CN110786965B

CN110786965B - Method for preparing multi-channel antibacterial nerve conduit by ingot-changing weaving method

Info

Publication number: CN110786965B
Application number: CN201911112709.XA
Authority: CN
Inventors: 许建梅; 赵明达; 蒋季; 戴佳莹; 陈钱
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2021-04-30
Anticipated expiration: 2039-11-14
Also published as: CN110786965A

Abstract

The invention relates to a method for preparing a multi-channel antibacterial nerve conduit by a variable ingot weaving method, which comprises the following steps: weaving a plurality of inner conduit weaving yarns outside the inner filling core material to form a conduit, wherein the conduit comprises the inner filling core material and a pipe body sleeved outside the inner filling core material; the color difference between the inner conduit knitting yarns and the inner filling core material is obvious, the inner filling core material is in a solid cylinder shape and has a smooth surface, and the number of the inner conduit knitting yarns can be estimated through the following formula;

wherein m represents the number of inner catheter-knitting yarns, d_yRepresents the diameter of the knitting yarn of the inner catheter, R represents the inner diameter of the outer catheter, n represents the number of the inner catheters in the multi-channel antibacterial nerve catheter, and R represents the inner radius of the inner catheter; k is more than 0 and less than or equal to 1, and lambda is more than 0 and less than or equal to 1; dividing the catheter into n tubes, arranging the n tubes side by side to serve as a core material, weaving outer catheter weaving yarns outside the core material to form the outer catheter outside the core material, and then removing the core material filled in the outer catheter to obtain the multichannel antibacterial nerve catheter.

Description

Method for preparing multi-channel antibacterial nerve conduit by ingot-changing weaving method

Technical Field

The invention relates to a preparation method of a nerve conduit, in particular to a method for preparing a multi-channel antibacterial nerve conduit by a spindle changing weaving method.

Background

Nerve injury is a treatment problem in the medical field at present, and when the distance of nerve defects is large, the standard method in clinic is to adopt an autologous nerve transplantation method. However, there are many problems in autologous nerve transplantation, and firstly, the nerve donor site is faced with functional or sensory disorders caused by secondary injury and nerve defect of the donor area; secondly, the different types of nerve fibers differ greatly in size, resulting in a mismatch. And the allogeneic nerve transplantation can generate immunological rejection reaction. Therefore, for long-distance nerve defects, a reliable method and an ideal material for preparing an artificial nerve conduit for nerve repair are continuously searched for to replace the autologous nerves.

At present, the preparation method of the artificial nerve conduit mainly uses a lot of materials including polylactic acid, chitosan, collagen, fibroin, sodium alginate and the like with good biocompatibility, and the preparation method mainly adopts a mold method, an extraction method, an extrusion molding method, an electrostatic spinning method, a weaving method and the like. The nerve conduit materials on the market at present are mainly nerve conduits such as Neurotube, NeuraGen, Neuroflex and the like in the United states. Neurotube is mainly prepared from polyglycolic acid (PGA), while neurogen and Neuroflex materials are type I collagen. These catheters have been used clinically, but because they are hollow, they can only be used for short distance (less than 30mm) neurological defects.

At present, in the field of preparation of artificial nerve conduits, the repair of nerve defects by a hollow nerve conduit structure is far inferior to that of a structure of a filling stent in a conduit. At present, the structure of the stent filled in the catheter mainly comprises two structures, one structure is that the catheter is filled with fibers arranged in parallel to guide nerve cells and axons to grow along the fiber direction, and repair of defective nerves is accelerated. The other is that a microporous channel is formed in the conduit. There are a certain number of papers about the preparation technology of the microporous channel artificial nerve conduit, but most of them adopt the methods of electrostatic spinning, mold method, etc. The nerve conduits prepared by the methods have the common defect of insufficient mechanical properties. For example, Jeffries et al (Eric M Jeffries, Yang Wang. introduction of parallel electronic fibers for improved porous guiding in 3D neural guides, Biochemical, 2013, (5):1-8.) of the university of Pittsburgh, USA discloses a method for preparing a multichannel microporous nerve conduit using electrospinning technology. The method has the advantages of more manual operation parts in the preparation process, larger batch-to-batch difference and deficient mechanical property of the finished product. The poor mechanical properties are mainly reflected in poor compression resistance and tensile property, and the conduit is hard and has poor non-deforming capability in bending. Tansey et al (K.E. Tansey, J.L. seifer, B.Botterman, et al.Periphery neural pair through multi-luminal biological assays, Annals of biological Engineering,2011, 39(6):1815-1826.) of Emeric university, U.S. Emeric university discloses a method for preparing a multi-channel nerve conduit by using a mold method, the length and the diameter of the nerve conduit prepared by the method are obviously limited by the mold, the length and the diameter of the conduit cannot be freely controlled, and the length of the nerve conduit prepared by the method is obviously limited, and if a slightly longer conduit is prepared, the problems of long distance permeation and solidification of a solution to a lumen in the conduit exist, and the mechanical properties of the conduit are not ideal. CN200420009148.3 discloses a special mold method for making an axial multichannel nerve conduit, which uses a movable stainless steel needle to generate a channel. CN201510270788.2 discloses a method and a mold for manufacturing a multichannel nerve conduit, the mold includes an outer tube and an inner tube inserted into the outer tube, one end of the outer tube is connected to a liquid tank, the other end is provided with a cavity for inserting the inner tube, and an alloy wire is inserted and then removed to form multiple channels. Patent CN201010595866.3 discloses a method for preparing a multichannel nerve conduit by combining a die and an electrospinning method. The method adopts a method of adding iron wires into a polytetrafluoroethylene tubular mold to prepare the gelatin multichannel nerve conduit, and then uses the conduit as a receiving device to spin a layer of polylactic acid-caprolactone copolymer (PLCL) electrostatic spinning membrane on the outer layer of the conduit. The cross-sectional view of the catheter disclosed in the patent of the method shows that the formed internal channels are different in size and have larger shape difference, and the preparation technology of the catheter is immature. CN201310674367.7 discloses a method for constructing a multi-channel spongy nerve conduit by two-time forming and a special mould, wherein the mould comprises a single-channel forming mould and a multi-channel forming mould, the single-channel forming mould is firstly used for preparing the single-channel conduit, then the single-channel forming mould is filled with a multi-channel mould, polymer solution is injected, and the multi-channel spongy nerve conduit is obtained after freeze drying.

In summary, the prior art for preparing the microporous channel artificial nerve conduit is mostly limited to the electrostatic spinning method and the die method or the combination of the two methods. The nerve conduits prepared by the methods have the common defects of poor repeatability of sample preparation, large batch-to-batch difference and poor mechanical property. The spinning membrane prepared by the electrostatic spinning method has poor membrane operability in the process of preparing the nerve conduit and is easy to deform and tear. The catheter manufactured by the die method usually adopts a method of solvent volatilization and chemical crosslinking, the manufactured catheter may have the problem that the crosslinking agent has toxicity, and if the genipin is adopted as the crosslinking agent, although the toxicity is not high, the cost is too high. If no cross-linking agent is used, the mechanical properties of the catheter are not ideal.

Disclosure of Invention

In order to solve the above technical problems, an object of the present invention is to provide a method for preparing a multi-channel antibacterial nerve conduit by a spindle-changing braiding method, which can prepare multi-channel antibacterial nerve conduits having different channel numbers and pore diameters and good mechanical properties, and having excellent antibacterial properties.

The invention aims to provide a method for preparing a multi-channel antibacterial nerve conduit by a variable ingot weaving method, wherein the multi-channel antibacterial nerve conduit comprises a plurality of inner conduits arranged in parallel and outer conduits wrapped outside the inner conduits, the axes of the inner conduits are parallel to the axes of the outer conduits, and the inner conduits and the outer conduits are in a hollow cylindrical shape, and the method for preparing the multi-channel antibacterial nerve conduit is characterized by comprising the following steps:

(1) tightly weaving a plurality of inner conduit weaving yarns outside a rigid and smooth-surface inner filling core material to form a conduit, wherein the conduit comprises the inner filling core material and a pipe body sleeved outside the inner filling core material; the inner conduit weaving yarn and the inner filling core material have different colors and obvious difference, the inner conduit weaving yarn is a medical polymer material, the inner filling core material is in a solid cylinder shape, the outer surface is smooth, in order to realize the specific number of pores, the number of inner conduit weaving spindles, namely the number of the inner conduit weaving yarns, is changed to obtain a multi-channel conduit within a certain diameter range, and the number of the spindles of the inner conduit weaving yarns is estimated by the following formula;

wherein m represents the number of inner catheter-knitting yarns, d_yRepresents the diameter of the knitting yarn of the inner catheter, R represents the inner diameter of the outer catheter, n represents the number of the inner catheters in the multi-channel antibacterial nerve catheter, and R represents the inner radius of the inner catheter (namely the radius of the inner core material); k is more than 0 and less than or equal to 1, and lambda is more than 0 and less than or equal to 1; m is obtained by rounding off and rounding up the numerical value calculated according to the formula;

(2) dividing the conduit into n tubes, arranging the n tubes side by side to serve as a core material, tightly weaving outer conduit weaving yarns outside the core material, and weaving at least two layers to form the outer conduit outside the core material; the outer catheter knitting yarn is made of medical polymer material;

(3) and (3) removing the core material filled in the catheter obtained in the step (2), and repeatedly leaching and drying the obtained material in an antibacterial solution to obtain the multi-channel antibacterial nerve catheter.

Further, in the steps (1) and (2), a 16-spindle braiding machine is adopted for braiding, the inner guide pipe is braided by using the number of the spindles obtained through estimation in the braiding process, and the redundant spindles are not used for hoisting.

Further, the number of spindles which can be used for knitting by the spindle changing method is in the range of 6 to 16.

Further, in the steps (1) and (2), the inner catheter-knitting yarn and the outer catheter-knitting yarn are independently selected from bio-compatible natural color yarns such as polylactic acid yarn, degummed silk twisted yarn, and chitosan yarn.

Further, in the step (1), the inner filling core material is a black monofilament, the surface of the black monofilament is smooth and flat, the diameter of the black monofilament is larger than 300 μm, and the braided inner conduit can be used for further use after being cleaned and dried. Preferably, the inner core material is black polypropylene fiber.

Because the invention needs to be tightly woven, the hollow catheter cannot be automatically formed, the hollow catheter needs to be woven by using the inner filling core material, and the through hole channel is formed only by drawing out the inner filling core material after the weaving is finished. The inner filling core material is required to be smooth and easy to draw out, meanwhile, the inner filling core material is not easy to deform and difficult to draw out due to extrusion, and the color of the inner filling core material is clearly contrasted with that of the woven yarn, so that the inner filling core material is easy to distinguish and draw out. Preferably, in step (1), the color of the core material of the inner filler is black. The inner catheter weaving yarn is white.

Further, in the step (1), d_y＝80-150μm，R＝0.8-1.1mm，n＝4-12，r＝0.3-0.6mm。

Further, after the step (2), if the outer layer catheter-knitting yarn is a thermoplastic high molecular polymer such as polylactic acid, the method further comprises a step of heat-setting the obtained catheter at a suitable temperature point between the glass transition temperature and the flow temperature of the material, wherein the temperature point is selected so that the fibers are slightly melt-bonded and the two ends of the catheter are not separated.

Further, after the heat setting, the step of washing the obtained material at room temperature is also included.

Further, in the step (3), the braided catheter is cleaned and dried, and then the core material of the inner filler is drawn out from the core material.

Further, in the step (3), the antibacterial solution includes tea polyphenol, chitosan, gelatin, acetic acid, glycerin and water. The obtained material is soaked in the antibacterial solution, so that the antibacterial solution permeates into each gap of the multichannel antibacterial nerve conduit, a layer of biocompatible membrane surface which is easy for cell migration and proliferation is formed in the conduit, a long-acting local antibacterial environment is provided for the damaged nerves in repair, the use of antibiotics for the whole organism is reduced, and the possible wound brought to the autoimmune function of the organism by a large amount of antibiotic medicines after the operation is reduced. For natural high molecular polymers such as silk, chitosan yarn and the like, the leaching times are increased, and the coating is thickened, so that the aim of the coating is to increase the antibacterial property, and solve the problem of the disseminating property of two ends of the woven catheter.

Furthermore, in the antibacterial solution, the concentration of tea polyphenol is 0.5-2% (w/v), the concentration of chitosan is 0.5-2% (w/v), and the concentration of gelatin is 0.5-2% (w/v). The concentration of each component of the antibacterial solution is required to be in a proper range, the concentration is too high, the prepared solution is too viscous, an excessively thick film can be formed by one-time leaching, and the thickness of the film is not uniform; if the concentration is too low, the leaching times need to be increased, and the ideal film thickness may not be obtained, which affects the antibacterial effect of the catheter.

Further, the preparation method of the antibacterial solution is as follows:

firstly, preparing an acetic acid solution of chitosan, wherein the volume fraction of acetic acid is 1%; adding a proper amount of tea polyphenol powder into the chitosan solution; preparing a gelatin aqueous solution, and dropwise adding the prepared chitosan/tea polyphenol solution into the gelatin aqueous solution to prepare a mixed solution; adding appropriate amount of glycerol into the mixed solution, and mixing.

Further, in step (3), after the braided catheter is dried by the antibacterial coating, it should be soaked in Phosphate Buffered Saline (PBS) solution three times with circumferential oscillation at a certain speed to remove substances such as acetic acid and glycerol which are unfavorable for cell growth.

The invention also discloses application of the multi-channel antibacterial nerve conduit in preparing an artificial nerve conduit for repairing peripheral nerves.

In the invention, the corresponding number of channels are formed by the number of the tubes divided in the step (2), and the schematic diagram of the arrangement of the multiple channels in the conduit is shown in figure 1. The internal channel aperture of each type of conduit may vary. If the aperture of the inner channel is kept consistent, the wall thickness of the inner conduit can be changed by controlling the number of the weaving yarns of the inner conduit, and the number of the apertures is arranged by changing the wall thickness of the inner conduit. That is, the number of radial yarns of a single inner pipe, that is, the number of spindles in weaving, can be calculated from the number of predicted holes. In step (1), most of the area in the outer conduit is filled by the inner conduit, k represents the filling rate of the inner conduit in the outer conduit, the filling rate is related to the number of the channels, the more the number of the channels is, the tighter the filling is, the higher the filling rate is, and the filling rate satisfies the following formula (1):

k×πR²＝nπ(r+d)²； (1)

wherein R represents the inner diameter of the outer catheter, n represents the number of inner catheters in the multi-channel antibacterial nerve catheter, R represents the inner radius of the inner catheter, and d represents the wall thickness of the inner catheter.

If the inner filling core material is drawn out, the cross section of the circular ring of the inner conduit can be completely formed by the knitting yarns, so that the cross section area of the whole circular ring can be formed by the cross section of the knitting yarns, after the filling yarns are drawn out, the pipe diameter of the inner conduit can be changed, because the yarns are in a highly-compressed state before the inner filling core material is drawn out, the yarns can naturally move to the positions of the holes after the inner filling core material is drawn out, so that the spaces of the holes are extruded, the extrusion degree is related to the number of the holes, the number of the holes is small, after the filling yarns are drawn out, because the whole conduit is not completely filled during weaving, the holes exist, so that the extrusion into the inner conduit is less, the holes are more, the core material is basically not in the inner conduit, and once the inner filling is drawn out, the space in. It is thus possible to set the degree of looseness at which the inner radius of the inner duct decreases to lambda (0 < lambda < 1), assuming that the braided yarn is round. The circular cross-sectional area of the inner conduit can be calculated in two ways and therefore has the equation

Substituting equation (1) into this equation, equation (2) is obtained:

and (3) determining the number of the inner catheter knitting yarns, the inner core filling materials and the number of the channels of the multi-channel antibacterial nerve catheters to be prepared, and calculating the number of the inner catheter knitting yarns (namely the number of the ingots of the knitting machine) according to the formula (2). When a 16-spindle braiding machine is used for braiding, the number of braided spindles can be selected from 4 to 16, and the spindles are not needed, and the yarn tubes are only needed to be lifted (namely, the multi-channel antibacterial nerve conduit is prepared by the spindle changing braiding method). The values of the parameters k and lambda in the formula (2) are related to the number of the pore channels, and the specific values are shown in table 1.

TABLE 1 correspondence between values of parameters k and lambda and number of channels in preparation of multi-channel antibacterial nerve conduit by ingot-changing weaving method

Number of channels	Fill factor k	Degree of looseness lambda
			4	0.74	0.95
5	0.81	0.9
			6	0.83	0.87
7	0.85	0.83
			8	0.87	0.81
9	0.91	0.79
			10	0.94	0.78
11	0.96	0.76
			12	0.97	0.75

By the scheme, the invention at least has the following advantages:

the invention adopts a weaving method to prepare the multi-channel antibacterial artificial nerve conduit, and the number of weaving ingots required during weaving can be calculated through a given formula and basic size parameters of the nerve conduit required to be prepared. The method is simple and easy to implement, has high repeatability, is easy to control the diameter, the length, the number of pore passages and the diameter of the inner catheter of the multi-channel antibacterial nerve catheter, and can be flexibly changed according to the type of the nerve to be repaired; the multi-channel antibacterial artificial nerve conduit has the advantages of good mechanical property, ideal tensile strength and good bending deformability. In addition, the nerve conduit has long-acting antibacterial capacity by adopting the antibacterial solution obtained by mixing tea polyphenol/chitosan/gelatin for treatment.

The invention provides a method for designing multi-channel ducts with various specifications by controlling the number of channels, the diameter of an inner filling core material, the diameter of knitting yarns of the inner duct and the outer duct, the number of knitting yarns and the like, and provides a relational expression between the variables, so that the design of the multi-channel ducts is standardized, digitized, controllable and diversified. The most reasonable multi-channel catheter with the most inosculated size can be designed according to the actual diameter of the nerve to be repaired, and an effective artificial nerve standardized preparation method is provided for the long-distance repair of the nerve defect.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following description is made with reference to the preferred embodiments of the present invention and the accompanying detailed drawings.

Drawings

FIG. 1 is a schematic cross-sectional view of several multichannel nerve conduits prepared according to the present invention;

FIG. 2 is a cross-sectional electron micrograph of a multichannel nerve conduit prepared according to example 1 of the present invention;

FIG. 3 is a cross-sectional electron micrograph of a multichannel nerve conduit prepared according to example 2 of the present invention;

FIG. 4 is a cross-sectional electron micrograph of a multichannel nerve conduit prepared according to example 3 of the present invention;

FIG. 5 shows the results of a test for Staphylococcus aureus inhibition by the antibacterial solution of the present invention;

FIG. 6 shows the results of the Escherichia coli inhibition test using the antibacterial solution of the present invention.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The antibacterial artificial nerve conduit prepared by the following embodiment of the invention can be used as a peripheral nerve conduit for repairing damaged peripheral nerves.

Example 1

The embodiment provides a preparation method of a 6-channel antibacterial artificial nerve conduit, which adopts polylactic acid (PLA) yarn as weaving yarn and a 16-spindle weaving machine as a tool, and comprises the following specific steps:

1. determining design parameters of the nerve conduit: white polylactic acid (PLA) yarns with the diameter of 120 mu m are respectively selected as the inner catheter weaving yarns and the outer catheter weaving yarns (d)_y120 μm), black polypropylene (PP) monofilament having a diameter of 600 μm as an inner filler material (R300 μm), an inner diameter R of the prepared antibacterial artificial nerve conduit of 0.9mm, a number of channels n of 6, k 0.83, λ 0.87, and the like, by substituting these parameters into the formula

The calculation yields m-12.2. I.e. 12 braids are selected.

2. Preparing a knitting machine: and (4) using a 12-spindle braiding machine, and hoisting the redundant spindles by using rubber bands without threading.

3. Weaving a catheter: tightly weaving 12 inner catheter weaving yarns outside the inner core filling material to form a catheter, wherein the weaving length is 3m, and cutting the catheter into 6 sections according to each section of 0.5m after weaving; the method comprises the following steps of arranging 6 PLA catheters in parallel to serve as a core material, tightly weaving outer catheter weaving yarns outside the core material through a 16-spindle weaving machine to form two layers, wherein the weaving yarns are still the PLA yarns, and the outer catheter weaving yarns use 16 spindles.

4. Heat setting: and (3) putting the braided catheter into an oven for heat setting at the temperature of 140 ℃ for half an hour.

5. Cleaning and drying: cleaning with a detergent at room temperature for 10 minutes; and (5) drying in an oven.

6. Core pulling: and drawing out the PP wires to obtain the hollow multichannel nerve conduit. The cross-sectional view of the resulting multichannel nerve conduit is shown in fig. 2.

7. Preparing a tea polyphenol-chitosan-gelatin antibacterial solution: the concentration of tea polyphenol in the antibacterial solution is 1.6% (w/v), the concentration of chitosan is 0.9% (w/v), and the concentration of gelatin is 1% (w/v). The preparation method of the antibacterial solution comprises the following steps:

firstly, preparing 135mL of 1% (w/v) chitosan acetic acid solution, wherein the volume fraction of acetic acid is 1%, and adding 1.2g of tea polyphenol into the chitosan solution; then 15mL of 10% (w/v) gelatin solution is prepared, the prepared chitosan acetic acid solution is dropwise added into the gelatin solution, and the volume ratio of chitosan to gelatin is 9: 1; and adding a proper amount of glycerol into the mixed solution, and stirring for 0.5h for later use.

8. Dip coating: and (3) putting the multichannel nerve conduit prepared in the step (6) into the prepared tea polyphenol-chitosan-gelatin antibacterial solution for soaking, taking out the multichannel nerve conduit, drying the multichannel nerve conduit at normal temperature, and repeating the step for a plurality of times to obtain the multichannel antibacterial nerve conduit. Wherein the first dipping time is 5 minutes to ensure the antibacterial solution on the inner coating of the catheter, and the dipping time is 1 minute each time thereafter.

In this example, an antibacterial experiment was performed on the tea polyphenol chitosan gelatin antibacterial solution prepared in step 7. For facilitating the antibacterial experiment, the solution is blownDry film formation, antimicrobial effect of the film observed. The first day: cutting the sample into square fragment samples of 0.5cm multiplied by 0.5cm, wrapping the samples with weighing paper and storing the samples in a culture dish; and preparing nutrient broth, and after sterilization treatment of all experimental medicaments and instruments is finished, respectively taking the streaked staphylococcus aureus and escherichia coli by using sterilized bacteria-taking rings to disperse in the nutrient broth for later use. The next day: preparing PBS buffer solution, sterilizing, diluting bacteria to viable count of 3 × 10⁵cfu/ml～4×10⁵In the cfu/ml range; and then respectively adding the blank control sample and the test sample into PBS, respectively inoculating staphylococcus aureus and escherichia coli, shaking uniformly and standing by. And on the third day: preparing nutrient agar, sterilizing, adding the mixed solution of bacteria and a sample into PBS, and culturing the bacteria after a dilution process. The fourth day: counting colonies, taking out the culture dish, taking a picture, observing the growth conditions of bacteria in the culture dish with different gradients, and calculating the bacteriostasis rate according to the following formula:

in the formula: y is the bacteriostatic rate,%; w_bThe concentration of viable bacteria in a standard blank sample is obtained; w_cThe concentration of viable bacteria in the experimental sample.

The results of the antibacterial tests are shown in FIGS. 5 and 6, in which (k), (b) and (c) respectively show the antibacterial results of the blank sample, the gelatin/chitosan composite film formed without tea polyphenol, and the gelatin/chitosan/tea polyphenol composite film containing 0.8% tea polyphenol. The experimental result shows that the blank control sample has no antibacterial property, and the gelatin/chitosan composite membrane has certain antibacterial property (the antibacterial inhibition rate to two bacteria is 65.32 percent and 60.52 percent) to staphylococcus aureus and escherichia coli; the gelatin/chitosan/tea polyphenol composite membrane added with the tea polyphenol has very excellent antibacterial property (the bacteriostasis rate to the two bacteria is 99.99 percent and 99.24 percent), so that the tea polyphenol-chitosan-gelatin composite solution has a good antibacterial function and can provide a sterile environment for a certain time in vivo.

Example 2

The embodiment provides a method for preparing an 8-channel antibacterial artificial nerve conduit, which adopts polylactic acid (PLA) yarns as weaving yarns and a 16-spindle weaving machine as a tool, and comprises the following specific steps:

1. determining design parameters of the nerve conduit: white polylactic acid (PLA) yarns with the diameter of 120 mu m are respectively selected as the inner catheter weaving yarns and the outer catheter weaving yarns (d)_y120 μm), black polypropylene (PP) monofilament having a diameter of 600 μm as an inner filler material (R300 μm), an inner diameter R of the prepared antibacterial artificial nerve conduit of 0.9mm, a number of channels n of 8, k 0.87, λ 0.81, and the like, into which the formula is substituted

The calculation yields m 8.07. I.e. 8 spindles of knitting are selected.

2. Preparing a knitting machine: and (4) using an 8-spindle braiding machine, and hoisting the redundant spindles by using rubber bands without threading.

3. Weaving a catheter: tightly weaving 8 inner catheter weaving yarns outside the inner core filling material to form a catheter, wherein the weaving length is 3m, and after weaving is finished, cutting the catheter into 8 sections according to each section of 0.5 m; 8 PLA catheters are arranged in parallel to be used as a core material, and then the outer catheter weaving yarn is tightly woven outside the core material through a 16-spindle weaving machine to form two layers, wherein the weaving yarn is still the PLA yarn, and the outer catheter weaving yarn uses 16 spindles.

6. Core pulling: and drawing out the PP wires to obtain the hollow multichannel nerve conduit. The cross-sectional view of the resulting multichannel nerve conduit is shown in fig. 3.

7. A tea polyphenol-chitosan-gelatin antimicrobial solution was prepared as in example 1: the concentration of tea polyphenol in the antibacterial solution is 1.6% (w/v), the concentration of chitosan is 0.9% (w/v), and the concentration of gelatin is 1% (w/v).

8. Dip coating: and (4) putting the multichannel nerve conduit prepared in the step (6) into the prepared tea polyphenol-chitosan-gelatin antibacterial solution for leaching for multiple times to obtain the multichannel antibacterial nerve conduit. The first dipping time was 5 minutes to ensure that the catheter was coated with the antimicrobial solution, and the catheter coated with the solution was air dried at room temperature, after which the dipping time was 1 minute.

The bacteriostatic rate of the catheter is shown in fig. 5(d) and fig. 6(d), and the results show that the bacteriostatic rate of the catheter reaches 99.99 percent.

Example 3

The embodiment provides a preparation method of a 6-channel antibacterial artificial nerve conduit, which adopts degummed 20/22 silk twisted wire as a woven yarn and a 16-spindle knitting machine as a tool and comprises the following specific steps:

1. determining design parameters of the nerve conduit: degumming 20/22 silk twisted yarn with a diameter of 85 μm is selected as the inner catheter weaving yarn and the outer catheter weaving yarn respectively (d)_y85 μm), black polypropylene (PP) monofilament having a diameter of 600 μm as an inner filler material (R300 μm), an inner diameter R of the prepared antibacterial artificial nerve conduit of 0.85mm, a number of channels n of 8, k 0.87, λ 0.81, and the like, into which the formula is substituted

The calculation yields m 16.08. I.e. 16 spindles of knitting are selected.

2. Preparing a knitting machine: a 16-spindle braiding machine is used, i.e. all spindles are used.

3. Weaving a catheter: tightly weaving 8 inner catheter weaving yarns outside the inner core filling material to form a catheter, wherein the weaving length is 3m, and after weaving is finished, cutting the catheter into 8 sections according to each section of 0.5 m; 8 silk pipes are arranged in parallel to serve as a core material, then the outer pipe weaving yarn is tightly woven outside the core material through a 16-spindle weaving machine to form two layers, the weaving yarn is still silk twisted wire, and the outer pipe weaving yarn also uses 16 spindles.

4. Cleaning and drying: cleaning with a detergent at room temperature for 10 minutes; and (5) drying in an oven.

5. Core pulling: and drawing out the PP wires to obtain the hollow multichannel nerve conduit. The cross-sectional view of the resulting multichannel nerve conduit is shown in fig. 4.

6. A tea polyphenol-chitosan-gelatin antimicrobial solution was prepared as in example 1: the concentration of tea polyphenol in the antibacterial solution is 1.6% (w/v), the concentration of chitosan is 0.9% (w/v), and the concentration of gelatin is 1% (w/v).

7. Dip coating: and (4) putting the multichannel nerve conduit prepared in the step (6) into the prepared tea polyphenol-chitosan-gelatin antibacterial solution for leaching for multiple times to obtain the multichannel antibacterial nerve conduit. The first dipping time is 5 minutes, so as to ensure that the antibacterial solution is coated on the inner coating of the catheter, and the catheter coated with the antibacterial solution is placed at normal temperature for air drying. The immersion time was then 1 minute.

Table 1 shows the strength test data of several multi-channel antibacterial nerve conduits prepared in examples 1 to 3 of the present invention, and the results show that they have excellent mechanical strength.

TABLE 1 axial tensile Strength and elongation at Break of nerve conduits of examples

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a multi-channel antibacterial nerve conduit by a variable ingot weaving method comprises a plurality of inner conduits arranged in parallel and outer conduits wrapped outside the inner conduits, wherein the axes of the inner conduits are parallel to the axes of the outer conduits, and the inner conduits and the outer conduits are in a hollow cylindrical shape, and is characterized in that the method for preparing the multi-channel antibacterial nerve conduit comprises the following steps:

(1) tightly weaving a plurality of inner conduit weaving yarns outside a rigid and smooth-surface inner filling core material by adopting a spindle changing weaving method to form a conduit, wherein the conduit comprises the inner filling core material and a pipe body sleeved outside the inner filling core material; the inner catheter weaving yarn and the inner filling core material are different in color, the inner catheter weaving yarn is made of medical high polymer materials, the inner filling core material is in a solid cylinder shape, the outer surface of the inner filling core material is smooth, and the number of spindles for inner catheter weaving meets the following formula;

；

wherein the content of the first and second substances,mrepresenting the number of the spindle braided by the inner catheter, namely the number of the braided yarns of the inner catheter, which is rounded off according to the calculation result of a formula,d _yrepresents the diameter of the inner catheter weaving yarn,Rrepresents the inner diameter of the outer catheter tube,nrepresents the number of inner catheters in the multi-channel antibacterial nerve catheter,rrepresents the inner radius of the inner conduit; 0 < (R) >k≤1，0＜λ≤1；

(2) Dividing the conduit intonRoot canal of general vesselnThe method comprises the following steps that root canals are arranged side by side to serve as a core material, outer conduit weaving yarns are tightly woven outside the core material, and at least two layers are woven to form the outer conduits outside the core material; the outer catheter knitting yarn is made of medical high polymer material;

2. The method of claim 1, wherein: in the steps (1) and (2), a knitting machine is adopted for knitting, and the number of spindles used in the knitting process is the number of the knitting yarns of the inner conduit.

3. The method of claim 1, wherein: in the steps (1) and (2), the material of the inner catheter knitting yarn and the material of the outer catheter knitting yarn are independently selected from natural color yarns with biocompatibility.

4. The method of claim 1, wherein: in the step (1), the core material is black monofilament.

5. The method of claim 1, wherein: in the step (1), the first step of the method,d _y=80～150µm，R=0.8～1.1mm，n=4～12，r=0.3～0.6mm。

6. the method of claim 1, wherein: after the step (2), when the material of the outer conduit knitting yarn is thermoplastic high molecular polymer, the method further comprises the step of performing heat setting on the obtained conduit, wherein the value range of the heat setting temperature is from the glass transition temperature to the flow temperature of the thermoplastic high molecular polymer.

7. The method of claim 1, wherein: in the step (3), the braided catheter is cleaned and dried, and then the core material is drawn out from the core material.

8. The method of claim 1, wherein: in the step (3), the antibacterial solution comprises tea polyphenol, chitosan, gelatin, acetic acid, glycerol and water.

9. The method of claim 8, wherein: in the antibacterial solution, the concentration of the tea polyphenol is 0.5-2%, the concentration of the chitosan is 0.5-2%, the concentration of the gelatin is 0.5-2%, and the concentration unit is w/v.

10. Use of a multichannel antibacterial nerve conduit prepared by the method of any one of claims 1 to 9 in the preparation of an artificial nerve conduit for repairing peripheral nerves.