CN220593823U - Biological film pressing freeze-drying mould and biological film - Google Patents

Abstract

The utility model provides a biological film pressing freeze-drying mold which comprises a first surface and a second surface which are oppositely arranged, wherein the first surface is an indentation surface, the indentation surface is provided with a convex structure and a concave structure, and the second surface is a smooth surface. The mold can be used for pressing and freeze-drying the biological film material into the biological film with different double surfaces having different structures, namely, a convex structure and a concave structure can be arranged on one surface of the pressed and freeze-dried biological film, so that the bonding degree and the contact surface area of the biological film and a part to be repaired can be effectively increased, the bonding degree of the biological film medical material and a tissue defect part is improved, and the clinical use and the treatment effect are improved. The utility model also provides a biological film which is formed by adopting the biological film pressing and freeze-drying mold for pressing and freeze-drying. The biomembrane prepared by the die has simple processing procedure and can carry out rapid pressing freeze-drying treatment on biomembrane raw materials.

Description

Biological film pressing freeze-drying mould and biological film

Technical Field

The utility model relates to the technical field of medical equipment production equipment, in particular to a biological film pressing freeze-drying mold and a biological film.

Background

Membrane guided tissue regeneration (Guided Tissue Regeneration, GTR) techniques have been widely used in the field of tissue repair, the principle of which is to prevent soft tissue cells from entering the bone growth area by the physical barrier action of the membrane material, and to reserve space for new bone growth in the bone defect area, the key of the GTR technique being to guide the use of membranes. The tissue structure and active ingredients of raw materials can be reserved to the greatest extent by vacuum freeze drying, and most of biological implantable medical device products are freeze-dried film products. Most of the existing biomembrane pressing and freeze-drying devices are of an integrated pressing type, and two sides of a biomembrane material obtained by pressing and freeze-drying are smooth and flat. However, in the actual clinical treatment process, the tissue defect is always in an irregular state, and the adhesion degree between the smooth and flat biomembrane and the tissue defect part has a certain defect, so that gaps exist between the biomembrane and the tissue defect part, and fibroblasts and epithelial cells with higher growth migration rate enter a bone defect area to form competitive inhibition with osteoblasts with slower growth migration rate, thereby adversely affecting the healing of bone tissues and further affecting the treatment effect. And most of the existing biomembrane pressing freeze-drying devices have complex structures and higher manufacturing cost.

Chinese patent publication No. CN210832769U discloses a freeze-drying mold for decellularized matrix material, comprising a bottom plate, a pressing plate and a fixing device; the bottom plate with the clamp plate size is unanimous, the bottom plate with be provided with the round hole that runs through the panel on the clamp plate, the clamp plate with the one side of bottom plate contact is provided with bellied gridlines. The raised grid lines can further increase the friction and binding force of the acellular matrix material and the pressing plate, and prevent the acellular matrix material from sliding and deforming; however, the freeze-drying mold is required to be specially provided with a fixing hole penetrating through the plate, the operation steps are complex, and the manufacturing cost is high; the pressed biofilm surface has vent holes and grid lines, which can affect the appearance of the product, i.e. the finally prepared biofilm.

Chinese patent publication No. CN215571644U discloses a tool for preparing decellularized extracellular matrix material, which comprises a bottom plate and a pressing plate, wherein the bottom plate and the pressing plate are square plates, the edge around the surface of the bottom plate is provided with needles perpendicular to the plate surface, the pressing plate is provided with pinholes, the diameter of the pinholes is 0.5-1 cm larger than that of the needles, and the pinholes on the pressing plate correspond to the needles on the bottom plate one by one. But the preparation is solid stainless steel, the freeze-drying efficiency is low, and the freeze-drying effect is poor.

Accordingly, there is a need to provide a novel biofilm compression lyophilization die and biofilm to solve the above-described problems in the prior art.

Disclosure of Invention

The utility model aims to provide a biomembrane pressing freeze-drying mold and a biomembrane, so that biomembrane materials can be pressed and freeze-dried into biomembranes with different structures on two sides by using the mold, namely, one surface of the pressed and freeze-dried biomembrane can be provided with a convex structure and a concave structure, thereby effectively increasing the bonding degree and the contact surface area of the biomembrane and a part to be repaired, improving the bonding degree of biomembrane medical materials and a tissue defect part, and improving clinical use and treatment effects.

In order to achieve the above purpose, the biological film pressing freeze-drying mold comprises a first surface and a second surface which are oppositely arranged, wherein the first surface is an indentation surface, the indentation surface is provided with a convex structure and a concave structure, and the second surface is a smooth surface.

The biological film pressing freeze-drying mold has the beneficial effects that: the first surface is an indentation surface, the indentation surface is provided with a convex structure and a concave structure, and the second surface is a smooth surface, so that the die can be used for pressing and freeze-drying a biological film material into biological films with different structures on two surfaces; namely, the indentation surface provided with the convex structures and the concave structures enables the convex structures and the concave structures to be arranged on one surface of the biological film formed by compression freeze-drying, so that the fitting degree and the contact surface area of the biological film and the part to be repaired can be effectively increased, the fitting degree of the medical material of the biological film and the tissue defect part is improved, and the clinical use and the treatment effect are improved. Solves the problems that in the prior art, gaps exist between the biological film with smooth and flat surfaces and the tissue defect part, so that fibroblasts and epithelial cells with higher growth migration rate enter the bone defect area and form competitive inhibition with osteoblasts with lower growth migration rate, thereby adversely affecting the healing of bone tissues.

Preferably, the die comprises a first layer body and a second layer body, the first layer body and the second layer body are vertically overlapped and fixed, the opposite surfaces of the first layer body and the second layer body are respectively the first surface and the second surface, and the first layer body and the second layer body are woven by adopting 316L-shaped stainless steel wires. The beneficial effects are that: the stainless steel mold has the advantages of simple structure, simple manufacturing process and low manufacturing cost, and the stainless steel material has corrosion resistance and weldability, so that the mold has good stability and plasticity and high mechanical strength.

Preferably, the first layer body is woven in a close-stitch weaving mode, and the second layer body is woven in a twill weaving mode. The beneficial effects are that: the first layer body is woven in a close-grained manner, so that the first surface of the first layer body can effectively form the protruding structure and the recessed structure, and the second layer body is woven in a twill manner, so that the second surface of the second layer body is smooth and even.

Preferably, warp yarn diameter of the stainless steel wires for weaving the first layer body is 0.2-0.28 mm, weft yarn diameter is 0.14-0.2 mm, aperture of the first layer body is 60-100 meshes, and thickness of the first layer body is 1.2-3.4 mm. The beneficial effects are that: the first surface of the die can better form the protruding structures and the recessed structures, so that the protruding structures and the recessed structures on the pressed and freeze-dried biological film can effectively increase the fitting degree and the contact surface area of the film material and the part to be repaired.

Preferably, the diameter of the stainless steel wire for weaving the second layer body is 0.04-0.045 mm, the aperture of the second layer body is 250-300 meshes, and the thickness of the second layer body is 0.3-0.7 mm. The beneficial effects are that: the second surface of the second layer body is flat, and the aperture is dense and fine.

Preferably, the protruding structures and the recessed structures are alternately arranged, and the space between every two adjacent protruding structures in the warp direction is 0.14-0.2 mm, and the space between every two adjacent protruding structures in the weft direction is 0.2-0.28 mm. The beneficial effects are that: the formed biological film has the convex structure and the concave structure, so that the biological film can be tightly attached to a tissue defect part, external soft tissue cells are prevented from entering, the effect of isolating soft tissue from growing into a bone defect area is achieved, and a good treatment effect is achieved.

Preferably, the length of the die is 6-10 cm, the width is 4-8 cm, and the thickness is 1.5-4.1 mm. The beneficial effects are that: the die is light in weight, the biological film is not crushed when being prepared, the pressing effect is ensured, meanwhile, materials are saved, and the input cost is reduced.

Preferably, the first layer body and the second layer body are welded by adopting a micro-point resistance welding mode or a seamless butt welding mode. The beneficial effects are that: the die is free of protruding welding spots and burrs, the first layer body and the second layer body are combined tightly without gaps, and layering and falling-off phenomena can be avoided.

Preferably, the first layer and the second layer each comprise 4-8 layers of stainless steel wire mesh. The beneficial effects are that: if the number of layers is too large, the air permeability and the permeability are poor, the freeze-drying effect of the biological film can be affected, and if the number of layers is too small, the whole weight is light, and the pressing effect of the die on the biological film can be affected.

The biological film is formed by pressing and freeze-drying the biological film by adopting the biological film pressing and freeze-drying mold, the biological film comprises an upper surface and a lower surface which are oppositely arranged, the upper surface and the lower surface are any one of a smooth surface and an indentation surface, the indentation surface is provided with the convex structure and the concave structure which are pressed by the indentation surface of the mold, and the smooth surface is provided with the smooth structure which is pressed by the smooth surface of the mold.

The beneficial effects of the biological film of the utility model are as follows: the biomembrane is formed by adopting the biomembrane pressing freeze-drying mold to press freeze-dry, so that the biomembrane can be manufactured into a structure with different surfaces, when one surface of the biomembrane is provided with a convex structure and a concave structure, the fitting degree and the contact surface area of the biomembrane and a part to be repaired can be effectively increased, the fitting degree of a biomembrane medical material and a tissue defect part is improved, the clinical use and the treatment effect are improved, the problem that gaps exist between the biomembrane and the tissue defect part, which are smooth and flat on both surfaces, in the prior art, cause fibroblasts and epithelial cells with higher growth migration rate to enter a bone defect area, form competitive inhibition with osteoblasts with slower growth migration rate, and have adverse effects on the healing of bone tissues is solved. The die has wide application range and strong universality, namely two identical surfaces of the die can be used according to requirements to press freeze-dry the biomembrane material, so that the biomembrane with both surfaces being indentation surfaces or the biomembrane with both surfaces being smooth surfaces can be obtained, and the biomembrane material can be pressed freeze-dried by using different surfaces of the die, so that the biomembrane with one surface being indentation surfaces and the other surface being smooth surfaces can be obtained.

Drawings

FIG. 1 is a schematic view of a mold for press-freeze-drying a biological film according to a first embodiment of the present utility model;

FIG. 2 is a schematic view of a mold for press-freeze-drying a biological film according to a second embodiment of the present utility model;

FIG. 3 is an enlarged schematic view of the surface of the first layer in the mold for lyophilizing a biological film shown in FIG. 2;

fig. 4 is an enlarged schematic view of the structure of the surface of the second layer in the mold for press-freeze-drying of a biological film shown in fig. 2.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions in the embodiments of the present utility model will be clearly and completely described below, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model. Unless otherwise defined, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this utility model belongs. As used herein, the word "comprising" and the like means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof without precluding other elements or items.

In order to overcome the problems in the prior art, the embodiment of the utility model provides a biomembrane pressing freeze-drying mold and a biomembrane, so that biomembrane materials can be pressed and freeze-dried into biomembranes with different structures on two sides by using the mold, namely, one surface of the pressed and freeze-dried biomembrane can be provided with a convex structure and a concave structure, thereby effectively increasing the bonding degree and the contact surface area of the biomembrane and a part to be repaired, improving the bonding degree of biomembrane medical materials and a tissue defect part, and improving clinical use and treatment effects.

In some embodiments of the present utility model, the biofilm pressing freeze-drying mold includes a first surface and a second surface that are disposed opposite to each other, the first surface is an indentation surface, the indentation surface is provided with a convex structure and a concave structure, and the second surface is a smooth surface. The mold can be used for pressing and freeze-drying the biological film material into biological films with different structures on the two surfaces; namely, the indentation surface provided with the convex structures and the concave structures enables the convex structures and the concave structures to be arranged on one surface of the biological film formed by compression freeze-drying, so that the fitting degree and the contact surface area of the biological film and the part to be repaired can be effectively increased, the fitting degree of the medical material of the biological film and the tissue defect part is improved, and the clinical use and the treatment effect are improved. Solves the problems that in the prior art, gaps exist between the biological film with smooth and flat surfaces and the tissue defect parts, so that fibroblasts and epithelial cells with higher growth migration rate enter the bone defect areas and form competitive inhibition with osteoblasts with lower growth migration rate, thereby adversely affecting the healing of bone tissues; and the second surface of the die with the smooth surface enables a smooth surface with uniform internal pore size to be obtained on the other surface of the pressed and lyophilized biological film.

Fig. 1 is a schematic view of a mold for press-freeze-drying a biological film according to a first embodiment of the present utility model.

In some embodiments of the present utility model, the mold for pressing and freeze-drying a biological film is in an integrally formed structure, and the mold includes a first surface and a second surface that are disposed opposite to each other, referring to fig. 1, the first surface is an indentation surface 1, the indentation surface 1 is provided with a convex structure (not labeled in the figure) and a concave structure (not labeled in the figure), and the second surface (not labeled in the figure) is a smooth surface.

Fig. 2 is a schematic diagram of a mold for press-freeze-drying a biological film according to a second embodiment of the present utility model.

In some embodiments of the present utility model, referring to fig. 2, the mold includes a first layer 11 and a second layer 12, the first layer 11 and the second layer 12 are fixed in an overlapping manner, opposite surfaces of the first layer 11 and the second layer 12 are the first surface 111 and the second surface (not labeled in the drawing) respectively, and the first layer 11 and the second layer 12 are both woven by 316L stainless steel wires. The stainless steel mold has the advantages of simple structure, simple manufacturing process and low manufacturing cost, and the stainless steel material has corrosion resistance and weldability, so that the mold has good stability and plasticity and high mechanical strength.

FIG. 3 is an enlarged schematic view of the surface of the first layer in the mold for lyophilizing a biological film shown in FIG. 2; fig. 4 is an enlarged schematic view of the structure of the surface of the second layer in the mold for press-freeze-drying of a biological film shown in fig. 2.

In some embodiments of the present utility model, referring to fig. 3 and 4, the first layer 11 is woven by a closed-weave weaving method, so that the first surface 111 of the first layer 11 is an indentation surface, and the indentation surface is provided with the protruding structures 101 and the recessed structures 102 that are orderly arranged. The dense knitting refers to that warp threads and weft threads are different in thread diameter and mesh number, and is characterized by thin warp and weft densities, thick warp and thin weft. The warp yarn is in the longitudinal direction, the weft yarn is in the width direction, the direction indicated by a in fig. 3 is in the longitudinal direction, and the direction perpendicular to a is in the width direction. The specific structure of the micro-pattern woven is shown in fig. 3, and the weaving method is conventional in the art, and will not be described herein. The second layer 12 is woven in a twill weaving manner, so that the second surface (not labeled in the figure) of the second layer 12 is a smooth surface, and the surface is relatively smooth, and the aperture is dense and fine. The twill knitting refers to a knitting method that each warp yarn passes through every two weft yarns in an intersecting manner, each weft yarn passes through every two warp yarns in an intersecting manner, and the specific structure after the twill knitting is shown in fig. 4. The first layer 11 woven by the micro-pattern weaving mode has good acid resistance, alkali resistance, high temperature resistance, strong pressure resistance, strong wear resistance and the like; the second layer 12 woven by the twill weaving method has the characteristics of flat and smooth surface, strong corrosion resistance, firmness, durability and the like. The first layer 11 is woven by a close-stitch weaving mode, so that the surface of the first layer 11 can effectively form a convex structure 101 and a concave structure 102, and the second layer 12 is woven by a twill weaving mode, so that the surface of the second layer 12 is smooth and even.

In some embodiments of the present utility model, the warp yarn diameter of the stainless steel wire used for weaving the first layer body is 0.2-0.28 mm, the weft yarn diameter is 0.14-0.2 mm, the aperture of the first layer body is 60-100 meshes, and the thickness of the first layer body is 1.2-3.4 mm. The first surface of the die can better form the protruding structures and the recessed structures, so that the protruding structures and the recessed structures on the pressed and freeze-dried biological film can effectively increase the fitting degree and the contact surface area of the film material and the part to be repaired.

In some embodiments of the present utility model, the stainless steel wires woven into the first layer have warp diameters of 0.25 mm and weft diameters of 0.18 mm, the first layer has a pore diameter of 80 mesh, and the first layer has a thickness of 2 mm.

In some embodiments of the present utility model, the diameter of the stainless steel wire used for braiding the second layer body is 0.04-0.045 mm, the aperture of the second layer body is 250-300 meshes, and the thickness of the second layer body is 0.3-0.7 mm. The second surface of the second layer body is flat, and the aperture is dense and fine.

In some embodiments of the utility model, the second layer has a pore size of 0.0446-0.0556 mm.

In some embodiments of the present utility model, the second layer of the mold is made of stainless steel wire with a diameter of 0.042 mm, the aperture of the second layer is 0.05 mm, and the thickness of the second layer is 0.5 mm. The pore diameter of the second surface of the die is dense and tiny by adopting finer stainless steel wire braiding, the surface is smooth, and a smoother morphology structure can be pressed on the biomembrane material.

In some embodiments of the present utility model, the protruding structures and the recessed structures are arranged alternately, and the spacing between adjacent protruding structures in the warp direction is 0.14-0.2 mm, and the spacing between adjacent protruding structures in the weft direction is 0.2-0.28 mm. The formed biological film has the convex structure and the concave structure, so that the biological film can be tightly attached to a tissue defect part, external soft tissue cells are prevented from entering, the effect of isolating soft tissue from growing into a bone defect area is achieved, and a good treatment effect is achieved.

In some embodiments of the present utility model, the protruding structures and the recessed structures are arranged alternately, and the spacing between adjacent protruding structures in the warp direction is 0.15 mm, and the spacing between adjacent protruding structures in the weft direction is 0.26 mm.

In some embodiments of the present utility model, the weft yarn diameter of the stainless steel wire of the first layer is a first yarn diameter, the warp yarn diameter of the stainless steel wire of the first layer is a second yarn diameter, the protruding structures and the recessed structures are alternately arranged, the space between adjacent protruding structures in the warp direction is equal to the first yarn diameter, and the space between adjacent protruding structures in the weft direction is equal to the second yarn diameter.

In some embodiments of the present utility model, warp yarn diameters of the stainless steel yarns weaving the first layer body are second yarn diameters, the protruding structures and the recessed structures are alternately arranged, and a height difference between the protruding structures and the recessed structures is equal to the second yarn diameters.

In some embodiments of the present utility model, the protruding structures and the recessed structures are arranged at intervals, and a height difference between the protruding structures and the recessed structures is 0.2-0.28 mm.

In some embodiments of the utility model, the mold has a length of 6-10 cm, a width of 4-8 cm, and a thickness of 1.5-4.1 mm. The die is light in weight, the biological film is not crushed when being prepared, the pressing effect is ensured, meanwhile, materials are saved, and the input cost is reduced.

In some embodiments of the utility model, the mold has a sheet structure of 8 cm×6 cm, which not only can meet the size required by the existing biological film pressing and freeze-drying treatment, but also can not deform the biological film material, and can save the production material of the freeze-drying mold.

In some embodiments of the present utility model, the first layer and the second layer are welded by micro-point resistance welding or seamless butt welding. The die is free of protruding welding spots and burrs, the first layer body and the second layer body are combined tightly without gaps, layering and falling-off phenomena are avoided, and the die has high stability.

In some embodiments of the utility model, the first layer and the second layer each comprise 4-8 layers of stainless steel mesh. If the number of layers is too large, the air permeability and the permeability are poor, the freeze-drying effect of the biological film can be affected, and if the number of layers is too small, the whole weight is light, and the pressing effect of the die on the biological film can be affected.

In some embodiments of the present utility model, the preparation step of the mold comprises:

step one, knitting the 316L stainless steel wires into two stainless steel wire nets with different structures by adopting a close-weave mode and a twill weave mode respectively, and manufacturing five stainless steel wires respectively;

step two, laminating and pressing five stainless steel wires woven in a close-grained weaving mode in a surface flush mode, and then vacuum sintering to obtain the first layer body, laminating and pressing other five stainless steel wires woven in a diagonal weaving mode in a surface flush mode, and then vacuum sintering to obtain the second layer body;

and thirdly, adopting a seamless butt welding technology to obtain the die by the first layer body and the second layer body.

In some embodiments of the utility model, the 316L stainless steel wire surface is electropolished so that it will not rust during use, cleaning, etc.

In some embodiments of the utility model, the vacuum sintering process is simple and convenient to operate, and can improve the purity of the hard alloy, so that the hard alloy has higher pressure resistance and good plasticity, and is convenient for subsequent processing, welding and assembly.

In some embodiments of the present utility model, the biofilm is formed by pressing and freeze-drying the biofilm by using the biofilm pressing and freeze-drying mold, and the biofilm includes an upper surface and a lower surface which are oppositely arranged, wherein the upper surface and the lower surface are any one of a smooth surface and an indentation surface, the indentation surface is provided with the convex structure and the concave structure pressed by the indentation surface of the mold, and the smooth surface is provided with the smooth structure pressed by the smooth surface of the mold. The biological membrane can be manufactured into two sides with different structures, when one surface of the biological membrane is provided with a convex structure and a concave structure, the bonding degree and the contact surface area of the biological membrane and a part to be repaired can be effectively increased, the bonding degree of the biological membrane medical material and a tissue defect part is improved, the clinical use and the treatment effect are improved, the problems that gaps exist between the biological membrane and the tissue defect part, which are smooth and flat on two sides, cause fibroblasts and epithelial cells with higher growth migration rate to enter a bone defect area, form competitive inhibition with osteoblasts with slower growth migration rate, and adversely affect the healing of bone tissues in the prior art are solved. The biomembrane prepared by the die has simple processing procedure and can carry out rapid pressing freeze-drying treatment on biomembrane raw materials. The die has wide application range and strong universality, namely two dies can be used on the same side according to requirements to press and freeze-dry the biological film material, so that the biological film with both surfaces being indentation surfaces or the biological film with both surfaces being smooth surfaces can be obtained, and the biological film material can be pressed and freeze-dried by using two dies on different sides of the die, so that the biological film with one surface being indentation surface and the other surface being smooth surface can be obtained.

In some embodiments of the present utility model, when the biofilm is processed, firstly, the biofilm material is put on the die of sterile stainless steel, one surface of the biofilm material is attached to the first surface of the first die to form the indentation surface, even if the manufactured biofilm surface forms the convex structure and the concave structure, and then the second surface of the second die is covered on the other surface of the biofilm material to form the smooth surface. After the biomembrane material is clamped between the dies, another layer is paved again, namely one surface of the other biomembrane material is attached to the first surface of the second die to form the indentation surface, the indentation surfaces are overlapped layer by layer, then the dies clamping the biomembrane material are placed into a vacuum freeze dryer, a program is set for freeze drying, and the required biomembrane is obtained after freeze drying is completed. The number of layers of the biomembrane material is generally 2-6, so that the freeze-drying material is prevented from being deformed by pressing due to the overlarge weight of the pressing freeze-drying mold, and the energy consumption required by freeze-drying is reduced. The biological film obtained after compression freeze-drying has two structures of an indentation surface and a smooth surface, the indentation surface can be tightly attached to a tissue defect part, and external soft tissue cells are prevented from growing in, so that a good treatment effect is achieved.

In some embodiments of the utility model, the opposing surfaces of the biofilm are an indentation surface and a smooth surface, respectively.

In other embodiments of the utility model, the opposing surfaces of the biofilm are an indentation surface and an indentation surface, respectively.

In still other embodiments of the utility model, the opposing surfaces of the biofilm are smooth and planar surfaces, respectively.

While embodiments of the present utility model have been described in detail hereinabove, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. It is to be understood that such modifications and variations are within the scope and spirit of the present utility model as set forth in the following claims. Moreover, the utility model described herein is capable of other embodiments and of being practiced or of being carried out in various ways.

Claims (10)

1. The biological film pressing freeze-drying mold is characterized by comprising a first surface and a second surface which are oppositely arranged, wherein the first surface is an indentation surface, the indentation surface is provided with a convex structure and a concave structure, and the second surface is a smooth surface.

2. The mold for pressing and freeze-drying the biological film according to claim 1, comprising a first layer body and a second layer body, wherein the first layer body and the second layer body are vertically overlapped and fixed, the opposite surfaces of the first layer body and the second layer body are respectively the first surface and the second surface, and the first layer body and the second layer body are both woven by 316L-shaped stainless steel wires.

3. The mold for press-freeze-drying of a biological film according to claim 2, wherein the first layer body is woven by a close-weave manner, and the second layer body is woven by a twill weave manner.

4. A mold for press freeze-drying of a biological film according to claim 3, wherein the warp yarn diameter of the stainless steel wire for weaving the first layer body is 0.2-0.28 mm, the weft yarn diameter is 0.14-0.2 mm, the pore diameter of the first layer body is 60-100 mesh, and the thickness of the first layer body is 1.2-3.4 mm.

5. A mould according to claim 3, wherein the stainless steel wires used for braiding the second layer have a wire diameter of 0.04-0.045 mm, the pore diameter of the second layer is 250-300 mesh, and the thickness of the second layer is 0.3-0.7 mm.

6. The mold according to claim 1 or 2, wherein the protruding structures and the recessed structures are arranged alternately, and the pitch between the adjacent protruding structures in the warp direction is 0.14-0.2 mm, and the pitch between the adjacent protruding structures in the weft direction is 0.2-0.28 mm.

7. The mold for press-freeze-drying of a biological film according to claim 1 or 2, wherein the mold has a length of 6-10 cm, a width of 4-8 cm, and a thickness of 1.5-4.1 mm.

8. The mold for press freeze-drying of a biological film according to claim 2, wherein the first layer body and the second layer body are welded by micro-point resistance welding or seamless butt welding.

9. The mold for press freeze-drying of a biological film according to claim 2, wherein the first layer and the second layer each comprise 4-8 layers of stainless steel wire mesh.

10. A biofilm, characterized in that the biofilm is formed by pressing and freeze-drying by using a biofilm pressing and freeze-drying mould according to any one of claims 1-9, wherein the biofilm comprises an upper surface and a lower surface which are oppositely arranged, the upper surface and the lower surface are any one of a smooth surface and an indentation surface, the indentation surface is provided with the convex structure and the concave structure pressed by the indentation surface of the mould, and the smooth surface is provided with the smooth structure pressed by the smooth surface of the mould.