CN107898533B - Artificial drug-loaded coaxial regenerated vascular stent and its composite process preparation method - Google Patents

Abstract

The invention discloses an artificial drug-loaded coaxial regenerated vascular stent and a composite process preparation method thereof. The vascular stent has a three-layer structure and is prepared by different processes, wherein the inner layer material is deferoxamine DFO+PVA core layer solution Coaxial electrospinning forming process is adopted with PCL shell solution; PVA+SA mixed solution is used as the middle layer material, and the impregnation forming process is adopted, and calcium chloride is used for cross-linking after electrospinning the outer layer; the outer layer material is selected from Qing The core layer solution of damycin GS+PVA and the shell layer solution of PCL are formed by coaxial electrospinning. The present invention uses two kinds of processes to combine different materials to prepare a three-layer drug-loaded vascular stent, and well simulates the three-layer structure of natural blood vessels, shortens the time and success rate required for in vitro culture and transplantation, and has broad prospects in clinical application .

Description

Artificial drug-loaded coaxial regenerated vascular stent and its composite process preparation method

technical field

The invention relates to an artificial blood vessel and a preparation method thereof, in particular to a regenerated blood vessel support and a composite process preparation method thereof, which are applied in the technical field of biomanufacturing.

Background technique

Cardiovascular disease, especially coronary heart disease caused by arteriosclerosis, has become one of the main causes of human death, and one of the main means of treatment is vascular transplantation. Due to the limited sources of autologous blood vessels, a large number of artificial blood vessels are required for clinical use.

With the increase in the demand for artificial blood vessels, artificial blood vessels prepared by various processes have been produced one after another. Among them, artificial blood vessels prepared by bioprinting technology are increasingly used in blood vessel preparation due to their outstanding performance in function and efficiency.

The traditional preparation of artificial blood vessels, one is made by single-process electrospinning, but the biocompatibility or mechanical properties are not very good, the other is to prepare artificial blood vessels by combining electrospinning with biomaterials, but drug loading is considered during the preparation process The application of technology is less. Although the vascular stents currently prepared can simply simulate the natural vascular structure, infection and tissue compatibility problems are often encountered during the transplantation process. Therefore, the preparation process and selection of vascular stents need to be improved and perfected.

Contents of the invention

In order to solve the problems of the prior art, the object of the present invention is to overcome the deficiencies in the prior art, and provide an artificial drug-loaded coaxial regenerative vascular stent and its composite process preparation method, because the multi-process composite method is used to prepare the vascular stent , which overcomes the limitation of a single process and shortens the preparation time of the scaffold. The first layer and the second layer are tightly combined by capillary phenomenon, and the second layer and the third layer are tightly combined by chemical cross-linking method, which improves the overall strength of the scaffold. Mechanical properties, due to the use of drug-loaded coaxial technology, the drug can be released slowly in the body on time, reducing the infection rate of the artificial blood vessel after transplantation, because the process uses PVA, SA, PCL and other biomaterials, it improves the efficiency of regenerated blood vessels Histocompatibility.

To achieve the above object, the present invention adopts the following technical solutions:

An artificial drug-loaded coaxial regenerative vascular stent, from the inside to the outside of the drug-loaded coaxial regenerative vascular stent, is composed of a coaxial inner layer, a hydrogel middle layer and an outer layer, which simulate the three layers of natural blood vessels structure, wherein the inner layer is formed by tightly combining the deferoxamine DFO composite core layer and the first polycaprolactone PCL shell layer in turn, forming the first polycaprolactone PCL shell layer wrapping the deferoxamine DFO composite core layer Layered composite inner layer structure, the deferoxamine DFO composite core layer is made of a composite material of deferoxamine DFO and PVA, and the deferoxamine DFO composite core layer is directly set towards the lumen of the drug-loaded coaxial regenerated blood vessel , the hydrogel middle layer is made of a composite material of sodium alginate SA and PVA, and the outer layer is tightly combined with a gentamicin GS composite core layer and a second polycaprolactone PCL shell layer in turn, Form the second polycaprolactone PCL shell layer to wrap the layered composite outer layer structure of the gentamicin GS composite core layer, and the gentamicin GS composite core layer is made of a composite material of gentamicin GS and PVA , the first polycaprolactone PCL shell layer and the gentamycin GS composite core layer are tightly combined with the two sides of the hydrogel middle layer respectively, and the second polycaprolactone PCL shell layer directly faces the drug-loaded same External setup of axis revascularization.

Preferably, the component mass ratio of the composite material of deferoxamine DFO and PVA of the above-mentioned deferoxamine DFO composite core layer is (15-64): 1000; the preferred gentamicin GS of the above-mentioned gentamicin GS composite core layer The component mass ratio of the composite material with PVA is (3-8):1000.

Preferably, the component mass ratio of the composite material of sodium alginate SA and PVA in the hydrogel middle layer is (2.4-9.6):(1-5).

As a preferred technical solution of the present invention, the first polycaprolactone PCL shell layer or the second polycaprolactone PCL shell layer is made of polycaprolactone PCL and a matrix material blended, and the matrix material is made of N, It is made by mixing N-dimethylformamide DMF and dichloromethane DCM; the volume ratio of N,N-dimethylformamide DMF and dichloromethane DCM is 1:1, and the ratio of polycaprolactone PCL to the base material The mass volume ratio is (1-10) g: 100ml.

Preferably, the overall wall thickness of the artificial drug-loaded coaxial regenerated vascular stent is controlled by adjusting the thickness of the hydrogel intermediate layer.

The invention provides a method for preparing a drug-loaded coaxial regenerative vascular stent by a composite process, comprising the following steps:

a. PVA is dissolved in deionized water, heated in a water bath on a magnetic stirrer, and stirred until the PVA is completely dissolved to obtain a PVA solution with a mass percent concentration of 3-8wt.%.

b. dissolving deferoxamine DFO in the PVA solution prepared in step a, and preparing a DFO inner layer coaxial electrospinning core layer solution with a mass percentage of 50-80wt.%;

c. Use a mixture of N,N-dimethylformamide DMF and dichloromethane DCM with a volume ratio of 1:1 as a solvent, dissolve polycaprolactone PCL in the solvent, and prepare polycaprolactone PCL and solvent The mass volume ratio is (1-10) g: 100ml of PCL coaxial electrospinning shell solution;

d. Sodium alginate SA is dissolved in deionized water, is mixed with the SA solution that mass fraction is 1-5wt.%, then the PVA solution and the SA solution prepared in said step a are in mass ratio (0.8-1.2 ): mixed in a ratio of 1 to be prepared as an intermediate layer solution of a stent;

e. dissolving gentamycin GS in the PVA solution prepared in step a, and configuring it as a 0.3-0.8wt.% GS outer layer coaxial electrospinning core layer solution;

f. Prepare the DFO inner layer coaxial electrospinning core layer solution in the step b and prepare the PCL coaxial electrospinning shell solution in the step c respectively, and adopt the coaxial electrospinning forming process, The PCL coaxial electrospinning core layer and the polycaprolactone PCL shell layer were sequentially prepared to obtain the inner layer of the drug-loaded regenerative vascular stent;

g. Using the dipping forming process, remove the round shaft that has been prepared in the inner layer of the drug-loaded regenerative vascular stent in the step f, and immerse it in the intermediate layer solution prepared in the step d, and let it stand for 15 to 60 After that, take out the round shaft impregnated with hydrogel in the inner layer of the drug-loaded regenerative vascular stent, and place the two ends of the round shaft overhead until there are no more drops of hydrogel dripping from the round shaft, and then put the round shaft on the After freezing in the refrigerator at -40～-60℃ for 10-15 hours, take out the round shaft, and thaw the round shaft at room temperature for 4-8 hours, then put it in the refrigerator for freezing, and experience 1-5 times of freezing - a thawing process whereby a formed hydrogel intermediate layer is obtained on the outside of the inner layer of the drug-loaded regenerative vascular stent;

h. Prepare the GS outer layer coaxial electrospinning core solution in the step e and the PCL coaxial electrospinning shell solution in the step c respectively, and adopt the coaxial electrospinning forming process, The coaxial electrospun core layer of the GS outer layer and the polycaprolactone PCL shell layer were sequentially prepared to obtain the outer layer of the drug-loaded regenerative vascular stent, so that the outer layer of the drug-loaded regenerative vascular stent was wrapped outside the middle layer of the hydrogel to obtain Formed drug-loaded coaxial regenerated vascular stent preform;

i. Soak the drug-loaded coaxial regenerated vascular stent preform prepared in step h in a calcium chloride solution with a mass fraction of 1-5wt.% for 15-60 minutes to carry out chemical cross-linking. After coupling, the drug-loaded coaxial regenerative vascular stent is obtained, and then the drug-loaded coaxial regenerative vascular stent is freeze-dried and taken out to obtain the finished drug-loaded coaxial regenerative vascular stent.

As a preferred technical solution of the present invention, when preparing the inner and outer layers of the vascular stent in the step f and step h, the rotational speed of the circular shaft is controlled to be 200-400 rpm, and the X direction, that is, the horizontal axial reciprocating speed of the circular shaft is 0.3-0.6mm/s, control the voltage of electrospinning to be 10-13KV, make the electrospinning solution feed through the micropump, wherein the electrospinning time in the step f is 3-10min, in the step h The electrospinning time is 4-20min, and the thickness of the electrospun membrane is adjusted by controlling the electrospinning time, so as to adjust the thickness of the inner or outer layer of the drug-loaded regenerative stent. The longer the electrospinning time, the thicker the electrospun membrane.

As a preferred technical solution of the present invention, when preparing the middle layer of the vascular stent in the step g, the number of times of freezing-thawing is determined by the required wall thickness of the regenerated blood vessel, and the prepared water is adjusted by controlling the number of times of freezing-thawing. The thickness of the middle layer of the gel can regulate the overall wall thickness of the artificial drug-loaded coaxial regenerative vascular stent. The more times of freezing-thawing, the thicker the regenerated blood vessel wall.

As a preferred technical solution of the present invention, when preparing the inner and outer layers of the vascular stent in the steps f and h, the feed rate of the micropump is controlled to be 30-60ul/min, and the height of the coaxial nozzle from the circular axis is 140-160mm.

As a preferred technical solution of the present invention, when preparing the inner and outer layers of the vascular stent in the step f and step h, the circular shaft is made of conductive stainless steel, and the diameter of the circular shaft is 2-9 mm; the inner diameter of the coaxial nozzle is not more than 0.3 mm. mm, the outer diameter is not greater than 1mm.

Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant advantages:

1. The vascular stent of the present invention is biocompatible and degradable;

2. The inner layer structure of the stent of the present invention is loaded with deferoxamine DFO, which can promote the production of vascular endothelial growth factor (VEGF). Because the outer layer wraps PCL, DFO can be released slowly on time, thereby promoting the generation of cells on regenerated blood vessels and clinging;

3. The middle layer structure of the vascular stent of the present invention is generated by PVA freezing-physical cross-linking, and can control the wall thickness of the regenerated blood vessel, and can improve the mechanical and biological properties of the regenerated vascular stent, and increase tissue compatibility;

4. The outer structure of the vascular stent of the present invention is loaded with gentamicin GS. Through coaxial electrospinning, the outer layer is wrapped with protective PCL, so that the GS can be released slowly on time and reduce the risk of infection after the vascular stent is moved into the body;

5. The vascular stent of the present invention is prepared by an electrospinning composite process, has the characteristics of a nanofiber structure, and has a large porosity and specific surface area, creating good conditions for cell adhesion.

Description of drawings

FIG. 1 is a schematic structural view of an artificial drug-loaded coaxial regenerated vascular stent according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the formation of the inner layer and the outer layer of the drug-loaded coaxial regenerated vascular stent during electrospinning in Embodiment 1 of the present invention.

Fig. 3 is a schematic diagram of the principle of the composite forming process for the preparation of the drug-loaded coaxial regenerated vascular stent according to Embodiment 1 of the present invention.

Detailed ways

Below in conjunction with specific implementation example, above-mentioned scheme is described further, and preferred embodiment of the present invention is described in detail as follows:

Embodiment one:

In this embodiment, referring to Figures 1-3, a method for preparing drug-loaded coaxial regenerated vascular stents by a composite process includes the following steps:

a. PVA is dissolved in deionized water, heated in a water bath on a magnetic stirrer, and stirred until the PVA is completely dissolved, and the obtained mass percent concentration is 5wt.% PVA solution 35g;

b. Dissolve 20 mg of deferoxamine DFO in 10 g of the PVA solution prepared in step a to prepare the DFO inner layer coaxial electrospinning core layer solution;

c. Use a mixture of N,N-dimethylformamide DMF and dichloromethane DCM with a volume ratio of 1:1 as a solvent, dissolve 2g of polycaprolactone PCL in 20ml of the above solvent, and prepare a PCL coaxial electrode Spin shell solution, divide into two equally again;

d. Sodium alginate SA is dissolved in deionized water to prepare 10 g of SA solution with a mass fraction of 3wt.%, and then the PVA solution and SA solution prepared in step a are in a mass ratio of 1:1 Mix and prepare the middle layer solution of the stent;

e. Gentamicin GS is dissolved in 10 g of the PVA solution prepared in step a, and configured as a 0.5 wt.% GS outer layer coaxial electrospinning core layer solution;

f. As shown in Figures 1 to 3, use the DFO inner layer coaxial electrospinning core layer solution prepared in the step b and a part of the PCL coaxial electrospinning shell solution prepared in the step c, respectively, And the coaxial electrospinning forming process is adopted, in which the DFO inner layer coaxial electrospinning core solution and the PCL coaxial electrospinning shell solution are spun through the coaxial nozzle, and the PCL coaxial electrospinning core is sequentially prepared on the circular shaft U Layer and polycaprolactone PCL shell layer to prepare the inner layer of the drug-loaded regenerative vascular stent; when preparing the inner layer of the vascular stent, control the rotation speed of the circular axis U to 300 rpm, and the X direction is the horizontal axis of the circular axis U The reciprocating speed is 0.5mm/s, and the electrospinning voltage is controlled to be 10KV, so that the electrospinning solution is fed through a micropump. The electrospinning time is 5min, and the feeding speed of the micropump is controlled to be 35ul/min. The height from the circular shaft U is 150mm, the circular shaft U is made of conductive stainless steel, the diameter of the circular shaft U is 5mm; the inner diameter of the coaxial nozzle is 0.3mm, and the outer diameter is 1mm;

g. Using the dipping forming process, remove the round shaft that has been prepared in the inner layer of the drug-loaded regenerative vascular stent in the step f, and immerse it in the intermediate layer solution prepared in the step d, and let it stand for 30 minutes. Afterwards, take out the round shaft impregnated with the hydrogel attached to the inner layer of the drug-loaded regenerative stent, and place the two ends of the round shaft overhead until there are no more drops of hydrogel dripping from the round shaft, and then put the round shaft on- After freezing in a refrigerator at 50°C for 12 hours, take out the shaft, and thaw the shaft at room temperature for 6 hours, then put it in the refrigerator for freezing, and experience a freezing-thawing process in this way, so that the drug-loaded regenerated vascular stent The exterior of the inner layer results in a shaped hydrogel middle layer;

h. Using the GS outer layer coaxial electrospinning core layer solution prepared in the step e and another part of the PCL coaxial electrospinning shell solution prepared in the step c, and using the coaxial electrospinning forming process , the coaxial electrospun core layer of the GS outer layer and another layer of polycaprolactone PCL shell layer were sequentially prepared on the circular axis U to prepare the outer layer of the drug-loaded regenerative vascular stent, so that the outer layer of the hydrogel middle layer was wrapped with The outer layer of the drug-loaded regenerative vascular stent is obtained to obtain the prefabricated drug-loaded coaxial regenerative vascular stent; when preparing the outer layer of the drug-loaded coaxial regenerative vascular stent, the parameters of the circular axis U, the micro pump and the nozzle are the same as those in the step f The process conditions are the same when preparing the inner layer of the vascular stent, and the special feature is that the electrospinning time for preparing the outer layer of the drug-loaded regenerative vascular stent is 15 minutes;

i. Soak the drug-loaded coaxial regenerated vascular stent prefabricated body prepared in the step h in a calcium chloride solution with a mass fraction of 3wt.% for 30 minutes to carry out chemical cross-linking, and after completing the chemical cross-linking, obtain The drug-loaded coaxial regenerative vascular stent has a structure as shown in Figure 1, and then the drug-loaded coaxial regenerative vascular stent is freeze-dried and then taken out to obtain the finished drug-loaded coaxial regenerative vascular stent.

In this example, referring to Figures 1-3, the drug-loaded coaxial regenerative vascular stent is prepared by a composite process. The vascular stent shown has a three-layer structure, and different forming methods are used respectively, wherein the inner layer is a coaxial electrospun DFO solution, The middle layer is made of PVA+SA solution, and the freeze-thaw physical cross-linking method is adopted, and the outermost layer is coaxial electrospun GS solution. This example combines three different forming methods, simulating the three-layer structure of natural blood vessels, and shortens the time for in vitro culture of vascular stents. Because of the coaxial drug loading technology, the vascular stents can be released slowly in vivo on time, The DFO in the first layer can promote the formation of new blood vessels, the middle layer can guarantee the wall thickness and mechanical strength of the blood vessels, and the GS in the outer layer can reduce the infection rate of the tissue, so it has broad application prospects in clinical practice.

Embodiment two:

This embodiment is basically the same as Embodiment 1, especially in that:

In this embodiment, a method for preparing a drug-loaded coaxial regenerated vascular stent by a composite process includes the following steps:

a. PVA is dissolved in deionized water, heated in a water bath on a magnetic stirrer, and stirred until the PVA is completely dissolved, and the obtained mass percent concentration is 3wt.% PVA solution 35g;

b. Dissolve 20mg of deferoxamine DFO in the PVA solution prepared in the step a, and prepare a DFO inner layer coaxial electrospinning core layer solution with a mass percentage of 50wt.%.

c. Use a mixture of N,N-dimethylformamide DMF and dichloromethane DCM with a volume ratio of 1:1 as a solvent, dissolve 0.2g polycaprolactone PCL in 20ml of the above solvent, and prepare a PCL coaxial The electrospinning shell solution was divided into two equally;

d. Sodium alginate SA is dissolved in deionized water to prepare 10g of SA solution with a mass fraction of 1wt.%, and then the PVA solution and SA solution prepared in the step a are in a mass ratio of 0.8:1 Mix and prepare the middle layer solution of the stent;

e. Gentamicin GS is dissolved in 10 g of the PVA solution prepared in step a, and configured as a 0.3 wt.% GS outer layer coaxial electrospinning core layer solution;

f. Using the DFO inner layer coaxial electrospinning core layer solution prepared in the step b and a part of the PCL coaxial electrospinning shell solution prepared in the step c, and using the coaxial electrospinning forming process , wherein the DFO inner coaxial electrospinning core layer solution and the PCL coaxial electrospinning shell solution are spun through the coaxial nozzle, and the PCL coaxial electrospinning core layer and the polycaprolactone PCL shell are sequentially prepared on the circular shaft U layer to prepare the inner layer of the drug-loaded regenerative vascular stent; when preparing the inner layer of the vascular stent, control the rotation speed of the circular axis U to 400 rpm, and the X direction, that is, the horizontal and axial reciprocating speed of the circular axis U to be 0.6 mm/s , control the voltage of electrospinning to 13KV, make the electrospinning solution feed through the micropump, wherein the electrospinning time is 3min, control the feeding speed of the micropump to 60ul/min, and the height of the coaxial nozzle from the circular axis U is 160mm , the circular shaft U is made of conductive stainless steel, the diameter of the circular shaft U is 9mm; the inner diameter of the coaxial nozzle is 0.3mm, and the outer diameter is 1mm;

g. Using the dipping method forming process, the circular shaft that has been prepared in the inner layer of the drug-loaded regenerative vascular stent in the step f is removed, and immersed in the intermediate layer solution prepared in the step d, and left to stand for 15 minutes, Afterwards, take out the round shaft impregnated with the hydrogel attached to the inner layer of the drug-loaded regenerative stent, and place the two ends of the round shaft overhead until there are no more drops of hydrogel dripping from the round shaft, and then put the round shaft on- After freezing in a refrigerator at 40°C for 10 hours, take out the shaft, and thaw the shaft at room temperature for 4 hours, then put it in the refrigerator for freezing, and experience 3 times of freezing-thawing process, so that the drug-loaded regenerated vascular stent The exterior of the inner layer results in a shaped hydrogel middle layer;

h. Using the GS outer layer coaxial electrospinning core layer solution prepared in the step e and another part of the PCL coaxial electrospinning shell solution prepared in the step c, and using the coaxial electrospinning forming process , the coaxial electrospun core layer of the GS outer layer and another layer of polycaprolactone PCL shell layer were sequentially prepared on the circular axis U to prepare the outer layer of the drug-loaded regenerative vascular stent, so that the outer layer of the hydrogel middle layer was wrapped with The outer layer of the drug-loaded regenerative vascular stent is obtained to obtain the prefabricated drug-loaded coaxial regenerative vascular stent; when preparing the outer layer of the drug-loaded coaxial regenerative vascular stent, the parameters of the circular axis U, the micro pump and the nozzle are the same as those in the step f The process conditions are the same when preparing the inner layer of the vascular stent, and the special feature is that the electrospinning time for preparing the outer layer of the drug-loaded regenerative vascular stent is 4 minutes;

i. Soak the drug-loaded coaxial regenerative vascular stent prefabricated body prepared in the step h in a calcium chloride solution with a mass fraction of 1wt.% for 60 minutes to perform chemical cross-linking, and after completing the chemical cross-linking, obtain The drug-loaded coaxial regenerative vascular stent is then taken out after being freeze-dried to obtain the drug-loaded coaxial regenerative vascular stent.

In this example, the drug-loaded coaxial regenerative vascular stent is prepared by a composite process. The vascular stent shown has a three-layer structure, and different forming methods are used respectively. The inner layer is coaxial electrospun DFO solution, and the middle layer is PVA+SA The solution adopts the freeze-thaw physical cross-linking method, and the outermost layer is the coaxial electrospun GS solution. This example combines three different forming methods, simulating the three-layer structure of natural blood vessels, and shortens the time for in vitro culture of vascular stents. Because of the coaxial drug loading technology, the vascular stents can be released slowly in vivo on time, The DFO in the first layer can promote the formation of new blood vessels, the middle layer can guarantee the wall thickness and mechanical strength of the blood vessels, and the GS in the outer layer can reduce the infection rate of the tissue, so it has broad application prospects in clinical practice.

Embodiment three:

This embodiment is basically the same as the previous embodiment, and the special features are:

In this embodiment, a method for preparing a drug-loaded coaxial regenerated vascular stent by a composite process includes the following steps:

a. PVA is dissolved in deionized water, heated in a water bath on a magnetic stirrer, and stirred until the PVA is completely dissolved, and the obtained mass percent concentration is 8wt.% PVA solution 35g;

b. Dissolve 20mg deferoxamine DFO in the PVA solution prepared in the step a, and prepare a DFO inner layer coaxial electrospinning core layer solution with a mass percentage of 80wt.%.

c. Use a mixture of N,N-dimethylformamide DMF and dichloromethane DCM with a volume ratio of 1:1 as a solvent, dissolve 2g of polycaprolactone PCL in 20ml of the above solvent, and prepare a PCL coaxial electrode Spin shell solution, divide into two equally again;

d. Sodium alginate SA is dissolved in deionized water, and the mass fraction is prepared into 10g of SA solution of 5wt.%, and then the PVA solution and SA solution prepared in the step a are in the ratio of 1.2:1 by mass ratio Mix and prepare the middle layer solution of the stent;

e. Gentamicin GS is dissolved in 10 g of the PVA solution prepared in step a, and configured as a 0.8 wt.% GS outer layer coaxial electrospinning core layer solution;

f. Using the DFO inner layer coaxial electrospinning core layer solution prepared in the step b and a part of the PCL coaxial electrospinning shell solution prepared in the step c, and using the coaxial electrospinning forming process , wherein the DFO inner coaxial electrospinning core layer solution and the PCL coaxial electrospinning shell solution are spun through the coaxial nozzle, and the PCL coaxial electrospinning core layer and the polycaprolactone PCL shell are sequentially prepared on the circular shaft U layer to prepare the inner layer of the drug-loaded regenerative vascular stent; when preparing the inner layer of the vascular stent, control the rotation speed of the circular axis U to 200 rpm, and the X direction, that is, the horizontal and axial reciprocating speed of the circular axis U to be 0.3mm/s , control the voltage of electrospinning to 13KV, make the electrospinning solution feed through the micropump, wherein the electrospinning time is 10min, control the feeding speed of the micropump to 30ul/min, and the height of the coaxial nozzle from the circular axis U is 140mm , the circular shaft U is made of conductive stainless steel, the diameter of the circular shaft U is 2mm; the inner diameter of the coaxial nozzle is 0.3mm, and the outer diameter is 1mm;

g. Using the dipping method forming process, the circular shaft that has been prepared in the inner layer of the drug-loaded regenerative vascular stent in the step f is removed, and immersed in the intermediate layer solution prepared in the step d, and left to stand for 60 minutes, Afterwards, take out the round shaft impregnated with the hydrogel attached to the inner layer of the drug-loaded regenerative stent, and place the two ends of the round shaft overhead until there are no more drops of hydrogel dripping from the round shaft, and then put the round shaft on- After freezing in a refrigerator at 60°C for 15 hours, take out the shaft, and thaw the shaft at room temperature for 8 hours, then put it in the refrigerator for freezing, and go through 5 times of freezing-thawing process, so that the drug-loaded regenerated vascular stent The exterior of the inner layer results in a shaped hydrogel middle layer;

h. Using the GS outer layer coaxial electrospinning core layer solution prepared in the step e and another part of the PCL coaxial electrospinning shell solution prepared in the step c, and using the coaxial electrospinning forming process , the coaxial electrospun core layer of the GS outer layer and another layer of polycaprolactone PCL shell layer were sequentially prepared on the circular axis U to prepare the outer layer of the drug-loaded regenerative vascular stent, so that the outer layer of the hydrogel middle layer was wrapped with The outer layer of the drug-loaded regenerative vascular stent is obtained to obtain the prefabricated drug-loaded coaxial regenerative vascular stent; when preparing the outer layer of the drug-loaded coaxial regenerative vascular stent, the parameters of the circular axis U, the micro pump and the nozzle are the same as those in the step f The process conditions are the same when preparing the inner layer of the vascular stent, and the special feature is that the electrospinning time for preparing the outer layer of the drug-loaded regenerative vascular stent is 20 minutes;

i. Soak the drug-loaded coaxial regenerative vascular stent prefabricated body prepared in the step h in a calcium chloride solution with a mass fraction of 1wt.% for 15 minutes to carry out chemical cross-linking, and after completing the chemical cross-linking, obtain The drug-loaded coaxial regenerative vascular stent is then taken out after being freeze-dried to obtain the drug-loaded coaxial regenerative vascular stent.

In this example, the drug-loaded coaxial regenerative vascular stent is prepared by a composite process. The vascular stent shown has a three-layer structure, and different forming methods are used respectively. The inner layer is coaxial electrospun DFO solution, and the middle layer is PVA+SA The solution adopts the freeze-thaw physical cross-linking method, and the outermost layer is the coaxial electrospun GS solution. This example combines three different forming methods, simulating the three-layer structure of natural blood vessels, and shortens the time for in vitro culture of vascular stents. Because of the coaxial drug loading technology, the vascular stents can be released slowly in vivo on time, The DFO in the first layer can promote the formation of new blood vessels, the middle layer can guarantee the wall thickness and mechanical strength of the blood vessels, and the GS in the outer layer can reduce the infection rate of the tissue, so it has broad application prospects in clinical practice.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and various changes can also be made according to the purpose of the invention of the present invention. The changes, modifications, substitutions, combinations or simplifications should be equivalent replacement methods, as long as they meet the purpose of the present invention, as long as they do not deviate from the technical principle of the artificial drug-loaded coaxial regenerative vascular stent and its composite process preparation method of the present invention and inventive concepts all belong to the protection scope of the present invention.

Claims (10)

1. a kind of artificial carry the coaxial regeneration vessel bracket of medicine, it is characterised in that: from the coaxial regeneration vessel internal stent of medicine is carried to outer Portion is successively combined closely by coaxial internal layer, hydrogel middle layer and outer layer, simulates the three-decker of native blood vessels, Described in internal layer successively combined closely by the compound sandwich layer of Deferoxamine DFO and the first polycaprolactone (PCL) shell, it is poly- to form first Caprolactone PCL shell wrap up the compound sandwich layer of Deferoxamine DFO lamellar composite endothecium structure, the compound sandwich layer of Deferoxamine DFO by The composite material of Deferoxamine DFO and PVA are made, and the compound sandwich layer of Deferoxamine DFO, which is directly toward, carries the coaxial regeneration vessel of medicine Inner cavity setting, the hydrogel middle layer are made of the composite material of sodium alginate SA and PVA, and the outer layer is successively big mould by celebrating The compound sandwich layer of plain GS and the second polycaprolactone (PCL) shell are combined closely, and it is big to form the package celebrating of the second polycaprolactone (PCL) shell The lamellar composite layer structure of the compound sandwich layer of mycin GS, the compound sandwich layer of gentamicin GS the answering by gentamicin GS and PVA Condensation material is made, the first polycaprolactone (PCL) shell and the compound sandwich layer of gentamicin GS respectively with hydrogel middle layer two Side is combined closely, and the second polycaprolactone (PCL) shell is directly toward the external setting for carrying the coaxial regeneration vessel of medicine.

2. manually carrying the coaxial regeneration vessel bracket of medicine according to claim 1, it is characterised in that: the Deferoxamine DFO is compound The constituent mass proportion of the composite material of the Deferoxamine DFO and PVA of sandwich layer is (15-64): 1000；The gentamicin GS is compound The constituent mass proportion of the composite material of the gentamicin GS and PVA of sandwich layer is (3-8): 1000.

3. the coaxial regeneration vessel bracket of artificial load medicine according to claim 1 or claim 2, it is characterised in that: among the hydrogel The constituent mass proportion of the composite material of the sodium alginate SA and PVA of layer is (2.4-9.6): (1-5).

4. the coaxial regeneration vessel bracket of artificial load medicine according to claim 1 or claim 2, it is characterised in that: described first gathers in oneself Ester PCL shell or the second polycaprolactone (PCL) shell are made of polycaprolactone (PCL) and basis material blending, described matrix material by N,N-dimethylformamide DMF and methylene chloride DCM are mixed；Wherein N,N-dimethylformamide DMF and methylene chloride DCM Volume ratio be 1:1, the mass volume ratio of polycaprolactone (PCL) and basis material is (1-10) g:100ml.

5. the coaxial regeneration vessel bracket of artificial load medicine according to claim 1 or claim 2, it is characterised in that: by adjusting hydrogel The thickness of middle layer manually carries the whole wall thickness of the coaxial regeneration vessel bracket of medicine to control.

6. a kind of method that combination process preparation carries the coaxial regeneration vessel bracket of medicine, which comprises the steps of:

A. PVA is dissolved in deionized water, the heating water bath on magnetic stirring apparatus, and stir until PVA be completely dissolved, be made Mass percent concentration is the PVA solution of 3-8wt.%；

B., Deferoxamine DFO is dissolved in the PVA solution prepared in the step a, being configured to mass percent is 50-80wt.% DFO internal layer coaxial electrically spun sandwich layer solution；

C. using the mixture of n,N-Dimethylformamide DMF and methylene chloride DCM that volume ratio is 1:1 as solvent, oneself will be gathered Lactone PCL is dissolved in solvent, and it is same for the PCL of (1-10) g:100ml to be configured to the mass volume ratio of polycaprolactone (PCL) and solvent Axis electrospinning shell solution；

D. sodium alginate SA is dissolved in deionized water, is configured to the SA solution that mass fraction is 1-5wt.%, it then will be The PVA solution and SA solution prepared in the step a is (0.8-1.2) in mass ratio: 1 ratio mixing is configured to blood vessel branch The intermediate layer solution of frame；

E. gentamicin GS is dissolved in the PVA solution prepared in the step a, being configured to mass fraction is 0.3- The GS outer layer coaxial electrically spun sandwich layer solution of 0.8wt.%；

F. it is respectively adopted and prepares DFO internal layer coaxial electrically spun sandwich layer solution in the step b and prepare PCL in the step c Coaxial electrically spun shell solution, and use coaxial electrically spun forming technology, be sequentially prepared on circular shaft (U) PCL coaxial electrically spun sandwich layer and Polycaprolactone (PCL) shell is made and carries medicine regeneration vessel bracket internal layer；

G. infusion process forming technology is used, the circular shaft for completing to carry the preparation of medicine regeneration vessel bracket internal layer in the step f is taken Under, and be immersed in the intermediate layer solution prepared in the step d, 15~60 minutes are stood, medicine regeneration vessel branch will be carried later The circular shaft of frame internal layer dipping attachment hydrogel takes out, and by the aerial standing in circular shaft both ends, until there is no hydrogel drops for circular shaft Until dripping, then circular shaft is put in -40~-60 DEG C of refrigerator after carrying out frost 10-15 hours, takes out circular shaft, and will justify It axis defrosting 4-8 hours at room temperature, places into refrigerator and is freezed, so undergo 1-5 freeze-thawing process, thus Carry the hydrogel middle layer that the outside of medicine regeneration vessel bracket internal layer is shaped；

H. the preparation GS outer layer coaxial electrically spun sandwich layer solution in the step e is respectively adopted and preparation PCL is same in the step c Axis electrospinning shell solution, and use coaxial electrically spun forming technology, be sequentially prepared on circular shaft (U) GS outer layer coaxial electrically spun sandwich layer and Polycaprolactone (PCL) shell is made and carries medicine regeneration vessel bracket outer layer, so that the external package in hydrogel middle layer carries medicine regeneration Intravascular stent outer layer obtains the molding coaxial regeneration vessel supporting frame prefabrication body of load medicine；

I. the coaxial regeneration vessel supporting frame prefabrication body of the load medicine prepared in the step h is immersed in mass fraction is 1- It is chemically crosslinked within 15~60 minutes in the calcium chloride solution of 5wt.%, after completing chemical crosslinking, obtains load medicine and coaxially regenerate Intravascular stent will take out after then carrying the coaxial regeneration vessel bracket freeze-drying of medicine, has just obtained the coaxial regeneration vessel branch of load medicine Put up product.

7. the method that combination process preparation carries the coaxial regeneration vessel bracket of medicine according to claim 6, it is characterised in that: in institute It states when preparing intravascular stent ectonexine in step f and step h, the rotation speed of control circular shaft (U) is 200-400 revs/min, X It is 0.3-0.6mm/s that direction, that is, circular shaft (U) horizontal axis, which moves back and forth speed, and the voltage for controlling Electrospun is 10-13KV, makes electricity Liquid is spun to be fed by micro pump；Wherein the electrospinning time in the step f is 3-10min, when electrospinning in the step h Between be 4-20min, adjust the thickness of electrospinning film, by the control Electrospun time so as to adjust medicine regeneration vessel bracket internal layer is carried Or the thickness of outer layer.

8. the method that combination process preparation carries the coaxial regeneration vessel bracket of medicine according to claim 6, it is characterised in that: in institute It states when preparing intravascular stent middle layer in step g, the number of freeze-thawing is determined by required regeneration vessel wall thickness, is led to The number of control freeze-thawing is crossed to adjust the thickness for leading to prepared hydrogel middle layer, and then regulation manually carries medicine coaxially again The whole wall thickness of green blood pipe holder.

9. the method that the preparation of the combination process according to any one of claim 6~8 carries the coaxial regeneration vessel bracket of medicine, Be characterized in that: when preparing intravascular stent ectonexine in the step f and step h, the feeding speed for controlling micro pump is 30- 60ul/min, Coaxial nozzle are highly 140-160mm from circular shaft (U).

10. the method that the preparation of the combination process according to any one of claim 6~8 carries the coaxial regeneration vessel bracket of medicine, It is characterized by: circular shaft (U) uses conductive stainless steel when preparing intravascular stent ectonexine in the step f and step h Material, the diameter of circular shaft (U) are 2-9mm；The internal diameter of Coaxial nozzle is not more than 0.3mm, and outer diameter is not more than 1mm.