AU2020348320B2

AU2020348320B2 - Developable composite biological mesh containing barium sulfate and preparation method therefor

Info

Publication number: AU2020348320B2
Application number: AU2020348320A
Authority: AU
Inventors: Qiyang GUO; Peng Li; Yongjun Wang; Yumin Yang; Luzhong ZHANG
Original assignee: Nantong University
Current assignee: Nantong University
Priority date: 2019-09-17
Filing date: 2020-06-15
Publication date: 2024-04-18
Anticipated expiration: 2040-06-15
Also published as: CN110522954B; CN110522954A; WO2021051902A1; AU2020348320A1

Abstract

A developable composite biological mesh containing barium sulfate and a preparation method therefor. The mass percentage of barium sulfate in the composite biological mesh is 15%-35%, and therefore, the composite biological mesh has better mechanical property and developing strength. The preparation method for the composite biological mesh comprises: (1) preparing a polypropylene solution, adding nano barium sulfate, and mixing the two well to obtain a polypropylene/nano barium sulfate solution; (2) adding the polypropylene/nano barium sulfate solution to a coagulating bath for phase inversion curing, takin out the product, washing and vacuum drying same to obtain a polypropylene/nano barium sulfate composite; (3) extruding and granulating the polypropylene/nano barium sulfate composite by means of a twin-screw extruder to obtain a composite biological mesh raw material; and (4) obtaining composite fibers by means of extrusion spinning by a single-screw extruder, weaving the composite fibers to obtain a developable composite biological mesh containing barium sulfate. The preparation method is simple and suitable for industrial production.

Description

DEVELOPABLE COMPOSITE BIOLOGICAL MESH CONTAINING BARIUM SULFATE AND PREPARATION METHOD THEREFOR TECHNICALFIELD

[0001] The present disclosure relates to the field of biomedical engineering, and particularly relates to a developable composite biological mesh containing barium sulfate and a preparation method therefor.

BACKGROUND

[0002] Hernia is one of the common and frequently-occurring diseases in the general surgery department, and attacks all ages. Related data shows that about 20 million cases of herniorrhaphy are performed every year around the world, with 80% needing hernia meshes. Tension-free herniorrhaphy is applied most extensively at present; and the biological meshes prepared from polymer materials such as polypropylene are widely used as hernia meshes. The implantation of a hernia mesh into human body primarily aims to resist the internal pressure of the human body and support new tissues. Therefore, the mesh must have a stable structure and enough strength and softness. Hence, major physical and mechanical properties for measuring the mesh quality include indexes such as tensile breaking strength, bursting strength, rigidity and flexibility and crease recovery.

[0003] According to the needs of clinical surgery, the future hernia meshes should be researched and developed toward good antibacterial ability, prevention of tissue adhesion and hemolytic reaction, good tissue support, complete or partial absorption by human body, reduction of influence of postoperative mesh shrinkage on wounds and the like. Moreover, the hernia meshes are expected to assist in regeneration of endogenous tissues, repair the operative wound areas and reduce generation of postoperative scar tissues, so as to minimize the patients'pain and improve prognosis.

[00041 A polypropylene material has the advantages of stable chemical properties, strong physical tensile strength, firm weaving, good handfeel, infection tolerance, repeated bending and the like. A polypropylene mesh weaved from the polypropylene material is characterized by easy tissue ingrowth and granulation tissue proliferation; and also, the large weaving aperture of the polypropylene mesh makes it easier for white blood cells and macrophages to go in and out to kill bacteria in the mesh grids. Therefore, such meshes have excellent anti-infection effect and are widely applied in hemiorrhaphy. Meanwhile, the polypropylene mesh has the advantages of low price, stimulation of tissue healing, small operative wound, fast postoperative recovery and the like, and thus is an artificially synthesized non-absorbable mesh that is most commonly used in the hemiorrhaphy. However, in current use, the polypropylene mesh is found to have some shortcomings: for example, due to a rough surface of the polypropylene mesh, direct contact with the abdominal viscera may cause relatively serious abdominal adhesion; and even worse, the polypropylene mesh may invade the intestinal wall to cause intestinal fistula or intestinal obstruction.

[0005] The meshes of a single material often have the problems of incompatible and unstable biomechanical properties, heavy weight and serious adhesion. To solve the above-mentioned problems, composite hernia repair materials integrating the advantages of two materials keep emerging. Composite hernia meshes are prepared generally by means of overall weaving, sewing, bonding, laminating and the like. Common composite meshes can be classified into mechanically strengthened meshes, partially degradable meshes and anti-adhesion meshes according to composite uses, and can be classified into polypropylene and expanded polytetrafluoroethylene combined meshes, polypropylene and absorbable material combined meshes, polypropylene and absorbable material combined multilayer meshes and the like according to the materials.

[0006] It is found in clinical use that, since after a biological mesh prepared from a polymer material is used for herniorrhaphy, the postoperative scar shrinks obviously (with a shrinkage rate of up to 20-50%), the biological mesh of the polymer material is distorted, and the irregular surface thereof irritates and even damages surrounding tissues to cause formation of dermal sinus tracts and occurrence of infection. In this case, a second operation should be performed to take out the distorted mesh for replacement.

[0007] After the herniorrhaphy, bacterial infection is also one of relatively serious complications. A large amount of clinical statistical data published at home and abroad indicates that the infection rate after hemiorrhaphy is 6-10%; and particularly, after incisional herniorrhaphy, the infection rate is around 40%. Serious postoperative infection can lead to prolonged hospital stay and poor prognosis of the patients, and even requires follow-up operations to clear up the infection site.

[0008] Therefore, postoperative infection of the herniorrhaphy is also one of relatively serious complications. There are two infection factors. One is bacterial infection. A large amount of clinical statistical data published at home and abroad indicates that the infection rate after the hemiorrhaphy is 6-10%. The other one is that the biological mesh of a polymer material is distorted, and the irregular surface thereof irritates and even damages surrounding tissues, to cause formation of dermal sinus tracts and occurrence of infection. Clinical treatments for the two infections are totally different. The former is subjected to anti-infection treatment while the later requires a second operation. At present, the clinical distinction between these two lesions still relies on the clinical experience of doctors. Sometimes, the two are really hard to distinguish, and only surgical exploration can be carried out, which brings extra pain and burden to the patients. Therefore, how to explore the cause of postoperative infection through a non-surgical means and provide a basis for clinical diagnosis and treatment has become an urgent problem to be solved.

[0009] The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

SUMMARY

[0010] In view of this, an objective of the present disclosure is to provide a developable composite biological mesh containing barium sulfate and a preparation method therefor. The composite biological mesh prepared by the preparation method provided by the present disclosure has better mechanical property and developing strength.

[0011] To solve the above-mentioned technical problem, the present disclosure provides a developable composite biological mesh containing barium sulfate, wherein the composition of the composite biological mesh by mass percentage is: 65-85% of polypropylene and 15-35% of nano barium sulfate.

[0012] Preferably, the thickness of the developable composite biological mesh is 0.6 mm; and the aperture of the developable composite biological mesh is 2 mm.

[0013] Preferably, the polypropylene is medical-grade isotactic polypropylene, with a melting point of 164°C -170°C and an isotactic index greater than or equal to 96%.

[0014] Preferably, the particle size of the nano barium sulfate ranges from 30nm -70 nm.

[0015] The present disclosure also provides a preparation method for a developable composite biological mesh containing barium sulfate as herein described, comprising the following steps:

[0016] Step 1: Dissolving polypropylene in an organic solvent to obtain a polypropylene solution, adding nano barium sulfate to the polypropylene solution, and stirring to mix the two well to obtain a polypropylene/nano barium sulfate solution;

[00171 Step 2: Adding the polypropylene/nano barium sulfate solution obtained in step (1) to a coagulating bath of the same volume for phase inversion curing; obtaining, after the curing is finished, a cured product, taking out, washing and vacuum drying the cured product to obtain a polypropylene/nano barium sulfate composite;

[0018] Step 3: Extruding and granulating the polypropylene/nano barium sulfate composite by means of a co-rotating twin-screw extruder to obtain a composite biological mesh raw material; and

[0019] Step 4: Extruding and spinning the composite biological mesh raw material by means of a single-screw extruder to obtain composite fibers; and weaving the composite fibers to obtain the developable composite biological mesh containing barium sulfate.

[0020] Preferably, in step 1, the organic solvent is one or more of toluene, xylene and decalin.

[0021] Preferably, in step 1, the polypropylene is dissolved in the organic solvent at a temperature of 100-120°C; the concentration of the polypropylene in the polypropylene solution is 100-125 g/L; and the stirring time is 2 hour -4 hour.

[0022] Preferably, in step 2, the coagulating bath comprises one of absolute ethanol or acetone.

[0023] Preferably, in step 3 the extruding temperature is 150°C -200°C; and the screw speed is 60 r/min -120 r/min.

[0024] Preferably, in step 4, the extruding temperature is 150°C -220°C.

[0025] Compared with the prior art, in the present disclosure, by adding a certain amount (15-35%) of developable barium sulfate to the polymer raw material of the biological mesh, the tensile strength of the biological mesh is guaranteed, and whether the biological mesh is distorted can be judged only through X-ray examination, thereby providing a basis for clinical diagnosis and treatment.

[0026] The present disclosure further provides, a developable composite biological mesh containing barium sulfate, wherein the composition of the composite biological mesh by mass percentage is: 65-85% of polypropylene and 15-35% of nano barium sulfate; the thickness of the developable composite biological mesh is 0.6 mm, and the aperture of the developable composite biological mesh is 2 mm ; the particle size of the nano barium sulfate ranges from 30 nm -70 nm.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[00271 For further understanding of the present disclosure, the preferred implementations of the present disclosure are described below with reference to examples. However, it should be understood that these descriptions are only intended to further explain the features and advantages of the present disclosure, and do not constitute a limitation on the claims of the present disclosure.

[0028] All raw materials in the present disclosure are not particularly limited in source, and may be commercially purchased or prepared by conventional methods known to those skilled in the art.

[0029] The present disclosure provides a developable composite biological mesh containing barium sulfate, where the composition of the composite biological mesh by mass percentage is: 65-85% of polypropylene and 15-35% of nano barium sulfate.

[0030] In the present disclosure, the thickness of the composite biological mesh is preferably 0.6 mm; and the aperture of the composite biological mesh is preferably 2 mm.

[0031] In the present disclosure, the polypropylene is medical-grade isotactic polypropylene, with a melting point of 164-170°C and an isotactic index greater than or equal to 96%.

[0032] The composite biological mesh provided by the present disclosure comprises polypropylene and nano barium sulfate. A polypropylene material has the advantages of stable chemical properties, strong physical tensile strength, firm weaving, good handfeel, infection tolerance, repeated bending and the like. A polypropylene mesh weaved from the polypropylene material is characterized by easy tissue ingrowth and granulation tissue proliferation; and also, the large weaving aperture of the polypropylene mesh makes it easier for white blood cells and macrophages to go in and out to kill bacteria in the mesh grids. Therefore, such meshes have excellent anti-infection effect and can stimulate tissue healing and have the advantages of small operative wounds, fast postoperative recovery and the like. In the present disclosure, the content of polypropylene is 65-85% by mass percentage, such that the tensile strength of the composite biological mesh meets the requirement for strength of the biological mesh for hernia surgery. The barium sulfate is white loose fine powder and serves as an X-ray double contrast medium. Fine and uniform barium is generally synthetic barium. Featuring fine and uniform granules, round shape in general, light specific weight and slow and consistent settlement, the barium is extensively applicable to single and double contrast examinations for oesophagus, stomach, duodenum, small intestine and colon. The content of barium sulfate influences the developing effect as well as the mechanical property of the composite biological mesh. With the increasing content of barium sulfate, the mechanical property of the composite biological mesh declines. However, if the content of barium sulfate is too low, the developing strength of the biological mesh is not enough. Experiments indicate that meshes containing 15-35% of barium sulfate can meet the requirements for both the developing strength and mechanical property.

[0033] In the present disclosure, the particle size of the nano barium sulfate preferably ranges from 30-70 nm. The nano barium sulfate with a particle size of 30-70 nm has a large specific surface area and is more likely to trigger a physical or chemical interaction with a polymer material, which leads to stronger ability of being adsorbed on a melt such as polypropylene; and also, the interface bonding force is enhanced, and the strength and tensile property are better since the interface layer is relatively thin.

[0034] The present disclosure also provides a preparation method for the developable composite biological mesh containing barium sulfate, including the following steps:

[0035] Step 1: Dissolving polypropylene in an organic solvent to obtain a polypropylene solution, adding nano barium sulfate to the polypropylene solution, and stirring to mix the two well to obtain a polypropylene/nano barium sulfate solution;

[0036] Step 2: Adding the polypropylene/nano barium sulfate solution obtained in step (1) to a coagulating bath of the same volume for phase inversion curing; obtaining, after the curing is finished, a cured product, taking out, washing and vacuum drying the cured product to obtain a polypropylene/nano barium sulfate composite;

[00371 Step 3:Extruding and granulating the polypropylene/nano barium sulfate composite by means of a co-rotating twin-screw extruder to obtain a composite biological mesh raw material; and

[00381 Step 4: Extruding and spinning the composite biological mesh raw material by means of a single-screw extruder to obtain composite fibers; and weaving the composite fibers to obtain the developable composite biological mesh containing barium sulfate.

[0039] In order to increase the addition of barium sulfate and prepare a uniform barium sulfate polymer blend material, the present disclosure adopts a solution blending method for granulation. Specifically, polypropylene is dissolved in an organic solvent to obtain a polypropylene solution, nano barium sulfate is added to the polypropylene solution, and the two are stirred to mix well to obtain a polypropylene/nano barium sulfate solution. In the present disclosure, the polypropylene is not particularly limited in source, and may be one known to those skilled in the art. In the present disclosure, the organic solvent is preferably selected from one or more of toluene, xylene and decalin. In the present disclosure, the polypropylene is dissolved in the organic solvent preferably at a temperature of 100-120°C; the concentration of the polypropylene in the polypropylene solution is preferably 100-125 g/L; and the stirring time is preferably 2-4 h. The stirring in the present disclosure aims to mix the components well.

[0040] The obtained polypropylene/nano barium sulfate solution is added to a coagulating bath of the same volume for phase inversion curing; after the curing is finished, the product is taken out, washed and vacuum-dried to obtain a polypropylene/nano barium sulfate composite. The coagulating bath in the present disclosure is preferably selected from one of absolute ethanol or acetone.

[0041] The obtained polypropylene/nano barium sulfate composite is extruded and granulated by means of a co-rotating twin-screw extruder to obtain a composite biological mesh raw material. In the present disclosure, the extruding temperature of the co-rotating twin screw is preferably 150-200°C; and the screw speed is preferably 60-120 r/min, and more preferably 60 r/min.

[0042] The obtained composite biological mesh raw material is extruded and spun by means of a single-screw extruder to obtain composite fibers; and the composite fibers are woven to obtain a developable composite biological mesh containing barium sulfate.

In the present disclosure, the extruding temperature of the single-screw extruder is preferably 150-220°C, and more preferably 220°C.

[0043] For further understanding of the present disclosure, the developable composite biological mesh containing barium sulfate and the preparation method therefor provided by the present disclosure are described below in detail with reference to examples, and the scope of the present disclosure is not limited thereto. Example 1:

[0044] 80 mL of toluene and 10 g of polypropylene (85% based on the mass of a polypropylene/nano barium sulfate composite) were added into a reaction kettle, and stirred for dissolution, where the stirring rate of the reaction kettle was 200 r/min; and also, the reaction kettle was heated to 100°C. After the polypropylene was completely dissolved, 1.7647 g of nano barium sulfate powder (15% based on the mass of the polypropylene/nano barium sulfate composite) was added into the reaction kettle, where the average particle size of the nano barium sulfate powder was 70 nm. After the addition was complete, the mixture was further stirred for 2 h until the nano barium sulfate powder and the polypropylene were fully mixed well. Then, the polypropylene/nano barium sulfate solution was slowly poured into 80 mL of absolute ethanol coagulating bath, where the stirring rate of the coagulating bath was 30 r/min. Then, the polypropylene/nano barium sulfate composite was subjected to twin-screw extrusion and granulation to obtain a composite biological mesh raw material, where the extruder temperature was 150-200°C; and the screw speed was 60 r/min. The raw material particles were subjected to single-screw melt spinning to obtain composite fibers, where the spinning temperature was 220°C. The composite fibers were woven to obtain a biological mesh with a thickness of 0.6 mm and a pore size of 2 mm.

[0045] Tests showed that the mesh had a weight of 82 g/m2 and a tensile strength of 1,275 mmHg; and X-ray examination showed that the composite biological mesh was developed clearly. Example 2:

[00461 90 mL of toluene and 10 g of polypropylene (75% based on the mass of a polypropylene/nano barium sulfate composite) were added into a reaction kettle, and stirred for dissolution, where the stirring rate of the reaction kettle was 200 r/min; and also, the reaction kettle was heated to 100°C. After the polypropylene was completely dissolved, 3.3333 g of nano barium sulfate powder (25% based on the mass of the polypropylene/nano barium sulfate composite) was added into the reaction kettle, where the average particle size of the nano barium sulfate powder was 70 nm. After the addition was complete, the mixture was further stirred for 2 h until the nano barium sulfate powder and the polypropylene were fully mixed well. Then, the polypropylene/nano barium sulfate solution was slowly poured into 90 mL of absolute ethanol coagulating bath, where the stirring rate of the coagulating bath was 30 r/min. Then, the polypropylene/nano barium sulfate composite was subjected to twin-screw extrusion and granulation to obtain a composite biological mesh raw material, where the extruder temperature was 150-200°C; and the screw speed was 60 r/min. The raw material particles were subjected to single-screw melt spinning to obtain composite fibers, where the spinning temperature was 220°C. The composite fibers were woven to obtain a biological mesh with a thickness of 0.6 mm and a pore size of 2 mm.

[00471 Tests showed that the mesh had a weight of 84 g/m2 and a tensile strength of 1,065 mmHg; and X-ray examination showed that the composite biological mesh was developed clearly. Example 3:

[0048] 100 mL of toluene and 10 g of polypropylene (65% based on the mass of a polypropylene/nano barium sulfate composite) were added into a reaction kettle, and stirred for dissolution, where the stirring rate of the reaction kettle was 200 r/min; and also, the reaction kettle was heated to 100°C. After the polypropylene was completely dissolved, 5.3846 g of nano barium sulfate powder (35% based on the mass of the polypropylene/nano barium sulfate composite) was added into the reaction kettle, where the average particle size of the nano barium sulfate powder was 70 nm. After the addition was complete, the mixture was further stirred for 2 h until the nano barium sulfate powder and the polypropylene were fully mixed well. Then, the polypropylene/nano barium sulfate solution was slowly poured into 100 mL of absolute ethanol coagulating bath, where the stirring rate of the coagulating bath was 30 r/min. Then, the polypropylene/nano barium sulfate composite was subjected to twin-screw extrusion and granulation to obtain a composite biological mesh raw material, where the extruder temperature was 150-200°C; and the screw speed was 60 r/min. The raw material particles were subjected to single-screw melt spinning to obtain composite fibers, where the spinning temperature was 220°C. The composite fibers were woven to obtain a biological mesh with a thickness of 0.6 mm and a pore size of 2 mm.

[0049] Tests showed that the mesh had a weight of 86 g/m2 and a tensile strength of 820 mmHg; and X-ray examination showed that the composite biological mesh was developed clearly.

Comparative example 1

[0050] 80 mL of toluene and 10 g of polypropylene (90% based on the mass of a polypropylene/nano barium sulfate composite) were added into a reaction kettle, and stirred for dissolution, where the stirring rate of the reaction kettle was 200 r/min; and also, the reaction kettle was heated to 100°C. After the polypropylene was completely dissolved, 1.1111 g of nano barium sulfate powder (10% based on the mass of the polypropylene/nano barium sulfate composite) was added into the reaction kettle, where the average particle size of the nano barium sulfate powder was 70 nm. After the addition was complete, the mixture was further stirred for 2 h until the nano barium sulfate powder and the polypropylene were fully mixed well. Then, the polypropylene/nano barium sulfate solution was slowly poured into 80 mL of absolute ethanol coagulating bath, where the stirring rate of the coagulating bath was 30 r/min. Then, the polypropylene/nano barium sulfate composite was subjected to twin-screw extrusion and granulation to obtain a composite biological mesh raw material, where the extruder temperature was 150-200°C; and the screw speed was 60 r/min. The raw material particles were subjected to single-screw melt spinning to obtain composite fibers, where the spinning temperature was 220°C. The composite fibers were woven to obtain a biological mesh with a thickness of 0.6 mm and a pore size of 2 mm.

[0051] Tests showed that the mesh had a weight of 81 g/m2 and a tensile strength of 1,340 mmHg; and X-ray examination showed that the composite biological mesh was not developed clearly.

Comparative example 2

[0052] 100 mL of toluene and 10 g of polypropylene (60% based on the mass of a polypropylene/nano barium sulfate composite) were added into a reaction kettle, and stirred for dissolution, where the stirring rate of the reaction kettle was 200 r/min; and also, the reaction kettle was heated to 100°C. After the polypropylene was completely dissolved, 6.6666 g of nano barium sulfate powder (40% based on the mass of the polypropylene/nano barium sulfate composite) was added into the reaction kettle, where the average particle size of the nano barium sulfate powder was 70 nm. After the addition was complete, the mixture was further stirred for 2 h until the nano barium sulfate powder and the polypropylene were fully mixed well. Then, the polypropylene/nano barium sulfate solution was slowly poured into 100 mL of absolute ethanol coagulating bath, where the stirring rate of the coagulating bath was 30 r/min. Then, the polypropylene/nano barium sulfate composite was subjected to twin-screw extrusion and granulation to obtain a composite biological mesh raw material, where the extruder temperature was 150-200°C; and the screw speed was 60 r/min. The raw material particles were subjected to single-screw melt spinning to obtain composite fibers, where the spinning temperature was 220°C. The composite fibers were woven to obtain a biological mesh with a thickness of 0.6 mm and a pore size of 2 mm.

[0053] Tests showed that the mesh had a weight of 90 g/m2 and a tensile strength of 530 mmHg; and X-ray examination showed that the composite biological mesh was developed clearly.

[0054] The barium sulfate content in the materials, mesh weight, thickness, pore size, tensile strength and developing strength of the composite biological meshes in the examples 1-3 and comparative examples 1-2 are shown in Table 1. It can be seen from the examples and comparative examples that when the mass percentage of the barium sulfate is lower than 15%, the developing strength of the materials is not clear; and when the mass percentage of the barium sulfate is greater than 35%, the mechanical property of the material declines obviously. Table 1 Mass percentage Weight Thickness Pore size Tensile Developing Group of barium sulfate strength strength (%) (mmHg) 1 15 82 0.6 2 1,275 Clear Example 2 25 84 0.6 2 1,065 Clear 3 35 86 0.6 2 820 Clear Comparati 1 10 81 0.6 2 1,340 Not clear ve example 2 40 90 0.6 2 530 Clear

[0055] The present disclosure provides a composite biological mesh and a preparation method therefor. Whether the biological mesh is distorted can be judged by means of X-ray examination. Therefore, the judging method for postoperative lesions of hemiorrhaphy is simplified, the judging efficiency is improved, the patient's pain is relieved, and the needs of clinical application are satisfied.

[0056] The basic principles and main features as well as advantages of the present disclosure are shown and described above. It is obvious to those skilled in the art that, the present disclosure is not limited to the details of the above-mentioned exemplary examples; and the present disclosure can be implemented in other specific forms without departing from the spirit or basic features of the present disclosure. Therefore, from any point of view, the examples shall be deemed as exemplary and non-limiting. The scope of the present disclosure is defined by the attached claims rather than the descriptions above, and therefore, it is intended that all changes falling within the meanings and scope of equivalent elements of the claims are included in the present disclosure. Although the examples of the present disclosure have been shown and described, it can be understood by those of ordinary skill in the art that many changes, modifications, substitutions and variations may be made to these examples without departing from the principles and spirit of the present disclosure; and the scope of the present disclosure is defined by the attached claims and equivalents thereof.

[00571 Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention.

[00581 The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprise", "comprises," "comprising," "including," and "having," or variations thereof are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0059] Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of possible implementations. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of possible implementations includes each dependent claim in combination with every other claim in the claim set.

[0060] The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

Claims

What is claimed is: 1. A developable composite biological mesh containing barium sulfate, wherein the

composition of the composite biological mesh by mass percentage is: 65-85% of

polypropylene and 15-35% of nano barium sulfate;

the thickness of the developable composite biological mesh is 0.6 mm, and the

aperture of the developable composite biological mesh is 2 mm;

the particle size of the nano barium sulfate ranges from 30 nm -70 nm.
2. The developable composite biological mesh containing barium sulfate according to

claim 1, wherein the polypropylene is medical-grade isotactic polypropylene, with a

melting point of 164°C -170°C and an isotactic index greater than or equal to 96%.
3. A preparation method for the developable composite biological mesh containing

barium sulfate according to claim 1 or 2, comprising the following steps:

Step 1: Dissolving polypropylene in an organic solvent to obtain a polypropylene

solution, adding nano barium sulfate to the polypropylene solution, and stirring to

mix the two well to obtain a polypropylene/nano barium sulfate solution;

Step 2: Adding the polypropylene/nano barium sulfate solution obtained in step 1 to

a coagulating bath of the same volume for phase inversion curing; and obtaining,

after the curing is finished, a cured product, taking out, washing and vacuum drying

the cured product to obtain a polypropylene/nano barium sulfate composite;

Step 3: Extruding and granulating the polypropylene/nano barium sulfate composite

by means of a co-rotating twin-screw extruder to obtain a composite biological mesh

raw material; and

Step 4: Extruding and spinning the composite biological mesh raw material by means

of a single-screw extruder to obtain composite fibers; and weaving the composite

fibers to obtain the developable composite biological mesh containing barium

sulfate.
4. The preparation method for the developable composite biological mesh containing

barium sulfate according to claim 3, wherein in step 1, the organic solvent is one or more

of toluene, xylene and decalin.
5. The preparation method for the developable composite biological mesh containing

barium sulfate according to claim 3, wherein in step 1, the polypropylene is dissolved in

the organic solvent at a temperature of 100°C-120°C; the concentration of the

polypropylene in the polypropylene solution is 1OOg/L -125 g/L; and the stirring time is 2

hour -4 hour.
6. The preparation method for the developable composite biological mesh containing

barium sulfate according to any one of claims 3 to 5, wherein in step 2, the coagulating

bath comprises one of absolute ethanol or acetone.
7. The preparation method for the developable composite biological mesh containing

barium sulfate according to any one of claims 3 to 6, wherein in step 3, the extruding

temperature is 150°C -200°C; and the screw speed is 60 r/min -120 r/min.
8. The preparation method for the developable composite biological mesh containing

barium sulfate according to any one of claim 3 to 7, wherein in step 4, the extruding

temperature is 150°C -220°C.