more preferably 2 to 20% by weight, and most preferably 3 to 10% by weight of a water-soluble nucleophilic crosslinking agent.

[0077] The water-soluble nucleophilic crosslinking agent preferably has a solubility of at least 100 g / L, more preferably at least 200 g / L, in desalted water at pH 7 and 20°C.

[0078] The water-soluble nucleophilic crosslinking agent has a solubility of preferably less than 10 mg / L, more preferably less than 5 mg / L, and most preferably less than 1 mg / L in acetone at 20°C.

[0079] In a particularly preferred embodiment, the water-soluble nucleophilic crosslinking agent dissolves relatively slowly in water. When the water-soluble electrophilic polymer reacts with the water-soluble nucleophilic crosslinking agent at a relatively slow rate, the electrophilic polymer is thought to be able to react with the blood and proteins in the tissue at the bleeding site. By using a water-soluble nucleophilic crosslinking agent that dissolves relatively slowly, the dissolved electrophilic polymer has the potential to react (gradually) with the proteins in the blood and tissue as well as with the water-soluble nucleophilic crosslinking agent, thereby forming a strong and homogeneous sealing gel.

[0080] Water-soluble nucleophilic crosslinking agents having high molecular weights tend to dissolve relatively slowly in water. Therefore, in a very preferred embodiment, the water-soluble nucleophilic crosslinking agent has a molecular weight of at least 3 kDa, more preferably at least 10 kDa, and most preferably 20 to 3,000 kDa.

[0081] In the present invention, when a water-soluble electrophilic polymer releases an acidic substance when it reacts with a nucleophilic group, a water-soluble nucleophilic crosslinking agent that is soluble at an acidic pH can be suitably used. This applies, for example, when the electrophilic polymer contains an N-hydroxysuccinimide group.

[0082] According to a preferred embodiment, the water-soluble nucleophilic crosslinking agent has two or more amine groups, and the reactive electrophilic group of the water-soluble electrophilic polymer is selected from carboxylic acid esters, sulfonic acid esters, phosphonic acid esters, pentafluorophenyl esters, p-nitrophenyl esters, p-nitrothiophenyl esters, acid halide groups, anhydrides, ketones, aldehydes, isocyanates, thioisocyanates, isocyanos, epoxides, activated hydroxyl groups, glycidyl ethers, carboxyls, succinimidyl esters, sulfosuccinimidyl esters, imide esters, dihydroxyphenyl derivatives, and combinations thereof.

[0083] According to another preferred embodiment, the water-soluble nucleophilic crosslinking agent has two or more thiol groups, and the reactive electrophilic group of the water-soluble electrophilic polymer is selected from haloacetals, orthopyridyl disulfide, maleimide, vinyl sulfone, dihydroxyphenyl derivatives, vinyl, acrylate, acrylamide, iodoacetamide, succinimidyl ester, sulfosuccinimidyl ester, and combinations thereof. More preferably, the reactive electrophilic group is selected from succinimidyl ester, sulfosuccinimidyl ester, haloacetal, maleimide, or dihydroxyphenyl derivative, and combinations thereof. Most preferably, the reactive electrophilic group is selected from maleimide or dihydroxyphenyl derivative, and combinations thereof.

[0084] The combination of a water-soluble electrophilic polymer and a water-soluble nucleophilic crosslinking agent constitutes at least 20% by weight, more preferably 20-60% by weight, and most preferably 25-35% by weight of the encapsulation powder.

[0085] The ratio between the total number of reactive electrophilic groups provided by the water-soluble electrophilic polymer and the total number of reactive nucleophilic groups provided by the water-soluble nucleophilic crosslinking agent is preferably in the range of 1:0.05 to 1:0.4, more preferably in the range of 1:0.1 to 1:0.3, and most preferably in the range of 1:0.15 to 1:0.25.

[0086] The bioabsorbable encapsulating powder of the present invention contains water-absorbing particles, preferably containing 10-60% by weight, more preferably 12-40% by weight, and most preferably 15-30% by weight of a water-insoluble polymer containing reactive nucleophilic groups.

[0087] In a particularly preferred embodiment, the water-absorbing particles are water-resistant, meaning that these particles are not water-soluble and do not disintegrate in water to form a colloidal dispersion under neutral pH conditions (pH 7) and a temperature of 37°C. Gel foam particles can be suitably used as water-absorbing particles according to the present invention.

[0088] The water-absorbing particles contain, preferably at least 50% by weight, more preferably at least 70% by weight, of a water-insoluble polymer containing reactive nucleophilic groups selected from amine groups, thiol groups, and combinations thereof.

[0089] In a particularly preferred embodiment, the water-absorbing particles contain at least 10% by weight, more preferably at least 15% by weight, of a water-insoluble polymer containing reactive amine groups.

[0090] Water-insoluble polymers containing reactive nucleophilic groups preferably have a water solubility of less than 3 g / L, more preferably less than 2 g / L, in desalted water at pH 7 and 20°C.

[0091] Water-insoluble polymers containing reactive nucleophilic groups have a solubility in acetone at 20°C, preferably less than 10 mg / L, more preferably less than 5 mg / L, and most preferably less than 1 mg / L.

[0092] The water-insoluble polymer containing a reactive nucleophilic group contained in the water-absorbing particles is preferably selected from proteins, chitosan, and combinations thereof. Most preferably, the water-insoluble polymer containing the reactive nucleophilic group is a protein.

[0093] Chitosan is a biodegradable, non-toxic, complex carbohydrate derivative of chitin (poly-N-acetyl-D-glucosamine), a naturally occurring substance. Chitosan is a deacetylated form of chitin. The chitosan used according to the present invention preferably has a degree of deacetylation of more than 50%. The chitosan used according to the present invention preferably has a molecular weight of at least 5 kDa, more preferably 10 to 10,000 kDa.

[0094] Examples of proteins that can be used include gelatin, cross-linked gelatin, collagen, and combinations thereof. More preferably, the water-insoluble polymer containing reactive nucleophilic groups is cross-linked gelatin.

[0095] The cross-linked gelatin preferably has a molecular weight in the range of 30 to 3,000 kDa, more preferably in the range of 400 to 2,000 kDa, and most preferably in the range of 500 to 1,500 kDa.

[0096] The average primary amine content of cross-linked gelatin is preferably 5 × 10⁶ per 1 μg of reduced cross-linked gelatin. -4 ~2×10 -2 μmol, more preferably 1.0 × 10⁻⁶ -3 ~1.0×10 -2 It is a primary amine in the μmol range.

[0097] The water-absorbing particles used in the sealing powder of the present invention preferably have a volume-weighted average diameter (D[4,3]) in the range of at least 10 μm, more preferably in the range of 20 to 250 μm, and most preferably in the range of 25 to 180 μm.

[0098] The water absorption capacity of the absorbent particles is at least 0.2 grams of water per gram of absorbent particles, more preferably 0.5 to 3 grams of water per gram of absorbent particles, and most preferably 0.8 to 2 grams of water per gram of absorbent particles. The water absorption capacity can be suitably determined by gravimetric measurement.

[0099] The water-soluble dispersant contained in the sealing powder of the present invention is preferably selected from sucrose, trehalose, lactose, maltitol, mannitol, sorbitol, xylitol, cyclodextrin, maltodextrin, dextran, and combinations thereof, and more preferably the water-soluble dispersant is selected from sucrose, trehalose, mannitol, and combinations thereof.

[0100] The water-soluble dispersant preferably has a glass transition temperature of over 30°C, more preferably 50 to 200°C, and most preferably 75 to 95°C.

[0101] Preferably, the sealing powder contains 25-70% by weight, more preferably 30-65% by weight, and most preferably 40-60% by weight of a water-soluble dispersant.

[0102] In a preferred embodiment, the sealing powder contains particles comprising both components (a) and (d) in an amount of at least 30% by weight, more preferably at least 35% by weight, and most preferably at least 40% by weight.

[0103] According to another preferred embodiment, the sealing powder contains particles comprising both components (b) and (d) in an amount of at least 20% by weight, more preferably at least 30% by weight, and most preferably at least 40% by weight.

[0104] According to a particularly preferred embodiment, the sealing powder contains particles comprising both components (b), (c), and (d) in an amount of at least 20% by weight, more preferably at least 30% by weight, and most preferably at least 40% by weight.

[0105] The sealing powder of the present invention may consist of particles having the same composition, or it may be a mixture of different particles. Examples of mixtures of different particles include the following:

[0106] (a) A mixture of particles containing only components (a) and (d) (i) and particles containing only components (b), (c) and (d), (b) a mixture of (i) particles containing only components (a) and (d), (ii) particles containing only components (b) and (d), and (iii) particles containing only components (c) and (d).

[0107] Here, the term “only” is used to indicate that, in addition to the components mentioned, the particles do not contain any of the other components (a) to (d) of the sealing powder.

[0108] If the sealing powder consists of a mixture of different particles, the powder preferably comprises 30 to 70% by weight of particles containing only components (a) and (d), and 30 to 70% by weight of particles containing only components (b), (c), and (d). More preferably, the sealing powder comprises 40 to 60% by weight of particles containing only components (a) and (d), and 40 to 60% by weight of particles containing only components (b), (c), and (d).

[0109] Preferably, particles containing only components (a) and (d) and particles containing only components (b), (c), and (d) together constitute at least 60% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight of the sealing powder.

[0110] In a particularly preferred embodiment, the sealing powder of the present invention contains particles containing at least 60% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight of each of components (a), (b), (c), and (d). Such particles can be prepared, for example, by granulation of a mixture of the different particles described above.

[0111] According to another particularly preferred embodiment, the sealing powder contains particles containing at least 50% by weight, more preferably at least 70% by weight, and most preferably at least 80% by weight of each of components (a), (b), (c), and (d), in the form of aggregates of sub-particles A containing only components (a) and (d) and sub-particles B containing only components (b), (c), and (d). Preferably, the aggregates of sub-particles A and B contain 20 to 80% by weight of sub-particles A and 20 to 80% by weight of sub-particles B. More preferably, the aggregates of sub-particles A and B contain 40 to 60% by weight of sub-particles A and 40 to 60% by weight of sub-particles B.

[0112] Preferably, the particles of the sealing powder contain 0.05 to 5% by weight, more preferably 0.1 to 2% by weight, of a surfactant having a melting point of 30°C or higher.

[0113] In preferred embodiments, the surfactant is selected from block copolymer surfactants, polyoxyethylene stearate, sodium dodecyl sulfate, and combinations thereof, more preferably poloxamer, and most preferably poloxamer 188 or poloxamer 407.

[0114] In another preferred embodiment, the surfactant is contained in particles further containing components (b) and (d), more preferably in particles further containing components (b), (c) and (d), and most preferably in particles further containing components (a), (b), (c) and (d).

[0115] Another aspect of the present invention relates to a method for treating a wound or reducing bleeding at a site of bleeding, comprising topically administering the sealing powder according to the present invention to the wound or site of bleeding.

[0116] Preferably, in the therapeutic method of the present invention, the powder is 5 to 250 mg / cm³. 2 In amounts of 20-200 mg / cm³, more preferably 20-200 mg / cm³. 2 The amount is most preferably 50-125 mg / cm³. 2 It is administered locally in that amount.

[0117] The method of the present invention is particularly suitable for the local treatment of wounds selected from a) minor abrasions, cuts, scrapes, scratches, burns, sunburns, ulcers, internal and external venous bleeding, and b) gastrointestinal surgery, surgery of parenchymal organs; surgical interventions in the ear, nose and throat area (ENT), cardiovascular surgery, cosmetic surgery, spinal surgery, neurological surgery; fistulas of lymphatic vessels, bile ducts, and cerebrospinal fluid (CSF), surgery of the chest and lungs, respiratory surgery, orthopedic surgery; gynecological surgery; vascular surgery and emergency surgery, hepatectomy, and soft tissue injuries or wounds selected from surgery.

[0118] A further aspect of the present invention is a method for preparing the bioabsorbable encapsulating powder of the present invention, (a) A step of providing particles A comprising a water-soluble electrophilic polymer and a water-soluble dispersant, (b) A step of providing particles B comprising a water-soluble nucleophilic crosslinking agent, water-absorbing particles, and a water-soluble dispersant, (c) The present invention relates to a method comprising the step of combining particle A and particle B.

[0119] In the preparation method of the present invention, premature crosslinking reactions between a water-soluble electrophilic polymer and a water-insoluble polymer containing a reactive nucleophilic group are effectively avoided.

[0120] Particle A preferably contains 20-90% by weight of a water-soluble electrophilic polymer and 10-80% by weight of a water-soluble dispersant. More preferably, particle A contains 30-70% by weight of a water-soluble electrophilic polymer and 30-70% by weight of a water-soluble dispersant. Most preferably, it contains 40-60% by weight of a water-soluble electrophilic polymer and 40-60% by weight of a water-soluble dispersant.

[0121] The water-soluble electrophilic polymer and the water-soluble dispersant together preferably constitute at least 60% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight of particle A.

[0122] Particle A is preferably prepared by agglomerating particles of a water-soluble electrophilic polymer with particles of a water-soluble dispersant. Aggregation is preferably achieved by wet granulation.

[0123] Particle B preferably contains 5 to 20% by weight of a water-soluble nucleophilic crosslinking agent, 25 to 60% by weight of water-absorbing particles, and 30 to 70% by weight of a water-soluble dispersant. More preferably, particle B contains 6 to 18% by weight of a water-soluble nucleophilic crosslinking agent, 30 to 50% by weight of water-absorbing particles, and 35 to 65% by weight of a water-soluble dispersant. Most preferably, particle B contains 8 to 15% by weight of a water-soluble nucleophilic crosslinking agent, 35 to 45% by weight of water-absorbing particles, and 40 to 60% by weight of a water-soluble dispersant.

[0124] The water-soluble nucleophilic crosslinking agent, water-absorbing particles, water-absorbing particles, and water-soluble dispersant together constitute preferably at least 60% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight of particle B.

[0125] Particle B is preferably prepared by agglomerating particles of a water-soluble nucleophilic polymer, water-insoluble absorbent particles, and water-soluble dispersant particles. Aggregation is preferably achieved by wet granulation.

[0126] The combination of particles A and B is preferably achieved by simple mixing or granulation (to form aggregates).

[0127] When particles A and B are combined by simple mixing, particle A has a volume-weighted average diameter (D[4,3]) preferably in the range of 25 to 300 μm, more preferably in the range of 80 to 250 μm, and most preferably in the range of 125 to 180 μm. In the case of simple mixing, the volume-weighted average diameter (D[4,3]) of particle B is preferably in the range of 25 to 300 μm, more preferably in the range of 80 to 250 μm, and most preferably in the range of 125 to 180 μm.

[0128] Preferably, particles A and B are combined into an aggregate. In a particularly preferred embodiment, particles A and B are combined into an aggregate by wet granulation. More preferably, particles A and B are combined as an aggregate using a non-aqueous granulation solution containing at least 60% by weight of an organic solvent selected from acetone, isopropyl alcohol, ethanol, methanol, diethyl ether, heptane, hexane, pentane, cyclohexane, dichloromethane, and mixtures thereof. More preferably, the non-aqueous granulation solution contains at least 60% by weight, most preferably at least 85% by weight of an organic solvent selected from acetone, isopropyl alcohol, ethanol, and mixtures thereof. Even more preferably, the non-aqueous granulation solution contains at least 60% by weight, most preferably at least 85% by weight of acetone.

[0129] When particles A and B are combined by granulation, particle A has a volume-weighted average diameter (D[4,3]) preferably in the range of 10 to 200 μm, more preferably in the range of 20 to 150 μm, and most preferably in the range of 25 to 120 μm. In the case of granulation, the volume-weighted average diameter (D[4,3]) of particle B is preferably in the range of 10 to 200 μm, more preferably in the range of 20 to 150 μm, and most preferably in the range of 25 to 120 μm.

[0130] The non-aqueous granulation liquid preferably contains 1% by weight or less of water, more preferably 0.1% by weight or less of water.

[0131] The amount of non-aqueous granulation liquid used in this method to combine particles A and B is preferably in the range of 0.5 to 5% by weight of the total amount of particles A and B. More preferably, the amount of non-aqueous granulation liquid used is in the range of 1 to 4% by weight of the total amount of particles A and B, most preferably in the range of 1.5 to 3% by weight.

[0132] Another aspect of the present invention is an apparatus for applying powder, • A reservoir containing the bioabsorbable encapsulating powder according to the present invention, A long, slender hollow tubular structure having a proximal end and a distal end, wherein the distal end has a powder outlet and the proximal end is connected to a reservoir, The present invention relates to a device comprising: a reservoir-mounted manual air pump, which is arranged to generate an airflow that carries powder from the reservoir through an elongated hollow tubular structure to a powder outlet.

[0133] According to a preferred embodiment, the apparatus includes a porous filter placed in a reservoir between an air pump and a powder outlet, the powder being placed in the reservoir between the filter and the powder outlet, and the pump being in fluid communication with the powder outlet through the porous filter and the powder. The filter is preferably impermeable to the powder contained in the reservoir.

[0134] Preferably, the manual air pump is equipped with bellows.

[0135] An advantage of the sealing powder of the present invention is that it can be applied to a hemostatic sheet to improve its adhesion and hemostatic properties. Therefore, another aspect of the present invention is a biocompatible and flexible hemostatic sheet, • A three-dimensional, interconnected interstitial space is included in this adhesive fibrous carrier structure, • The bioabsorbable encapsulating powder according to the present invention, The present invention relates to a hemostatic sheet in which sealing powder is distributed within the interstitial space and / or fixed on a fibrous carrier structure.

[0136] The sealing powder can be suitably fixed onto a fibrous carrier structure by an adhesive containing a binder, preferably a meltable solid binder. Examples of such binders include polyester, polypropylene, acrylic, or polyethylene-based powders.

[0137] According to a preferred embodiment, the sealing powder is distributed within the interstitial space of the fibrous carrier.

[0138] The adhesive fibrous carrier structure of the hemostatic sheet is preferably water-resistant.

[0139] In a particularly preferred embodiment, the hemostatic sheet of the present invention is bioabsorbable. Reabsorption of the carrier structure and sealing powder generally requires the chemical decomposition (e.g., hydrolysis) of the polymers contained therein. Complete absorption of the hemostatic sheet by the human body is generally achieved in 1 to 10 weeks, preferably 2 to 8 weeks.

[0140] The hemostatic sheet of the present invention generally has an uncompressed average thickness of 0.5 to 25 mm. More preferably, the uncompressed average thickness is in the range of 1 to 10 mm, and most preferably in the range of 1.5 to 5 mm.

[0141] The dimensions of the hemostatic sheet are preferably such that the top and bottom surfaces of the sheet each have a width of at least 2 cm. 2 , more preferably at least 10 cm 2 Most preferably 25-50cm2 It is something that has a surface area of ​​[specified area]. Generally, the sheet is rectangular, with a length of 25 to 200 mm and a width of 25 to 200 mm.

[0142] The hemostatic sheet preferably contains 200 mg / cm³ 3 Less than 150 mg / cm³, more preferably 150 mg / cm³ 3 Less than 10-100 mg / cm³, most preferably 10-100 mg / cm³ 3 It has an incompressible density.

[0143] The hemostatic sheet of the present invention is preferably essentially anhydrous. Generally, the hemostatic sheet has a water content of 5% by weight or less, more preferably 2% by weight or less, and most preferably 1% by weight or less.

[0144] The water absorption capacity of the hemostatic sheet is preferably at least 50%, more preferably in the range of 100% to 800%, and most preferably in the range of 200% to 500%.

[0145] The hemostatic sheet of the present invention is preferably sterile.

[0146] The use of a fibrous carrier structure in the hemostatic sheet of the present invention offers the advantage of easily and uniformly distributing the sealing powder throughout the entire carrier structure. Such uniform distribution is far more difficult to achieve with, for example, a foamed carrier structure.

[0147] The fibers in the fibrous carrier structure preferably have an average diameter of 1 to 500 μm, more preferably 2 to 300 μm, and most preferably 5 to 200 μm. The average diameter of the fibers can be suitably determined using a microscope.

[0148] Generally, at least 50% by weight, more preferably at least 80% by weight, of the fibers in the fibrous carrier structure have a diameter of 1 to 300 μm and a length of at least 1 mm.

[0149] Preferably, at least 50% by weight, more preferably at least 80% by weight, of the fibers in the fibrous carrier structure have an aspect ratio (length to diameter ratio) of at least 1000.

[0150] The fibrous carrier structure used in accordance with the present invention is preferably a felt structure, a woven structure, or a knitted structure. Most preferably, the fibrous carrier structure is a felt structure. Here, the term "felt structure" refers to a structure manufactured by pressing fibers together to form an adhesive material.

[0151] The fibrous carrier structure preferably contains fibers comprising at least 50% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight of a fibrous polymer selected from gelatin, collagen, cellulose, modified cellulose, carboxymethyl dextran, poly(lactic-co-glycolic acid) (PLGA), sodium hyaluronate / carboxymethylcellulose, polyvinyl alcohol, chitosan, and combinations thereof.

[0152] In a particularly preferred embodiment, the fibrous carrier structure comprises fibers containing at least 50% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight of gelatin and / or modified cellulose. The gelatin used is preferably cross-linked gelatin. The modified cellulose used is preferably oxidized cellulose, and most preferably oxidized regenerated cellulose.

[0153] In another preferred embodiment, the fibrous carrier structure contains at least 50% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight of fibers, with at least 80% by weight of one or more of the above-mentioned fibrous polymers.

[0154] A preferred fibrous carrier structure has a flow rate of at least 0.1 L / min × cm 2, more preferably at least 0.5 L / min × cm 2 It has an open-hole structure with air permeability. Air permeability is determined according to EN ISO 9237:1995 (Textiles - Determination of the permeability of fabrics to air).

[0155] The fibers in the fibrous carrier structure can be produced by methods known in the art, such as electrospinning, electroblown spinning, and high-speed rotary spray spinning. The production of a fibrous carrier structure by high-speed rotary spray spinning is described in U.S. Patent Application Publication 2015 / 0010612. Commercially available hemostatic fibrous sheets can also be used as the fibrous carrier structure.

[0156] The sealing powder is present in the hemostatic sheet of the present invention in an amount of preferably 5 to 90% by weight, more preferably 10 to 80% by weight, even more preferably 20 to 75% by weight, and most preferably 50 to 70% by weight of the fibrous carrier structure.

[0157] A further aspect of the present invention is a kit of parts for preparing a bioabsorbable encapsulated suspension, • A first container or compartment containing a biocompatible liquid, The present invention also relates to a kit comprising a second container or compartment containing the bioabsorbable encapsulating powder of the present invention.

[0158] A bioabsorbable suspension can be prepared by mixing a biocompatible liquid with a sealing powder using the above-described kit. The suspension thus obtained can be effectively applied, for example, to fill and seal pleural cavities or hemorrhages.

[0159] The biocompatible liquid preferably contains one or more biocompatible liquids selected from polyethylene glycol, propylene glycol, triethyl citrate, polyglycerol, DMSO, glycerol, diacetin, triacetin, N-methylpyrrolidone (NMP), water, and mixtures thereof. The polyethylene glycol used in the suspension preferably has a molecular weight of 550 g / mol or less, more preferably 450 g / mol or less.

[0160] The biocompatible liquid in this kit may preferably contain water. The presence of water in the biocompatible liquid allows cross-linking reactions to occur between the components of the sealing powder before the sealing suspension is applied to tissue. These initial cross-linking reactions increase the viscosity and stickiness of the suspension, facilitating its application to tissue. The water content of the biocompatible liquid is preferably in the range of 1 to 50% by weight, more preferably not exceeding 2 to 30% by weight, and most preferably not exceeding 3 to 10% by weight.

[0161] The biocompatible liquid may preferably contain buffers and / or viscosity modifiers such as hyaluronic acid, alginates, carboxymethylcellulose, and combinations thereof.

[0162] Another aspect of the present invention is a bioabsorbable encapsulated suspension, - A biocompatible continuous liquid non-aqueous phase, -The present invention relates to a bioabsorbable encapsulation suspension comprising a dispersed phase containing a bioabsorbable encapsulation powder.

[0163] The non-aqueous phase of the encapsulated suspension preferably contains one or more biocompatible liquids selected from polyethylene glycol, propylene glycol, triethyl citrate, polyglycerol, DMSO, glycerol, diacetin, triacetin, N-methylpyrrolidone (NMP), and mixtures thereof. The polyethylene glycol used in the suspension preferably has a molecular weight of 550 g / mol or less, more preferably 450 g / mol or less.

[0164] The water content of the non-aqueous phase is preferably not more than 3% by weight, more preferably not more than 1% by weight, and most preferably not more than 0.3% by weight.

[0165] In addition to the sealing powder, the non-aqueous phase may suitably contain buffers and other components such as viscosity modifiers (e.g., hyaluronic acid, alginates, and / or carboxymethylcellulose).

[0166] The sealing suspension preferably contains 5 to 75% by weight, more preferably 10 to 40% by weight, and most preferably 15 to 30% by weight of sealing powder.

[0167] Because the particles of the sealed powder in the suspension may begin to settle or float over time, it may be necessary to shake or stir the suspension before use.

[0168] The present invention will be further explained by the following non-limiting embodiments. [Examples]

[0169] Generally, if the residual moisture content after drying (i.e., residual water in the dried powder, granules, and / or adhesive fibrous carrier structure) is not explicitly stated, its amount is less than 2.0 w / w%.

[0170] Preparation of NHS-POx An NHS-side-chain activated poly[2-(ethyl / hydroxy-ethyl-amide-ethyl / NHS-ester-ethyl-ester-ethyl-amide-ethyl)-2-oxazoline]terpolymer (=EL-POx, 20%NHS) containing 20% ​​NHS-ester groups was synthesized as follows. Poly[2-(ethyl / methoxycarbonylethyl)-2-oxazoline] copolymer (DP=+ / -100) was synthesized by CROP using 60% 2-ethyl-2-oxazoline (EtOx) and 40% 2-methoxycarbonylethyl-2-oxazoline (MestOx). A statistical copolymer containing 40% 2-methoxycarbonylethyl groups ( 1(H-NMR) was obtained.

[0171] Next, a polymer containing 40% 2-methoxycarbonylethyl groups was reacted with ethanolamine to obtain a copolymer having 40% 2-hydroxy-ethyl-amide-ethyl groups. 1 (H-NMR). Subsequently, when half of the 2-hydroxy-ethyl-amido-ethyl-group was reacted with succinic anhydride, 1 According to 1H-NMR, a terpolymer was obtained having 60% 2-ethyl groups, 20% 2-hydroxy-ethyl-amide-ethyl groups, and 20% 2-carboxy-ethyl-ester-ethyl-amide-ethyl groups.

[0172] Finally, the 2-carboxyethyl-ester-ethyl-amide-ethyl-group was activated with N-hydroxysuccinimide (NHS) and diisopropylcarbodiimide (DIC) to obtain EL-POx, corresponding to 100% NHS degree of functionalization (NHS-DF), and 20% NHS. 1 According to 1H-NMR, NHS-POx contained 20% NHS-ester groups.

[0173] NHS-POx was dissolved in water at 2-8°C (60g in 300mL), cooled at -80°C for 30 minutes, and then freeze-dried. The resulting freeze-dried powder was dried in a Rotavap at 40°C until the water content, as determined by Karl Fischer titration, was less than 0.8 w / w%. This dried (white) powder was ground using a ball mill (Retch MM400) until the average particle size was 40 μm (D[4,3]) or less, and then vacuum-sealed in an alu-alu bag.

[0174] Staining of NHS-POx powder 31.25 mg of Blue No. 1 dye (CAS 3844-45-9, SpectrumChem., VWR) was dissolved in 500 mL of cold ultrapure water using a high-performance disperser (Ultra-Turrax, IKA). After mixing (5 mins), 62.5 g of NHS-POx was dissolved in FD&C solution using a high-performance disperser (Ultra-Turrax, IKA). Immediately after mixing (5 mins), the solution was rapidly frozen and then freeze-dried. The freeze-dried powder was dried in a Rotavap at 40°C until the residual water content, as determined by Karl Fischer titration, was less than 0.8 w / w%. Next, the dried (blue) powder was ground using a ball mill (Retch MM400) to blue-stained NHS-POx powder with an average particle size (D[4,3]) of 40 μm or less, and vacuum-sealed in an alu-alu bag. The co-freeze-dried NHS-POx was then processed. 1 Analysis was performed using 1H-NMR spectroscopy. 15 mg of co-freezed powder was dissolved in deuterated dimethyl sulfoxide (DMSO-d6). The sample was transferred to an NMR tube. 1 1H-NMR spectra were recorded. From the obtained spectra, the amount of NHS bound to NHS-POx was calculated to be, on average, 90% to 100% NHS-DF.

[0175] Preparation of NU-POx Polyoxazolines having ethyl and amine groups in the alkyl side chains were synthesized by CROP of EtOx and MestOx and subsequent amidation of the methyl ester side chain with ethylenediamine to obtain poly(2-ethyl / aminoethylamidoethyl-2-oxazoline) copolymer (NU-POx).

[0176] NU-POx is, 1¹H-NMR revealed that it contained 10% NH2. NU-POx was dissolved in water at 2-8°C (60g in 300mL), cooled at -80°C for 30 minutes, and then freeze-dried. The resulting freeze-dried powder was dried in a Rotavap at 40°C until the water content, determined by Karl Fischer titration, was less than 0.8 w / w%. This dried powder was ground using a knife mill (Retsch GM200) until the average particle size was 100 μm (D[4,3]) or less, and then vacuum-sealed in an alu-alu bag.

[0177] Preparation of NHS-POx / sugar mixture by co-freeze-drying (Process A1) Co-freeze-dried NHS-POx / sugar powder was prepared as follows. 15 g of sugar was dissolved in 200 mL of cold ultrapure water using an Ultra-Turrax (IKA) high-performance dispersion apparatus. Next, after mixing (3 minutes), 15 g of blue-stained NHS-POx was dissolved in the sugar mixture using an Ultra-Turrax (IKA) high-performance dispersion apparatus. Immediately after mixing (3 minutes), the solution was frozen in liquid nitrogen and freeze-dried.

[0178] The freeze-dried powder was dried in a Rotavap at 40°C until the residual water content, as determined by Karl Fischer titration, was less than 0.8 w / w%. This dried powder was then ground in a knife mill until the particle size was 63 μm or less, and vacuum-sealed in an alu-alu bag.

[0179] Co-freeze-dried NHS-POx / sugar (1:1 w / w) 1 Analysis was performed using 1H-NMR spectroscopy. 15 mg of co-freeze-dried powder was dissolved in deuterated dimethyl sulfoxide (DMSO-d6). The sample was transferred to an NMR tube. 1 1H-NMR spectra were recorded. The NHS-DF, calculated from the obtained spectra, was found to be between 85% and 100% on average.

[0180] Preparation of NHS-POx / sugar granules (Process A2) NHS-POx / sugar granules were prepared as follows. 23 g of freeze-dried NHS-POx / sugar by process A1 was added to a mortar. Then, while mixing, 10 mL of acetone:water (95:5 v / v) was gradually added in 1 mL increments. The granules were dried in Rotavap at 40°C under reduced pressure for 1 hour and then ground in a knife mill for 10 seconds. The ground granules were then... 1 The material was dried again under reduced pressure until the acetone content, as determined by 1H-NMR and Karl Fischer titration, was less than 0.2% and the water content was less than 0.8%.

[0181] The dried granules were ground again until the particle size was within the desired range (see below), and then vacuum-sealed in an alu-alu bag.

[0182] NHS-POx / sugar granules (1:1 w / w) were analyzed using 1H-NMR spectroscopy. 25 mg of granules were dissolved in deuterated dimethyl sulfoxide (DMSO-d6) containing maleic acid (3 mg / mL) as an internal standard (1.0 mL), transferred to an NMR tube, and the 1H-NMR spectrum was recorded. The NHS-DF was calculated from the obtained spectrum and was found to be between 85% and 100% on average.

[0183] Preparation of NU-POx / gel foam / sugar granules (Process B1) 0.2 g of NU-POx, 0.8 g of gel foam (unless otherwise specified: GELITA-SPON powder, ex Gelita Medical AG, Germany), and 0.8 g of sugar were weighed and placed in a mortar. The excipients were granulated with 50 w / w% ultrapure water. The wet granules were dried in a 70°C oven until the water content, as determined by Karl Fischer titration, was less than 0.5%. The dried granules were ground to the desired particle size range (see below). The reactivity of the granules can be controlled by adjusting the pH to 9.5 with NaOH or to 9.2 with borate buffer before drying.

[0184] Preparation of NU-POx / gel foam / sugar / surfactant granules (Process B2) NU-POx / gel foam / sugar granules were prepared as described in process B1 by adding a surfactant dissolved in ultrapure water used for granulation, resulting in a final granule containing 0.10-0.50 w / w% surfactant in the NHS-POx / sugar and NU-POx / gel foam / sugar.

[0185] Preparation of NHS-POx sugar / NU-POx / gel foam / sugar / surfactant powder mixture (Process C1) The powder mixture was prepared as follows. NHS-POx sugar powder (process A2, desired particle size) and NU-POx / gel foam / sugar / surfactant granules (process B1 or B2, desired particle size) were added to a vial in a 1:1 weight ratio, mixed by shaking, and vacuum-sealed in an alu-alu bag.

[0186] Preparation of NHS-POx sugar / NU-POx / gel foam / sugar / surfactant powder mixture (Process C2) The powder mixture was prepared as follows. NHS-POx sugar powder (Process A1, particle size <63 μm) and NU-POx / gel foam / sugar / surfactant granules (Process B1 or B2, desired particle size) were added to a mortar in a 1:1 weight ratio, dried and mixed, and then vacuum-sealed in an alu-alu bag.

[0187] Preparation of NHS-POx sugar / NU-POx / gel foam / sugar / surfactant granules (process C3). The granules were prepared as follows: NHS-POx sugar granules (process A2, particle size <63 μm) and NU-POx / gel foam / sugar / surfactant granules (process B2, particle size <63 μm) were introduced into a mortar in a 1:1 weight ratio. Then, during grinding and mixing, 1 mL of acetone totaling 1 mL / g was added at a time.

[0188] The granules obtained in this way 1 The granules were dried under reduced pressure until the acetone content, as determined by 1H-NMR, was less than 0.2%. The dried granules were ground in a mortar and pestle until the particle size was 125-180 μm, and then vacuum-sealed in an alu-alu bag.

[0189] NHS-POX / sugar granules (1:1) were analyzed using 1H-NMR spectroscopy. 25 mg of granules were dissolved in deuterated dimethyl sulfoxide (DMSO-d6) containing maleic acid (3 mg / mL) as an internal standard (1.0 mL), transferred to an NMR tube, and the 1H-NMR spectrum was recorded. The NHS-DF was calculated from the obtained spectrum and averaged 85% to 100%.

[0190] Crushing and sieving Grinding was performed using either a mortar and pestle or a knife mill (Retsch GM 200). Sieving was performed to obtain fractions with the desired particle size and particle size distribution. For this purpose, a Retsch AS200 sieving tower was used with sieves of the following sizes: 45 μm, 63 μm, 90 μm, 125 μm, 180 μm, 250 μm, and 500 μm. The powder was ground and sieved to obtain the desired particle size. By sampling the desired sieved fractions, an appropriate powder particle size range was obtained.

[0191] Application of powder to areas of bleeding from punches, abrasions, and lung lesions. Punch bleeding site (using vial): Amount of powder contained in a closed vial with a diameter of 15 mm. The powder was applied by pouring it directly from the vial to the punch bleeding site. Once adequate coverage of the bleeding was achieved, pressure was applied with 0.9% NaCl moistened gauze for 1 minute, and the moistened gauze was carefully removed.

[0192] Abrasion (by bellows): A predetermined amount of powder was applied via a bellows applicator with an 80 mm long applicator tube. The powder was applied by puffing it directly onto the lesion (abrasion site), and the hemostatic effect was evaluated after 1 minute. If (complete) hemostatic coverage of the abrasion area was not achieved, further pressure was applied with 0.9% NaCl moistened gauze for 1 minute, and the moistened gauze was carefully removed.

[0193] Lung lesion: Powder was applied by hand to a 5 × 5 cm square area of ​​the lung surface surrounding the standardized defect. Once a uniform coating was achieved, pressure was applied with 0.9% NaCl-moistened gauze for 2 minutes. After 1 minute, the hand position was adjusted to prevent irregularities in the final hydrogel, and the moistened gauze was carefully removed.

[0194] Experiments on hemostasis and sealing Hemostatic effects were evaluated using standardized ex vivo and in vivo bleeding models. In all models, heparin was used to increase the blood clotting time to approximately 2–3 times the activated coagulation time (ACT).

[0195] Ex-vivo model: A living ex-vivo model with a fresh liver perfused with heparinized fresh blood from a slaughterhouse to reproduce actual in-vivo conditions as closely as possible. The liver is mounted in a perfusion machine that maintains oxygenation, blood pH, temperature, and blood pressure within the in-vivo range. Two livers and 10 liters of heparinized blood (5000 units / L) are collected at the slaughterhouse. The livers are transported on ice. The blood is allowed to reach ambient temperature. Within two hours of collection, the livers are inspected for lesions, gloved, and sealed with cyanoacrylate adhesive. • Perfusion parameters: Flow rate 600 ml / min, pressure 10-12 mmHg, temperature 37°C (+ / -1°C), carbogen 0.25 liters / min. Using a biopsy punch, a circular hemorrhagic wound (8 mm in diameter) is created on the liver surface using a rubber onlay, ensuring that the depth of the bleeding area from the punch is always 3 mm. Alternatively, a scratch lesion (3 x 3 cm) is created using sandpaper (approximately 1 mm thick). After the liver has been properly perfused (check color and temperature), test the sample according to the following procedure: Activate the camera. Determine the site number using the camera. Use an 8mm biopsy punch. Cut out the biopsy. Remove blood from the bleeding site with gauze (twice). Collect blood for 30 seconds with gauze that has been weighed beforehand. Score the bleeding site. Apply hemostatic powder to the bleeding site (punch or abrasion). In the case of punch bleeding, use a damp gauze (with saline solution) to distribute the powder and apply pressure for 1 minute. Observe the sealing and hemostasis status and evaluate it with a score.

[0196] In vivo model: Standardized compound penetrating splenic rupture was administered to anesthetized pigs (domestic pigs, male, weight range: 40kg-100kg adult). Midline laparotomy was performed to access the spleen and other organs. Using a surgical scalpel, n=3 standardized subcapsular lesions (10mm x 10mm) were created. Hemostatic powder was applied with gentle pressure using pre-moistened gauze (saline solution), held for 1 minute, and then the sealing and hemostasis status was scored.

[0197] Sealing experiment Using a standardized exvivovuda lung ventilation model, we evaluated sealing performance in the absence of blood, more specifically, aerostatic effectiveness.

[0198] Ex vivo model: Freshly collected pig cardiopulmonary specimens were ordered from the slaughterhouse and transported to the research facility on ice. After removing all excess tissue, ligating the main pulmonary artery, and suturing the remaining left atrial portion, the caudal lobes were selectively intubated and ventilated using manual inflation and manual recruitment techniques, following alveolar recruitment.

[0199] In the experimental setup, the lungs were suspended in 0.9% NaCl (37°C), and visual leakage assessment was performed by imaging from below. The measurement protocol was followed during each measurement, with the plateau ventilation pressure (Pplat) being increased. The ventilator settings were pressure-controlled ventilation, respiratory rate 12 / min, inspiration-to-expiration ratio 1:2, positive end-expiratory pressure (PEEP) 5cmH2O, and pressure above PEEP 5cmH2O. Every 90 seconds, the pressure above PEEP was increased by 5cmH2O until the Pplat reached 40cmH2O. First, baseline measurements were performed using this measurement protocol in order to measure compliance. Next, with the lung inflated with 10 cmH2O PEEP, the pleural margin was cut at a 45° angle using a sanding wheel attachment on a Dremel, and then the central pleura was carefully peeled away using forceps and scissors to create a standardized 25 × 25 mm superficial pleural defect on the dorsal surface of the caudal lobe. Baseline leakage measurements were then performed using the same protocol. Next, with the lung inflated at a PEEP of 0-5 cmH2O, the sealing powder was applied by hand to a 5 x 5 cm square area of ​​the lung surface surrounding the standardized defect (if air leaked through the dry powder, the PEEP was reduced until this was resolved). Once a uniform coating was achieved, pressure was applied with a 0.9% NaCl-moistened gauze for 2 minutes, and after 1 minute, the hand position was adjusted to prevent irregularities in the final hydrogel. After carefully removing the gauze, the hydrogel was cured for a further 5 minutes in a measuring device (0.9% NaCl, 37°C). Quantitative leakage (Pplat) was measured, and the failure mode was visually evaluated based on Macchiarini et al. (Macchiarini P, Wain J, Almy S, Dartevelle P. Experimental and clinical evaluation of a new synthetic, absorbable sealant to reduce air leaks in thoracic operations. J Thorac Cardiovasc Surg. 1999;117(4):751-8).

[0200] Powder sealing score evaluation system for bleeding (based on evaluation of adhesion and aggregation 1 minute after application): +++Extremely strong seal (The seal will only break if more than 80% by weight of powder is scraped off) ++Strong seal (the seal breaks when some of the powder is scraped off) +Good sealing (the seal breaks when the powder is mechanically handled) + / - Moderate sealing (the seal breaks when the surrounding tissue is manipulated) - Sealing is not achieved

[0201] Powder hemostatic score evaluation system for bleeding 1 minute after application: +++Very strong hemostasis (the powder is filled with blood only at the powder-lesion interface; bleeding has stopped) ++Strong hemostasis (The powder is partially filled with blood. A layer of powder without blood is present on top; bleeding has stopped) +Good hemostasis (the powder is completely filled with blood; bleeding has stopped) + / - Moderate hemostasis (the powder is completely filled with blood, and some blood passes through) - Hemostasis is not achieved (bleeding has not stopped)

[0202] The powder wetting score for bleeding is measured by applying gauze soaked in physiological saline (0.9% NaCl) for 1 minute, then removing it (wetting is scored by measuring the penetration depth into the powder layer 4 minutes after removing the gauze). - The saline solution is not easily absorbed by the powder layer, and only the surface of the powder layer remains wet, causing droplets of saline solution to easily roll off the powder surface. + / - saline solution partially permeated the powder layer. +The saline solution completely permeated the powder layer.

[0203] Comparative example A EL-POx was dry-mixed by co-grinding (using a mortar and pestle) with either gel foam alone (EL-POx:gel foam = 1:0.8 w / w) or gel foam and NU-POx (EL-POx:gel foam:Nu-POx = 1:0.8:0.2 w / w). The tap density of both powders was less than 0.2 g / mL.

[0204] The sealing and hemostatic properties of these two powders and two commercially available hemostatic powders were tested on exvivo porcine liver (heparinized). Each powder was applied in 1-gram quantities.

[0205] The test results are summarized in Table 1.

[0206] [Table 1] 1 GELITA-SPON® powder, Gelita Medical AG, Germany 2 Arista AH, Bard, USA

[0207] Example 2 A powder mixture (powder mixture 1) was prepared by process C2 using the powder obtained by process A1 (EL-POX:sugar = 1:1 w / w) and the powder obtained by process B1. Trehalose was used as the sugar component in both powders. A powder mixture (powder mixture 2) of the same composition was prepared by process C1 using the powder obtained by process A2 (EL-POX:sugar = 1:1 w / w, granulated using acetone / water (95:5) as the granulation solution) and the powder obtained by process B1.

[0208] The sealing and hemostatic properties of these two sealing powders were tested on ex vivo porcine liver (heparinized). Each powder was applied in 0.5-gram quantities.

[0209] The test results are summarized in Table 2.

[0210] [Table 2]

[0211] Example 3 Using the powder obtained by process A2 (EL-POX:sugar = 1:1 w / w) and three different powders obtained by process B1, three different powder mixtures were prepared by process C1. Trehalose was used as the sugar component in all powders.

[0212] The three powder mixtures differed only in that the powder obtained by process B1 contained different amounts of NU-POx.

[0213] [Table 3]

[0214] The sealing and hemostatic properties of these two sealing powders were tested on ex vivo porcine liver (heparinized). Each powder was applied in 0.5-gram quantities.

[0215] The test results are summarized in Table 3.

[0216] [Table 4]

[0217] Example 4 Two different powders were prepared by mixing 1 part by weight of NHS-POx powder (sugar-free) with either 2 parts by weight of trehalose-containing powder obtained by process B1, or 1 part by weight of sugar-free powder obtained by process B1.

[0218] The composition of the powder obtained by process B1 was as follows:

[0219] [Table 5]

[0220] The sealing and hemostatic properties of these two sealing powders were tested on exvivo porcine liver (heparinized). The powders were applied in 0.5-gram quantities using a bellows applicator (Surgicel®).

[0221] The test results are summarized in Table 4.

[0222] [Table 6]

[0223] Powder mixture 1 could be easily applied using a bellows applicator. However, powder mixture 2 was difficult to apply because the powder particles were very fluffy. To allow for comparability of sealing, hemostasis, and wetting properties, powder mixture 2 was applied in a tube in this experiment.

[0224] Example 5 Using the powder obtained by process A2 (EL-POX:sugar = 1:1 w / w) and five different powders obtained by process B1, five different powder mixtures were prepared by process C1. Trehalose was used as the sugar component in all of the powders.

[0225] The five different powder mixtures differed only in that the powder obtained by process B1 contained different amounts of trehalose.

[0226] [Table 7]

[0227] The sealing and hemostatic properties of these two sealing powders were tested on ex vivo porcine liver (heparinized). The powder was applied in 0.5 g amounts using a bellows applicator.

[0228] The test results are summarized in Table 5.

[0229] [Table 8]

[0230] Powder mixtures 1, 3, 4, and 5 could be easily applied with a bellows applicator. Powder mixture 2 was not as easy to apply because the particles were very fluffy.

[0231] Example 6 Three different powder mixtures were prepared by Process C1 using the powder obtained by Process A2 (EL-POX:sugar = 1:1 w / w) and three different powders obtained by Process B1. The three different powders obtained by Process B1 differed only in the type of sugar used. In all cases, NU-POx, gel foam, and sugar were present in the powder from Process B in a weight ratio of 2:8:8.

[0232]

Table 9

[0233] The sealing and hemostatic properties of these two sealing powders were tested in an ex vivo porcine liver system (heparinized). The powder was applied in an amount of 0.5 grams.

[0234] The test results are summarized in Table 6.

[0235]

Table 10

[0236] Example 7 Four different powder mixtures were prepared by Process C1 using the powder obtained by Process A2 (EL-POX:sugar = 1:1 w / w), one powder obtained by Process B1, and three different powders obtained by Process B2. The three different powders obtained by Process B2 differed in the amount of surfactant (Pluronic F-127) used. In all powders, trehalose was applied as the sugar component.

[0237]

Table 11

[0238] The sealing and hemostatic properties of these two sealing powders were tested in an ex vivo porcine liver system (heparinized). The powder was applied in an amount of 0.5 grams.

[0239] Summarize the test results in Table 7.

[0240]

Table 12

[0241] Example 8 In this example, Example 7 was repeated except that sodium dodecyl sulfate (SDS) was used as the surfactant.

[0242]

Table 13

[0243] The sealing and hemostatic properties of these two sealing powders were tested in an ex vivo porcine liver system (heparinized). The powders were applied in an amount of 0.5 grams.

[0244] Summarize the test results in Table 8.

[0245]

Table 14

[0246] Example 9 In this example, Example 7 was repeated except that poloxamer P-188 was used as the surfactant.

[0247]

Table 15

[0248] The sealing and hemostatic properties of these two sealing powders were tested in an ex vivo porcine liver system (heparinized). The powders were applied in an amount of 0.5 grams.

[0249] Summarize the test results in Table 9.

[0250] [Table 16]

[0251] Example 10 Using one powder (EL-POX:sugar = 1:1 w / w) obtained by process A2 and three different powders obtained by process B1, three different powder mixtures were prepared by process C1. The three powders obtained by process B2 differed in that they contained different types of gel foam.

[0252] [Table 17] 1 Gelita Medical AG, Germany 2 Mascia Brunelli Spa, Italy 3 Aegis Lifesciences PVT Ltd, India

[0253] The sealing and hemostatic properties of these sealing powders were tested on ex vivo porcine liver (heparinized). Each powder was applied in an amount of 1.0 gram.

[0254] The test results are summarized in Table 10.

[0255] [Table 18]

[0256] Example 11 Using the powder obtained by process A2 (EL-POX:sugar = 1:1 w / w) and the powder obtained by process B1, different powder mixtures were prepared by process C1. Trehalose was added as the sugar component to all powders. The particle size of each powder was varied as shown in Table 11.

[0257] The sealing and hemostatic properties of these sealing powders were tested on ex vivo porcine liver (heparinized). 0.5 grams of powder was applied.

[0258] The test results are summarized in Table 11.

[0259] [Table 19]

[0260] Example 12 Using the powder obtained by process A1 or A2 (EL-POX:sugar = 1:1 w / w) and the powder obtained by process B2, different powder mixtures were prepared by powder mixing process C1 or C2, or by granulation process C3.

[0261] [Table 20]

[0262] Trehalose was added as a sugar component to all of the powders.

[0263] The sealing and hemostatic properties of these two sealing powders were tested on ex vivo porcine liver (heparinized). Each powder was applied in 0.5-gram quantities.

[0264] The test results are summarized in Table 12.

[0265] [Table 21]

[0266] Example 13 In vivo tests were conducted on heparinized pig spleen using a powder mixture (0.5 g) prepared by process C1, using powders obtained by process A2 (EL-POX:sugar = 1:1 w / w) and process B1. Trehalose was applied as the sugar component in all powders. The only difference between the powders was their particle size. The test results are summarized in Table 13.

[0267] [Table 22]

[0268] Example 14 The performance of the powder mixture in Example 12 was also evaluated using an in vivo spleen test (heparinization) with 0.5 grams of the powder mixture. The results are shown in Table 14.

[0269] [Table 23]

[0270] Example 15 Ex vivo studies were performed on heparinized pig livers with abrasion lesions (3 × 3 cm). The encapsulated powders (1 gram) used were prepared by either dry mixing process C1 (powder mixture 1) or granulation process C3 (granules 2). In both cases, powders obtained by process A2 and powders obtained by process B2 were used. The powders were administered using a bellows applicator. Trehalose was added as a sugar component to all powders.

[0271] The test results are summarized in Table 15.

[0272] [Table 24]

[0273] Example 16 The sealing properties of the sealing powder in the absence of blood were evaluated using the ex vivo ventilated lung model described above in this specification. The pressure at which leakage began after application of the sealing powder was recorded.

[0274] Each tested encapsulating powder was obtained by dry mixing (process C1) or granulation (process C3) of NHS-POx-containing powder and NU-POx-containing powder. The NHS-POx-containing powder consisted of NHS-POx or granules of NHS-POx and trehalose obtained by process A2. The NU-POx-containing powder further contained gel foam and trehalose and was obtained as granules by process B1 or B2.

[0275] The results of each test are summarized in Table 16.

[0276] [Table 25] 1 Pluronic F-177

[0277] Example 17 Granules were prepared using the powder obtained by process A2 (EL-POX:trehalose = 1:1 w / w) and the powder obtained by process B2 (particles containing NU-POx) by granulation process C3, except that in each case the gel foam in the latter powder was replaced with another water-insoluble polymer containing the reactive nucleophilic group shown below.

[0278] [Table 26] 1 ex Sigma Aldrich, MW 100,000-300,000, 85% deacetylation. 2. Prepared according to the procedure described in International Publication No. 2021 / 009014 (page 29, lines 3-14).

[0279] The sealing and hemostatic properties of these two sealing powders were tested on exvivo porcine liver (heparinized). Each granule was applied in a 0.5 g dose. Two tests were performed. The test results are summarized in Table 17.

[0280] [Table 27]

[0281] Comparative example B Granules were prepared by granulation process C3 using the powder obtained by process A2 (EL-POX:trehalose = 1:1 w / w) and the powder obtained by process B2 (particles containing NU-POx), except that in this case the gel foam was replaced with oxidative-absorbing cellulose (GeltaCel®, manufactured by Gelita Medical GmbH).

[0282] The sealing and hemostatic properties of the granules were tested using the exvivobuta liver system (heparinized). A 0.5-gram dose of granules was applied. Two tests were conducted. The test results are summarized in Table 18.

[0283] [Table 28]

[0284] Example 18 Granules were prepared by granulation process C3 using the powder obtained by process A2 (EL-POX:sugar = 1:1 w / w) and the powder obtained by process B2 (particles containing NU-POx), except that in this case, trehalose in the first powder was replaced with mannitol.

[0285] The sealing and hemostatic properties of the granules were tested using the exvivobuta liver system (heparinized). A 0.5-gram dose of granules was applied. Two tests were conducted. The test results are summarized in Table 19.

[0286] [Table 29]

[0287] Example 19 Granules were prepared using the powder obtained by process A2 (EL-POX:sugar = 1:1 w / w) and the powder obtained by process B2, with the exception that in the latter powder, 8-arm polyethylene glycol with 8 amine groups (8-arm PEG-NH@ex Creative PEGWorks) was used instead of NU-POx.

[0288] The sealing and hemostatic properties of the granules were tested using the exvivobuta liver system (heparinized). A 0.5-gram dose of granules was applied. Two different tests were conducted. The test results are summarized in Table 20.

[0289] [Table 30]

[0290] [Implementation Method] (1) A bioabsorbable encapsulating powder, (a) A water-soluble electrophilic polymer comprising at least 5% by weight, having at least 3 reactive electrophilic groups that can react with amine groups under the formation of covalent bonds, (b) A water-soluble nucleophilic crosslinking agent in an amount of 1 to 50% by weight, having at least two reactive nucleophilic groups that can react with the reactive electrophilic groups of the electrophilic polymer in the presence of water, forming a covalent bond between the electrophilic polymer and the nucleophilic crosslinking agent, (c) Absorbent particles comprising 1 to 60% by weight of water-absorbing particles, and at least 50% by weight of a water-insoluble polymer containing reactive nucleophilic groups selected from amine groups, thiol groups, and combinations thereof, calculated by the weight of the absorbent particles, (d) A water-soluble dispersant comprising 10 to 75% by weight, which is solid at 20°C, and is selected from monosaccharides, disaccharides, oligosaccharides, sugar alcohols and combinations thereof, The combination of components (a), (b), (c), and (d) constitutes at least 60% by weight of the sealing powder. The sealing powder has a tap density in the range of 0.3 to 0.9 g / ml. At least 90% by weight of the powder has a diameter of less than 600 μm, and 10% by weight or less of the powder has a diameter of less than 10 μm. A bioabsorbable encapsulated powder in which components (a), (b), (c), and (d) may be contained in the same particle or in different particles. (2) The powder according to Embodiment 1, wherein the electrophilic polymer is selected from electrophilic polyoxazoline, electrophilic polyethylene glycol, and combinations thereof. (3) The powder according to Embodiment 1 or 2, wherein the nucleophilic crosslinking agent is selected from nucleophilic polyoxazoline, nucleophilic polyethylene glycol, polyethyleneimine, and combinations thereof. (4) The powder according to any one of Embodiments 1 to 3, wherein the water-insoluble polymer containing a reactive nucleophilic group is selected from proteins, chitosan, and combinations thereof. (5) The powder according to any one of Embodiments 1 to 4, wherein the ratio of the total number of reactive electrophilic groups provided by the electrophilic polymer to the total number of reactive nucleophilic groups provided by the nucleophilic crosslinking agent is in the range of 1:0.05 to 1:0.4.

[0291] (6) The powder according to any one of Embodiments 1 to 5, wherein the powder comprises 20 to 80% by weight of particles containing only components (a) and (d), and 20 to 80% by weight of particles containing only components (b), (c), and (d). (7) The powder according to Embodiment 6, wherein the particles containing only components (a) and (d) and the particles containing only components (b), (c), and (d) together constitute at least 60% by weight of the sealing powder. (8) The powder according to any one of Embodiments 1 to 5, wherein the powder contains at least 60% by weight of particles containing each of components (a), (b), (c), and (d). (9) The powder according to Embodiment 8, wherein the powder contains at least 50% by weight of the particles containing each of the components (a), (b), (c), and (d) in the form of aggregates of subparticles A containing only components (a) and (d) and subparticles B containing only components (a), (c), and (d). (10) A method for preparing a bioabsorbable encapsulating powder according to any one of Embodiments 1 to 9, (a) A step of providing particles A containing the electrophilic polymer and the water-soluble dispersant, (b) A step of providing particles B comprising the nucleophilic crosslinking agent, the water-absorbing particles, and the water-soluble dispersant, (c) A method comprising the step of combining particle A and particle B.

[0292] (11) The method according to embodiment 10, wherein the particle A and the particle B are combined to form an aggregate. (12) Apparatus for applying sealing powder, A reservoir containing the bioabsorbable encapsulating powder described in any of Embodiments 1 to 9, A long, slender hollow tubular structure having a proximal end and a distal end, wherein the distal end has a powder outlet and the proximal end is connected to the reservoir, The apparatus comprises: a manual air pump disposed to generate an airflow from the reservoir through the elongated hollow tubular structure to carry the powder through the powder outlet. (13) A biocompatible and flexible hemostatic sheet, • A three-dimensional, interconnected interstitial space is included in this adhesive fibrous carrier structure, The system comprises a bioabsorbable encapsulating powder as described in any of Embodiments 1 to 9, A hemostatic sheet in which the sealing powder is distributed within the interstitial space and / or fixed on the fibrous carrier structure. (14) A parts kit for preparing a bioabsorbable encapsulated suspension, • A first container or compartment containing a biocompatible liquid, A parts kit comprising: a second container or compartment containing a bioabsorbable encapsulating powder as described in any of Embodiments 1 to 9. (15) A bioabsorbable encapsulated suspension, • A biocompatible continuous liquid non-aqueous phase, A bioabsorbable encapsulation suspension comprising a dispersed phase containing a bioabsorbable encapsulation powder according to any one of embodiments 1 to 9.

Claims

1. A bioabsorbable encapsulating powder, (a) A water-soluble electrophilic polyoxazoline comprising at least 5% by weight, having at least 3 N-hydroxysuccinimide ester groups that can react with an amine group under the formation of a covalent bond, (b) A water-soluble nucleophilic polyoxazoline in an amount of 1 to 50% by weight, wherein the water-soluble nucleophilic polyoxazoline has at least two amine groups that can react with the N-hydroxysuccinimide ester group of the electrophilic polyoxazoline in the presence of water, in the event of covalent bond formation between the electrophilic polyoxazoline and the nucleophilic polyoxazoline, (c) Absorbent particles comprising 1 to 60% by weight of water-absorbing particles, and at least 50% by weight of gelatin containing reactive nucleophilic groups selected from amine groups, thiol groups, and combinations thereof, calculated by the weight of the water-absorbing particles, (d) A water-soluble dispersant comprising 10 to 75% by weight, which is solid at 20°C, and is selected from monosaccharides, disaccharides, oligosaccharides, sugar alcohols and combinations thereof, The combination of components (a), (b), (c), and (d) constitutes at least 60% by weight of the bioabsorbable encapsulating powder. The bioabsorbable encapsulating powder has a tap density in the range of 0.3 to 0.9 g / ml. The bioabsorbable encapsulating powder comprises 20 to 80% by weight of particles A containing only components (a) and (d), and 20 to 80% by weight of particles B containing only components (b), (c), and (d), The weight ratio of component (b) to component (c) in particle B is 0.25 or greater. The weight ratio of component (d) to component (c) in particle B is 0.5 or more. The bioabsorbable encapsulating powder has a particle size in the range of 63 μm to 250 μm.

2. The bioabsorbable encapsulating powder according to claim 1, wherein the ratio of the total number of N-hydroxysuccinimide ester groups provided by the electrophilic polyoxazoline to the total number of amine groups provided by the nucleophilic polyoxazoline is in the range of 1:0.05 to 1:0.

4.

3. The bioabsorbable encapsulating powder according to claim 1, wherein the particles A containing only components (a) and (d) and the particles B containing only components (b), (c), and (d) together constitute at least 60% by weight of the bioabsorbable encapsulating powder.

4. A method for preparing a bioabsorbable encapsulating powder according to any one of claims 1 to 3, (a) A step of providing the particles A comprising the electrophilic polyoxazoline and the water-soluble dispersant, (b) A step of providing the particles B comprising the nucleophilic polyoxazoline, the water-absorbing particles, and the water-soluble dispersant, (c) A method comprising the step of combining particle A and particle B.

5. The method according to claim 4, wherein the particle A and the particle B are combined to form an aggregate.

6. Apparatus for applying bioabsorbable encapsulating powder, A reservoir containing the bioabsorbable encapsulating powder according to any one of claims 1 to 3, - An elongated hollow tubular structure having a proximal end and a distal end, wherein the distal end has a powder outlet and the proximal end is connected to the reservoir, The apparatus comprises: a manual air pump disposed to generate an airflow from the reservoir through the elongated hollow tubular structure and through the powder outlet to carry the bioabsorbable encapsulating powder.

7. A biocompatible and flexible hemostatic sheet, - A three-dimensional, interconnected, adhesive fibrous carrier structure including interstitial spaces, - comprising the bioabsorbable encapsulating powder according to any one of claims 1 to 3, A hemostatic sheet in which the bioabsorbable sealing powder is distributed within the interstitial space and / or fixed on the adhesive fibrous carrier structure.

8. A parts kit for preparing bioabsorbable encapsulated suspensions, - A first container or compartment containing a biocompatible liquid, A parts kit comprising: a second container or compartment containing the bioabsorbable encapsulating powder described in any one of claims 1 to 3.

9. A bioabsorbable encapsulated suspension, • A biocompatible continuous liquid non-aqueous phase, A bioabsorbable encapsulation suspension comprising: a dispersed phase containing the bioabsorbable encapsulation powder described in any one of claims 1 to 3.

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