阅读说明：本技术 一种可自发电刺激的压电支架组合物及其制备方法与应用 (Piezoelectric stent composition capable of spontaneous electrical stimulation and preparation method and application thereof ) 是由 袁伟恩 程媛 钱运 徐阳 陈璇 苑子涵 于 2019-08-23 设计创作，主要内容包括：本发明提供了一种可自发电刺激的压电支架组合物及其制备方法与应用,涉及生物医学技术领域。所述组合物由生物可降解代谢材料和压电材料组成；利用3D打印、喷射、浇注、挤出、模具成型或静电纺丝的方法,将生物降解材料和压电材料的共融物或有机溶剂按照一定比例成型各种生物医学应用的支架,尤其是神经导管支架。本发明公开的生物医用压电支架,能够将体内环境中的机械能转换为电刺激,促进神经、肌肉、骨、血管等再生、增殖、分化,而不需要外部电源或电极的植入,具有制备简单、成本低、质量容易控制、应用广等优点。大鼠体内实验显示,本发明的压电导管支架具有促进神经再生,血管生成,缓解肌肉萎缩等功能,有良好的临床应用前景。(The invention provides a piezoelectric stent composition capable of spontaneous electrical stimulation and a preparation method and application thereof, and relates to the technical field of biomedicine. The composition consists of a biodegradable metabolic material and a piezoelectric material; the scaffold for various biomedical applications, in particular to a nerve conduit scaffold is formed by using a 3D printing, jetting, pouring, extruding, die forming or electrostatic spinning method and a eutectic substance or an organic solvent of a biodegradable material and a piezoelectric material according to a certain proportion. The biomedical piezoelectric stent disclosed by the invention can convert mechanical energy in an internal environment into electrical stimulation and promote regeneration, proliferation and differentiation of nerves, muscles, bones, blood vessels and the like without implantation of an external power supply or electrodes, and has the advantages of simplicity in preparation, low cost, easiness in quality control, wide application and the like. The in vivo experiment of rats shows that the piezoelectric catheter stent has the functions of promoting nerve regeneration, angiogenesis, relieving muscular atrophy and the like, and has good clinical application prospect.)

1. The piezoelectric scaffold composition capable of spontaneous electrical stimulation is characterized by comprising 70-99 wt% of biodegradable material and 1-30 wt% of piezoelectric material;

the biodegradable material comprises one or more of polylactic acid, polylactic acid-polyethylene glycol, polylactic acid-polyglycolic acid, polycaprolactone-polyethylene glycol, fibroin, collagen, gelatin, hyaluronic acid and chitosan;

the piezoelectric material comprises one or more of zinc oxide nano-tubes, boron nitride nano-tubes, barium titanate nano-tubes and fluorine resin.

2. The spontaneously electrically excitable piezoelectric scaffold composition of claim 1, wherein the zinc oxide nanoparticles comprise single layer zinc oxide nanoparticles, multiple layer zinc oxide nanoparticles, or a mixture of single and multiple layer zinc oxide nanoparticles.

3. The spontaneously electrically excitable piezoelectric scaffold composition of claim 1, wherein the boron nitride nanotubes comprise single-walled boron nitride nanotubes, multi-walled boron nitride nanotubes, or a mixture of single-walled and multi-walled boron nitride nanotubes.

4. The spontaneously electrically stimulated piezoelectric scaffold composition of claim 1, wherein the barium titanate nanoparticles comprise one or more of tetragonal barium titanate nanoparticles, orthorhombic barium titanate nanoparticles, and trigonal barium titanate nanoparticles.

5. The spontaneously electrically excitable piezoelectric scaffold composition of claim 1, wherein the fluororesin includes one or more of a vinylidene fluoride polymer, a trifluoroethylene polymer, a chlorotrifluoroethylene polymer.

6. A preparation method of a piezoelectric scaffold capable of spontaneous electric stimulation is characterized by comprising the following steps:

A. preparing a spontaneously electrically excitable piezoelectric scaffold composition according to any one of claims 1 to 5;

B. the piezoelectric stent composition capable of spontaneous electric stimulation is subjected to a three-dimensional forming method to obtain a single-layer uniform piezoelectric stent capable of spontaneous electric stimulation or a multilayer tubular piezoelectric stent capable of spontaneous electric stimulation;

the three-dimensional forming method comprises an electrostatic spinning method, a casting method, a spraying method, a 3D printing method and an extrusion-die forming method.

7. The method for preparing a piezoelectric scaffold capable of spontaneous electrical stimulation according to claim 6, wherein the step A specifically comprises:

dissolving zinc oxide nano-tubes, boron nitride nano-tubes and barium titanate nano-tubes in 2-20 times of solvent to form suspension, or dissolving fluororesin in 2-20 times of solvent to form solution, or adding piezoelectric materials into a biodegradable material which is hot melted at 50-250 ℃ and mixing uniformly to obtain a mixture;

the solvent comprises one or more of dichloromethane, water, N-dimethylformamide, ethyl acetate, tetrahydrofuran and acetone.

8. The method for preparing a piezoelectric scaffold capable of spontaneous electrical stimulation according to claim 7,

the electrostatic spinning method specifically comprises the following steps: removing bubbles of the piezoelectric stent composition solution or suspension subjected to spontaneous electric stimulation by using an ultrasonic machine, injecting the piezoelectric stent composition solution or suspension into an injection instrument, outputting at the speed of 0.001-1ml/min of flow, spraying the piezoelectric stent composition solution or suspension onto a mold with the rotation speed of 1-5000rpm and the diameter of 0.01cm-10cm, controlling the voltage to be 2-50KV, and controlling the receiving distance to be 5-50 cm; the electrostatic spinning nozzle reciprocates at the speed of 1-100cm/min in the horizontal direction to form a piezoelectric bracket; after drying, the piezoelectric support is taken off from the die;

the casting method specifically comprises the following steps: pouring the piezoelectric stent composition solution or suspension subjected to spontaneous electrical stimulation onto a glass plate, and then drying at 20-200 ℃ to obtain a 2D planar stent; cutting the 2D planar support into a rectangle, fixing one end of the rectangle with a cylindrical model with the diameter of 0.01cm-10cm, rolling the tail end around the outer periphery of the cylindrical model, and rolling the cylindrical model into a 3D three-dimensional tubular piezoelectric support; the piezoelectric support is taken off from the die after the tail end and the support body are heat sealed;

the spraying method specifically comprises the following steps: injecting the piezoelectric stent composition solution or suspension subjected to spontaneous electrical stimulation into a spraying machine, spraying at the flow rate of 0.001-0.1ml/min, spraying onto a mold with the rotation speed of 500-5000rpm and the diameter of 0.01-10 cm, and receiving the distance of 5-50cm to form a piezoelectric stent; after drying, the piezoelectric support is taken off from the die;

the 3D printing method specifically comprises the following steps: injecting the spontaneous electrical stimulation piezoelectric stent composition molten liquid into an ink box of a 3D printer, and printing at 50-250 ℃ to obtain a piezoelectric stent with the inner diameter of 0.01-10 cm and the tube wall thickness of 0.01-1 cm;

the extrusion-die molding method specifically comprises the following steps: injecting the piezoelectric support composition molten liquid subjected to spontaneous electric stimulation into a high-temperature container at 50-250 ℃, extruding the piezoelectric support composition molten liquid in a mould, and cooling and solidifying the piezoelectric support composition molten liquid to obtain a three-dimensional tubular piezoelectric support; removing the piezoelectric support from the die and cutting;

the piezoelectric support is tubular, the pipe diameter of the piezoelectric support is 0.01cm-10cm, and the thickness of the pipe wall is 0.01cm-1 cm.

9. The method for preparing a piezoelectric scaffold composition capable of spontaneous electrical stimulation according to claim 6, wherein the single-layer homogeneous piezoelectric scaffold capable of spontaneous electrical stimulation is a piezoelectric scaffold capable of spontaneous electrical stimulation having a homogeneous composition obtained directly by a 3D printing method, a spraying method, a casting method, an extrusion-molding method or an electrospinning method;

the piezoelectric scaffold with the multilayer tubular structure and capable of spontaneous electrical stimulation is a 3D three-dimensional scaffold with the same or different composition of each layer obtained by utilizing a 3D printing method, a spraying method or an electrostatic spinning method to print and spray layer by layer; or obtaining the 2D planar support by using a casting method and then manufacturing the 3D three-dimensional support.

10. Use of a piezoelectric spontaneously excitable stent according to claims 6-9, including use in any one of, or luminal assisted regeneration of, a bone regeneration or repair stent, nerve regeneration or repair, blood vessel regeneration or repair, muscle regeneration or repair, tendon regeneration or repair, skin regeneration or repair, bile duct regeneration or repair, lymphatic vessel regeneration or repair, oesophagus regeneration or repair, trachea regeneration or repair, gut regeneration or repair, ureter regeneration or repair.

Technical Field

The invention relates to the technical field of biomedicine, in particular to a piezoelectric stent composition capable of performing spontaneous electric stimulation and a preparation method and application thereof.

Background

Peripheral nerve injury is a common disease worldwide. Traffic accidents, industrial injuries, natural disasters, wars, cancers and the like can cause peripheral nerve injuries, large-section nerve defects can not be sutured, and nerve transplantation or artificial nerve conduits are required to be used for repairing; the nerve conduit has certain strength, elasticity and hardness, can guide nerve growth, provide mechanical support and provide a good microenvironment for nerve regeneration; since the speed of nerve regeneration is generally slow, electrical stimulation has been found to promote nerve regeneration, and therefore, various electrically conductive nerve conduits have been studied in combination with electrical stimulation; however, the current way of applying the electrical stimulation is to insert the metal electrode into the body of the patient and supply power through an external power supply, which increases the pain and inconvenience of the patient and makes the location of the electrical stimulation not accurate enough.

The Chinese invention patent with the publication number of 109793594A provides a block structure conductive nerve conduit capable of spontaneous electrical stimulation and a preparation method thereof, wherein the conduit integrates an anode and a cathode on a conductive substrate; the conductive substrate is formed by compounding conductive components with a base material; the anode is formed by compounding a conductive substrate with a glucose oxidation catalyst; the cathode is formed by a conductive substrate and a composite oxygen reduction catalyst; the nerve conduit in the invention can spontaneously generate electrical stimulation by utilizing glucose and oxygen existing in a human body to promote nerve growth without inserting a metal electrode in the human body, thereby reducing the pain and inconvenience of a patient; in addition, the catheter can also be used for electrically stimulating the defective nerve part in a concentrated manner, so that the accuracy and the efficiency of electrical stimulation are improved.

The method utilizes glucose and oxygen in vivo to generate energy for generating spontaneous electrical stimulation in the nerve conduit, but because the conduit is not degradable, if the conduit is not treated after nerve regeneration is finished, tissue fibrosis can be caused, toxic and side effects such as inflammation and the like are caused, and a second operation of removing an implant is required after treatment is finished, so that secondary damage is caused to a patient.

Moreover, clinical tests prove that inflammation and gliosis are easy to cause due to invasion of the implanted electrode; the clinical application effect is not very ideal. Various biodegradable materials are developed to prepare various biomedical stents or catheters, such as collagen, polylactic acid, etc., but the single use of these materials also has some problems, such as: unsuitable strength, mismatched material degradation rate and tissue regeneration speed, toxic and side effects and the like.

Disclosure of Invention

In view of the shortcomings of the prior art, it is an object of the present invention to provide a piezoelectric stent composition capable of spontaneous electrical stimulation.

In order to achieve the above object of the present invention, the present invention provides the following technical solutions: a piezoelectric stent composition capable of spontaneous electrical stimulation comprises 70-99 wt% of biodegradable material and 1-30 wt% of piezoelectric material;

the biodegradable material comprises one or more of polylactic acid (PLA), polylactic acid-polyethylene glycol (PLA-PEG), polylactic acid-polyglycolic acid (PLGA), Polycaprolactone (PCL), polycaprolactone-polyethylene glycol (PCL-PEG), fibroin, collagen, gelatin, hyaluronic acid and chitosan;

the piezoelectric material comprises one or more of zinc oxide nano-tubes, boron nitride nano-tubes, barium titanate nano-tubes and fluorine resin.

More preferably, the material comprises 80-95 wt% of biodegradable material and 5-20 wt% of piezoelectric material.

Preferably, the zinc oxide nano-particles comprise single-layer zinc oxide nano-particles, multi-layer zinc oxide nano-particles or a mixture of single-layer and multi-layer zinc oxide nano-particles.

Preferably, the boron nitride nanotubes comprise single-walled boron nitride nanotubes, multi-walled boron nitride nanotubes, or a mixture of single-walled and multi-walled boron nitride nanotubes.

Preferably, the barium titanate nano-scale comprises one or more of tetragonal system barium titanate nano-scale, orthorhombic system barium titanate nano-scale and trigonal system barium titanate nano-scale.

Preferably, the fluororesin includes one or more of a polymer of vinylidene fluoride, a polymer of trifluoroethylene, and a polymer of chlorotrifluoroethylene.

The second purpose of the invention is to provide a preparation method of the piezoelectric stent composition capable of spontaneous electric stimulation.

In order to achieve the above object of the present invention, the present invention provides the following technical solutions: a preparation method of a piezoelectric scaffold capable of spontaneous electric stimulation comprises the following steps:

A. preparing any one of the above piezoelectric scaffold compositions capable of spontaneous electrical stimulation;

B. the piezoelectric stent composition capable of spontaneous electric stimulation is subjected to a three-dimensional forming method to obtain a single-layer uniform piezoelectric stent capable of spontaneous electric stimulation or a multilayer tubular piezoelectric stent capable of spontaneous electric stimulation;

the three-dimensional forming method comprises an electrostatic spinning method, a casting method, a spraying method, a 3D printing method and an extrusion-die forming method.

Preferably, the step a specifically includes: dissolving zinc oxide nano-tubes, boron nitride nano-tubes and barium titanate nano-tubes in 2-20 times of one or more of dichloromethane, water, N-dimethylformamide, ethyl acetate, tetrahydrofuran and acetone to form a suspension or dissolving fluororesin in 2-20 times of one or more of dichloromethane, water, N-dimethylformamide, ethyl acetate, tetrahydrofuran and acetone to form a solution or adding a piezoelectric material into a biodegradable material which is hot-melted at 50-250 ℃ and mixing uniformly to obtain a mixture.

Preferably, the electrospinning method specifically comprises the following steps: removing bubbles of the piezoelectric stent composition solution or suspension subjected to spontaneous electric stimulation by using an ultrasonic machine, injecting the piezoelectric stent composition solution or suspension into an injection instrument, outputting at the speed of 0.001-1ml/min of flow, spraying the piezoelectric stent composition solution or suspension onto a mold with the rotation speed of 1-5000rpm and the diameter of 0.01cm-10cm, controlling the voltage to be 2-50KV, and controlling the receiving distance to be 5-50 cm; the electrostatic spinning nozzle reciprocates at the speed of 1-100cm/min in the horizontal direction to form a piezoelectric bracket; after drying, the piezoelectric support is taken off from the die and cut into different length specifications;

the casting method specifically comprises the following steps: the casting method specifically comprises the following steps: pouring the piezoelectric stent composition solution or suspension subjected to spontaneous electrical stimulation onto a glass plate, and then drying at 20-200 ℃ to obtain a 2D planar stent; cutting the 2D planar support into a rectangle, fixing one end of the rectangle with a cylindrical model with the diameter of 0.01cm-10cm, rolling the tail end around the outer periphery of the cylindrical model, and rolling the cylindrical model into a 3D three-dimensional tubular piezoelectric support; the piezoelectric support is taken off from the die after the tail end and the support body are heat sealed;

the spraying method specifically comprises the following steps: injecting the piezoelectric stent composition solution or suspension subjected to spontaneous electrical stimulation into a spraying machine, spraying at the flow rate of 0.001-0.1ml/min, spraying onto a mold with the rotation speed of 500-5000rpm and the diameter of 0.01-10 cm, and receiving the distance of 5-50cm to form a piezoelectric stent; after drying, the piezoelectric support is taken off from the die and cut into different length specifications;

the 3D printing method specifically comprises the following steps: injecting the spontaneous electrical stimulation piezoelectric stent composition molten liquid into an ink box of a 3D printer, and printing at 50-250 ℃ to obtain a piezoelectric stent with the diameter of 0.01-10 cm and the tube wall thickness of 0.01-1 cm;

the extrusion-die molding method specifically comprises the following steps: injecting the piezoelectric support composition molten liquid subjected to spontaneous electric stimulation into a high-temperature container at 50-250 ℃, extruding the piezoelectric support composition molten liquid in a mould, and cooling and solidifying the piezoelectric support composition molten liquid to obtain a three-dimensional tubular piezoelectric support; the piezoelectric support is taken off from the die and cut into different length specifications;

the piezoelectric support is tubular, the average pipe diameter of the piezoelectric support is 0.01cm-10cm, and the average pipe wall thickness is 0.01cm-1 cm.

Preferably, the single-layer uniform piezoelectric scaffold capable of spontaneous electrical stimulation is a piezoelectric scaffold which can be directly subjected to 3D stereoscopic spontaneous electrical stimulation and has uniform composition by using a 3D printing method, a spraying method, a casting method, an extrusion-die forming method or an electrostatic spinning method;

the piezoelectric scaffold with the multilayer tubular structure and capable of spontaneous electrical stimulation is a 3D three-dimensional scaffold with the same or different composition of each layer obtained by utilizing a 3D printing method, a spraying method or an electrostatic spinning method to print and spray layer by layer; or obtaining the 2D planar support by using a casting method and then manufacturing the 3D three-dimensional support.

The composition of the integral forming method is uniformly mixed, and the preparation is simple and quick; the composition of each layer of the multilayer preparation method can be the same or different. For example, catheters for multilayer fabrication: if the innermost layer is a less toxic piezoelectric material/degradable material composition; the middle layer is a piezoelectric material/degradable material composition with larger piezoelectric performance and larger toxicity; the outermost layer is degradable material. Thus, the biocompatibility can be improved, the structure is fine, and the effect is better.

The invention also aims to provide application of the piezoelectric stent composition capable of spontaneous electric stimulation.

In order to achieve the above object of the present invention, the present invention provides the following technical solutions: use of a piezoelectric scaffold composition capable of spontaneous electrical stimulation, the use of the piezoelectric scaffold comprising use in any one of bone regeneration or repair scaffolds, nerve regeneration or repair, blood vessel regeneration or repair, muscle regeneration or repair, tendon regeneration or repair, skin regeneration or repair, bile duct regeneration or repair, lymphatic vessel regeneration or repair, oesophagus regeneration or repair, trachea regeneration or repair, intestinal regeneration or repair, ureter regeneration or repair or assisted regeneration of the lumen thereof.

In summary, compared with the prior art, the invention has the following beneficial effects:

(1) a piezoelectric support capable of spontaneous electrical stimulation is provided, the symmetry of crystals with piezoelectricity in the material is low, when the piezoelectric support deforms under the action of external force, the relative displacement of positive and negative ions in unit cells enables the centers of the positive and negative charges not to coincide any more, so that the crystals are subjected to macroscopic polarization, and therefore, when the piezoelectric material deforms under the action of pressure, opposite charges appear on two end faces, and local electrical stimulation is generated; under the condition of micro mechanical displacement, different surface charges can be generated, the mechanical energy in the environment in vivo is converted into electric signals by converting the mechanical energy of the environment into electric signals, the regeneration, proliferation and differentiation of tissues such as nerves, muscles, bones, blood vessels, skin and the like are promoted, and biological signals are transmitted to promote the tissue repair; it has enough strength, elasticity and hardness, can guide the tissue to grow towards the proper direction, and has ideal biomedical function;

(2) the material has small toxic and side effects, good biocompatibility and proper degradation period, can be completely degraded and automatically absorbed by a human body after the regeneration of the damaged tissue is finished, does not need to perform an operation to take out the residual stent, avoids secondary damage and prevents other complications such as adhesion and fibrocystic formation;

(3) the implantation of an external power supply or an electrode is not needed, the tissue regeneration speed can be effectively improved, the pain and inconvenience of a patient are reduced, and the infection risk is reduced;

(4) animal in vivo experiments show that the piezoelectric catheter stent has the functions of promoting nerve regeneration, angiogenesis, relieving muscular atrophy and the like, and has good clinical application prospects.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a topographical view of a catheter stent prepared in example 1 of the present invention, wherein (1a) is a macroscopic view; (1b) is SEM picture;

FIG. 2 is a topographical view of a catheter stent prepared in example 4 of the present invention, wherein (2a) is a macroscopic view; (2b) is SEM picture;

FIG. 3 is a topographical view of a catheter stent prepared in example 7 of the present invention, wherein (3a) is an in vivo image of an implanted rat; (3b) is SEM picture;

FIG. 4 is a topographical view of a catheter stent prepared in example 10 of the present invention, wherein (4a) is a macroscopic view; (4b) is SEM picture;

FIG. 5 is a topographical view of a catheter stent prepared in example 11 of the present invention, wherein (5a) is a macroscopic view; (5b) is a conduit SEM picture;

FIG. 6 is a diagram of the result of transmission electron microscopy for the regeneration of nerve of a piezoelectric catheter stent of the present invention and a PCL catheter stent of a control group;

FIG. 7 is a diagram showing the results of the immunofluorescent microangiogenic staining of a piezoelectric catheter stent of the present invention and a PCL catheter stent of a control group;

fig. 8 is a graph showing results of gastrocnemius HE staining of the piezoelectric catheter stents of the present invention and the PCL catheter stents of the control group.

Detailed Description

The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. The present invention will be described in detail with reference to the following specific examples:

examples 1 to 11, comparative examples 1 to 2