Iron-based polymer composite fiber, preparation method therefor, and use thereof

Abstract

An iron-based polymer composite fiber, a preparation method therefor, and a use thereof. The provided iron-based polymer composite fiber is prepared by means of: uniformly mixing a polymer, a ferric salt and a solvent to obtain a spinning solution, and using electrostatic spinning to prepare the spinning solution into a uniform polymer / FeCl3 composite fiber; immersing the polymer / FeCl3 composite fiber in an aqueous solution of NaOH, washing, and drying, to obtain a polymer / iron oxide-hydroxide composite fiber. The iron-based polymer composite fiber has MRI imaging (visualization) functionality, can implement a positive contrast function in a preferred iron concentration range, has good biocompatibility, and has a simple preparation process. Furthermore, by means of methods such as solvent annealing, interface bonding, heat treatment, or a soluble template layer, the composite fiber can be used in most polymer implantable medical instruments, providing an additional MRI imaging (visualization) function for implantable medical instruments. Thus the composite fiber has a good application prospects.

Description

Iron-based polymer composite fiber and its preparation method and application Technical Field

[0001] The present invention relates to the fields of functional fiber materials and biomedical materials, and in particular to an iron-based polymer composite fiber and a preparation method and application thereof. Background Art

[0002] MRI (magnetic resonance imaging) is a noninvasive imaging technique that uses powerful magnetic fields and harmless radio waves to generate signals to obtain detailed information about the internal structure and tissue of the human body. However, MRI imaging of polymer-based implantable medical devices, such as heart valves and vascular stents, presents certain challenges. Because polymers share similar magnetic properties to human tissue, it is difficult to produce good contrast in the images. Therefore, the development of MRI-visible implantable medical devices requires the addition of magnetically susceptible contrast agents to the polymer to enhance the imaging contrast of the implantable medical device in MRI. The principle of contrast-agent-doped polymer MRI imaging is that the contrast agent modifies the magnetic moment of protons in the water surrounding the polymer, increasing the contrast between the polymer and the surrounding tissue. This results in a positive contrast image, making the stent appear brighter than its original state, while a negative contrast image is negative. Contrast agents are primarily metal chelates or compounds. Factors influencing positive contrast include particle size, geometry, surface structure, and surface modification; factors influencing negative contrast include particle size, geometry, crystal structure, and aggregate structure. In clinical practice, stents or tissues with positive contrast exhibit clearer, sharper boundaries on MRI images and are, in some cases, preferred by physicians. Gadolinium possesses strong paramagnetism due to its seven lone electrons in the 4f orbital, making it an ideal element for MRI-positive contrast agents. However, free gadolinium is nephrotoxic in the human body, while iron ions are more biosafe. Therefore, iron-based MRI-positive contrast imaging in polymer-based implantable medical devices has great research value and potential application.

[0003] Summary of the Invention

[0004] The primary purpose of the present invention is to overcome the shortcomings and deficiencies of the existing technology, improve the problem that traditional iron-based polymer composite fibers cannot achieve positive imaging, and provide a method for preparing polymer / iron oxyhydroxide composite fibers with nuclear magnetic resonance imaging function and positive imaging function.

[0005] Another object of the present invention is to provide a polymer / iron oxyhydroxide composite fiber prepared by the above method.

[0006] Another object of the present invention is to provide applications of the polymer / iron oxyhydroxide composite fiber.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A method for preparing a polymer / iron oxyhydroxide composite fiber with nuclear magnetic resonance imaging function comprises the following steps:

[0009] (1) mixing a polymer, a trivalent iron salt, and a solvent to obtain a spinning solution, and using an electrospinning technique to prepare a uniform polymer / FeCl3 composite fiber from the spinning solution;

[0010] (2) The polymer / FeCl3 composite fiber obtained in step (1) is immersed in an aqueous solution of NaOH, then washed to pH = 7, and dried to obtain a polymer / iron oxyhydroxide composite fiber.

[0011] Preferably, the polymer described in step (1) includes polylactic acid, polycaprolactone, polyglycolide, polylactide, polyglycolic acid, hyaluronic acid, fibrin, silk protein, polyethylene glycol, chitosan, collagen, gelatin, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyamide, polycarbonate, polyformaldehyde, polybutylene terephthalate, polyethylene terephthalate, cellulose acetate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, cyanoethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl starch, carboxymethyl starch, polyvinylpyrrolidone, At least one of tackifier, polyol, polyacrylonitrile, polyethylene glycol-polylactic acid block copolymer, polyethylene glycol-polycaprolactone block copolymer, polyethylene glycol-polyvinyl pyrrolidone block copolymer, polystyrene-polybutadiene block copolymer, styrene-butadiene-styrene triblock copolymer, polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, styrene-isoprene / butadiene-styrene block copolymer, polystyrene-polybutadiene-polystyrene block copolymer; more preferably at least one of polyamide, polylactic acid, polymethyl methacrylate and polystyrene.

[0012] Preferably, the ferric iron salt in step (1) includes ferric chloride and ferric chloride hydrate, more preferably FeCl3·6H2O.

[0013] Preferably, the solvent described in step (1) includes at least one of water, dichloromethane, chloroform, dichloroethane, tetrachloroethane, methyl acrylate, tetrahydrofuran, methyltetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ether, petroleum ether, acetone, formic acid, acetic acid, trifluoroacetic acid, carbon tetrachloride, xylene, toluene, phenol, chlorobenzene, nitrobenzene, pentane, n-hexane, methylcyclohexane, N-methylpyrrolidone, anisole, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, pentanol, N-methylmorpholine-N-oxide, methylimidazolium chloride and cresol.

[0014] Preferably, the mass fraction of the polymer in the spinning solution in step (1) is 5 to 50%.

[0015] Preferably, the Fe in the spinning solution in step (1) 3+ The mass of the precipitate is 0.1 to 10% of the mass of the polymer.

[0016] Preferably, the electrospinning conditions in step (1) are as follows: a positive pressure of 5 to 50 kV; a distance between the needle and the collector of 5 to 30 cm; an injection speed of 0.1 to 10 mL / h; the collector is a flat plate, a drum or a cage collector; when the collector is a drum collector, the rotation speed of the drum collector is 0 to 3000 r / min and the diameter is 10 to 15 cm. More preferably, the electrospinning conditions in step (1) are as follows: a positive pressure of 15 to 30 kV; a distance between the needle and the collector of 10 to 30 cm; an injection speed of 0.1 to 1 mL / h; when the collector is a drum collector, the rotation speed of the drum collector is 1000 to 3000 r / min and the diameter is 10 to 15 cm.

[0017] Preferably, the pH value of the aqueous solution of NaOH in step (2) is 8-14.

[0018] Preferably, the washing in step (2) is washing with deionized water.

[0019] Preferably, the drying in step (2) is performed at a temperature below 40°C.

[0020] A polymer / iron oxyhydroxide composite fiber with nuclear magnetic resonance imaging function is prepared by the above method.

[0021] Application of the above polymer / iron oxyhydroxide composite fiber in the preparation of nuclear magnetic resonance imaging materials.

[0022] The application of the polymer / iron oxyhydroxide composite fiber in the preparation of positive contrast materials. Preferably, in the preparation method of the polymer / iron oxyhydroxide composite fiber, the Fe 3+ The mass of the precipitate is 0.1 to 4% of the mass of the polymer.

[0023] Application of the polymer / iron oxyhydroxide composite fiber in the preparation of medical devices; the medical devices have nuclear magnetic resonance imaging function.

[0024] Preferably, the nuclear magnetic resonance imaging function includes a positive contrast imaging function.

[0025] Preferably, the medical devices include artificial joints, heart valves, vascular stents, cranial gaskets, hernia patches and neural electrical stimulators.

[0026] Preferably, the use of the polymer / iron oxyhydroxide composite fiber in the preparation of medical devices comprises the following steps:

[0027] The polymer / iron oxyhydroxide composite fiber is covered and fixed on the surface of the medical device; the covering and fixing on the surface of the medical device can be achieved by solvent annealing, interface bonding, heat treatment or soluble template layer.

[0028] More preferably, the solvent annealing method comprises the following steps:

[0029] A1. Plasma treatment of polyamide implantable medical device surfaces;

[0030] A2. Using the surface of a polyamide implantable medical device as the coating substrate, cover the polymer / iron oxyhydroxide composite fiber on the pretreated surface of the polyamide implantable medical device in S1. Compact the fiber to ensure a close bond with the treated surface. Anneal the polymer / iron oxyhydroxide composite fiber in a common solvent atmosphere for both the fiber and the substrate to further enhance the bonding strength.

[0031] More preferably, the plasma treatment atmosphere in step A1 is oxygen, the gas flow rate is 1 to 100 sccm, the power is 10 to 200 W, and the treatment time is 0.5 to 10 minutes.

[0032] Further preferably, the annealing solvent in step A2 is at least one of water, dichloromethane, chloroform, dichloroethane, tetrachloroethane, methyl acrylate, tetrahydrofuran, methyltetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ether, petroleum ether, acetone, formic acid, acetic acid, trifluoroacetic acid, carbon tetrachloride, xylene, toluene, phenol, chlorobenzene, nitrobenzene, pentane, n-hexane, methylcyclohexane, N-methylpyrrolidone, anisole, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, pentanol, N-methylmorpholine-N-oxide, methylimidazolium chloride and cresol.

[0033] More preferably, the annealing conditions in step A2 are: annealing temperature is 30-80° C., and annealing time is 5-300 min.

[0034] More preferably, the interface bonding method specifically comprises the following steps:

[0035] B1. Apply the interfacial adhesive solution evenly to the surface of the polymer implantable medical device by spin coating, dip coating, or spraying, ensuring complete coverage.

[0036] B2. Covering the polymer / iron oxyhydroxide composite fiber on the surface of the polymer implantable medical device treated in step B1, and drying and curing.

[0037] Further preferably, the interfacial adhesive described in step B1 includes at least one of an aqueous polymer emulsion, an organic solvent-based adhesive, a silane coupling agent, a polymer mixture and a hot melt adhesive; most preferably, the aqueous polymer emulsion includes polylactic acid (PLA) emulsion and polyacrylic acid (polyamide A) emulsion; the organic solvent-based adhesive includes methyl methacrylate / methyl acrylate adhesive and chlorinated polybutadiene (CSBR) adhesive; the silane coupling agent includes 3-aminopropyltrimethoxysilane and 3-aminopropyltrimethoxysilane; the polymer mixture includes a polylactic acid / polycaprolactam mixture; and the hot melt adhesive includes hot melt polyvinyl acid (EVA) adhesive and hot melt polyamide adhesive.

[0038] More preferably, the concentration of the interface adhesive in step B1 is 0.5 to 50 wt %.

[0039] More preferably, the heat treatment method comprises the following steps:

[0040] The polymer / iron oxyhydroxide composite fiber is covered on the surface of the polymer implantable medical device and hot-pressed to form the surface, so that the two are tightly combined and a good combination is formed at the interface.

[0041] The hot pressing conditions are: temperature of 150-180° C. and pressure of 10-20 MPa.

[0042] More preferably, the soluble template layer method comprises the following steps:

[0043] C1. Uniformly coat a layer of compatible soluble template material on the surface of a polymer implantable medical device.

[0044] C2. Cover the polymer / iron oxyhydroxide composite fiber on the surface of the polymer implantable medical device treated in step C1 to ensure good adhesion between the two; and heat-treat the coated implantable medical device to melt the soluble template layer and allow the polymer / iron oxyhydroxide composite fiber to interpenetrate with the polymer body of the polymer implantable medical device.

[0045] Further preferably, the component of the soluble template layer in step C1 is at least one of polymethyl acrylate, polymethyl methacrylate, gelatin, cellulose, polyvinyl alcohol, polyethylene glycol, waxy polymer and cerotic acid.

[0046] More preferably, the temperature of the heat treatment in step C2 is 40-90°C.

[0047] The present invention has the following advantages and effects compared to the prior art:

[0048] 1) The present invention utilizes electrospinning technology to achieve good dispersion of FeCl3 in the fiber, and converts it into ferric oxyhydroxide in situ to achieve good dispersion of ferric oxyhydroxide in the fiber, thereby achieving the effect of positive nuclear magnetic resonance imaging of iron-based polymer composite fibers. There are many types of polymers to choose from, the preparation process is relatively simple, the controllability is strong, and the size can be adjusted.

[0049] 2) The MRI effect of the polymer / iron oxyhydroxide composite fiber coating prepared by the present invention is dependent on the ferric oxyhydroxide concentration. When the ferric oxyhydroxide concentration is low, it is positive, and when the ferric oxyhydroxide concentration is high, it is negative. The MRI effect is suitable for different usage scenarios in the body.

[0050] 3) The polymer / iron oxyhydroxide composite fiber coating prepared in this invention can adjust the adhesion between the coating and the medical device as needed. By changing the process parameters or adjusting the material combination, it is possible to achieve adaptation between different medical devices and the fiber coating, ensuring optimal adhesion.

[0051] 4) This patented technology utilizes a unique process and material combination to achieve a high bond strength between the polymer / iron oxyhydroxide composite fiber membrane and the medical device. This high-strength bond effectively secures and maintains the connection between the fiber membrane and the medical device, reducing the risk of loosening or falling off during prolonged use. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG1 is an in vitro nuclear magnetic resonance imaging image obtained in Example 9.

[0053] FIG2 is a graph showing the in vitro relaxivity performance obtained in Example 9. DETAILED DESCRIPTION

[0054] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0055] Example 1

[0056] 1) Take 3g of polyamide and dissolve it in 6.94mL of formic acid (polyamide mass fraction is 25wt%), add 0.1448g of FeCl3·6H2O (to make Fe 3+ The mass of the mixture is 0.1% of the polymer) and stirred for 24 hours to form a uniform spinning solution.

[0057] 2) The spinning solution was added to a syringe, which was fixed to a syringe pump with a needle-to-drum distance of 10 cm and a flow rate of 0.1 mL / h. The receiver was a flat plate receiver, the spinning voltage was 30 kV, and the flat needle had an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polyamide / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0058] 3) The polyamide / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 10, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0059] 4) Select a polyamide implantable medical device as the coating substrate, place the surface to be treated in a plasma reaction chamber, ensure that the sample is exposed to the plasma, turn on the plasma equipment, and treat at an oxygen gas flow rate of 100 sccm and a power of 200 W for 10 minutes.

[0060] 5) Cover the polyamide / iron oxyhydroxide composite fiber film and bond it tightly, then anneal it at 80° C. in a formic acid atmosphere for 5 minutes.

[0061] Example 2

[0062] 1) Take 3g of polylactic acid and dissolve it in a mixed solvent of formic acid: chloroform: acetone in a volume ratio of 9:7:7 (polylactic acid mass fraction is 10wt%), add 1.014g of FeCl3·6H2O (to make Fe in the solution 3+ The mass of the mixture is 7% of the polymer) and stirred for 24 hours to form a uniform spinning solution.

[0063] 2) Add the spinning solution to a syringe, attach it to a syringe pump, and set the needle-to-drum distance to 10 cm. A flow rate of 0.1 mL / h was used. The receiver was a flat plate receiver, the spinning voltage was 30 kV, and the flat needle had an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polylactic acid / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0064] 3) The polylactic acid / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 14, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0065] 4) Select a polylactic acid implantable medical device as the coating substrate, clean the surface and dip it in a 0.5wt% 3-aminopropyltrimethoxysilane solution for 2 hours, cover it with the polyamide / iron oxyhydroxide composite fiber coating and adhere it tightly, and place it under ventilation equipment for natural evaporation to completely evaporate the solvent.

[0066] Example 3

[0067] 1) Dissolve 3g of polymethyl methacrylate in 17g of ethyl acetate (EA) and add 0.1448g of FeCl3·6H2O (so that Fe 3+ The mass of the mixture is 0.1% of the polymer) and stirred for 24 hours to form a uniform spinning solution.

[0068] 2) The spinning solution was added to a syringe and attached to a syringe pump. The distance from the needle to the roller was 15 cm, the flow rate was 1 mL / h, and the receiver was a roller receiver with a rotation speed of 3000 rpm, a diameter of 15 cm, a spinning voltage of 15 kV, and a flat-point needle with an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polymethyl methacrylate / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0069] 3) The polymethyl methacrylate / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 10, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0070] 4) Select polymethyl methacrylate implantable medical device as the coating substrate, clean the surface and dip it in 50wt% hot-melt polyethylene acid solution for 2 hours, cover it with polyamide / iron oxyhydroxide composite fiber coating and adhere it tightly, and place it under ventilation equipment for natural evaporation to completely evaporate the solvent.

[0071] Example 4

[0072] 1) Dissolve 3g of polystyrene in 15g of N,N-dimethylformamide (DMF) and add 0.1448g of FeCl3·6H2O (so that Fe 3+ The mass of the mixture is 0.1% of the polymer) and stirred for 24 hours to form a uniform spinning solution.

[0073] 2) The spinning solution was added to a syringe and attached to a syringe pump. The distance from the needle to the drum was 30 cm, the flow rate was 1 mL / h, and the receiver was a drum receiver with a speed of 1000 rpm, a drum diameter of 10 cm, a spinning voltage of 10 kV, and a flat-point needle with an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polystyrene / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0074] 3) The polystyrene / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 14, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0075] 4) Select a polystyrene implantable medical device as the coating substrate, clean the surface, and place the prepared polystyrene / iron oxyhydroxide composite fiber membrane on the surface of the polystyrene implantable medical device to ensure that the two are well bonded.

[0076] 5) Placing the polystyrene implantable medical device covered with the electrospun fiber membrane in a hot press, controlling the temperature of the hot press to 180° C. and the pressure to 10 MPa, and maintaining a certain pressure and temperature for a period of time to promote adhesion of the electrospun fiber membrane to the surface of the implantable medical device.

[0077] Example 5

[0078] 1) Dissolve 3g of polyamide in 10g of formic acid (polyamide mass fraction is 30wt%), add 0.1448g of FeCl3·6H2O (to make Fe 3+ The mass of the polymer is 0.1%), and stirred for 24 hours to form a uniform spinning solution.

[0079] 2) Add the spinning solution to a syringe, secure it to a syringe pump, and maintain a needle-to-drum distance of 10 cm. A flow rate of 0.1 mL / h was maintained using a flat receiver. The spinning voltage was 30 kV, and the flat-ended needle had an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polyamide / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0080] 3) The polyamide / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 10, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0081] 4) Selecting a polypropylene implantable medical device as the coating substrate, cleaning the polypropylene surface, using a 5 wt % polyvinyl alcohol aqueous solution as a soluble template layer solution, and evenly coating the solution on the polypropylene substrate surface.

[0082] 5) Cover the polyamide / iron oxyhydroxide composite fiber film and bond it tightly, place it in a 90°C oven to dry for a period of time to remove the soluble template layer.

[0083] Example 6

[0084] 1) Take 3g of polyamide and dissolve it in 6.94mL of formic acid (polyamide mass fraction is 25wt%), add 0.1448g of FeCl3·6H2O (to make Fe 3+ The mass of the mixture is 0.1% of the polymer) and stirred for 24 hours to form a uniform spinning solution.

[0085] 2) The spinning solution was added to a syringe, which was fixed to a syringe pump with a distance of 10 cm between the needle and the flat plate receiver. The flow rate was 0.1 mL / h, the receiving mode was a flat plate receiver, the spinning voltage was 30 kV, and the flat needle had an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polyamide / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0086] 3) The polyamide / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 10, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0087] 4) Select a polyamide implantable medical device as the coating substrate, place the surface to be treated in a plasma reaction chamber, ensure that the sample is exposed to the plasma, turn on the plasma equipment, and treat with an oxygen gas flow rate of 1 sccm and a power of 10 W for 0.5 minutes.

[0088] 5) Cover the polyamide / iron oxyhydroxide composite fiber film and bond it tightly, then anneal it at 30° C. in a formic acid atmosphere for 300 minutes.

[0089] Example 7

[0090] 1) Dissolve 3g of polystyrene in 15g of DMF and add 0.1448g of FeCl3·6H2O (to make Fe 3+ The mass of the mixture is 0.1% of the polymer) and stirred for 24 hours to form a uniform spinning solution.

[0091] 2) The spinning solution was added to a syringe, which was attached to a syringe pump with a distance of 30 cm between the needle and the flat receiver. The flow rate was 1 mL / h. The receiver was a drum with a speed of 1000 rpm, a drum diameter of 10 cm, a spinning voltage of 10 kV, and a flat-ended needle with an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polystyrene / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0092] 3) The polystyrene / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 14, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0093] 4) Select a polystyrene implantable medical device as the coating substrate, clean the surface, and place the prepared polystyrene / iron oxyhydroxide composite fiber membrane on the surface of the polystyrene implantable medical device to ensure that the two are well bonded.

[0094] 5) Placing the polystyrene implantable medical device covered with the electrospun fiber membrane in a hot press, controlling the temperature of the hot press to 150° C. and the pressure to 20 MPa, and maintaining a certain pressure and temperature for a period of time to promote adhesion of the electrospun fiber membrane to the surface of the implantable medical device.

[0095] Example 8

[0096] 1) Dissolve 3g of polyamide in 10g of formic acid (polyamide mass fraction is 30wt%), add 0.1448g of FeCl3·6H2O (to make Fe 3+ The mass of the mixture is 0.1% of the polymer) and stirred for 24 hours to form a uniform spinning solution.

[0097] 2) The spinning solution was added to a syringe, which was fixed to a syringe pump with a distance of 10 cm between the needle and the flat plate receiver. The flow rate was 0.1 mL / h, the receiving mode was a flat plate receiver, the spinning voltage was 30 kV, and the flat needle had an inner diameter of 0.61 mm and an outer diameter of 0.91 mm. A polyamide / FeCl3 composite fiber membrane was prepared. The fiber membrane was removed from the aluminum foil of the receiver.

[0098] 3) The polyamide / FeCl3 composite fiber membrane was immersed in a NaOH aqueous solution with a pH of 10, reacted for 12 hours, taken out, washed with deionized water to a pH of 7, dried at 40°C, and set aside.

[0099] 4) Selecting a polypropylene implantable medical device as the coating substrate, cleaning the polypropylene surface, using a 20 wt % polyethylene glycol aqueous solution as a soluble template layer solution, and evenly coating the solution on the polypropylene substrate surface.

[0100] 5) Cover the polyamide / iron oxyhydroxide composite fiber film and adhere it tightly, then place it in a 40°C oven to dry for a period of time to remove the soluble template layer.

[0101] Example 9

[0102] Polyamide / iron oxyhydroxide composite fibers (PA6 / FeOOH) were prepared according to the method of Example 1, polymethyl methacrylate / iron oxyhydroxide composite fibers (PMMA / FeOOH) were prepared according to the method of Example 3, and polystyrene / iron oxyhydroxide composite fibers (PS / FeOOH) were prepared according to the method of Example 4. The amount of FeCl3·6H2O added was adjusted so that the Fe in the spinning solution was 3+ The mass ratios of the PA6, PMMA, and PS were 0-7%, 0-4%, and 0-4%, respectively. The specific percentages are shown in Figure 1 for each group. In vitro magnetic resonance imaging (MRI) was performed with the following imaging parameters: T1-weighted images with TE = 20 ms, TR = 2045 ms, TI = 800 ms, voxel size 0.65 mm × 0.81 mm, and slice thickness 4 mm; T2-weighted images with TE = 105 ms, TR = 3000 ms, TSEes / SHOT = 7.8 / 171 ms, voxel size 0.3 mm × 0.3 mm, and slice thickness 1 mm. The in vitro MRI images are shown in Figure 1. The imaging effect of iron oxyhydroxide is concentration-dependent, with positive contrast at low concentrations and negative contrast at high concentrations.

[0103] According to the method of Example 1, polyamide / iron oxyhydroxide composite fiber (PA6 / FeOOH) was prepared, and the amount of FeCl3·6H2O added was adjusted so that the Fe in the spinning solution was 3+ The mass of PA6 is 0.16, 0.33, 0.67, 0.93, 1.38, 3.11, and 4.61% (corresponding to 0.0286, 0.0589, 0.120, 0.166, 0.246, 0.555, and 0.823 mmol Fe in Figure 2, respectively). 3+ / g PA6), and the obtained polyamide / iron oxyhydroxide composite fiber was subjected to low-field nuclear magnetic resonance testing. The test parameters are as follows: the T1 value was tested using an inversion recovery pulse sequence, recycle delay = 20s, gain = 53dB, scan times = 4, first separation = 0.5ms, final separation = 4000ms, fitting number of points = 10; the T2 value was tested using a Carr Purcell Meiboom Gill sequence, recycle delay = 20s, scan times = 8, gain = 56dB. R1 = 1 / T1, R2 = 1 / T2, with R1 and R2 as the vertical coordinates, respectively. The Fe content in 1g PA6 is 2.347 W / m2. 3+ The amount of substance is the horizontal axis (unit: mmol Fe 3+ / gPA), and a linear fit was performed on the scattered points to plot Figure 2. The slopes of the resulting lines are r1 and r2, respectively. As shown in Figure 2, the imaging effect of iron oxyhydroxide is concentration-dependent, with positive contrast at low concentrations (r2 / r1 < 5) and negative contrast at high concentrations.

[0104] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a polymer / iron oxyhydroxide composite fiber, characterized in that: The following steps are involved: (1) mixing a polymer, a trivalent iron salt, and a solvent to obtain a spinning solution, and using an electrostatic spinning technique to prepare a uniform polymer / FeCl3 composite fiber from the spinning solution; (2) The polymer / FeCl3 composite fiber obtained in step (1) is immersed in an aqueous solution of NaOH, then washed to pH = 7, and dried to obtain a polymer / iron oxyhydroxide composite fiber.

2. The method according to claim 1, characterized in that: The polymer described in step (1) includes polylactic acid, polycaprolactone, polyglycolide, polylactide, polyglycolic acid, hyaluronic acid, fibrin, silk protein, polyethylene glycol, chitosan, collagen, gelatin, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyamide, polycarbonate, polyoxymethylene, polybutylene terephthalate, polyethylene terephthalate, cellulose acetate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, cyanoethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl At least one of 1,2-dextrin starch, ... The ferric iron salt in step (1) comprises at least one of ferric chloride and ferric chloride hydrate; Fe in the spinning solution described in step (1) 3+ The mass of the polymer is 0.1 to 10%.

3. The method according to claim 1, characterized in that: The solvent described in step (1) includes at least one of water, dichloromethane, chloroform, dichloroethane, tetrachloroethane, methyl acrylate, tetrahydrofuran, methyltetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ether, petroleum ether, acetone, formic acid, acetic acid, trifluoroacetic acid, carbon tetrachloride, xylene, toluene, phenol, chlorobenzene, nitrobenzene, pentane, n-hexane, methylcyclohexane, N-methylpyrrolidone, anisole, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, amyl alcohol, N-methylmorpholine-N-oxide, methylimidazolium chloride and cresol; The mass fraction of the polymer in the spinning solution described in step (1) is 5 to 50%; The conditions for electrospinning described in step (1) are: positive pressure 5 to 50 kV; the distance between the needle and the collector is 5 to 30 cm; the injection speed is 0.1 to 10 mL / h; the collector is a flat plate, a drum or a cage collector; The pH value of the aqueous solution of NaOH described in step (2) is 8-14.

4. A polymer / iron oxyhydroxide composite fiber prepared by the preparation method of claims 1 to 3.

5. Use of the polymer / iron oxyhydroxide composite fiber according to claim 4 in the preparation of nuclear magnetic resonance imaging materials.

6. Use of the polymer / iron oxyhydroxide composite fiber according to claim 4 in the preparation of a medical device with nuclear magnetic resonance imaging function, characterized in that: The following steps are involved: The polymer / iron oxyhydroxide composite fiber is covered and fixed on the surface of the medical device.

7. The use according to claim 6, characterized in that: The method of covering and fixing the polymer / iron oxyhydroxide composite fiber on the surface of the medical device specifically comprises the following steps: A1. Plasma treatment of polyamide implantable medical device surfaces; A2. Using the surface of the polyamide implantable medical device as the coating substrate, the polymer / iron oxyhydroxide composite fiber is covered on the surface of the polyamide implantable medical device pretreated in S1, compacted, and annealed in a common solvent atmosphere of the polymer / iron oxyhydroxide composite fiber and the substrate.

8. The use according to claim 6, characterized in that: The method of covering and fixing the polymer / iron oxyhydroxide composite fiber on the surface of the medical device specifically comprises the following steps: B1. The solution containing the interfacial adhesive is evenly coated on the surface of the polymer implantable medical device by spin coating, dip coating or spray coating; B2. Covering the polymer / iron oxyhydroxide composite fiber on the surface of the polymer implantable medical device treated in step B1, and drying and curing.

9. The use according to claim 6, characterized in that: The method of covering and fixing the polymer / iron oxyhydroxide composite fiber on the surface of the medical device specifically comprises the following steps: The polymer / iron oxyhydroxide composite fiber is covered on the surface of the polymer implantable medical device and hot-pressed to combine the two.

10. The use according to claim 6, characterized in that: The method of covering and fixing the polymer / iron oxyhydroxide composite fiber on the surface of the medical device specifically comprises the following steps: C1. Uniformly coating a layer of compatible soluble template material on the surface of polymer implantable medical devices; C2. Covering the polymer / iron oxyhydroxide composite fiber on the surface of the polymer implantable medical device treated in step C1; performing heat treatment to melt the soluble template layer and allow the polymer / iron oxyhydroxide composite fiber to interpenetrate with the polymer body of the polymer implantable medical device.

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