RU2836134C1 - Combined haemostatic sponge - Google Patents

Abstract

FIELD: medicine; pharmaceutics.

SUBSTANCE: invention refers to medicine and pharmaceutical industry, namely to a haemostatic sponge. Haemostatic sponge is characterized by that it is obtained on the basis of dry marine collagen, isolated from deep-sea squid, maintained in a solution of formic acid at pH 3–4, mixed with glutaric aldehyde, solution of sodium salt of carboxymethyl cellulose and glycerine in ratio collagen: Na-CMC in wt.% 50:50, 25:75 or 15:85, by lyophilisation.

EFFECT: invention provides more pronounced collagen expression in wound healing and higher haemostatic properties.

1 cl, 3 ex

Description

The invention relates to medicine, in particular to surgery based on collagen and sodium carboxymethylcellulose, used to stop bleeding of various origins: domestic injuries, gunshot and mine-explosive wounds, subcapsular ruptures of parenchymatous organs of the abdominal cavity and retroperitoneal space.

Relevance of the topic. Currently, organ-preserving operations are one of the priority areas of modern surgery. This trend has led to the development of a large number of local hemostatic agents. Today, the world market offers a significant number of application hemostatic implants from domestic and foreign manufacturers. However, many of them, against the background of low hemostatic activity, have weak adhesive capacity, which requires fixation of the implant to the organ, thereby causing additional damage to it and, as a result, increasing the existing parenchymal bleeding. Some samples of hemostatic materials provoke the development of adhesions in the abdominal cavity, and also increase its severity, contribute to the prolongation of the inflammatory process. In this regard, there is a need to develop a standardized methodology for studying hemostatic implants, in particular their hemostatic activity, both in laboratory conditions and in vivo experiments.

In modern abdominal surgery, stopping bleeding during planned and emergency surgeries remains one of the pressing issues. Bleeding from parenchymatous organs (liver, spleen, kidneys, etc.) is accompanied by significant blood loss, high bleeding intensity and difficulties in achieving reliable hemostasis, since not only small arteries and arterioles are damaged at the same time, but also veins and capillaries closely associated with the organ parenchyma. In recent years, one of the main tasks of abdominal surgery has become the search for new effective hemostatic agents capable of replacing hemostatic sutures, as well as other surgical treatment methods that have significant drawbacks, such as the development of adhesions, recurrent bleeding, trauma and necrotic damage to organ tissues. Such methods include tamponade, omentopexy, wrapping with absorbable meshes, films, suturing of tissues of the damaged organ, etc.

The prototype of the invention is a hemostatic porous composite sponge containing a matrix of a biopolymer, which can be collagen, gelatin, fibrin, chitosan, a synthetic biodegradable biomaterial (polylactic acid or polyglycolic acid, their derivatives). The second component is a hydrophilic polymer component, which is a multielectrophilic polyalkylene oxide polymer, for example, multielectrophilic PEG, including two or more electrophilic groups, such as CON(COCH ₂ ) ₂ , -CHO, -N=C=O and/or -N(COCH ₂ ) ₂ (USSR Author's Certificate No. 908357, A61K 35/32, A61F 13/00, 19.09.78/28.02.82). The low availability of the hydrophilic polymer component used should be noted as a disadvantage of such a material.

The technical result of the invention is a more pronounced expression of collagen during wound surface healing and higher hemostatic properties.

The technical result is achieved due to the fact that it is obtained on the basis of dry marine collagen isolated from deep-sea squid, kept in a solution of formic acid at pH 3-4, mixed with glutaraldehyde, a solution of sodium carboxymethylcellulose (Na-CMC) and glycerin in the ratio of collagen: Na-CMC in wt.%: 50:50, 25:75, 15:85, by lyophilization.

Sodium carboxymethylcellulose (Na-CMC) dissolves in water and aqueous alkali solutions, but is insoluble in organic solvents and mineral oils. At the same time, this salt forms transparent viscous solutions characterized by pseudoplasticity, and some types of the product - thixotropy, the ability to spontaneously restore the original structure destroyed by mechanical action. Sodium carboxymethylcellulose interacts with the contents of the wound and tissues, distributing evenly over the wound surface, thereby ensuring rapid and complete delivery of accompanying components to the site of injury, exhibiting an osmotic effect when applied to the wound by absorbing wound discharge.

Collagen is a connective tissue protein of animal origin, the structural, chemical, physical properties of which are due to the unique three-helix organization of macromolecules, which at physiological temperature, pH, ionic strength aggregate to form a three-dimensional network of intermolecular bonds of various natures. Platelets aggregated by a collagen molecule undergo normal morphological changes - they degranulate, releasing ADP, serotonin, thromboxane A2, which helps to form a clot. The hemostatic mechanism of collagen action is based on the aggregation and activation of platelets. Lyophilized hemostatic collagen sponge has a high sorption capacity and absorbs an amount of moisture that is many times greater than its own weight, practically without increasing in size. Collagen forms a water- and air-permeable gel-like layer within 5 minutes, but the sponge plate must be tightly pressed to the wound surface. When collagen interacts with calcium-containing solutions, cations are tightly bound, entering the triple helix. As a result, its conformation changes in such a way that water molecules are no longer held by this section of the triple helix, which leads to local loss of water and "cross-linking" of the structure - a more rigid spongy material is formed.

THE METHOD IS IMPLEMENTED AS FOLLOWS

To produce a combined hemostatic sponge, dry deep-sea squid collagen is dispersed in an aqueous solution of formic acid (pH 3.0-4.0). The resulting suspension with a collagen content of 3% is left for 10-12 hours for collagen swelling, resulting in a homogeneous translucent mass, into which glutaraldehyde is then added. At the same time, a 1% solution of sodium carboxymethyl cellulose (Na-CMC) is prepared. The resulting polymer solutions are mixed, glycerin is added in an amount of 50% of the total mass of dry polymers, after thorough mixing, they are poured into molds with a layer thickness of 15 mm, frozen at -60 ° C and lyophilized. A white or cream-colored spongy material with a thickness of about 10-11 mm is obtained.

EXAMPLES OF THE METHOD OF OBTAINING

Example 1. A 1 g sample of dry marine collagen obtained from deep-sea squid is dispersed in 32 ml of formic acid solution with pH 3-4 and kept for 12 hours for swelling, then 0.1 g of glutaraldehyde is added. A 1 g sample of sodium carboxymethyl cellulose (Na-CMC) powder of medium viscosity (dynamic viscosity 4000-8000 cP) is dissolved in 99 ml of distilled water with stirring. The polymer solutions are mixed, ensuring a collagen: Na-CMC ratio in the mixture equal to 50:50 in wt.% . Then 0.5-1 g of glycerol is added to the mixture, thoroughly mixed, poured into molds in a 1 cm thick layer, frozen at -50°C and lyophilized.

Example 2. Differs from that described in Example 1 in that a 0.5 g sample of marine collagen is dispersed in 16 ml of formic acid solution, and a 1.5 g sample of Na-CMC is dissolved in 148.5 ml of distilled water, ensuring a collagen:Na-CMC ratio of 25:75 in wt.%.

Example 3. Differs from that described in Example 1 in that a 0.3 g sample of marine collagen is dispersed in 10 ml of formic acid solution, and a 1.7 g sample of Na-CMC is dissolved in 168.3 ml of distilled water, providing a collagen:Na-CMC ratio of 15:85 in wt.%.

EXPERIMENTAL APPLICATION EXAMPLE

The study of hemostatic activity was carried out in an experiment on male rabbits of the “Soviet Chinchilla” breed weighing 2.5–4 kg.

The surgical intervention was performed using a videoendoscopic complex. After processing the surgical field using the standard method and delimiting it in the mesogastrium, laparocentesis was performed using a Veresh needle and carboxyperitoneum was applied with preset parameters: pressure 7 mm Hg, flow 1 l/min. An optical cannula and a 5-mm endoscope were inserted into the abdominal cavity, after which the abdominal cavity was inspected and the liver was identified. Then, 2 trocars, each 3 mm in diameter, were sequentially inserted for the manipulator instruments.

Using an endoscopic dissector, the parenchyma of the middle lobe of the liver was bluntly divided in the cranial direction at a distance of 5 cm from its edge to the full depth and width of the dissector branches. Parenchymatous bleeding developed in the wound. Then a 1×1 cm piece of the test sample was placed in the wound and tightly fixed by pressing the instrument. The animals were excreted on the 30th day after the experiment using the cervical dislocation method, and an autopsy of the liver parenchyma was performed in the area of the injury model.

Four study groups were formed: group No. 1 - collagen hemostatic sponge, group No. 2 - two-component hemostatic sponge with 15% collagen content, group No. 3 - two-component hemostatic sponge with 25% collagen content, group No. 4 - two-component hemostatic sponge with 50% collagen content.

As a result of the study of liver tissue 30 days after the use of samples of group No. 1, an area of demarcation necrosis was visualized around the remaining fragments of the hemostatic agent, which was delimited from the liver parenchyma by a fairly wide connective tissue capsule - 0.63 [0.55; 0.79] μm. At the same time, the process of collagen formation was noted, which spread to the nearby liver lobules with fibrosis of the septa. The parenchyma as a whole retained its structure, however, signs of granular dystrophy were found in the hepatocytes, and perivascular edema and lumen expansion were noted in the bloodstream.

When examining the liver section after using the hemostatic agent of group No. 2 on the 30th day after the liver injury, a narrow strip of fibrous tissue was determined in the resection area, which formed a connective tissue capsule. There was no infiltrate. The thickness of the connective tissue capsule was 0.23 [0.12; 0.39] μm, statistically significantly less than when using the material of group No. 1. It is worth noting separately that the differences in the thickness of the capsule in groups No. 3 and No. 4 are not statistically significant.

In the area where the sponge was applied, there was mild swelling; the liver tissue had a normal morphological structure.

Thus, based on the results of the morphological study, it was found that all the tested materials were fragmentarily determined in the area of liver tissue trauma, despite the significant time after the injury (30 days). Also noted was the presence of a pronounced demarcation zone separating the MCS materials from the liver parenchyma, due to the proliferation of connective tissue, as a result of the inflammatory reaction of the tissues of the damaged organ. However, the degree of expression of these processes differs in the experimental groups. Thus, in group No. 1, the capsule width is on average 2.73 times greater than the values of groups No. 2, No. 3 and No. 4, which indicates more intense inflammation and reparation, which are aimed at maximum delimitation of the trauma area.

Claims (1)

A hemostatic sponge characterized by the fact that it is obtained on the basis of dry marine collagen isolated from deep-sea squid, kept in a solution of formic acid at pH 3-4, mixed with glutaraldehyde, a solution of sodium carboxymethylcellulose and glycerin in a ratio of collagen: Na-CMC in wt.% 50:50, 25:75 or 15:85, by lyophilization.