CN115944790A - Abdominal wall patch and preparation method thereof - Google Patents

Abstract

The application provides an abdominal wall patch and a preparation method thereof; the sheet material comprises acellular tissue material P-SIS and PLCL; wherein, the acellular tissue material P-SIS is attached with nano silver; the PLCL was fixed on the acellular tissue material P-SIS by electrospinning. The abdominal wall patch has high biocompatibility and high mechanical performance, and the degradation speed of the PLCL synthetic material of the patch is controlled, so that the anti-infection capacity and the repair success rate of abdominal wounds can be improved.

Description

Abdominal wall patch and preparation method thereof

Technical Field

The application relates to an abdominal wall repairing material, in particular to an abdominal wall repairing piece.

Background

At present, materials for repairing abdominal walls at home and abroad are mainly divided into two categories. The first category is biological materials such as autologous fascia, diaphragm, dura mater, amniotic membrane, and the like. The second type is non-biological materials, such as carbon fiber mesh, dacron, artificial polymer materials and the like. The non-biological material, namely the artificially synthesized patch material, has sufficient mechanical property and strong flexibility, can be continuously adjusted according to requirements, but lacks biological activity, is not degradable, and is easy to form tissue wrapping and chronic inflammation stimulation. Such as polypropylene, is widely used due to its high tensile strength, but has the defect of easy formation of scar tissue in or around the fibers of the patch material, often resulting in severe adhesion of abdominal contents, and thus causing complications such as pain, intestinal obstruction, intestinal perforation and intestinal fistula.

The most significant source of biological patches is body parts other than skin, such as bovine or equine pericardium or porcine small intestine submucosa. The porcine Small Intestinal Submucosa (SIS) is a very strong extracellular matrix, comprises type I and type III collagen with the content of more than 90 percent, also contains a small amount of type IV, V and VI collagen and various cytokines, and is very similar to the abdominal tissues of a human body. The acellular porcine small intestine submucosa tissue serving as a biological derivative material has good biocompatibility, is a good tissue repair material, is widely used for repairing soft tissue defects, and can promote tissue reconstruction. However, SIS is also poor in biomechanical strength and mechanical properties due to its origin and inherent characteristics. However, the tissue repair material needs a certain strength of mechanical force, for example, a biological patch is implanted after a breast plastic operation, which can play a role of fixing and supporting, so that the displacement of the prosthesis is reduced, and if the mechanical property of the patch is insufficient, the sufficient mechanical property cannot be provided, and the operation fails.

The PLCL (poly-L-lactide-caprolactone) is a hydrophobic aliphatic polyester copolymer, has good mechanical strength, biocompatibility and degradation performance, is a common electrostatic spinning material, and has quite a plurality of results with scientific research values in the application of blood vessel and esophageal tissue engineering. The tissue engineering blood vessel constructed by PLCL has been applied to the treatment of congenital heart diseases as early as 2001, and has a precedent of successful implantation at present.

Currently, studies have been made to combine biological and non-biological materials, and the method adopted is to cover an Extracellular Matrix (ECM) gel uniformly on a polypropylene patch to produce a hybrid patch. The patch synthesized by the method indeed enhances the mechanical property, but simultaneously sacrifices the three-dimensional space structure of extracellular matrix, and the polypropylene material still remains in the body and still induces the chronic inflammatory reaction.

In recent years, after metal silver is processed into nano-scale silver particles by utilizing a nano technology, the nano-scale silver particles show obvious surface effect, small-size effect and macroscopic tunnel effect, and the antibacterial activity is greatly enhanced. Nano-silver (NS) as an antibacterial material is applied to medical catheters, internal fixation instruments, wound dressings and the like, and silver particles are gradually released along with the degradation of biological materials after the nano-silver is implanted into a body, so that the nano-silver can permanently play the roles of antibacterial colonization and infection resistance, and is beneficial to the infiltration growth of host cells and the regeneration of blood vessels. Foreign research finds that: the dressing containing nano silver is used locally, so that the wound healing can be accelerated, the appearance of scar healing can be improved, and the effect is very ideal.

Disclosure of Invention

In view of the above problems, the present application aims to provide an abdominal wall patch, which has high biocompatibility and high mechanical properties, and improves the infection resistance and the repair success rate of abdominal wounds through the application of the patch.

An abdominal wall patch of the present application formed as a sheet-like material comprising acellular tissue material P-SIS and PLCL; wherein, the acellular tissue material P-SIS is attached with nano silver; the PLCL was fixed on the acellular tissue material P-SIS by electrospinning.

The preparation method of the abdominal wall patch comprises the following steps: attaching nano silver to acellular tissue material P-SIS; the PLCL was fixed to the acellular tissue material P-SIS to which nano silver was attached by electrospinning to form a sheet-like material, thereby forming an abdominal wall patch.

The abdominal wall patch has high biocompatibility and high mechanical performance, and the anti-infection capacity and the repair success rate of abdominal wound can be improved through the application of the abdominal wall patch.

Drawings

FIG. 1 is a model creation picture of an animal experiment of an abdominal wall patch of the present application;

fig. 2 is a picture of an animal test of abdominal wall patches of the present application taken 30 days post-surgery;

fig. 3 is a 60 day post-operative picture of an animal trial of an abdominal wall patch of the present application;

fig. 4 is a photograph of an animal test with an abdominal wall patch of the present application at 90 days post-surgery.

Detailed Description

Hereinafter, the abdominal wall patch of the present application will be described in detail with reference to the accompanying drawings.

The abdominal wall patch is used for carrying out decellularization treatment on the tissue under the small intestine mucosa of a pig on the basis of an Abraham method, removing DNA, RNA and other extracellular substances in the tissue and producing a cell-free tissue material P-SIS; attaching nanosilver to the P-SIS; fixing the PLCL on the P-SIS by an electrostatic spinning method to form a sheet material to obtain the abdominal wall patch, namely an NS-PLCL-SIS patch; and (5) sterilizing and storing.

Mechanical property detection

And (3) detecting the thickness, the tensile force and the bending length of the prepared abdominal wall patch in vitro.

1. Determination of sample thickness

1. Principle of

And measuring the thicknesses of different samples to determine whether the thicknesses of the samples meet the design requirements. Reference standard: GB/T3280-2015

2. Instrument for measuring the position of a moving object

YG141N digital fabric thickness tester

3. Test method

5 different fabrics were selected for testing.

4. Test results

Watch 1

Sample number	Length (mm)	Width (mm)	Thickness (mm)
				1	10	7	0.562
2	10	7	0.558
				3	10	7	0.551
4	10	7	0.549
				5	10	7	0.553

2. Measurement of breaking force

1. Principle of

And fixing the two ends of the sample on a tension meter to be drawn so as to determine whether the tensile strength of the sample meets the design requirement. Reference mark

Preparing: standard for determination of tensile Properties of textiles

2. Instrument

Medicine packing performance tester MED-01

3. Test method

3.1 cutting the patch into 5.0cm × 1.0cm wide samples

3.2 put the sample into water to hydrate for 4 minutes

3.3 fixing the two ends of the specimen on the chuck of the tensile testing machine, and stretching at a speed of 100mm/min until the specimen breaks

3.4 recording the force at break of the test specimen in N

4. Test results

Watch two

Sample number	Length (mm)	Width (mm)	Thickness (mm)	Tensile Strength (N)
					1	10	7	0.562	31.256
2	10	7	0.558	32.264
					3	10	7	0.551	32.107
4	10	7	0.549	31.574
					5	10	7	0.553	31.649

3. Determination of bending Length

1. Principle of

The sample was placed above the electronic stiffness to determine if its bend length met the design requirements. Reference standard:

GB/T18318.1-2009

2. instrument for measuring the position of a moving object

LLY-01B electronic stiffness instrument

3. Test method

3.1 samples were trimmed to 25mm by 160mm size and hydrated in normal saline for 10 minutes prior to testing.

3.2 the sample is placed on the instrument, and the bending length of the sample is detected by adopting an inclined plane method. The test angle was set to 41.5 °, test

The sample bend length.

4. Test results

Watch III

Sample number	Length (mm)	Width (mm)	Thickness (mm)	Bending length (mmN. Cm)
					1	10	7	0.562	7.523
2	10	7	0.558	7.146
					3	10	7	0.551	7.157
4	10	7	0.549	7.139
					5	10	7	0.553	7.149

Animal testing

The test uses a New Zealand rabbit as a test system, and evaluates the safety and effectiveness of a test sample by observing the physiological state, clinical manifestation and general anatomy observation of a wound model animal after using the NS-PLCL-SIS patch. According to the test purpose and the test design requirement, 18 New Zealand rabbits are randomly divided into a test article group and a blank group, the safety and effectiveness research of the NS-PLCL-SIS patch is carried out, and 3 time nodes of 30d, 60d and 90d are set for blood routine, serum biochemical and gross anatomical observation. During the study, all animals were subjected to clinical observation, and the measured data were counted. The results show that the test article is degraded within 90 days, and the animals have no abnormal reaction and no death during the test. The change of animal body weight has no significant difference at each research node, the wound surface at the research position has no infectious inflammatory reaction, and the ocular wound surface is well healed after 7 days of operation.

Under the test condition, the test article has good repair performance for abdominal wall defects of New Zealand rabbits, and is safe in veterinary clinic.

1. Test method

1. Preoperative feeding prohibition: the animals are forbidden to feed and not forbidden to water 16h before operation.

2. Anesthesia: animals were weighed and first administered with Rakat somnift (Changshabet Biotech research institute, inc.; 2019.06.03) intramuscularly at a dose of 0.4 ml/kg. After the animal is fixed exactly, the animal is placed on an operating table, and is bound and fixed by the limbs lying on the back.

3. Blood is collected before operation.

Blood was collected in the auricular vein and used for measurement of blood routine and serum biochemistry.

4. Rabbits were prepared on their abdomen and then disinfected with active iodine. Laying a sterile surgical drape to expose the surgical area.

5. Incising abdominal skin, wherein the length is about 5cm, separating subcutaneous tissues and muscles bluntly, exposing abdominal wall, making 2cm defect, establishing a New Zealand rabbit abdominal wall defect model, implanting a 2.5cm multiplied by 2.5cm patch into the abdominal wall, suturing and fixing the periphery, and closing the abdomen layer by layer after finishing.

6. After the operation, 20IU/kg penicillin sodium (manufactured by North China pharmaceutical Co., ltd., lot number: 181201) was administered daily by intramuscular injection with 0.9% physiological saline to prevent infection twice a day for 1 day. Intensive care, detailed observation of clinical changes, and well documented. Can be used for daily treatment and prevention of infection.

7.18 animals are respectively dissected at the planned time point, and the abdominal wall defect repair condition, whether inflammatory reaction exists, whether a test sample is remained or not and the like are observed; general observation of other organs shows that if there is obvious change, the material is taken in time and pathological sections are made.

2. Test results

1. Animal feeding management

During the test period, no abnormality was found in the animal feeding management.

2. Gross index observations

2.1 mortality

No animals died during the entire course of the experiment.

2.2 clinical indices

After the animal is observed for 14 days after the operation, the behavior, the mental condition, the appetite and the feed intake of the animal are recovered to be normal after the animal is observed for 3 days after the operation, the animal is safe to pass through the perioperative period, and the appearance signs, the stool and urine characters, the gland secretion, the body weight and the like of the animal are not obviously changed before and after the operation.

3. Change in body weight

There was no significant change in body weight in each study node between the 18 animals before and after model formation.

Table four statistical table of individual body weight measurements

4. Observation of blood

The individual haematology and serum biochemical indexes of 18 animals are observed, the blood coagulation indexes do not find abnormal reaction of the animals, all numerical values are in a reasonable range in veterinary clinic, the immunological rejection reaction symptom does not appear, and the haematology indexes show that the individual health conditions of the animals are good. The hematology and serum biochemical indexes of 18 animals have no obvious change in each research node before and after model formation.

Table five animal blood routine test results

Biochemical test result of blood serum of animals

5. Evaluation results of in vivo adhesion

18 animals were euthanized at 30d, 60d and 90 d. And (5) dissecting and observing the adhesion condition in the abdominal cavity of the animal, and scoring the adhesion degree according to a scoring standard in the examination and guidance principle of the patch animal experimental technology.

Tachi-shaped patch and intra-abdominal tissue organ adhesion condition scoring table

Table eight patch and intra-abdominal tissue organ adhesion condition evaluation table

Comprehensive evaluation table for adhesion conditions of table nine

6. General observations

After operation, the patient is dissected according to a set time node, and the test sample group is generally observed, so that the patient does not have the operation area infection, and the shapes, colors, sizes and the like of other organs after the operation have no obvious changes.

At 30d, the wound was not completely healed and the patch remained visible on the eye. No adhesion was observed between the test sample group and the blank group. A small amount of pus was visible in the wound and abdominal wall.

At 60 days, the wound is completely healed, no patch is seen on the eye, and one side of the test sample, namely the inner side of the abdominal wall, is adhered to the abdominal cavity; no blocking was observed in the blank group. The wound and abdominal wall have no abscess and pus.

At 90d, the wound is completely healed, no patch is observed on the eye, and no adhesion is observed between the test sample group and the blank group. The wound and abdominal wall have no abscess and pus.

3. Conclusion of the experiment

Under the test condition, the test article has good repair performance for abdominal wall defects of New Zealand rabbits, and is safe in veterinary clinic.

Unless defined otherwise, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples set forth in this application are illustrative only and not intended to be limiting.

Although the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the teachings of this application and yet remain within the scope of this application.

Claims (2)

1. An abdominal wall patch formed as a sheet material including acellular tissue material P-SIS and PLCL; wherein, the acellular tissue material P-SIS is attached with nano silver; the PLCL was fixed on the acellular tissue material P-SIS by electrospinning.

2. A method for preparing an abdominal wall patch, comprising:

attaching nano silver to the acellular tissue material P-SIS;

the PLCL was fixed on the acellular tissue material P-SIS to which nano silver was attached by electrospinning to form a sheet-like material, thereby forming an abdominal wall patch.

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