Preparation method of implantable artificial organ, implantable artificial organ and application of implantable artificial organ

Abstract

The invention discloses a preparation method of an implantable artificial organ, the implantable artificial organ and application of the implantable artificial organ, and relates to the technical field of biomedical materials. The preparation method of the implantable artificial organ comprises the following steps: preparing zwitter-ion modified polyurethane from amphiphilic ion diol, monomer diol, diisocyanate, a catalyst, a chain extender and a reaction solvent through a solution polymerization method, dissolving the zwitter-ion modified polyurethane into a preparation solvent, and stirring to obtain the implantable artificial organ. The implantable artificial organ is prepared by a solution preparation method. According to the invention, bipolar ion diol is used as a hard segment, another monomer diol is used as a soft segment, and the influence of soft and hard segments with different molar ratios on the performance of the implantable artificial organ is studied. Wherein the hard segment can provide hydrophilicity, biocompatibility and antifouling property; the soft segment can provide flexibility and proper mechanical properties by regulating and controlling the molecular weight; diisocyanate is used as a chemical building block to connect soft and hard segments. The zwitter-ion modified polyurethane artificial blood vessel and heart valve prepared by the invention have good mechanical property, antifouling property and anticoagulation property, and the prepared artificial blood vessel also has the capability of resisting intimal hyperplasia and can keep unobstructed for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical materials, and more particularly to a preparation method of an implantable artificial organ, the implantable artificial organ and applications thereof. Background Art

[0002] Globally, cardiovascular diseases (CVDs) kill 17.9 million people annually, and the number of deaths worldwide is projected to increase significantly in the coming decades. The most common cause of CVD is hardening and stenosis of the coronary or peripheral arteries, leading to the accumulation of fatty deposits in the arterial walls, which impedes normal blood flow to the heart muscle. Currently, coronary artery bypass grafting (CABG) is considered the best treatment option for restoring normal blood supply. However, this approach is significantly limited by the availability of native arteries.

[0003] Synthetic artificial blood vessels are currently available as replacements for autologous blood vessels. Although large-caliber artificial blood vessels (inner diameter > 6 mm), such as expanded polytetrafluoroethylene (ePTFE) and polyethylene terephthalate (PET), have achieved clinical success, the clinical application of small-caliber synthetic artificial blood vessels is significantly limited due to their low patency rates. The high incidence of thrombosis and intimal hyperplasia (IH) is a key issue limiting the development of small-caliber artificial blood vessels.

[0004] In clinical practice, there are already a variety of methods for producing effective small-caliber artificial blood vessels. Among them, tissue-engineered vascular grafts have shown successful vascular regeneration and long-term patency in both animal models and humans, but the preparation process is complex, expensive and time-consuming. Another method is degradable artificial blood vessels, which can not only degrade in the human body, but also gradually fuse with host cells to produce new blood vessels, preventing the formation of blood clots. However, the mismatch between degradation rate and tissue regeneration rate remains the main problem in the clinical application research of degradable vascular grafts. If the degradation rate of the artificial blood vessel is fast, it will cause the graft to swell, while the degradation rate is too slow to induce chronic inflammation and thrombosis. In addition, another key issue is that during the degradation process, the mechanical strength of the artificial blood vessel decreases, which affects its overall performance.

[0005] Polyurethanes are widely used in vascular applications, including catheters, heart valves, and pacemakers, due to their excellent biocompatibility and mechanical properties. However, current polyurethane grafts are not only hydrophobic but also have poor anticoagulant properties, making them prone to acute thrombosis. Zwitterionic polymers, on the other hand, have attracted considerable research interest due to their ability to form a dense hydration layer on their surfaces, resulting in anticoagulant and antifouling properties. However, most zwitterionic polymers have poor mechanical properties, making them unsuitable for vascular transplantation. Therefore, there is a need to develop small-caliber artificial blood vessels with structural integrity, high mechanical and biostability, and the ability to achieve long-term patency as an alternative to autologous blood vessels.

[0006] Valvular heart disease (VHD) affects more than 100 million people worldwide and is a cardiovascular disease with high morbidity and mortality. Prosthetic valve replacement remains the gold standard in clinical practice, especially transcatheter heart valve replacement (THVR). Implantation of bioprosthetic heart valves has gradually become the first choice for the treatment of valvular heart disease. Bioprosthetic heart valves exhibit excellent hemodynamic performance and are closer to native valves, thus avoiding lifelong anticoagulation therapy. Currently, most bioprosthetic heart valves (BHVs) are made from animal pericardium cross-linked with glutaraldehyde. However, the disadvantages of bioprosthetic heart valves, such as thrombosis, calcification, structural degeneration and immune response, limit their durability. Summary of the Invention

[0007] To address the problems in the prior art, the present invention provides a method for preparing an implantable artificial organ, an implantable artificial organ, and its application. The present invention uses zwitterion-modified polyurethane to prepare small-caliber artificial blood vessels or heart valves, combining the excellent mechanical properties of polyurethane with the antifouling properties of zwitterions. The addition of zwitterion fragments to the polyurethane design significantly improves antifouling properties and in vitro antithrombotic properties, and reduces immune responses. The prepared artificial blood vessels have excellent mechanical strength, high elasticity, ease of suturing, good compliance, and are non-cytotoxic. Through electrospinning, they are processed into porous artificial blood vessels with mechanical properties comparable to those of natural arteries, exhibit long-term patency, and effectively reduce the formation of neointima. The prepared heart valves have excellent mechanical properties, anticoagulant properties, good anti-calcification ability, good antifouling properties, and good blood compatibility.

[0008] One of the purposes of the present invention is to provide a method for preparing an implantable artificial organ.

[0009] The method for preparing the implantable artificial organ of the present invention comprises:

[0010] After preparing a zwitterion-modified polyurethane by solution polymerization using a zwitterionic diol (hard segment), a monomeric diol (soft segment), a diisocyanate, a catalyst, a chain extender, and a reaction solvent, the zwitterion-modified polyurethane is dissolved in a preparation solvent, and the implantable artificial organ is prepared by a solution preparation method or other preparation technology (such as electrospinning, 3D printing, solvent casting, salting-out, phase separation, etc.).

[0011] Preferably, the method comprises:

[0012] (1) subjecting a zwitterionic diol, a monomeric diol, a diisocyanate, a catalyst, and a reaction solvent to a prepolymerization reaction, and then adding a chain extender to carry out a chain extension reaction to obtain the zwitterionic modified polyurethane;

[0013] (2) stirring and dissolving the zwitterion-modified polyurethane in a preparation solvent to prepare a preparation solution;

[0014] (3) The prepared solution is subjected to at least one of electrospinning, 3D printing, solvent casting, salting-out, and phase separation methods to prepare the implantable artificial organ.

[0015] Preferably,

[0016] The structural formula of the zwitterionic diol is:

[0017]

[0018] Wherein, n is any integer from 1 to 50;

[0019] A1 is

[0020] One of the following;

[0021] A2 is

[0022] m0, m1, m2, m3, m4, m5, m6, m7, and m8 may be the same or different and are independently any integer from 1 to 50;

[0023] Preferably, as the hard segment material of the polyurethane, the zwitterionic diol is at least one of sulfobetaine diol (SB-Diol), carboxybetaine diol (CB-Diol), phosphorocholine diol (PC-Diol), sulfobetaine diol-amino, and sulfobetaine diol-(pentyloxy)amino.

[0024] When A1 is And A2 is When , is the structural formula of sulfobetaine diol;

[0025] When A1 is And A2 is When , is the structural formula of carboxybetaine diol;

[0026] When A1 is And A2 is When , is the structural formula of phosphocholine diol;

[0027] When A1 is And A2 is When , it is the structural formula of sulfobetaine diol-amino;

[0028] When A1 is And A2 is When , it is the structural formula of sulfobetaine diol-(pentyloxy)amino.

[0029] Sulfobetaine diol can be prepared according to the prior art Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). Carboxybetaine diol can be prepared according to the prior art Jiang J, Fu Y, Zhang Q, et al. Novel amphiphilic poly(dimethylsiloxane)-based polyurethane networks tethered with carboxybetaine and their combined antibacterial and anti-adhesive properties [J]. Applied Surface Science, 2017, 412: 1-9. Sulfobetaine diol-amino can be prepared according to the prior art description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). Sulfobetaine diol-(pentyloxy)amino can be prepared according to the prior art description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014).

[0030] Preferably,

[0031] As the soft segment material of the polyurethane, the monomer diol is at least one of polyethylene glycol, polypropylene glycol, polyhexamethylene glycol, polyoctamethylene glycol, polydecamethylene glycol, polycarbonate diol (PC-Diol), polytetramethylene glycol (PTMG-Diol), polyethylene adipate glycol, poly1,4-butylene adipate, and polycaprolactone diol (PCL-Diol). Preferably, the number average molecular weight of the monomer diol is 1000-8000; and / or,

[0032] The diisocyanate is at least one of hexamethylene diisocyanate (HDI), methylene phenyl isocyanate (MDI), m-xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate (NDI), p-phenylene diisocyanate, dimethyl diphenyl diisocyanate, triphenylmethane triisocyanate, tris(4-phenylisocyanate)phosphorothioate, methylcyclohexyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, and L-lysine ethyl ester diisocyanate; and / or

[0033] The catalyst is at least one of dibutyltin dilaurate (DBTDL), tin 2-ethylhexanoate, zinc isooctanoate, bismuth isooctanoate, lead isooctanoate, potassium oleate, zinc naphthenate, cobalt naphthenate, ferric acetylacetonate, phenylmercuric acetate, phenylmercuric propionate, dimethylcyclohexylamine, triethylenediamine, triethylamine, methyldicyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N,N'-dimethylpiperazine, N,N'-diethylpiperazine, 1,1,3,3-tetramethylpiperidine, bis(2-dimethylaminoethyl) ether, tetramethylbutanediamine, 2,4,6-tris(dimethylaminomethyl)phenol, pentamethyldipropylenetriamine, trimethylhydroxyethylethylenediamine, dimethylethanolamine, oleic acid, azelaic acid, and adipic acid; and / or,

[0034] The chain extender is 1,4-butanediol (BD), 1,2-propylene glycol, methylpropylene glycol, diethylene glycol, 1,4-cyclohexanol, neopentyl glycol, 1,4-cyclohexanediamine, ethylene glycol, 1,4-diaminobutane, hydroquinone dihydroxyethyl ether, resorcinol dihydroxyethyl ether, N-methyldiethanolamine, 3,3'-dichloro-4,4'-diaminophenylmethane, diethyltoluenediamine, 4,4'-methylene-bis(3-chloro-2,6-diethylaniline), bis-sec-butylaminodiphenylmethane, 1,6-hexanediol, ethylenediamine, 1,3-propylene glycol-bis(4-aminobenzoate), 3,5-dimethylthiotoluenediamine, 3,5-diamino-4-chlorobenzoic acid isobutyl ester, di- at least one of (4-phenyl) disulfide, diethylene glycol bis(4-aminobenzoate), 3,5-diamino-4-trifluoromethylphenyl ether, 3,5-diamino-4-chlorophenylacetic acid isopropyl ester, 3-amino-4-chlorobenzyl-4'-aminobenzoate, 1,4-bis(2-aminophenylthioethoxy)benzene, 1,4-bis(2-aminophenylthioethyl)benzoate, methylenebis(4-amino-3-benzoic acid methyl ester), 4,4'-methylenebis(2,6-diisopropylaniline), ethylenebis(2-aminophenyl sulfide), 4,4'-methylenebis(2,6-diethyl)aniline, and 2,4-diamino-3-methylthio-5-propyltoluene; and / or

[0035] The reaction solvent is at least one of dimethyl sulfoxide (DMSO), dimethylformamide, methanol, acetone, dichloromethane, tetrahydrofuran, and toluene; and / or,

[0036] The preparation solvent is at least one of hexafluoroisopropanol (HFIP), dimethylformamide (DMF), dichloromethane, tetrahydrofuran, trifluoroethanol, methyl ethyl ketone, dimethylacetamide, 1,4-dioxane, trifluoroacetic acid, and chloroform.

[0037] Preferably,

[0038] The molar ratio of the zwitterionic diol to the monomeric diol is (0.1-20):1, preferably (0.5-5):1;

[0039] The molar ratio of the sum of the moles of the zwitterionic diol and the monomeric diol, the diisocyanate, and the chain extender is 1:(0.1-3):(0.1-3), preferably 1:(1-2):(1-2);

[0040] The mass ratio of the sum of the mass of the zwitterionic diol and the monomeric diol to the mass of the catalyst is (150-2500):1, preferably in the range of (1000-1500):1;

[0041] The mass ratio of the sum of the mass of the zwitterionic diol and the monomeric diol to the reaction solvent is 1:(2-30), preferably in the range of 1:(10-20);

[0042] The concentration of the zwitterion-modified polyurethane after being dissolved in the preparation solvent is 5%-30% w / v, preferably 8%-25% w / v;

[0043] The above w / v is mass concentration, wherein "w" represents the mass of zwitterion-modified polyurethane and "v" represents the volume of the preparation solvent.

[0044] Preferably,

[0045] In step (1),

[0046] The reaction temperature of the prepolymerization reaction is 25-120° C., and / or the reaction time is 20 min-10 h; and / or,

[0047] The reaction temperature of the chain extension reaction is 25-120° C., and / or the reaction time is 20 min-100 h.

[0048] Preferably,

[0049] In step (2), the stirring temperature is 15-80° C., and / or the stirring time is 10-240 h.

[0050] Preferably,

[0051] In step (3),

[0052] The receiver for electrospinning is a tubular receiver or a drum receiver, preferably, the tubular receiver is a tubular receiver of 1-6 mm, and / or the drum receiver is a drum receiver of 250 mm in length and 100 mm in diameter, and / or the voltage of electrospinning is 8-25 kV, and / or the receiving distance is 5-25 cm, and / or the receiver rotation speed is 50-1500 rpm, and / or the syringe pump speed is 0.5-2 ml / h; preferably, the artificial blood vessel or heart valve completed by electrospinning is carefully removed from the receiver, thoroughly washed with deionized water, and sterilized with ethylene oxide before use to obtain the desired zwitterionic polyurethane artificial blood vessel or heart valve; and / or,

[0053] The 3D printing parameters are: printing speed 5-15 mm / s, and / or, extrusion speed 0.08-0.1 mm / s, and / or, printing temperature 100-500°C, and / or, platform temperature 30-50°C, and / or, layer height 0.1-0.3 mm; and / or,

[0054] The solvent casting method for preparing a heart valve comprises: uniformly casting the prepared solution on a substrate, and drying to obtain the implantable artificial organ in the form of a thin film. Preferably, the substrate is a glass cover with a diameter of 10-15 mm. Specifically, the prepared solution can be slowly and uniformly poured on a glass cover with a diameter of 10-15 mm, and then the solution cast on the glass cover is dried to obtain a zwitterionic polyurethane film. And / or, the specific steps of preparing an artificial blood vessel by the solvent casting method can be referred to the literature Melchiorri, AJ, Hibino, N., Brandes, ZR, Jonas, RA & Fisher, JP Development and assessment of a biodegradable solvent cast polyester fabric small-diameter vascular graft. Journal of Biomedical Materials Research Part A102, 1972-1981 (2014). states: depositing the prepared solution into a polypropylene tube with a diameter of 1.4 mm, allowing the solution to penetrate the felt, and then freezing at -20°C, freeze-drying the sealed tube to eliminate the 1,4-dioxane solvent, and after complete drying, removing the artificial blood vessel from the test tube and storing it at -20°C for future use; and / or,

[0055] The salting-out method for preparing a heart valve comprises: precipitating the prepared solution in an inorganic salt solution, and drying to form a thin film heart valve, and / or, the specific steps of preparing an artificial blood vessel by the salting-out method can be referred to the document AsadpourS, Yeganeh H, Ai J, et al. A novel polyurethane modified with biomacromolecules for small-diameter vascular graft applications [J]. Journal of Materials Science, 2018, 53(14): 9913-9927. The salting-out method comprises: adding salt particles (NaCl) to the prepared solution and stirring to obtain a uniform mixture, grinding and sieving the salt particles, pouring the mixture into a cylindrical glass mold, drying the stent under vacuum after the solvent evaporates, and then immersing the stent in a 20% ethanol solution, leaching the pore-forming bacteria in ultrapure deionized water, and then freeze-drying to prepare an artificial blood vessel; and / or,

[0056] The phase separation method can be referred to in the literature Mi HY, Jing X, McNulty J, et al. Approaches to fabricating multiple-layered vascular scaffolds using hybrid electrospinning and thermally induced phase separation methods [J]. Industrial & Engineering Chemistry Research, 2016, 55 (4): 882-892. The prepared solution is poured into the gap between the core rod and the mold, and then ice-quenched to allow phase separation to occur. The mold is then placed in a -80 ° C refrigerator to completely freeze the solution, and freeze-dried using a freeze dryer to obtain the implantable artificial organ. Artificial organs of different shapes can be prepared using different molds.

[0057] Among them, artificial blood vessels can also be prepared by a method combining electrostatic spinning and phase separation. For specific steps, reference can be made to the literature Mi HY, Jing X, McNulty J, et al. Approaches to fabricating multiple-layered vascular scaffolds using hybrid electrospinning and thermally induced phase separation methods [J]. Industrial & Engineering Chemistry Research, 2016, 55 (4): 882-892. The inner layer is produced by electrostatic spinning. In order to prevent the electrostatic spinning inner layer from being dissolved and improve the biocompatibility of the stent, a chitosan coating can be added to the outer surface of the inner layer. Specifically, the following method can be used: the polyurethane tube obtained by electrostatic spinning is immersed in a chitosan solution for 1 minute, air-dried overnight, and after the chitosan coating is formed, the rod with the polyurethane inner layer is installed in the center of a cylindrical aluminum mold, the same as the mandrel of the tubular stent, and then the middle layer of the tubular stent is prepared by using the phase separation method. The outer layer of the tubular stent is prepared by electrostatic spinning from the middle layer.

[0058] A second object of the present invention is to provide an implantable artificial organ.

[0059] A third object of the present invention is to provide an implantable artificial organ for use as a substitute for autologous blood vessels or heart valves.

[0060] Compared with the prior art, the present invention has at least the following technical effects:

[0061] This study uses a zwitterionic diol as the hard segment and another monomeric diol as the soft segment to investigate the effects of varying molar ratios of the hard and soft segments on the performance of implantable artificial organs. The hard segment provides hydrophilicity, biocompatibility, and antifouling properties; the soft segment can be tailored to provide flexibility and suitable mechanical properties through molecular weight control. Diisocyanates serve as chemical building blocks to connect the hard and soft segments.

[0062] (1) The zwitterionic polyurethane small-caliber artificial blood vessels prepared by the present invention have excellent mechanical strength, high elasticity, easy suturing, and good compliance. By changing the electrospinning conditions, the mechanical properties of the artificial blood vessels prepared are adjusted to have mechanical properties similar to those of natural blood vessels.

[0063] (2) The zwitterionic polyurethane small-caliber artificial blood vessels prepared by the present invention have the ability to reduce protein adsorption, platelet deposition, and macrophage attachment. They can also significantly reduce the deposition of white blood cells, neutrophils, monocytes, B cells, and T cells. The antifouling properties and in vitro antithrombotic properties of the prepared artificial blood vessels are significantly improved, and the immune response is reduced.

[0064] (3) The zwitterionic polyurethane small-caliber artificial blood vessels prepared by the present invention can maintain long-term antithrombotic properties. This demonstrates that zwitterionic polymers have good in vivo antithrombotic properties as blood-contacting biomedical devices. The introduction of zwitterionic groups into the design of artificial blood vessels has the ability to prevent acute thrombosis and resist intimal hyperplasia. After zwitterionic modification, the prepared polyurethane artificial blood vessels have good biocompatibility and long-term patency.

[0065] (4) The zwitterion artificial heart valve prepared by the present invention has excellent biomechanical properties, good anti-calcification ability, good anti-fouling properties, blood compatibility and anti-thrombotic properties. The artificial heart valve modified with zwitterions has better stability, long-term anti-coagulation and anti-calcification capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 Schematic diagram of an artificial blood vessel prepared by electrospinning in the present invention;

[0067] Figure 2 This is a SEM structural morphology representation of the artificial blood vessel or heart valve prepared in Example 2 of the present invention;

[0068] Figure 3 Graph showing the tensile stress test results of the artificial blood vessels prepared in Example 2 and Example 3;

[0069] Figure 4 Graph showing the tensile elongation test results of the artificial blood vessels prepared in Example 2 and Example 3;

[0070] Figure 5 Graph showing the suture retention test results of the artificial blood vessels prepared in Example 2 and Example 3;

[0071] Figure 6 Graph showing compliance test results of the artificial blood vessels prepared in Example 2 and Example 3;

[0072] Figure 7 Fluorescence microscope images of the artificial blood vessels or heart valves prepared in Example 2 and Comparative Example 1;

[0073] Figure 8 Graphs showing the adsorption results of fluorescein isothiocyanate-labeled fibrinogen and lysozyme on the artificial vascular cell membranes or heart valves of Example 2 and Comparative Example 1;

[0074] Figure 9 The following are scanning electron micrographs of the artificial vascular membranes or heart valves prepared in Example 2 and Comparative Example 1 stained with sheep platelets;

[0075] Figure 10 Statistical graphs of the density of sheep platelets on the artificial vascular membranes or heart valves prepared in Example 2 and Comparative Example 1;

[0076] Figure 11 Schematic diagram of artificial blood vessel implantation in the left carotid artery of a rat;

[0077] Figure 12 Digital images of the open artificial blood vessel prepared in Example 2 60 days after implantation and the occluded artificial blood vessel prepared in Comparative Example 1 7 days after implantation; wherein the arrows indicate the anastomosis between the original artery and the artificial blood vessel;

[0078] Figure 13 This is an ultrasound image of the artificial blood vessel prepared in Example 2 in brightness mode after 90 days of implantation; wherein the arrow indicates the anastomosis site;

[0079] Figure 14 (b) is an ultrasound image of the open artificial blood vessel prepared in Example 2 in color mode 90 days after implantation; wherein the arrow indicates the anastomosis site;

[0080] Figure 15 The diameter of the lumen of the artificial blood vessel prepared in Example 2 60-90 days after transplantation;

[0081] Figure 16 The blood flow velocity of the artificial blood vessel prepared in Example 2 90 days after transplantation;

[0082] Figure 17 The peak blood flow velocities of the artificial blood vessel prepared in Example 2 at 60 and 90 days after transplantation. DETAILED DESCRIPTION

[0083] The present invention will be described in detail below with reference to specific drawings and embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0084] The raw materials used in the examples and comparative examples of the present invention are all commercially available products, and their specific information is shown in Table 1 below.

[0085] Table 1

[0086]

[0087] Example 1

[0088] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0089] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the mixture was precipitated and washed with ether to obtain SB-Diol as a white powder.

[0090] Step 2: SB-Diol and PC-Diol were dissolved in anhydrous dimethyl sulfoxide (DMSO) at a molar ratio of 0.5:1. PC-Diol had an Mn of 2000, and the mass ratio of the combined mass of SB-Diol and PC-Diol to DMSO was 1:25. HDI and DBTDL catalysts were added to the flask. The reaction temperature was raised to 60°C, and the reaction was continued for 2 hours to obtain a prepolymer. Subsequently, 1,4-diaminobutane was added to the solution as a chain extender. The reaction was continued at 60°C with continuous stirring for 6 hours. The molar ratio of the combined mass of SB-Diol to PC-Diol, HDI, and 1,4-diaminobutane was 1:2:1, and the mass ratio of the combined mass of SB-Diol and PC-Diol to the DBTDL catalyst was 300:1. Finally, the viscous polymer solution was purified to obtain a zwitterion-modified polyurethane as a white solid.

[0091] Step 3: The zwitterion-modified polyurethane prepared above was dissolved in 10% (w / v) hexafluoroisopropanol (HFIP) at room temperature for 24 hours. The resulting polymer solution was loaded into a syringe equipped with a blunt needle, and the nanofibers were continuously collected by rotating a 2 mm stainless steel tubular receiver (rotation speed: 375 rpm). Unless otherwise specified, the applied voltage was 13 kV, and the distance between the blunt needle and the collector was fixed at 12 cm. The polymer solution was pumped out using a syringe pump at a rate of 1.0 mL per hour. The graft was then carefully removed from the receiver, thoroughly rinsed with deionized water, and sterilized with ethylene oxide before use, resulting in a small-caliber graft made of zwitterion-modified polyurethane.

[0092] The preparation method of a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that the tubular receiver in the above step 3 is replaced with a roller receiver with a length of 250 mm and a diameter of 100 mm.

[0093] Example 2

[0094] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0095] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the mixture was precipitated and washed with ether to obtain SB-Diol as a white powder.

[0096] Step 2: SB-Diol and PC-Diol were dissolved in anhydrous dimethyl sulfoxide (DMSO) at a molar ratio of 2.5:1. PC-Diol had an Mn of 2000, and the mass ratio of the combined mass of SB-Diol and PC-Diol to DMSO was 1:25. HDI and DBTDL catalysts were added to the flask, and the reaction temperature was raised to 60°C for 2 hours to yield a prepolymer. Subsequently, 1,4-diaminobutane was added to the solution as a chain extender, and the reaction was continued at 60°C with continuous stirring for 6 hours. The molar ratio of the combined mass of SB-Diol to PC-Diol, HDI, and 1,4-diaminobutane was 1:2:1, and the mass ratio of the combined mass of SB-Diol and PC-Diol to the DBTDL catalyst was 300:1. Finally, the viscous polymer solution was purified to yield a zwitterion-modified polyurethane as a white solid.

[0097] Step 3: The zwitterion-modified polyurethane prepared above was dissolved in 15% (w / v) hexafluoroisopropanol (HFIP) at room temperature for 24 hours. The resulting polymer solution was loaded into a syringe equipped with a blunt needle, and the nanofibers were continuously collected by rotating a 3 mm stainless steel tubular receiver (rotation speed: 375 rpm). Unless otherwise specified, the applied voltage was 13 kV, and the distance between the blunt needle and the collector was fixed at 12 cm. The polymer solution was pumped out using a syringe pump at a rate of 1.0 mL per hour. The graft was then carefully removed from the receiver, thoroughly rinsed with deionized water, and sterilized with ethylene oxide before use, resulting in a small-caliber zwitterion-modified polyurethane graft.

[0098] The preparation method of a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that the tubular receiver in the above step 3 is replaced with a roller receiver with a length of 250 mm and a diameter of 100 mm.

[0099] Example 3

[0100] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0101] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the mixture was precipitated and washed with ether to obtain SB-Diol as a white powder.

[0102] Step 2: SB-Diol and PC-Diol were dissolved in anhydrous dimethyl sulfoxide (DMSO) at a molar ratio of 4:1. PC-Diol had an Mn of 2000, and the mass ratio of the combined mass of SB-Diol and PC-Diol to DMSO was 1:25. HDI and DBTDL catalyst were added to the flask, and the reaction temperature was raised to 60°C for 2 hours to yield a prepolymer. Subsequently, 1,4-diaminobutane was added to the solution as a chain extender, and the reaction was continued at 60°C with continuous stirring for 6 hours. The molar ratio of the combined mass of SB-Diol to PC-Diol, HDI, and 1,4-diaminobutane was 1:2:1, and the mass ratio of the combined mass of SB-Diol and PC-Diol to the DBTDL catalyst was 300:1. Finally, the viscous polymer solution was purified to yield a zwitterion-modified polyurethane as a white solid.

[0103] Step 3: The zwitterion-modified polyurethane prepared above was dissolved in 15% (w / v) hexafluoroisopropanol (HFIP) at room temperature for 24 hours. The resulting polymer solution was loaded into a syringe equipped with a blunt needle, and the nanofibers were continuously collected by rotating a 4 mm stainless steel tubular receiver (rotation speed: 375 rpm). Unless otherwise specified, the applied voltage was 13 kV, and the distance between the blunt needle and the collector was fixed at 12 cm. The polymer solution was pumped out using a syringe pump at a rate of 1.0 mL per hour. The graft was then carefully removed from the receiver, thoroughly rinsed with deionized water, and sterilized with ethylene oxide before use, resulting in a small-caliber graft made of zwitterion-modified polyurethane.

[0104] The preparation method of a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that the tubular receiver in the above step 3 is replaced with a roller receiver with a length of 250 mm and a diameter of 100 mm.

[0105] Example 4

[0106] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0107] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the mixture was precipitated and washed with ether to obtain SB-Diol as a white powder.

[0108] Step 2: SB-Diol and PC-Diol were dissolved in anhydrous dimethyl sulfoxide (DMSO) at a molar ratio of 15:1. PC-Diol had an Mn of 2000, and the mass ratio of the combined mass of SB-Diol and PC-Diol to DMSO was 1:25. HDI and DBTDL catalyst were added to the flask, and the reaction temperature was raised to 60°C for 2 hours to yield a prepolymer. Subsequently, 1,4-diaminobutane was added to the solution as a chain extender, and the reaction was continued at 60°C with continuous stirring for 6 hours. The molar ratio of the combined mass of SB-Diol to PC-Diol, HDI, and 1,4-diaminobutane was 1:2:1, and the mass ratio of the combined mass of SB-Diol and PC-Diol to the DBTDL catalyst was 300:1. Finally, the viscous polymer solution was purified to yield a zwitterion-modified polyurethane as a white solid.

[0109] Step 3: The zwitterion-modified polyurethane prepared above was dissolved in 15% (w / v) hexafluoroisopropanol (HFIP) at room temperature for 24 hours. The resulting polymer solution was loaded into a syringe equipped with a blunt needle, and the nanofibers were continuously collected by rotating a 2 mm stainless steel tubular receiver (rotation speed: 375 rpm). Unless otherwise specified, the applied voltage was 13 kV, and the distance between the blunt needle and the collector was fixed at 12 cm. The polymer solution was pumped out using a syringe pump at a rate of 1.0 mL per hour. The graft was then carefully removed from the receiver, thoroughly rinsed with deionized water, and sterilized with ethylene oxide before use, resulting in a small-caliber graft made of zwitterion-modified polyurethane.

[0110] The preparation method of a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that the tubular receiver in the above step 3 is replaced with a roller receiver with a length of 250 mm and a diameter of 100 mm.

[0111] Example 5

[0112] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0113] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the precipitate was washed with diethyl ether to obtain SB-Diol as a white powder.

[0114] Step 2: Methylene phenyl isocyanate (MDI), a tin 2-ethylhexanoate catalyst, polytetrahydrofuran (PTMG) (Mn=2000) and SB-Diol dissolved in dimethylformamide (DMF) were reacted at 80°C for 3 hours. The molar ratio of SB-Diol to PTMG was 2.5:1, and the mass ratio of the combined mass of SB-Diol and PTMG to DMF was 1:15. The reaction was then cooled to room temperature, and 1,4-butanediol (BD) was added. The reaction temperature was raised to 50°C and allowed to react for 3 hours. The molar ratio of the combined mass of SB-Diol to PTMG, MDI to BD was 1:0.5:0.5, and the mass ratio of the combined mass of SB-Diol and PTMG to the tin 2-ethylhexanoate catalyst was 1200:1. The final polymer solution was cooled to room temperature, precipitated in methanol, and dried naturally.

[0115] Step 3: The product was dissolved in 1,4-dioxane at 10% (w / v), and the solution was then deposited into a polypropylene tube with a diameter of 1.4 mm. The solution was allowed to penetrate the felt, and the system was then frozen at -20°C. The sealed tube was freeze-dried to eliminate the 1,4-dioxane solvent. After complete drying, the artificial blood vessel was removed from the test tube and stored at -20°C for future use.

[0116] A method for preparing a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that step three is modified as follows: dissolving the product in a DMF solution to prepare a 10% (w / v) polymer solution, stirring the solution at room temperature for 24 hours, slowly and evenly pouring the polymer solution onto a glass cover with a diameter of 12 mm, and then drying the solution cast on the glass cover to prepare a zwitterionic polyurethane film.

[0117] Example 6

[0118] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0119] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the precipitate was washed with diethyl ether to obtain SB-Diol as a white powder.

[0120] Step 2: Methylene phenyl isocyanate (MDI), a tin 2-ethylhexanoate catalyst, polytetrahydrofuran (PTMG) (Mn=2000) and SB-Diol dissolved in dimethylformamide (DMF) were reacted at 80°C for 3 hours. The molar ratio of SB-Diol to PTMG was 2.5:1, and the mass ratio of the combined mass of SB-Diol and PTMG to DMF was 1:15. The reaction was then cooled to room temperature, and 1,4-butanediol (BD) was added. The reaction temperature was raised to 50°C and allowed to react for 3 hours. The molar ratio of the combined mass of SB-Diol to PTMG, MDI, and BD was 1:1.5:1, and the mass ratio of the combined mass of SB-Diol and PTMG to the tin 2-ethylhexanoate catalyst was 1200:1. The final polymer solution was cooled to room temperature, precipitated in methanol, and dried naturally.

[0121] Step 3: The product was dissolved in 1,4-dioxane at 10% (w / v), and the solution was then deposited into a polypropylene tube with a diameter of 1.4 mm. The solution was allowed to penetrate the felt, and the system was then frozen at -20°C. The sealed tube was freeze-dried to eliminate the 1,4-dioxane solvent. After complete drying, the artificial blood vessel was removed from the test tube and stored at -20°C for future use.

[0122] A method for preparing a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that step three is modified as follows: dissolving the product in a DMF solution to prepare a 10% (w / v) polymer solution, stirring the solution at room temperature for 24 hours, slowly and evenly pouring the polymer solution onto a glass cover with a diameter of 12 mm, and then drying the solution cast on the glass cover to prepare a zwitterionic polyurethane film.

[0123] Example 7

[0124] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0125] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the precipitate was washed with diethyl ether to obtain SB-Diol as a white powder.

[0126] Step 2: Methylene phenyl isocyanate (MDI), a tin 2-ethylhexanoate catalyst, polytetrahydrofuran (PTMG) (Mn=2000) and SB-Diol dissolved in dimethylformamide (DMF) were reacted at 80°C for 3 hours. The molar ratio of SB-Diol to PTMG was 2.5:1, and the mass ratio of the combined mass of SB-Diol and PTMG to DMF was 1:15. The reaction was then cooled to room temperature, and 1,4-butanediol (BD) was added. The reaction temperature was raised to 50°C and allowed to react for 3 hours. The molar ratio of the combined mass of SB-Diol to PTMG, MDI, and BD was 1:2:1, and the mass ratio of the combined mass of SB-Diol and PTMG to the tin 2-ethylhexanoate catalyst was 1200:1. The final polymer solution was cooled to room temperature, precipitated in methanol, and dried naturally.

[0127] Step 3: The product was dissolved in 1,4-dioxane at 10% (w / v), and the solution was then deposited into a polypropylene tube with a diameter of 1.4 mm. The solution was allowed to penetrate the felt, and the system was then frozen at -20°C. The sealed tube was freeze-dried to eliminate the 1,4-dioxane solvent. After complete drying, the artificial blood vessel was removed from the test tube and stored at -20°C for future use.

[0128] A method for preparing a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that step three is modified as follows: dissolving the product in a DMF solution to prepare a 10% (w / v) polymer solution, stirring the solution at room temperature for 24 hours, slowly and evenly pouring the polymer solution onto a glass cover with a diameter of 12 mm, and then drying the solution cast on the glass cover to prepare a zwitterionic polyurethane film.

[0129] Example 8

[0130] A small-caliber artificial blood vessel with anticoagulation, intimal hyperplasia and long-term patency functions, the preparation method of which comprises the following steps:

[0131] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the precipitate was washed with diethyl ether to obtain SB-Diol as a white powder.

[0132] Step 2: Methylene phenyl isocyanate (MDI), a tin 2-ethylhexanoate catalyst, polytetrahydrofuran (PTMG) (Mn=2000) and SB-Diol dissolved in dimethylformamide (DMF) were reacted at 80°C for 3 hours. The molar ratio of SB-Diol to PTMG was 2.5:1, and the mass ratio of the combined mass of SB-Diol and PTMG to DMF was 1:15. The reaction was then cooled to room temperature, and 1,4-butanediol (BD) was added. The reaction temperature was raised to 50°C and allowed to react for 3 hours. The molar ratio of the combined mass of SB-Diol to PTMG, MDI, and BD was 1:3:2, and the mass ratio of the combined mass of SB-Diol and PTMG to the tin 2-ethylhexanoate catalyst was 1200:1. The final polymer solution was cooled to room temperature, precipitated in methanol, and dried naturally.

[0133] Step 3: The product was dissolved in 1,4-dioxane at 10% (w / v), and the solution was then deposited into a polypropylene tube with a diameter of 1.4 mm. The solution was allowed to penetrate the felt, and the system was then frozen at -20°C. The sealed tube was freeze-dried to eliminate the 1,4-dioxane solvent. After complete drying, the artificial blood vessel was removed from the test tube and stored at -20°C for future use.

[0134] A method for preparing a heart valve with anti-coagulation and anti-calcification capabilities is the same as the above steps, except that step three is modified as follows: dissolving the product in a DMF solution to prepare a 10% (w / v) polymer solution, stirring the solution at room temperature for 24 hours, slowly and evenly pouring the polymer solution onto a glass cover with a diameter of 12 mm, and then drying the solution cast on the glass cover to prepare a zwitterionic polyurethane film.

[0135] Example 9

[0136] A small-caliber artificial blood vessel with anti-coagulation, intimal hyperplasia and long-term patency functions or a heart valve with anti-coagulation and anti-calcification capabilities, the preparation method of which comprises the following steps:

[0137] Step 1: Carboxybetaine diol (CB-Diol) was prepared according to Jiang J, Fu Y, Zhang Q, et al. Novel amphiphilic poly(dimethylsiloxane)based polyurethane networks tethered with carboxybetaine and their combined antibacterial and anti-adhesive property [J]. Applied Surface Science, 2017, 412: 1-9. Butyl t-bromoacetate (11.70 g, 60 mmol), N-methyldiethanolamine (6.20 g, 60 mmol) and acetonitrile (100 mL) were mixed in a nitrogen-filled flask. The mixture was stirred at 65 ° C for 24 hours. The desired CB-Diol with a protected t-butyl group was precipitated by adding icy ether (300 mL) to the product solution. The solvent was separated by vigorous stirring, vacuum filtered, washed with ether, and dried to obtain a white solid.

[0138] Step 2: Carboxybetaine diol and polycaprolactone diol (Mn=2000) with a molar ratio of 2.5:1 were mixed with isophorone diisocyanate, m-xylylene diisocyanate and zinc isooctanoate in tetrahydrofuran solution at 70°C for 3h, and then bis(4-phenyl) disulfide dissolved in tetrahydrofuran solution was added and the reaction was continued at 70°C with stirring for 5h. The mass ratio of the sum of the moles of carboxybetaine diol and polycaprolactone diol to tetrahydrofuran is 1:5; the molar ratio of the sum of the moles of isophorone diisocyanate and meta-xylylene diisocyanate, and bis(4-phenyl) disulfide is 1:2:1; the molar ratio of isophorone diisocyanate to meta-xylylene diisocyanate is 1:1; and the mass ratio of the sum of the mass of carboxybetaine diol and polycaprolactone diol to zinc isooctanoate is 2000:1. Finally, the viscous polymer solution is purified to obtain a white solid.

[0139] Step 3: The product was dissolved in a mixture of dimethylacetamide and methyl ethyl ketone (dimethylacetamide:methyl ethyl ketone, volume ratio: 1:2) to prepare a 25% (w / v) polymer solution. The solution was stirred at room temperature for 24 hours. Zwitterion-modified artificial blood vessels or heart valves were then prepared using 3D printing technology according to different modeling shapes. The printing speed was 10 mm / s, the extrusion speed was 0.09 mm / s, the printing temperature was 200°C, the platform temperature was 40°C, and the layer height was 0.2 mm.

[0140] Example 10

[0141] A small-caliber artificial blood vessel with anti-coagulation, intimal hyperplasia and long-term patency functions or a heart valve with anti-coagulation and anti-calcification capabilities, the preparation method of which comprises the following steps:

[0142] Step 1: Prepare sulfobetaine diol (SB-Diol) according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014). N-butyldiethanolamine, 1,3-propane sultone and dichloromethane were added to a round-bottom flask and stirred at 40 ° C under a nitrogen atmosphere for 24 hours. Then, the solvent was removed and the precipitate was washed with diethyl ether to obtain SB-Diol as a white powder.

[0143] Step 2: The sulfobetaine diol and polycaprolactone diol (Mn=2000) with a molar ratio of 2.5:1 were mixed with isophorone diisocyanate, m-xylyl diisocyanate and zinc isooctanoate in tetrahydrofuran solution at 70°C for 3h, and then bis(4-phenyl) disulfide dissolved in tetrahydrofuran solution was added and the reaction was continued at 70°C with stirring for 5h. The mass ratio of the sum of the moles of sulfobetaine diol and polycaprolactone diol to tetrahydrofuran is 1:5; the molar ratio of the sum of the moles of sulfobetaine diol and polycaprolactone diol, the molar sum of isophorone diisocyanate and m-xylylene diisocyanate, and bis(4-phenyl) disulfide is 1:2:1, and the molar ratio of isophorone diisocyanate to m-xylylene diisocyanate is 1:1; the mass ratio of the sum of the mass of sulfobetaine diol and polycaprolactone diol to tin isooctanoate is 2000:1. Finally, the viscous polymer solution is purified to obtain a white solid.

[0144] Step 3: The product was dissolved in a mixture of dimethylacetamide and methyl ethyl ketone (dimethylacetamide:methyl ethyl ketone, volume ratio: 1:2) to prepare a 20% (w / v) polymer solution. The solution was stirred at room temperature for 24 hours. Zwitterion-modified artificial blood vessels or heart valves were then prepared using 3D printing technology based on different modeling shapes. The printing speed was 10 mm / s, the extrusion speed was 0.09 mm / s, the printing temperature was 200°C, the platform temperature was 40°C, and the layer height was 0.2 mm.

[0145] Example 11

[0146] A small-caliber artificial blood vessel with anti-coagulation, intimal hyperplasia and long-term patency functions or a heart valve with anti-coagulation and anti-calcification capabilities, the preparation method of which comprises the following steps:

[0147] Step 1: Prepare sulfobetaine diol-amino according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014): Add N, N-dimethyl-2-((pentyloxy)amino)-1-diethanolamine, 1, 3-propane sultone and acetonitrile to a round-bottom flask. Stir at 40°C under a nitrogen atmosphere for 48 hours. After the reaction is completed, remove the solvent using a rotary evaporator. The product is pre-precipitated with anhydrous ether and washed with dry ether to obtain a white powder. Finally, treat with a mixture of trifluoroacetic acid (TFA) and dichloromethane, leave at room temperature overnight, evaporate by rotary evaporation, and precipitate in anhydrous ether to obtain the white product sulfobetaine diol-amino.

[0148] Step 2: The sulfobetaine diol-amino and polycaprolactone diol (Mn=2000) with a molar ratio of 2.5:1 were mixed with isophorone diisocyanate, m-xylyl diisocyanate and zinc isooctanoate in tetrahydrofuran solution at 70°C for 3h, and then bis(4-phenyl) disulfide dissolved in tetrahydrofuran solution was added and the reaction was continued at 70°C with stirring for 5h. The mass ratio of the sum of the moles of sulfobetaine diol-amino and polycaprolactone diol to tetrahydrofuran is 1:5; the molar ratio of the sum of the moles of isophorone diisocyanate and meta-xylylene diisocyanate, and bis(4-phenyl) disulfide is 1:2:1, and the molar ratio of isophorone diisocyanate and meta-xylylene diisocyanate is 1:1; the mass ratio of the sum of the mass of sulfobetaine diol-amino and polycaprolactone diol to tin isooctanoate is 2000:1. Finally, the viscous polymer solution is purified to obtain a white solid.

[0149] Step 3: The product was dissolved in a mixture of dimethylacetamide and methyl ethyl ketone (dimethylacetamide:methyl ethyl ketone, volume ratio: 1:2) to prepare a 25% (w / v) polymer solution. The solution was stirred at room temperature for 24 hours. Zwitterion-modified artificial blood vessels or heart valves were then prepared using 3D printing technology according to different modeling shapes. The printing speed was 10 mm / s, the extrusion speed was 0.09 mm / s, the printing temperature was 200°C, the platform temperature was 40°C, and the layer height was 0.2 mm.

[0150] Example 12

[0151] A small-caliber artificial blood vessel with anti-coagulation, intimal hyperplasia and long-term patency functions or a heart valve with anti-coagulation and anti-calcification capabilities, the preparation method of which comprises the following steps:

[0152] Step 1: Prepare sulfobetaine diol-(pentyloxy)amino according to the description of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014): Add N, N-dimethyl-2-((pentyloxy)amino)-1-diethanolamine, 1, 3-propane sultone, and acetonitrile to a round-bottom flask. Stir at 40°C under a nitrogen atmosphere for 48 hours. After the reaction is completed, remove the solvent using a rotary evaporator. Preprecipitate the product with anhydrous ether and wash with dry ether to obtain sulfobetaine diol-(pentyloxy)amino as a white powder.

[0153] Step 2: The sulfobetaine diol-(pentyloxy)amino and polycaprolactone diol (Mn=2000) with a molar ratio of 2.5:1 were mixed with isophorone diisocyanate, m-xylyl diisocyanate and zinc isooctanoate in tetrahydrofuran solution at 70°C for 3h, and then bis(4-phenyl) disulfide dissolved in tetrahydrofuran solution was added and the reaction was continued at 70°C with stirring for 5h. The mass ratio of the sum of the moles of sulfobetaine diol-(pentyloxy)amino and polycaprolactone diol to tetrahydrofuran is 1:5; the molar ratio of the sum of the moles of isophorone diisocyanate and meta-xylylene diisocyanate, and bis(4-phenyl) disulfide is 1:2:1, and the molar ratio of isophorone diisocyanate and meta-xylylene diisocyanate is 1:1; the mass ratio of the sum of the mass of sulfobetaine diol-(pentyloxy)amino and polycaprolactone diol to tin isooctanoate is 2000:1. Finally, the viscous polymer solution is purified to obtain a white solid.

[0154] Step 3: The product was dissolved in a mixture of dimethylacetamide and methyl ethyl ketone (dimethylacetamide:methyl ethyl ketone, volume ratio: 1:2) to prepare a 25% (w / v) polymer solution. The solution was stirred at room temperature for 24 hours. Zwitterion-modified artificial blood vessels or heart valves were then prepared using 3D printing technology according to different modeling shapes. The printing speed was 10 mm / s, the extrusion speed was 0.09 mm / s, the printing temperature was 200°C, the platform temperature was 40°C, and the layer height was 0.2 mm.

[0155] Comparative Example 1

[0156] An artificial blood vessel, the preparation method of which comprises the following steps:

[0157] Step 1: Dissolve polycarbonate diol (PC-Diol) (Mn=2000) in anhydrous dimethyl sulfoxide (DMSO). Add HDI and DBTDL catalyst to the flask. The reaction temperature is then raised to 80°C and allowed to react for 3 hours to yield a prepolymer. Subsequently, 1,4-diaminobutane is added to the solution as a chain extender. The reaction is continued at 80°C with continuous stirring for 6 hours. The molar ratio of PC-Diol, HDI, and 1,4-diaminobutane is 1:2:1; the mass ratio of PC-Diol to DMSO is 1:25; and the mass ratio of PC-Diol to DBTDL catalyst is 300:1. Finally, the viscous polymer solution is purified to yield a white solid polyurethane.

[0158] Step 2: The polyurethane prepared above was dissolved in 15% (w / v) hexafluoroisopropanol (HFIP) at room temperature for 24 hours. The resulting polymer solution was loaded into a syringe equipped with a blunt needle, and the nanofibers were continuously collected by rotating a 3 mm stainless steel tubular receiver (rotation speed: 375 rpm). Unless otherwise specified, the applied voltage was 13 kV, and the distance between the blunt needle and the collector was fixed at 12 cm. The polymer solution was pumped out by a syringe pump at a rate of 1.0 mL per hour. The graft was then carefully removed from the receiver, thoroughly rinsed with deionized water, and sterilized with ethylene oxide before use, resulting in a small-caliber graft without zwitterion-modified polyurethane.

[0159] A method for preparing a heart valve is the same as the above steps, except that the tubular receiver in step 2 is replaced with a roller receiver with a length of 250 mm and a diameter of 100 mm.

[0160] The above examples and comparative examples were tested as follows:

[0161] 1. Structural morphology characterization

[0162] The artificial blood vessel or heart valve prepared in Example 2 was adhered to the sample stage of a scanning electron microscope and sprayed with gold. The structure and morphology thereof were observed by scanning electron microscope. The results are as follows: Figure 2 shown.

[0163] Depend on Figure 2 It can be seen that the polyurethane artificial blood vessel or heart valve modified with zwitterions has a randomly oriented fiber structure.

[0164] 2. Mechanical properties

[0165] According to the records of Liu Q, Wang X, Chiu A, et al. A Zwitterionic Polyurethane Nanoporous Device with Low Foreign-Body Response for Islet Encapsulation [J]. Advanced Materials, 2021, 33 (39): 2102852., the mechanical properties of the artificial blood vessels prepared in Example 2 and Example 3 were characterized. The artificial blood vessels were subjected to tensile and suture retention strength tests in a wet state on an electronic tensile testing machine. In the tensile test, a 10 mm long artificial blood vessel was first stretched 10 times to a strain of 10%, and then stretched at a rate of 6 mm / min until the artificial blood vessel broke. In order to test the suture retention strength of the artificial blood vessel in the rat study, the suture was passed through the blood vessel wall at a distance of 1 mm from the edge of the blood vessel end. Clamp the suture and blood vessel and stretch at a speed of 120 mm / min until the top edge of the blood vessel breaks. Suture retention refers to the maximum force recorded. The artificial blood vessel was immersed in deionized water, and a tube was connected to each end of the blood vessel for compliance testing. The results are shown as follows. Figure 3-6 shown.

[0166] Depend on Figure 3-6 As can be seen, the artificial blood vessel prepared in Example 2 has good mechanical stability and elasticity. Since sulfobetaine, as a hard segment, improves properties such as hydrophilicity, while the soft segment primarily provides mechanical properties, increasing the sulfobetaine (SB) group content reduces the tensile strength and breaking strain of the artificial blood vessel, significantly impairing its mechanical properties. When the zwitterion is added in a moderate amount, the artificial blood vessel exhibits better mechanical properties.

[0167] 3. Antifouling performance

[0168] According to the records of Liu Q, Wang X, Chiu A, et al. AZwitterionic Polyurethane Nanoporous Device with Low Foreign-Body Response for Islet Encapsulation [J]. Advanced Materials, 2021, 33 (39): 2102852., a protein adsorption experiment was performed on the artificial blood vessels or heart valves prepared in Example 2 and Comparative Example 1 to evaluate their antifouling properties. The artificial vascular membranes or heart valves in Example 2 and Comparative Example 1 were immersed in FITC-labeled fibrinogen or FITC-labeled lysozyme solution and imaged using a fluorescence microscope. The fluorescence intensity of the adsorbed protein on the membrane was quantitatively determined using Image J software. The test results are as follows: Figure 7 and 8 shown.

[0169] Depend on Figure 7 and 8 It can be seen that compared with the polyurethane artificial blood vessel or heart valve that has not been modified with zwitterions (Comparative Example 1), the adsorption of fibrinogen and lysozyme on the artificial blood vessel or heart valve modified with zwitterions is significantly reduced, indicating that the artificial blood vessel or heart valve prepared in Example 2 reduces the adsorption of nonspecific proteins.

[0170] 4. In vitro anticoagulant properties

[0171] According to the record of Ye, S.-H. et al. Nonthrombogenic, biodegradable elastomeric polyurethanes with variable sulfobetaine content. ACS applied materials & interfaces 6, 22796-22806 (2014), platelet adhesion experiments were performed on the artificial blood vessels or heart valves prepared in Example 2 and Comparative Example 1 to evaluate their in vitro anticoagulant properties. After centrifugation, the supernatant was collected as platelet-rich plasma (PRP), and the diluted PRP was inoculated on the membrane. Finally, scanning electron microscopy imaging was performed. After the sample was immersed in sheep platelet-rich plasma for 3 hours, the SEM image was as follows: Figure 9 As shown, the platelets deposited on the surface of the artificial blood vessel or heart valve prepared in Example 2 are sparse, while a large number of deposited platelets can be observed on the surface of the non-zwitterionic polyurethane artificial blood vessel or heart valve prepared in Comparative Example 1. Figure 10 Statistics of sheep platelet density on artificial vascular membranes or heart valves show that the platelet density on the artificial vascular membrane or heart valve prepared in Example 2 is 98.9% lower than that on the artificial vascular membrane or heart valve prepared in Comparative Example 1. This result demonstrates that the incorporation of zwitterionic fragments into the polyurethane design significantly improves the in vitro anti-thrombotic properties of the graft.

[0172] 5. Evaluation of in vivo anticoagulant properties, anti-intimal hyperplasia ability, and patency rate in rat models

[0173] According to Zhu T, Gu H, Zhang H, et al. Covalent grafting of PEG and heparin improves biological performance of electrospun vascular grafts for carotidartery replacement [J]. Acta Biomaterialia, 2021, 119: 211-224., the artificial blood vessels in Example 2 and Comparative Example 1 were subjected to rat model tests to evaluate in vivo anticoagulant properties, anti-intimal hyperplasia ability and patency rate.

[0174] like Figure 11 and 12 As shown, the artificial blood vessels (inner diameter 1.2 mm, wall thickness 200-230 μm, length 1 cm) of Example 2 and Comparative Example 1 were implanted into the left carotid artery of rats, and the artificial blood vessels were anastomosed end-to-end to the two ends of the left carotid artery. The patency, lumen diameter, and blood flow rate of the grafts were monitored by ultrasound. The results are shown in FIG. Figure 12-17 shown.

[0175] Depend on Figure 12-17 It can be seen that the vascular patency was monitored by ultrasound and acute thrombosis occurred in Comparative Example 1. In addition, the native arteries at both ends of the graft in Comparative Example 1 near the occlusion became narrow and abnormal ( Figure 12 ). In contrast, ultrasound confirmed that Figure 13 and Figure 14 The artificial blood vessel prepared in Example 2 remained patency within 60 days after implantation (patency rate 100%). The experimental results show that the introduction of zwitterionic groups into the design of artificial blood vessels has the ability to prevent the occurrence of acute thrombosis. Ultrasound was used to measure the lumen diameter during the implantation period. The average lumen diameter of the artificial blood vessel prepared in Example 2 at 60 and 90 days after implantation was similar to the lumen diameter before implantation ( Figure 15 The blood flow of the artificial blood vessel prepared in Example 2 was examined by ultrasound at 60 and 90 days after implantation, and its flow rate was equivalent to that of the right carotid artery ( Figure 16 and 17 The above results show that the artificial blood vessel prepared in Example 2 did not become narrowed or expanded, and remained unobstructed throughout.

[0176] Based on the above in vivo and in vitro results, it can be seen that the zwitterion-modified polyurethane artificial blood vessels and heart valves prepared by the present invention have good mechanical properties, anti-fouling properties and anti-coagulation properties, and the prepared artificial blood vessels also have the ability to resist intimal hyperplasia and can maintain long-term patency.

[0177] The above embodiments are preferred implementation modes of the present invention, but are not limitations on the implementation modes of the present invention. Any modifications, equivalent substitutions, and combinations that do not deviate from the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for preparing an implantable artificial organ, characterized in that The method comprises: After preparing zwitterion-modified polyurethane by solution polymerization of zwitterion diol, monomer diol, diisocyanate, catalyst, chain extender and reaction solvent, the zwitterion-modified polyurethane is dissolved in the preparation solvent, and the implantable artificial organ is prepared by solution preparation.

2. The preparation method according to claim 1, wherein The method comprises: (1) subjecting a zwitterionic diol, a monomeric diol, a diisocyanate, a catalyst, and a reaction solvent to a prepolymerization reaction, and then adding a chain extender to carry out a chain extension reaction to obtain the zwitterionic modified polyurethane; (2) stirring and dissolving the zwitterion-modified polyurethane in a preparation solvent to prepare a preparation solution; (3) The prepared solution is subjected to at least one of electrospinning, 3D printing, solvent casting, salting-out, and phase separation methods to prepare the implantable artificial organ.

3. The preparation method according to claim 1 or 2, characterized in that: The structural formula of the zwitterionic diol is: Wherein, n is any integer from 1 to 50; A1 is One of the following; A2 is m0, m1, m2, m3, m4, m5, m6, m7, and m8 may be the same or different and are independently any integer from 1 to 50; Preferably, the zwitterionic diol is at least one of sulfobetaine diol, carboxybetaine diol, phosphocholine diol, sulfobetaine diol-amino, and sulfobetaine diol-(pentyloxy)amino.

4. The preparation method according to claim 1 or 2, characterized in that: The monomer diol is at least one of polyethylene glycol, polypropylene glycol, polyhexamethylene glycol, polyoctamethylene glycol, polydecamethylene glycol, polycarbonate diol, polytetrahydrofuran, polyethylene adipate diol, poly1,4-butene adipate, and polycaprolactone diol. Preferably, the number average molecular weight of the monomer diol is 1000-8000; and / or, The diisocyanate is at least one of hexamethylene diisocyanate, methylene phenyl isocyanate, m-xylylene diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, dimethyl diphenyl diisocyanate, triphenylmethane triisocyanate, tris(4-phenylisocyanate)thiophosphate, methylcyclohexyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, toluene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and L-lysine ethyl diisocyanate; and / or The catalyst is at least one of dibutyltin dilaurate (DBTDL), tin 2-ethylhexanoate, zinc isooctanoate, bismuth isooctanoate, lead isooctanoate, potassium oleate, zinc naphthenate, cobalt naphthenate, ferric acetylacetonate, phenylmercuric acetate, phenylmercuric propionate, dimethylcyclohexylamine, triethylenediamine, triethylamine, methyldicyclohexylamine, N-methylmorpholine, N-ethylmorpholine, N,N'-dimethylpiperazine, N,N'-diethylpiperazine, 1,1,3,3-tetramethylpiperidine, bis(2-dimethylaminoethyl) ether, tetramethylbutanediamine, 2,4,6-tris(dimethylaminomethyl)phenol, pentamethyldipropylenetriamine, trimethylhydroxyethylethylenediamine, dimethylethanolamine, oleic acid, azelaic acid, and adipic acid; and / or, The chain extender is 1,4-butanediol, 1,2-propylene glycol, methylpropylene glycol, diethylene glycol, 1,4-cyclohexanol, neopentyl glycol, 1,4-cyclohexanediamine, ethylene glycol, 1,4-diaminobutane, hydroquinone dihydroxyethyl ether, resorcinol dihydroxyethyl ether, N-methyldiethanolamine, 3,3'-dichloro-4,4'-diaminophenylmethane, diethyltoluenediamine, 4,4'-methylene-bis(3-chloro-2,6-diethylaniline), bis-sec-butylaminodiphenylmethane, 1,6-hexanediol, ethylenediamine, 1,3-propylene glycol-bis(4-aminobenzoate), 3,5-dimethylthiotoluenediamine, 3,5-diamino-4-chlorobenzoic acid isobutyl ester, bis(4 At least one of 1,2-diamino-3,4-diphenyl)disulfide, diethylene glycol bis(4-aminobenzoate), 3,5-diamino-4-trifluoromethylphenyl ether, 3,5-diamino-4-chlorophenylacetic acid isopropyl ester, 3-amino-4-chlorobenzyl-4'-aminobenzoate, 1,4-bis(2-aminophenylthioethoxy)benzene, 1,4-bis(2-aminophenylthioethyl)benzoate, methylenebis(4-amino-3-benzoic acid methyl ester), 4,4'-methylenebis(2,6-diisopropylaniline), ethylenebis(2-aminophenyl sulfide), 4,4'-methylenebis(2,6-diethyl)aniline, and 2,4-diamino-3-methylthio-5-propyltoluene; and / or The reaction solvent is at least one of dimethyl sulfoxide, dimethylformamide, methanol, acetone, dichloromethane, tetrahydrofuran, and toluene; and / or, The preparation solvent is at least one of hexafluoroisopropanol, dimethylformamide, dichloromethane, tetrahydrofuran, trifluoroethanol, methyl ethyl ketone, dimethylacetamide, 1,4-dioxane, trifluoroacetic acid, and chloroform.

5. The preparation method according to claim 1 or 2, characterized in that: The molar ratio of the zwitterionic diol to the monomeric diol is (0.1-20):1, preferably (0.5-5):1; The molar ratio of the sum of the moles of the zwitterionic diol and the monomeric diol, the diisocyanate, and the chain extender is 1:(0.1-3):(0.1-3), preferably 1:(1-2):(1-2); The mass ratio of the sum of the mass of the zwitterionic diol and the monomeric diol to the mass of the catalyst is (150-2500):1, preferably in the range of (1000-1500):1; The mass ratio of the sum of the mass of the zwitterionic diol and the monomeric diol to the reaction solvent is 1:(2-30), preferably in the range of 1:(10-20); The concentration of the zwitterion-modified polyurethane after being dissolved in the preparation solvent is 5%-30% w / v, preferably 8%-25% w / v.

6. The preparation method according to claim 2, wherein: In step (1), The reaction temperature of the prepolymerization reaction is 25-120° C., and / or the reaction time is 20 min-10 h; and / or, The reaction temperature of the chain extension reaction is 25-120° C., and / or the reaction time is 20 min-100 h.

7. The preparation method according to claim 2, wherein: In step (2), the stirring temperature is 15-80° C., and / or the stirring time is 10-240 h.

8. The preparation method according to claim 2, wherein: In step (3), The receiver for electrospinning is a tubular receiver or a drum receiver, and the tubular receiver is preferably a tubular receiver of 1-6 mm, and / or the voltage for electrospinning is 8-25 kV, and / or the receiving distance is 5-25 cm, and / or the receiver speed is 50-1500 rpm, and / or the speed of the syringe pump is 0.5-2 ml / h; and / or, The 3D printing parameters are: printing speed 5-15 mm / s, and / or, extrusion speed 0.08-0.1 mm / s, and / or, printing temperature 100-500° C., and / or, platform temperature 30-50° C., and / or, layer height 0.1-0.3 mm.

9. An implantable artificial organ produced by the preparation method according to any one of claims 1 to 8.

10. Use of an implantable artificial organ prepared by the preparation method according to any one of claims 1 to 8 or the implantable artificial organ according to claim 9 as a substitute for autologous blood vessels or heart valves.

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