WO2021077894A1

WO2021077894A1 - Ear implant scaffold and preparation method therefor

Info

Publication number: WO2021077894A1
Application number: PCT/CN2020/111693
Authority: WO
Inventors: 黄文华; 吴耀彬; 殷俊飞扬; 钟静
Original assignee: 南方医科大学
Priority date: 2019-10-21
Filing date: 2020-08-27
Publication date: 2021-04-29
Also published as: CN110664509A

Abstract

A method for preparing an ear implant scaffold, which is a four-step method comprising building a scaffold model, 3D-printing a mold, preparing a DOPA solution, and performing surface adhesion of DOPA on a scaffold matrix, thus producing a novel ear implant scaffold. The matrix material of the mold is prepared by a 3D-Bioplotter instrument; the preparation process is simple and fast, and the geometric shape, pore size, porosity and pore distribution of the scaffold can also be precisely controlled according to different requirements and material characteristics. The prepared composite scaffold has a micron-scale porous structure, which is conducive to the proliferation of a large number of cells, the growth of tissue, the formation of an extracellular matrix, the transfer of oxygen and nutrients, the transportation of metabolites, and the in-growth of blood vessels, which can induce the formation of epidermal tissue long-term. At the same time, the adhesion of DOPA on the surface of the scaffold greatly improves the hydrophilicity, biocompatibility and epidermal induction effect of the scaffold, and also has good drug-loading and drug-releasing performance.

Description

Implanted ear bracket and preparation method thereof

Technical field

The invention relates to the technical field of biomedical materials, in particular to an implanted ear stent and a preparation method thereof.

Background technique

For the treatment of patients with auricle deformity, the conventional surgical method in clinical practice is to cut out the costal cartilage autologous for carving. However, cutting out the costal cartilage itself may cause complications such as pneumothorax and thoracic deformity, and the trauma is large. Once the patient has insufficient cost cartilage Or when the amount of local covering tissue is insufficient, the operation will be difficult to proceed. Bionic auricle stent is a good alternative to traditional surgery. Compared with traditional surgery, it does not require autologous costal cartilage for carving, which reduces secondary trauma, shortens the operation time, and ensures the realistic structure of reconstructed ears and avoids surgery. Complications such as deformation of the post-reconstruction ear occurred. In the early 1990s, porous high-density polyethylene (Medpor) ear stents produced by POREX in the United States began to be used. However, the texture of Medpor material is relatively hard and is a standardized product. There have been reports about the exposure of Medpor stents after surgery. Not easy to heal. The Medpor ear stent is directly used to obtain the reconstructed ear structure, which is evaluated by the shape of the contralateral auricle, but it is difficult to ensure that the manufactured ear stent structure has a high degree of stability, and it will also affect the exposure of the stent after the operation.

At present, medical-grade materials that can be used to synthesize exogenous auricles include: high-density polyethylene, silicone rubber, polytetrafluoroethylene, polyurethane, titanium alloy, ceramics, etc. But for ear stents, after silicone rubber is implanted in the body, thick fibrous tissue will be formed, resulting in increased local pressure, poor plasticity and easy collapse; polyurethane has ideal histocompatibility and physical properties, but due to its soft texture , Is more suitable for cell cartilage scaffolds; polytetrafluoroethylene materials have the disadvantage of poor mechanical strength. Therefore, the above-mentioned materials are prone to complications such as exposure of ear stents and cannot be promoted in clinical applications. High-density polyethylene (HDPE) has the characteristics of high mechanical strength, good biocompatibility, high heat resistance, and easy processing. It is currently a widely used plastic implant material. The material can be designed with different mechanical properties and porous structures according to product requirements, which is conducive to the growth of the tissue and the lasting stability of the structure at the implantation site.

3D printing can accurately control the geometric shape, pore size, porosity and pore distribution of the stent according to different requirements and material characteristics, and formulate a personalized treatment plan. It also has the advantages of large processing flexibility and a wide range of formable materials, which can meet the needs of the auricle bracket for complex structures and personalized manufacturing. At present, there are Fused Deposition Modeling (FDM), Selective Laser Sintering Technology (SLS), Three-dimensional Jet Printing Technology (3DP), Light Curing Molding Technology (SLA), Pneumatic Extrusion Technology, and a variety of material-based extrusion/injection molding All of the processes have been applied to the manufacture of tissue engineering scaffolds.

Therefore, in view of the shortcomings of the existing technology, it is necessary to provide a new type of implanted ear stent structure to overcome the shortcomings of the existing technology.

Summary of the invention

The purpose of the present invention is to avoid the shortcomings of the prior art and provide a method for preparing an implanted ear stent. The preparation process is simple and quick, and has a controllable shape and porous structure, which is beneficial to the transportation of nutrients and oxygen, and promotes cells. Adhesion, proliferation and differentiation of serotonin can induce the formation of epidermal tissue for a long time.

The above-mentioned objects of the present invention are achieved by the following technical means:

A method for preparing a novel implantable ear stent is prepared by the following steps:

Step (1), build the model of the scaffold

Specifically, it is to design a porous three-dimensional implanted ear stent structure model.

Step (2), 3D printing mold

Specifically: import the porous three-dimensional implanted ear stent structure model into 3D-Bioplotter, and perform data layering processing on the porous three-dimensional implanted ear stent structure model;

Add the matrix material to make the porous three-dimensional implanted ear stent structure model into the stainless steel barrel, and set the printing temperature T1, the platform temperature T2, the needle diameter R1, the extrusion pressure P, the extrusion speed v, the internal structure, and the internal structure in VisualMachines. The parameters of layered thickness h and pore diameter R2 are started, 3D-Bioplotter is started, and the porous three-dimensional implanted ear stent structure model is printed layer by layer to make a 3D porous implanted ear stent mold.

Step (3), prepare DOPA solution

Specifically: Use deionized water to prepare a Tris-HCl solution with a concentration of 10 mmol/L, where the pH of the Tris-HCl solution is 8.5, and then slowly add the DOPA powder to the Tris-HCl solution and stir evenly to obtain a pH of 8.5, 10 mmol /L of DOPA solution.

Step (4), the stent substrate is surface-adhered to DOPA

Specifically, the 3D porous ear holder mold is placed in the DOPA solution, and magnetically stirred for 24 hours at room temperature and protected from light. The magnetic stirring speed is 1000 rpm/min. After the stirring is completed, deionized water is used to repeatedly rinse to remove unpolymerized dopamine. Finally, the washed stent is placed at 40°C for drying to obtain a composite stent.

Preferably, the matrix material in step (2) is high-density polyethylene (HDPE);

The composite scaffold obtained in step (4) has a micron-scale porous structure.

Preferably, in step (2),

The printing temperature T1 is: 180℃≤T1≤240℃;

The platform temperature T2 is: 60℃≤T2≤90℃;

Needle diameter R1: 0.2mm≤R1≤0.6mm;

The extrusion pressure P is: 6.0bar≤P≤8.5bar;

The extrusion speed v is: 2mm/s≤v≤5mm/s;

The aperture R2 is: 0.2mm≤R2≤0.6mm;

The internal structure parameter is set as the nozzle angle 0°, 90° staggered arrangement, and the layer thickness h is set to 0.16mm≤h≤0.48mm.

Preferably, in step (3), the preparation method of the Tris-HCl solution is as follows: Under the same mass unit, stir the Tris-HCl powder with a mass ratio of 1.21:1 and deionized water to obtain a pH of 8.5. 10mmol/L Tris-HCl solution.

Preferably, the preparation method of the DOPA solution in step (3) is as follows: Under the same mass unit, stir the DOPA powder with a mass ratio of 2:1 and the Tris-HCl solution to a DOPA solution with PH=8.5,10mmol/L. .

Preferably, the porous structure of the ear support is composed of micro-pores with a pore diameter of 200-300 μm, and the micro-pores are holes in the matrix of the three-dimensional support.

Preferably, the porosity of the ear bracket is 45%-55%, and the pore connectivity ratio is 90%-98%.

A new type of implanted ear stent, the new type of implanted ear stent is a 3D porous implanted ear stent.

The method for preparing an implanted ear stent of the present invention manufactures a new type of implanted ear stent by a four-step method of building a stent model, a 3D printing mold, preparing a DOPA solution and a stent matrix to adhere DOPA on the surface. The base material of the mold is prepared by the 3D-Bioplotter instrument. Not only the preparation process is simple and fast, but also the geometric shape, pore size, porosity and pore distribution of the stent can be precisely controlled according to different requirements and material characteristics. The prepared composite scaffold has a micron-scale porous structure, which is conducive to the proliferation of a large number of cells, the growth of tissues, the formation of extracellular matrix, the transmission of oxygen and nutrients, the transport of metabolites, and the in-growth of blood vessels, which can induce epidermal tissues for a long time. Formation. At the same time, the adhesion of DOPA on the surface of the stent can not only greatly improve the hydrophilicity, biocompatibility and epidermal induction effect of the stent, but also has good drug-loading and drug-releasing properties.

Description of the drawings

FIG. 1 is a schematic diagram of the porous structure of the composite scaffold of Example 1. FIG.

Figure 2 is a physical view of the HDEP stent and HDPE/DOPA composite stent of Example 1.

Fig. 3 is a design diagram of the new implanted ear stent of Example 1.

Fig. 4 is a scanning electron micrograph of the HDEP stent magnified 30 times in Example 4 of the present invention.

Fig. 5 is a scanning electron micrograph of the HDEP stent magnified 1000 times in Example 4 of the present invention.

Fig. 6 is a scanning electron micrograph of the HDEP stent magnified 2000 times in Example 4 of the present invention.

Fig. 7 is a scanning electron micrograph of the HDPE/DOPA composite stent magnified 30 times in Example 4 of the present invention.

Fig. 8 is a scanning electron micrograph of the HDPE/DOPA composite stent magnified 1000 times in Example 4 of the present invention.

Figure 9 is a scanning electron micrograph of the HDPE/DOPA composite stent with 2000 times magnification in Example 4 of the present invention.

Detailed ways

The utility model will be further explained in combination with the following examples.

Example 1.

A method for preparing a new type of implantable ear stent, as shown in Figure 1 to Figure 3, is prepared by the following steps:

Step (1), build the model of the scaffold

Step (2), 3D printing mold

Step (3), prepare DOPA solution

Step (4), the stent substrate is surface-adhered to DOPA

The composite scaffold has a micron-scale porous structure, which is conducive to the proliferation of a large number of cells, the growth of tissues, the formation of extracellular matrix, the transmission of oxygen and nutrients, the transport of metabolites, and the in-growth of blood vessels, which can induce the formation of epidermal tissue for a long time. .

It should be noted that the drying conditions of the rinsed stent in this embodiment are drying at 40°C for 1 hour, or drying at 45°C for 1 hour. The specific implementation depends on the actual situation. The invention does not impose specific restrictions.

The preparation method of a new type of implantable ear stent of this embodiment, through a four-step method of building a stent model, 3D printing mold, preparing DOPA solution and stent matrix for surface adhesion of DOPA, to produce a new type of implanted ear Bracket. The preparation process of the new implantable ear bracket is simple and quick, and the materials are safe and gentle. The mold makes the ear bracket according to actual needs. At the same time, DOPA solution is used as the coating on the surface of the mold, which can be adhered to the surface of any matrix material. It has good drug-loading and drug-releasing performance.

Example 2.

A method for preparing a new type of implantable ear stent is different from Example 1. The difference lies in that, specifically, the base material is the following material: high-density polyethylene (HDPE).

The composite scaffold has a micron-sized porous structure.

High-density polyethylene (HDPE) has the characteristics of high mechanical strength, good biocompatibility, high heat resistance and easy processing. Different mechanical properties and porous structures can be designed according to product requirements, which is conducive to the growth of tissues at the implantation site and the lasting stability of the structure.

Specifically, in step (2),

The printing temperature T1 is: 180℃≤T1≤240℃;

The platform temperature T2 is: 60℃≤T2≤90℃;

Needle diameter R1: 0.2mm≤R1≤0.6mm;

The extrusion pressure P is: 6.0bar≤P≤8.5bar;

The extrusion speed v is: 2mm/s≤v≤5mm/s;

The aperture R2 is: 0.2mm≤R2≤0.6mm;

Specifically, in step (3), the preparation method of the Tris-HCl solution is as follows: Under the same mass unit, stir the Tris-HCl powder with a mass ratio of 1.21:1 and deionized water to obtain a PH=8.5. 10mmol/L Tris-HCl solution.

It should be noted that, in this example, the specific preparation method of the Tris-HCl solution is as follows: Add 30.25 mg of Tris-HCl powder and 25 ml of deionized water into a 250 ml beaker, stir evenly with a magnetic stirrer, and prepare 25ml of Tris-HCl solution, that is, pH=8.5, 10mM Tris-HCl solution.

Specifically, the preparation method of the DOPA solution in step (3) is as follows: Under the same mass unit, stir DOPA powder and Tris-HCl solution with a mass ratio of 2:1 to a DOPA solution with PH=8.5,10mmol/L. .

It should be noted that in this embodiment, the specific preparation method of the DOPA solution is as follows: add 50 mg of DOPA powder to the prepared Tris-HCl solution, stir evenly with a magnetic stirrer, and prepare a 2 mg/ml DOPA solution. That is, DOPA solution with PH=8.5, 10mmol/L.

Specifically, the porous structure of the ear support is composed of micro-pores with a pore diameter of 200-300 μm, and the micro-pores are holes in the matrix of the three-dimensional support.

The porous structure consists of 200-300μm micro-pores, which is conducive to the proliferation of a large number of cells, the growth of tissues, the formation of extracellular matrix, the transmission of oxygen and nutrients, the transport of metabolites, and the in-growth of blood vessels, which can induce epidermal tissues for a long time. Formation.

Specifically, the porosity of the ear bracket is 45%-55%, and the pore connectivity ratio is 90%-98%.

The preparation method of a new type of implantable ear stent of this embodiment is different from embodiment 1 in that it specifically describes the structure of the stent, the materials used, the configuration method of the solution, and the environmental parameters required when making the mold. The specific manufacturing process of the present invention is further explained. The DOPA adhesion on the surface of the stent can not only greatly improve the hydrophilicity, biocompatibility and epidermal induction effect of the stent, but also has good drug-carrying and drug-releasing performance.

Example 3.

A new type of implanted ear stent is different from Embodiment 1 and Embodiment 2, except that the new type of implanted ear stent in this embodiment is a 3D porous implanted ear stent.

The new implantable ear stent is a 3D porous implanted ear stent, and the 3D porous ear stent mold is prepared by 3D-Bioplotter.

The DOPA solution is prepared by the dissolution method, and the 3D porous ear bracket mold is placed in the DOPA solution by a magnetic stirring method at room temperature and protected from light, and the composite is prepared, rinsed and dried.

A new type of implanted ear bracket of this embodiment uses 3D printing technology to print out the mold, and magnetically stir in the prepared DOPA solution to better combine the mold with the DOPA solution, so that the ear bracket is in use Achieve better results in time.

Example 4.

A preparation method of a new type of implantable ear support is different from Examples 1 to 3, as shown in Figs. 4 to 9, the difference lies in how to prepare the ear support under different environmental parameters. Among them, HDPE uses high-density polyethylene with an analytical grade, a density of 0.95 g/cm ³ and a molecular weight of 100,000.

(1) Preparation of HDPE cube scaffold matrix with regular three-dimensional porous structure:

Use Bioplotter RP software to process the STL format data of a cube model of length 10mm, width 10mm, and height 0.6mm. Add 2g of HDPE powder material into a stainless steel barrel, select a needle with a diameter of R1 of 0.2mm, and open the tool software. Set the printing temperature T1 to 240°C, the platform temperature T2 to 80°C, the extrusion pressure P to 8.4bar, the extrusion speed v to 2mm/s, and the internal structure to set the nozzle 0° and 90° alternately, the layer thickness h is 0.16mm, the pore size R2 is 0.2mm, and then heat the material to the specified temperature and keep it for 30min. Start 3D-Bioplotter to print the three-dimensional structure model layer by layer to form the regular three-dimensional porous structure of the HDPE cube scaffold matrix in the CAD model.

(2) Prepare 2mg/ml DOPA solution:

Stir and mix 30.25mg of Tris-HCl powder with 25ml of deionized water until it is completely dissolved, then dissolve 50mg of DOPA powder in the Tris-HCl solution, stir evenly with a magnetic stirrer until it is completely dissolved, to obtain 2mg/ml The DOPA solution, where PF=8.5, the concentration is 10mmol/L.

(3) Preparation of HDPE/DOPA porous composite scaffold adhered to dopamine:

The HDPE stent was placed in a 2 mg/ml DOPA solution, where the pH was 8.5 and the concentration was 10 mmol/L. After 24 hours of magnetic stirring (1000 rpm/min) at room temperature and avoiding light, deionized water was repeatedly washed to remove unpolymerized DOPA, and dried at 40°C for 1 hour to obtain HDPE/DOPA porous composite scaffold.

The stent prepared in this example has hydrophilic properties, biocompatibility and epidermal induction effects, and also has good drug-loading and drug-releasing properties.

Example 5.

A preparation method of a novel implantable ear stent is different from Examples 1 to 4, except that the ear stent is prepared under different environmental parameters. Among them, HDPE uses high-density polyethylene with an analytical grade, a density of 0.95 g/cm ³ and a molecular weight of 100,000.

Use Bioplotter RP software to process the STL format data of a cube model of length 10mm, width 10mm, and height 0.9mm. Add 2g of HDPE powder material into a stainless steel barrel, select a needle with a diameter of R1 of 0.3mm, and open the VisualMachines software. Set the printing temperature T1 to 220°C, the platform temperature T2 to 80°C, the extrusion pressure P to 8.5bar, the extrusion speed v to 2mm/s, the internal structure to alternate between 0° and 90° of the nozzle, and the layer thickness h to 0.24mm, the pore diameter R2 is 0.3mm, then heat the material to the specified temperature and keep it for 30min, start 3D-Bioplotter to print the three-dimensional structure model layer by layer to form the regular three-dimensional porous structure of the HDPE cube scaffold matrix in the CAD model.

(2) Prepare 2mg/ml DOPA solution:

Stir and mix 30.25mg of Tris-HCl powder with 25ml of deionized water until it is completely dissolved, then dissolve 50mg of DOPA powder in the Tris-HCl solution, stir evenly with a magnetic stirrer until it is completely dissolved, to obtain 2mg/ml The DOPA solution in which the DOPA solution has a PH=8.5 and a concentration of 10mmol/L.

(3) Preparation of HDPE/DOPA composite scaffold adhered to dopamine:

Put the HDPE stent into a 2mg/ml DOPA (PH=8.5, 10mmol/L) solution, and after 24 hours of magnetic stirring (1000rpm/min) at room temperature away from light, deionized water is repeatedly rinsed to remove unpolymerized dopamine, and dried at 40℃ Dry for 1 hour to obtain HDPE/DOPA porous composite scaffold.

The stent prepared in this example has hydrophilic properties, biocompatibility, and epidermal induction effects, and also has good drug-loading and drug-releasing properties.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that Modifications or equivalent replacements are made to the technical solution of the present invention without departing from the essence and scope of the technical solution of the present invention.

Claims

A method for preparing an implanted ear stent is characterized in that it is prepared through the following steps:

Step (1), build the model of the scaffold

Specifically, design a porous three-dimensional implanted ear stent structure model;

Step (2), 3D printing mold

Specifically: import the porous three-dimensional implanted ear stent structure model into 3D-Bioplotter, and perform data layering processing on the porous three-dimensional implanted ear stent structure model;

Add the matrix material to make the porous three-dimensional implanted ear stent structure model into the stainless steel barrel, and set the printing temperature T1, the platform temperature T2, the needle diameter R1, the extrusion pressure P, the extrusion speed v, the internal structure, and the internal structure in VisualMachines. Layer thickness h and pore diameter R2 parameters, start 3D-Bioplotter, print the porous three-dimensional implant ear scaffold structure model layer by layer, and make a 3D porous implant ear scaffold mold;

Step (3), prepare DOPA solution

Specifically: Use deionized water to prepare a Tris-HCl solution with a concentration of 10 mmol/L, where the pH of the Tris-HCl solution is 8.5, and then add the DOPA powder to the Tris-HCl solution and stir evenly to obtain a pH of 8.5, 10 mmol/L. DOPA solution of L;

Step (4), the stent substrate is surface-adhered to DOPA

Specifically, the 3D porous ear bracket mold is placed in the DOPA solution, and under the condition of room temperature and dark, magnetic stirring is carried out for 24 hours, and the magnetic stirring speed is 1000 rpm/min. After the stirring, deionized water is used to rinse repeatedly to remove unpolymerized dopamine. Finally, the washed stent is placed at 40°C for drying to obtain a composite stent.
The method for preparing an implanted ear stent according to claim 1, wherein the matrix material in the step (2) is high-density polyethylene (HDPE);

The composite scaffold obtained in the step (4) has a micron-scale porous structure.
The method for preparing an implanted ear stent according to claim 2, characterized in that, in the step (2),

The printing temperature T1 is: 180°C≤T1≤240°C;

The platform temperature T2 is: 60°C≤T2≤90°C;

The needle diameter size R1 is: 0.2mm≤R1≤0.6mm;

The extrusion pressure P is: 6.0bar≤P≤8.5bar;

The extrusion speed v is: 2mm/s≤v≤5mm/s;

The aperture R2 is: 0.2mm≤R2≤0.6mm;

The internal structure parameters are set to be staggered arrangement of nozzle angles of 0° and 90°, and the layer thickness h is set to 0.16mm≤h≤0.48mm.
The preparation method of an implanted ear stent preparation method according to claim 3, wherein in step (3), the preparation method of the Tris-HCl solution is as follows: Tris-HCl powder with a mass ratio of 1.21:1 is mixed with Stir the ionized water evenly to prepare a Tris-HCl solution with pH=8.5, 10mmol/L.
The preparation method of an implanted ear stent preparation method according to claim 4, characterized in that the preparation method of DOPA solution in step (3) is as follows: DOPA powder and Tris-HCl solution with a mass ratio of 2:1 are stirred uniformly It is a DOPA solution with PH=8.5, 10mmol/L.
The method for preparing an implanted ear stent according to claim 5, wherein the porous structure of the ear stent is composed of micro-pores with a pore diameter of 200-300 m, and the micro-pores are holes in the matrix of the three-dimensional stent.
The method for preparing an implanted ear stent according to claim 6, wherein the porosity of the ear stent is 45%-55%, and the pore connectivity ratio is 90%-98%.
A new type of implanted ear stent, characterized in that it is prepared by the preparation method according to any one of claims 1 to 7, and the new type of implanted ear stent is a 3D porous implanted ear stent.