CN115487352B

CN115487352B - Degradable polyoxime urethane bionic vascular network based on metal ion coordination

Info

Publication number: CN115487352B
Application number: CN202211101732.0A
Authority: CN
Inventors: 游正伟; 沈傲
Original assignee: Donghua University
Current assignee: Donghua University
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2023-06-27
Anticipated expiration: 2042-09-09
Also published as: CN115487352A

Abstract

The invention relates to a metal ion coordination-based degradable polyoxime alamine bionic vascular network, which comprises metal ion coordination polyoxime alamine and polycaprolactone. The bionic vascular network has a microporous structure of the tube wall, and the multilevel network structure of the bionic vascular network can be used as a tissue repair device. Meanwhile, the coordination of the oxime group and the copper ion enables the copper ion to be slowly released, and the contained copper ion can relax vascular tension, inhibit platelet aggregation, regulate inflammatory reaction and promote vascularization. The bionic vascular network has great development potential in tissue engineering repair.

Description

Degradable polyoxime urethane bionic vascular network based on metal ion coordination

Technical Field

The invention belongs to the field of bionic materials, and particularly relates to a degradable polyoxime alamine bionic vascular network based on metal ion coordination.

Background

Tissue engineering has gained great attention as an important method for solving tissue and organ repair and regeneration. Biomedical elastomers are widely used in tissue engineering due to their stable mechanical properties, controllable chemical structures and good matching properties with soft tissues of human bodies. The ideal biomedical elastomer not only can well simulate the complex and fine three-dimensional structure of the soft tissue of the human body, but also has the characteristics of soft and tough mechanical property, degradability, no toxicity of degraded products to the human body and the like.

Vascularization is a critical process of tissue engineering and determines the performance and effectiveness of tissue engineering implants. Ischemia and hypoxia caused by insufficient vascularization are enough to cause death of transplanted cells, infection and necrosis of tissue engineering implants, so that the repair effect is greatly reduced. Therefore, it is highly necessary to design a rapid, efficient artificial tissue vascularization strategy.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a degradable polyoxime alamine bionic vascular network based on metal ion coordination. According to the invention, 3D printing is combined with sugar to serve as a sacrificial template, the metal ion coordinated polyoxime alamine and polycaprolactone are blended, and the permeable bionic vascular network is prepared by casting on the surface of the template. The bionic vascular network has a microporous structure of the tube wall, and the multilevel network structure of the bionic vascular network can be used as a tissue repair device.

The invention relates to a bionic vascular network material of metal ion coordinated polyoxime alamine, which comprises the components of metal ion coordinated polyoxime alamine and polycaprolactone.

Preferably, the structure of the metal ion coordinated polyoxime urethane is as follows:

m is 10000-100000; n is 10000-100000.

The invention relates to a preparation method of a metal ion coordinated polyoxime alamine bionic vascular network material, which comprises the following steps:

(1) Adding sugar into a 3D printer charging barrel, preheating and printing to obtain a sugar die;

(2) Dissolving the polyoxime alamine, the metal salt and the polycaprolactone in an organic solvent, immersing the sugar mould in the step (1) for 10-15s to obtain a solution, volatilizing the solvent, immersing in water, taking out, and freeze-drying to obtain the bionic vascular network.

The preferred mode of the preparation method is as follows:

preheating in the step (1) to 150-160 ℃ for 40-70min; the printing parameters are as follows: the line spacing is 1.5-2 times of the inner diameter of the needle head, the layer height is 0.8 times of the inner diameter of the needle head, the layer number is 2 layers or more, the printing temperature is 130-145 ℃ (the temperature and the time are limited to range values).

In the step (1), the thickness of single sugar lines in the sugar film is 0.5-0.8 mm, the spacing of the single sugar lines is 1-2 mm, the sugar film is of a multi-layer network structure, the height of each layer is 0.3-0.6 mm, the angle of each layer changes by 90 degrees, and the sugar is soft white sugar.

The molar ratio of the polyoxime alamine to the polycaprolactone in the step (2) is 1:2-1:4; the metal salt is copper chloride, zinc chloride, magnesium chloride, etc.

The polyoxime alamine in the step (2) is prepared by the following method which comprises the following steps:

mixing the dehydrated polymer dihydric alcohol, diisocyanate, an organic solvent and a catalyst, stirring and reacting for 3-4 hours at 60-80 ℃ under nitrogen atmosphere, then adding a dimethylglyoxime solution, keeping stirring and reacting for 12-20 hours under nitrogen atmosphere, washing, and vacuumizing to obtain the polyoxime alamine; wherein the mol ratio of the diisocyanate, the polymer diol and the dimethylglyoxime is required to meet the requirement, and the mol ratio of the diisocyanate, the polymer diol and the dimethylglyoxime is denoted as a:b:c, wherein b is 1000-10000, c is 1000-10000, and a=b+c.

And vacuumizing and dewatering the polymer dihydric alcohol at 110 ℃.

The polymer dihydric alcohol is polycaprolactone dihydric alcohol with the molecular weight of 2000; the diisocyanate is one or more of nontoxic diisocyanate such as isophorone diisocyanate, pentamethylene diisocyanate and hexamethyl diisocyanate; the catalyst is butyl tin dilaurate.

The addition amount of the catalyst is 0.1-0.3% of the total weight of the polymer dihydric alcohol, the diisocyanate and the dimethylglyoxime; in the step (2), the molar ratio of the metal ions to the dimethylglyoxime in the metal salt is 0.25:1-1:1, and the weight ratio of the metal ions to the polyoxime urethane is 1000:7.5-1000:30.

The washing is carried out by adopting diethyl ether.

The step (2) is to dissolve polyurethane, polycaprolactone and salt in an organic solvent, pour the solution into a surface dish for placing a sugar mold, submerge the sugar mold for 10-15s, ensure that the solution is fully soaked on the surface of the template, then clamp the sugar mold out by forceps, and hang the sugar mold in a fume hood. After the solvent is volatilized (about 1-2 h), soaking the sugar mould in water to dissolve sugar, taking out and freeze-drying to obtain the bionic vascular network.

The organic solvent in the step (2) is tetrahydrofuran.

The invention relates to application of a metal ion coordinated polyoxime alamine bionic vascular network material in a tissue repair device or a tissue patch.

The bionic blood vessel network is prepared by the 3D printing and sacrificial template method, the structure and the function of the simulated blood vessel are macroscopically provided with the mutually communicated pipeline structure, the hollow form and the multi-branch structure of the simulated blood vessel are simulated, and a channel can be provided for the perfusion of medicines and liquid; the micro-porous wall has a large number of micropores on the inner and outer surfaces, which simulate the metabolic waste characteristics of blood vessels. Meanwhile, the copper ions contained in the composite material can catalyze endogenous nitric oxide donors in blood to release nitric oxide, relax vascular tension, inhibit platelet aggregation, regulate inflammatory reaction and promote vascularization.

Advantageous effects

The invention prepares the degradable polyoxime alamine capable of being coordinated with metal ions, prepares the bionic vascular network with a three-dimensional structure by combining 3D printing with a sacrificial template method, can simulate the function of a natural vascular network, and can carry out mass transfer and exchange with the outside. The degradability ensures that materials are not left after tissue repair. Meanwhile, the coordination of the oxime group and the copper ion enables the copper ion to be slowly released, and the contained copper ion can relax vascular tension, inhibit platelet aggregation, regulate inflammatory reaction and promote vascularization. The bionic vascular network has great development potential in tissue engineering repair.

Drawings

FIG. 1 is a schematic diagram of a metal coordinated degradable polyoxime alamate synthesis process and a copper coordination process;

FIG. 2 is a schematic representation of the molecular weight distribution of a polyoxime axetil;

FIG. 3 is a schematic diagram of Fourier transform infrared spectra of a polyoxime axetil;

FIG. 4 is a schematic diagram of the microstructure of a biomimetic vascular network;

FIG. 5 is a schematic diagram of the perfusability and permeability of a biomimetic vascular network;

FIG. 6 is a schematic diagram showing the weight change of the bionic vascular network during degradation, wherein the sample of example 1 is named PCL-PU-Cu 25%, the sample of example 2 is named PCL-PU-Cu 50%, and the sample of example 3 is named PCL-PU-Cu 100%;

FIG. 7 is a schematic diagram showing the content of slow-released copper ions in a bionic vascular network immersed in a phosphate buffer solution, wherein a sample in example 1 is named PCL-PU-Cu 25%, a sample in example 2 is named PCL-PU-Cu 50%, and a sample in example 3 is named PCL-PU-Cu 100%;

fig. 8 is a schematic diagram of a biomimetic vascular network graft as a muscle and myocardium patch.

Detailed Description

The invention will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention. Further, it is understood that various changes and modifications may be made by those skilled in the art after reading the teachings of the present invention, and such equivalents are intended to fall within the scope of the claims appended hereto.

Example 1

(1) Dewatering of raw materials

Removal of water from polycaprolactone diol (PCL-diol): 5.00g of polycaprolactone diol (Mn=2000 g/mol,2.5 mmol) was weighed into a 100mL single neck eggplant-shaped flask, the rotor was added, the flask was placed into an oil bath at 110℃and held for 2h with a pump vacuum to remove moisture from the diol.

(2) Synthesis of Polyoxime urethanes

After the temperature was lowered to 70℃and the nitrogen atmosphere was maintained in the flask by inserting a nitrogen balloon, 0.77g of pentamethylene diisocyanate, 5mL of N, N-dimethylformamide, 0.01g of butyltin dilaurate were added to the flask and magnetically stirred at 250rpm for 4 hours. Then, 0.29g of a chain extender dimethylglyoxime solution dissolved in 5mL of N, N-dimethylformamide was added dropwise to the reaction mass, and magnetically stirred at 250rpm for 16 hours to obtain a PCL-PU polymer. Wherein the molar ratio of PCL diol/IPDI/DMG is 1:2:1. The resulting product was washed 3 times with diethyl ether and vacuum was applied for 24h to remove excess solvent to give a white solid of polyoxime axetil. The molecular weight distribution was obtained by Gel Permeation Chromatography (GPC), mw was 41367, and pdi was 2.50.

(3) Fourier transform infrared spectrum characterization of Polyoxime urethanes and copper coordinated Polyoxime urethanes

2g of polyoxime axetil is weighed, 15.0mg, 30.1mg and 60.2mg of anhydrous copper chloride are respectively weighed, pure polyoxime axetil, polyoxime axetil and copper chloride with different contents are respectively dissolved in 16mL of tetrahydrofuran, magnetically stirred for 8 hours at room temperature to form a yellowish green solution, and poured into a tetrafluoro mold to volatilize the solvent, so as to obtain a polyoxime axetil sheet and 3 groups of copper coordination polyoxime axetil sheets which are respectively named as PU-Cu 25%, PU-Cu 50% and PU-Cu 100%.

As shown in FIG. 3, 960.7cm in Fourier transform infrared spectrum ^-1 The peak at the peak is a telescopic peak of N-O bond in a dimethylglyoxime unit, 1720.55cm ^-1 And 3380.69cm ^-1 The peaks at this point are the stretching vibration peaks of the c=o and N-H bonds in the urethane group. The infrared spectrum corresponds to the designed molecular structure, which shows that the dimethylglyoxime is successfully introduced into polyurethane to form dimethylglyoxime urethane groups, and the dimethylglyoxime urethane material containing the dimethylglyoxime urethane groups is obtained. Meanwhile, after copper ions are introduced into the polyoxime alamate, the absorption wavelength of the characteristic peak of the N-O bond in the infrared spectrum is red-shifted from 960.70 to 962.26cm ^-1 And the peak intensity decreases with increasing copper content, indicating that the introduced copper ion coordinates to the "N" atom on the N-O bond in the dimethylglyoxime group.

(4) Preparation of bionic vascular network

0.6g of polycaprolactone and 0.2g of polyoxime urethane were weighed out, and 1.5mg of CuCl was weighed out ₂ This was dissolved in 16mL of tetrahydrofuran, and magnetically stirred at room temperature for 8 hours to form a yellowish green solution, to obtain a mixed solution.

Soft sugar is added into a 3D printer charging barrel, preheated at 160 ℃ for 40 minutes, and then cooled to 140 ℃ for printing. The method comprises the steps of using a needle diameter of 0.6 millimeter, printing a cube with a size of 2.4 x 1.35cm, setting a line spacing of 1.2 millimeter, a layer height of 0.45 millimeter, printing 3 layers, wherein each layer has a rotation angle of 90 degrees, a screw extrusion speed of 6 mu m/s and a needle printing speed of 3mm/s, and obtaining the sugar die.

Pouring the solution into a surface dish for placing the sugar mould, immersing the sugar mould for 10-15 seconds to ensure that the solution is fully immersed on the surface of the template, then clamping the sugar mould out by forceps, and suspending the sugar mould in a fume hood. After the solvent is volatilized (about 1-2 hours), soaking the sugar mould in water for 15-30 minutes, taking out, and freeze-drying to obtain the bionic vascular network.

(4) Surface structure characterization of bionic vascular network

As shown in fig. 4, the bionic vascular network shows a pipeline network structure which is mutually communicated, and the pipeline networks are stacked in a crossed manner layer by layer to form a multi-layer network bracket, so that the bionic vascular network has a complete and uniform surface.

And observing the multilevel microscopic structure of the bionic vascular network through a scanning electron microscope. As shown in fig. 4, the communicated tubular network structure and the surface coating with micropores can well simulate a vascular network in a living body, and the communicated pipeline structure can simulate a multi-branch structure of a blood vessel and can be used for conveying liquid or water-soluble medicines, so that the device has good perfusion and liquid conveying capacity; the surface coating and the pipe wall are provided with abundant micropore structures, so that the permeability of the pipe can be endowed, and the exchange of substances and nutrients inside the pipe and outside is promoted.

As shown in fig. 5, the red ink is poured under pressure into the biomimetic vascular network, flowing in the internal connected tubing until the entire tubing network is filled. Meanwhile, due to the micropore structure of the surface of the bionic vascular network, the ink can penetrate through the surface to the outside. The bionic vascular network can simulate the functions of a natural vascular network through a pipeline network and a micropore structure, and can carry out mass transmission and exchange with the outside.

(5) Degradation characterization of biomimetic vascular networks

The ester bond of PCL and the amine ester bond of polyurethane, which are soft segments, can be hydrolyzed and enzymatically hydrolyzed. In order to rapidly confirm the degradation capacity of the bionic vascular network, the bionic vascular network was degraded in vitro by a high concentration of lipase, and the lipase concentration was 20000u/ml in a phosphate buffer, and the degradation rate after 1 hour was about 23% as shown in FIG. 6.

(6) Copper ion slow release of bionic vascular network

The bionic vascular network was cut into small pieces weighing 10 mg, immersed in 5ml of phosphate buffer, the phosphate buffer was replaced daily, and the copper content in the phosphate buffer was measured using a plasma emission spectrometer. As shown in fig. 7, the bionic vascular network can keep copper slow release for a certain time, and the effect of releasing copper stably is achieved.

(7) Bionic vascular network as tissue patch

As shown in figure 8, the bionic vascular network is implanted in the body and can be used for promoting muscle and heart tissue repair.

Example 2

The preparation method of the degradable polyoxime alamine bionic vascular network based on metal ion coordination is the same as the first embodiment, and is different in that:

0.6g of polycaprolactone, 0.2g of polyoxime urethane and 3.0mg of CuCl are weighed ₂ This was dissolved in 16mL of tetrahydrofuran and magnetically stirred at room temperature for 8 hours to form a yellowish green solution, to give a mixed solution of another concentration.

Example 3

0.6g of polycaprolactone, 0.2g of polyoxime urethane and 6.0mg of CuCl are weighed out ₂ This was dissolved in 16mL of tetrahydrofuran and magnetically stirred at room temperature for 8 hours to form a yellowish green solution, to give a mixed solution of another concentration.

Example 4

the diisocyanate used in the synthesis is isophorone diisocyanate.

When the sugar mold is printed, the diameter of a needle head is 0.7 millimeter, the printing mold is a cube with the size of 1.4 x 1.8cm, the line spacing is set to be 1.4 millimeter, the layer height is 0.6 millimeter, 3 layers are printed, the rotation angle of each layer is 90 degrees, the screw extrusion speed is 4 mu m/s, and the printing speed of the needle head is 2.4mm/s, so that the sugar mold is obtained.

Claims

1. The bionic vascular network material of the metal ion coordinated polyoxime alamine is characterized in that the components comprise the metal ion coordinated polyoxime alamine and polycaprolactone;

the structure of the metal ion coordinated polyoxime urethane is as follows:

；

m is 10000-100000; n is 10000-100000.

2. A method for preparing the metal ion coordinated polyoxime alamate bionic vascular network material of claim 1, comprising:

(2) And (2) dissolving the polyoxime alamate, the metal salt and the polycaprolactone in an organic solvent, immersing the sugar mould 10-15s in the step (1) in the obtained solution, volatilizing the solvent, immersing in water, taking out, and freeze-drying to obtain the bionic vascular network.

3. The method according to claim 2, wherein the preheating in the step (1) is performed at 150-160 ℃ for 40-70min; the printing parameters are as follows: the line spacing is 1.5-2 times of the inner diameter of the needle head, the layer height is 0.8 times of the inner diameter of the needle head, the layer number is 2 layers or more, and the printing temperature is 130-145 ℃.

4. The preparation method according to claim 2, wherein the sugar lines in the step (1) have a thickness of 0.5-0.8 mm, a line spacing of 1-2 mm, the sugar film has a multi-layer network structure, the height of each layer is 0.3-0.6 mm, the angle of each layer is changed by 90 degrees, and the sugar is soft white sugar.

5. The preparation method according to claim 2, wherein the molar ratio of the polyoxime alamine to the polycaprolactone in the step (2) is 1:2-1:4; the metal salt is copper chloride.

6. The method according to claim 2, wherein the polyoxime alamate in the step (2) is prepared by a method comprising:

mixing the diisocyanate after water removal, the polymer dihydric alcohol, the organic solvent and the catalyst, stirring and reacting at 60-80 ℃ under nitrogen atmosphere for 3-4h, then adding a dimethylglyoxime solution, keeping stirring and reacting at the nitrogen atmosphere for 12-20h, washing, and vacuumizing to obtain the polyoxime urethane; wherein the molar ratio of diisocyanate, polymer dihydric alcohol and dimethylglyoxime is a:b:c, b is 1000-10000, c is 1000-10000, and a=b+c.

7. The method of claim 6, wherein the polymer diol is a polycaprolactone diol; the diisocyanate is one or more of isophorone diisocyanate, pentamethylene diisocyanate and hexamethyl diisocyanate; the catalyst is butyl tin dilaurate.

8. The preparation method according to claim 6, wherein the catalyst is added in an amount of 0.1-0.3% based on the total weight of the polymer diol, the diisocyanate and the dimethylglyoxime; the molar ratio of the metal ions in the metal salt to the dimethylglyoxime in the step (2) is 0.25:1-1:1.

9. Use of the metal ion coordinated polyoxime alamate bionic vascular network material according to claim 1 in tissue repair devices and tissue patches.