Composite polyester material as well as preparation method and application thereof

Abstract

The invention discloses a composite polyester material and a preparation method and application thereof, the composite hydrogel material comprises a high-molecular polymer and asymmetric Mg particles dispersed in the high-molecular polymer, and the asymmetric Mg particles comprise Mg particles and biodegradable polyester coating one side of the Mg particles. The composite hydrogel material has acid responsiveness, can slowly release hydrogen and Mg ions through the reaction of the asymmetric Mg (magnesium) particles and gastric acid, can be applied to medical stents, and can provide a continuous treatment effect.

Description

Technical Field

[0001] The present invention relates to the field of pharmaceutical technology, and particularly to a composite polyester material, a preparation method thereof, and an application thereof. Background Art

[0002] Existing esophageal stents are widely used in the treatment of diseases such as esophageal stenosis and gastroesophageal reflux disease (GERD). Especially in patients with reflux esophagitis, the esophageal stent physically supports the esophagus to help restore esophageal patency. However, most existing esophageal stents have certain limitations. Especially in the treatment of esophageal inflammation caused by gastric acid reflux, the problem still cannot be fundamentally solved.

[0003] Currently, common esophageal stents on the market mostly use metal materials such as stainless steel or nitinol. Although these metal stents perform well in terms of esophageal patency, they often cause discomfort and a series of complications when implanted in the body for a long time. The rigidity and relatively hard material of the metal stent often lead to friction between the stent and the esophageal wall, thereby causing a foreign body sensation, pain, or discomfort during swallowing. This discomfort will worsen over time, especially when patients need to use the stent for a long time. The foreign body sensation and discomfort will greatly affect the quality of life of the patients. In addition, the fixation of the metal stent in the esophagus may not be as expected. During long-term use, the stent is prone to displacement or detachment, causing further damage or discomfort to the esophagus. More importantly, the long-term presence of the metal stent may cause mechanical friction with the esophageal wall, resulting in damage, ulcers, or even bleeding of the esophageal mucosa. Some patients may even be at risk of infection, especially in the later stage of the implantation surgery. In addition, the hardness and rigidity of the metal stent may affect the natural peristaltic function of the esophagus, thereby causing dysphagia or food retention, which further exacerbates the discomfort and related complications.

[0004] On the other hand, although existing metal stents play a certain role in supporting the esophageal structure, they do not consider the continuous stimulation and inflammatory effect of gastric acid reflux on the esophagus. Traditional metal stents do not have the function of producing therapeutic effects. They cannot react with gastric acid or release substances with therapeutic effects, so they can only play a simple supporting role. Although some stents adopt a drug coating or drug carrier design in an attempt to release drugs to relieve symptoms, this design still has significant deficiencies. For example, the release rate of the drug is usually uneven and cannot provide a continuous and stable therapeutic effect. In addition, the treatment time of the drug-coated or drug-loaded stent is limited, and the drug efficacy may weaken after being used for a period of time. Patients still need to rely on drug treatment, and the problems of gastric acid reflux and esophageal inflammation cannot be fundamentally solved. Summary of the Invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems in the prior art. To this end, the object of the present invention is to provide a composite polyester material, a preparation method thereof, and an application thereof.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect of the present invention, there is provided a composite hydrogel material, comprising a polymer and asymmetric Mg particles dispersed in the polymer, wherein the asymmetric Mg particles comprise Mg particles and a biodegradable polyester coated on one side of the Mg particles.

[0008] In the present invention, a biodegradable polyester is coated on one side of the Mg particles to endow it with acid-responsive function, and a concave hole structure is formed on the uncoated side as the reaction interface between the Mg particles and the outside world. By reacting the Mg particles with gastric acid, hydrogen and Mg ions are continuously released, thereby treating inflammation and providing a continuous therapeutic effect.

[0009] In some embodiments of the present invention, the polymer comprises at least one of polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacrylic acid (PAA), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), and sodium alginate.

[0010] In some embodiments of the present invention, the molecular weight of the polymer is 100,000 - 200,000, such as 120,000 - 180,000.

[0011] In some embodiments of the present invention, the biodegradable polyester comprises at least one of poly(D,L-lactic acid-co-glycolic acid) (PLGA), polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), or polyhydroxybutyrate (PHB).

[0012] In some embodiments of the present invention, in the composite hydrogel material, the mass ratio of the polymer to the asymmetric Mg particles is 1:(0.5 - 3).

[0013] In some embodiments of the present invention, the mass fraction of Mg in the asymmetric Mg particles is 80 - 96 wt%, such as 85 - 95 wt%, 88 - 93 wt%, etc.

[0014] In some embodiments of the present invention, the average particle size of the asymmetric Mg particles is 18 - 28 μm, for example, 20 - 26 μm, 21 - 25 μm.

[0015] In some embodiments of the present invention, in the asymmetric Mg particles, the average particle size of the Mg particles is 12 - 18 μm, for example, 13 - 17 μm.

[0016] In some embodiments of the present invention, the other side of the asymmetric Mg particles has a concave structure, and the concave structure is at least partially distributed with pores in an amount of 5% to 90% (10% to 70%, 10% to 50%, 20% to 40%); the average diameter of the concave structure is 350 to 470 nm, such as 353 to 470 nm; the average diameter of the pores is 5 to 15 μm, for example 8 to 13 μm.

[0017] In some embodiments of the present invention, the composite hydrogel material has a porous network structure, and the average diameter of the pores is 100 to 400 nm.

[0018] In some embodiments of the present invention, the composite hydrogel material is further loaded with a drug.

[0019] In some embodiments of the present invention, the drug includes at least one of an anti-inflammatory agent, an antifungal agent, a cell growth inhibitor, a cytotoxic agent, an anti-proliferative agent, an anti-tubulin agent, an anti-angiogenic agent, an anti-restenosis agent, an antifungal agent, an anti-tumor agent, an anti-migration agent, a non-thrombogenic agent, and / or an anti-thrombogenic agent.

[0020] In some embodiments of the present invention, the drug includes at least one of sodium heparin, batroxobin, antithrombotic enzyme, aspirin, hirudin, colchicine, rapamycin, Everolimus, Biolimus, Zotarolimus, Tracrolimus, atorvastatin, pravastatin, cyclosporine, Anti-CD34, dexamethasone, bleomycin, plicamycin, mitomycin C, actinomycin D, paclitaxel, celastrol, methotrexate.

[0021] In some embodiments of the present invention, the anti-inflammatory agent includes at least one of melatonin, acetylsalicylic acid, indomethacin, piroxicam, sulindac, celecoxib, nimesulide, etodolac, meloxicam, ibuprofen, paracetamol, diclofenac, naproxen, phenylbutazone, nabumetone, hydrocortisone, cortisone, prednisone, prednisolone, methylprednisolone, triamcinolone, dexamethasone, betamethasone, betamethasone dipropionate, budesonide, fluticasone propionate, ciclesonide, hydrocortisone acetate, methylprednisolone acetate, prednisone acetate, dexamethasone acetate, betamethasone butyrate, triamcinolone acetonide, triamcinolone acetonide acetate, hydrocortisone butyrate, diflorasone diacetate, halometasone, clobetasol propionate.

[0022] In some embodiments of the present invention, the antifungal agent includes at least one of amphotericin B, miconazole, ketoconazole, itraconazole, fluconazole, terbinafine, mepartricin, griseofulvin, ciclopirox olamine, nystatin, naftifine, amorolfine, clotrimazole, econazole, chlorhexidine acetate, domiphen bromide.

[0023] The second aspect of the present invention provides a method for preparing the composite hydrogel material, comprising the following steps:

[0024] Coat a biodegradable polyester on one side of Mg particles to obtain asymmetric Mg particles, and then add the asymmetric Mg particles into a polymer solution and freeze-dry to obtain the composite hydrogel material.

[0025] In some embodiments of the present invention, coat an adhesive on a substrate, disperse Mg particles on the adhesive, and then coat a biodegradable polyester on one side of the Mg particles to obtain asymmetric Mg particles.

[0026] In some embodiments of the present invention, the mass concentration of the polymer solution is 15-35 wt%, such as 20-30 wt%, 22-27 wt%.

[0027] In some embodiments of the present invention, the mass concentration of the asymmetric Mg particles in the polymer solution is 5-45 mg / mL.

[0028] In some embodiments of the present invention, the temperature of the freeze-drying is -40 to -10 °C (such as -30 to -15 °C), and the time is 20 to 168 h.

[0029] In some embodiments of the present invention, the freeze-drying is first carried out for 20 to 36 h, then restored to 20 to 35 °C for 20 to 36 h, and these are alternated and repeated 3 to 8 times.

[0030] The third aspect of the present invention provides a medical stent, comprising the composite hydrogel material.

[0031] In some embodiments of the present invention, the preparation method of the medical stent includes being prepared by using the composite hydrogel material.

[0032] In some embodiments of the present invention, the preparation method of the medical stent includes injecting a polymer solution containing asymmetric Mg particles into a mold and freeze-drying to obtain the medical stent.

[0033] In some embodiments of the present invention, the medical stent includes any one of an esophageal stent, a vascular stent, an airway stent, a biliary stent, and a urethral stent.

[0034] In some embodiments of the present invention, the esophageal stent includes an upper flared opening, a middle main tube, and a lower flared opening;

[0035] The upper flared opening is arranged at the upper pipe orifice of the middle main tube, and the lower flared opening is arranged at the lower pipe orifice of the middle main tube;

[0036] A plurality of wavy circumferential convex ribs are arranged on the outer wall surface of the esophageal stent.

[0037] In some embodiments of the present invention, the middle main tube is circular tube-shaped and has no perforated structure on the tube wall. The height of the middle main tube is 7 - 15 mm (such as 7 - 12 mm), the inner diameter of the middle main tube is 1.7 - 2.7 mm, and the wall thickness of the middle main tube is 0.5 mm - 0.8 mm.

[0038] In some embodiments of the present invention, the maximum inner diameter of the upper flared opening and the lower flared opening is 2.5 - 5 mm, the height of the upper flared opening and the lower flared opening is 3 - 6 mm, and the wall thickness of the upper flared opening and the lower flared opening is 0.8 - 1.2 mm.

[0039] In some embodiments of the present invention, the cross-section of the wavy circumferential convex rib is semi-circular or semi-elliptical, the convex height of the wavy circumferential convex rib is 0.5 - 0.8 mm, and the distance between adjacent two convex ribs is 1.5 - 4 mm.

[0040] The beneficial effects of the present invention are:

[0041] 1. The composite hydrogel material of the present invention has acid responsiveness and can also slowly release hydrogen and Mg ions through the reaction of asymmetric Mg (magnesium) particles with gastric acid.

[0042] 2. Compared with traditional metal stents, the medical stent of the present invention uses a softer and better biocompatible composite hydrogel material, which can effectively reduce the friction with the esophageal wall, avoid complications such as infection and displacement that may be brought by metal stents, and has better safety and comfort. In addition, the medical stent can also slowly and stably release hydrogen and Mg ions, providing a continuous therapeutic effect.

[0043] 3. The medical stent of the present invention forms an obvious pore network, which is beneficial to cell adhesion and proliferation, and is also beneficial to the application of the medical stent in hydrogen and drug delivery. On the other hand, through the test of different drug loading amounts and release kinetics of the medical stent, it is found that the composite hydrogel material can allow different types of drugs to be loaded and exhibits good controlled release effects.

[0044] 4. The preparation method of the medical stent of the present invention avoids the residues of organic solvents and porogens, has a safer biological evaluation, a simpler preparation process, lower costs, and is more suitable for clinical applications; in particular, the esophageal stent can be used for reflux esophagitis. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic flow chart of the preparation of the asymmetric Mg particles of the present invention.

[0046] Figure 2 It is a scanning electron microscope characterization diagram of the asymmetric Mg particles of the present invention.

[0047] Figure 3 It is a schematic flow chart of the preparation of the personalized hydrogel stent of the present invention; wherein, A is a schematic diagram of the preparation of the Mg@PLGA-PVA solution; B is the 3D printing mold in the embodiment; C is a schematic flow chart of the preparation of the intelligent responsive PVA hydrogel stent in the embodiment of the present invention.

[0048] Figure 4 It is a picture of the asymmetric Mg (magnesium) particle-PVA esophageal stents prepared in Example 1 (upper), Example 2 (middle), and Comparative Example 1 (lower) of the present invention.

[0049] Figure 5 It is a scanning electron microscope characterization diagram of the asymmetric Mg (magnesium) particle-PVA stent in Example 1 of the present invention.

[0050] Figure 6 It is a picture of the X-ray diffraction result of the asymmetric Mg (magnesium) particle-PVA stent in Example 1 of the present invention.

[0051] Figure 7 It is a DSC curve of the thermal performance of the asymmetric Mg (magnesium) particle-PVA esophageal stents prepared in Example 1, Example 2, and Comparative Example 1 of the present invention.

[0052] Figure 8 It is a TGA curve of the thermal performance of the asymmetric Mg (magnesium) particle-PVA esophageal stents prepared in Example 1, Example 2, and Comparative Example 1 of the present invention.

[0053] Figure 9 It is the mechanical properties of the asymmetric Mg (magnesium) particle-PVA esophageal stents prepared in Examples 1 to 3 and Comparative Example 1 of the present invention; wherein, A is the tensile test curve, B is the Young's modulus, C is the tensile strength, D is the compression test curve, E is the compression tangent modulus curve, and F is the cyclic tensile test curve.

[0054] Figure 10Rheological test curves of the mechanical properties of the asymmetric Mg (magnesium) particle-PVA esophageal stents prepared in Example 1, Example 2, and Comparative Example 1 of the present invention; wherein, A is the elastic response characteristic curve, B is the curve of the storage modulus varying with time, and C is the viscoelastic characteristic curve.

[0055] Figure 11 Hydrogen release behavior of the asymmetric Mg (magnesium) particle-PVA esophageal stent prepared in Example 1 of the present invention.

[0056] Figure 12 Mg ion release behavior of the asymmetric Mg (magnesium) particle-PVA esophageal stent prepared in Example 1 of the present invention.

[0057] Figure 13 Dexamethasone release behavior of the esophageal stents in Example 5 and Comparative Example 3 of the present invention.

[0058] Figure 14 CCK-8 results of the asymmetric Mg (magnesium) particle-PVA esophageal stents prepared in Examples 1 to 3 and Comparative Example 1 of the present invention.

[0059] Figure 15 CCK-8 live and dead cell staining results of the asymmetric Mg (magnesium) particle-PVA esophageal stents prepared in Examples 1 to 3 and Comparative Example 1 of the present invention (data are mean ± SD, n = 3; scale bar: 100 μm).

[0060] Figure 16 Results of the quantitative determination of inflammatory factor levels in cells by enzyme-linked immunosorbent assay (ELISA) of the present invention (one-way ANOVA: *p < 0.05, **p < 0.01, ***p < 0.001; data are mean ± SD, n = 3; scale bar: 20 μm).

[0061] Figure 17 Results of the determination of the messenger RNA (mRNA) expression levels of inflammatory factors in cells by real-time fluorescence quantitative PCR of the present invention (one-way ANOVA: *p < 0.05, **p < 0.01, ***p < 0.001; data are mean ± SD, n = 3; scale bar: 20 μm).

[0062] Figure 18 Histological staining pictures of rats at each stage of the present invention (RE group: blue arrows indicate epithelial erosion and necrosis; green arrows point to infiltrating inflammatory cells; orange arrows indicate collagen fibers exposed in the lamina propria; scale bar: 50 μm).

[0063] Figure 19 Esophageal pictures of rats at each stage of the present invention.

[0064] Figure 20Results of the determination of the levels of inflammatory factors in the esophagus of rats by fluorescence real-time PCR analysis of the present invention (one-way ANOVA: *p < 0.05, **p < 0.01, ***p < 0.001; data are mean ± SD, n = 3; scale bar: 50 μm).

[0065] Figure 21 Staining results of immunohistochemistry of the esophagus of rats of the present invention (scale bar: 50 μm).

[0066] Figure 22 ROS staining, MPO staining and CD68 / CD206 double staining results of the esophageal tissues of rats of the present invention (scale bar: 20 μm). Detailed implementation manners

[0067] The content of the present invention will be further described in detail through specific examples below. The raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial channels or can be obtained by existing technical methods without special instructions. Unless otherwise specified, the test or measurement methods are conventional methods in the art.

[0068] In the following examples or comparative examples, the structure of the hydrogel scaffold is as follows:

[0069] The esophageal stent includes an upper flared opening, a middle main tube and a lower flared opening;

[0070] The upper flared opening is arranged at the upper pipe orifice of the middle main tube, and the lower flared opening is arranged at the lower pipe orifice of the middle main tube;

[0071] A plurality of wavy circumferential convex ribs are arranged on the outer wall surface of the esophageal stent.

[0072] The middle main tube is cylindrical and has no pore structure on the tube wall. The height of the middle main tube is 9 mm, the inner diameter of the middle main tube is 2 mm, and the wall thickness of the middle main tube is 0.6 mm to 0.7 mm.

[0073] The maximum inner diameters of the upper flared opening and the lower flared opening are 3 mm to 4 mm, the heights of the upper flared opening and the lower flared opening are both 4.5 mm, and the wall thicknesses of the upper flared opening and the lower flared opening are 0.8 mm to 1 mm.

[0074] The cross section of the wavy circumferential convex rib is semi-circular or semi-elliptical. The convex height of the wavy circumferential convex rib is 0.5 mm to 0.8 mm, and the distance between adjacent two convex ribs is 1.5 mm to 4 mm.

[0075] In the following examples or comparative examples, the preparation method of the asymmetric Mg (magnesium) particles is as follows:

[0076] The Mg particles were thoroughly cleaned with acetone to remove any excess MgO layer. Subsequently, a layer of polyvinylpyrrolidone (PVP) was carefully sprayed onto the glass plate to provide a base for the Mg particles. Next, the Mg particles were evenly spread on the surface of the PVP coating. Then, PLGA was carefully coated onto the surface of the Mg particles. After deposition, the asymmetric Mg (magnesium) particles were scraped off the glass plate and carefully collected.

[0077] Among them, the average diameter of the Mg particles was 15 μm; the average diameter of the asymmetric Mg (magnesium) particles was 23.32 μm; the actual content of Mg in the asymmetric Mg (magnesium) particles was approximately 91 wt%.

[0078] Figure 1 The flowchart for preparing the asymmetric Mg (magnesium) particles is shown. Figure 2 The scanning electron microscope characterization image of the asymmetric Mg (magnesium) particles is shown and Figure 6 The energy-dispersive X-ray spectroscopy results for the asymmetric Mg (magnesium) particles are shown. A perfect asymmetric spherical structure (Janus structure) can be seen, with a hole (~10 μm in diameter) on one side of the structure, which can serve as the Mg-water reaction interface for H 2 generation. At the same time, the elemental distribution of Mg from the Mg sphere and the distribution of carbon and oxygen from the shell were observed inside the micromotor, demonstrating the successful formation of the Janus structure.

[0079] Example 1

[0080] In this example, an intelligent responsive PVA hydrogel scaffold was prepared. The specific process was as follows:

[0081] S1: Referring to Figure 3 A, polyvinyl alcohol (PVA, molecular weight approximately 145000) was added to distilled water at a mass concentration of 20 wt%, stirred at room temperature for 2 hours, and heated in a water bath at 95 °C until completely dissolved. Then, the asymmetric Mg (magnesium) particles were added to the prepared PVA at a mass concentration of 20 mg / mL by stirring to obtain asymmetric Mg (magnesium) particle-PVA, which was reserved for use.

[0082] S2: Referring to Figure 3 B, a reverse mold model of the intelligent responsive PVA hydrogel scaffold was established in the computer, and the model of the reverse mold of the intelligent responsive PVA hydrogel scaffold was sliced using slicing software;

[0083] S3: The model data obtained after slicing was imported into a 3D printer (Fused Deposition Modeling, FDM). The printing speed of the 3D printer was 250 mm / s, and the processing temperature was 160 °C. A mold was printed using polylactic acid (PLA) as the material;

[0084] S4: Referencing Figure 3 C. After the 3D-printed intelligent responsive PVA hydrogel scaffold is removed after the mold is cooled and solidified, the prepared asymmetric Mg (magnesium) particle-PVA is poured into the mold of the intelligent responsive PVA hydrogel scaffold, and then it is placed in an environment of -20°C and frozen for 24 hours, and then thawed at room temperature for 24 hours. This process is repeated five times.

[0085] S5: After the intelligent responsive PVA hydrogel scaffold obtained from the mold of the intelligent responsive PVA hydrogel scaffold is solidified, it is removed to obtain an intelligent responsive PVA hydrogel scaffold, denoted as 20Mg@PLGA-PVA.

[0086] Example 2

[0087] In this example, an intelligent responsive PVA hydrogel scaffold was prepared. The preparation method refers to Example 1, except that in S1, the asymmetric Mg (magnesium) particles were added to the prepared PVA at a mass concentration of 10 mg / mL to obtain asymmetric Mg (magnesium) particle-PVA, denoted as 10Mg@PLGA-PVA.

[0088] Example 3

[0089] In this example, an intelligent responsive PVA hydrogel scaffold was prepared. The preparation method refers to Example 1, except that in S1, the asymmetric Mg (magnesium) particles were added to the prepared PVA at a mass concentration of 40 mg / mL to obtain asymmetric Mg (magnesium) particle-PVA, denoted as 40Mg@PLGA-PVA.

[0090] Example 4

[0091] In this example, an intelligent responsive PVA hydrogel scaffold was prepared. The preparation method refers to Example 2, except that step S6 was added: the intelligent responsive PVA hydrogel scaffold prepared in S5 was soaked in simulated gastric acid at pH = 1.5 for 12 hours, denoted as HCl-soaked 10Mg@PLGA-PVA.

[0092] Example 5

[0093] In this example, a PVA hydrogel containing dexamethasone was prepared. The preparation method refers to Example 1, except that in S1, 7.5 mg of dexamethasone was added to 37.5 mL of 10Mg@PLGA-PVA, denoted as 10Mg@PLGA-DXM-PVA.

[0094] Comparative Example 1

[0095] This comparative example prepared a PVA hydrogel scaffold, and its preparation method referred to Example 1, except that asymmetric Mg (magnesium) particles were not added, denoted as Pure PVA.

[0096] Figure 4 Shows pictures of the asymmetric Mg (magnesium) particle-PVA esophageal scaffolds prepared in Example 1 (upper), Example 2 (middle), and Comparative Example 1 (lower), indicating that the 3D printing personalized mold in the technical solution of the present invention can customize scaffolds of different sizes.

[0097] Comparative Example 2

[0098] This comparative example prepared a PVA hydrogel scaffold, and its preparation method referred to Example 1, except that Mg was added to the prepared PVA at a mass concentration of 9 mg / mL in S1, denoted as 9Mg-PVA.

[0099] Comparative Example 3

[0100] This comparative example prepared a dexamethasone-containing PVA hydrogel, and its preparation method referred to Comparative Example 1, except that 7.5 mg of dexamethasone was added to 37.5 mL of Pure PVA in S1, denoted as DXM-PVA.

[0101] Test Example

[0102] Figure 5 Is the scanning electron microscope characterization diagram of the asymmetric Mg (magnesium) particle-PVA scaffold in Example 1. Figure 6 Are the X-ray diffraction results of Mg, PLGA, Mg@PLGA, and Mg@PLGA-PVA in Example 1. The scanning electron microscope characterization diagram shows that the small opening structure on the surface of the micromotor not wrapped by PLGA remains intact. X-ray diffraction shows that the crystal structure of Mg particles in the asymmetric Mg (magnesium) particle-PVA remains stable and still has the ability to generate H 2 capacity.

[0103] The DSC and TGA diagrams of Example 1, Example 2, and Comparative Example 1 are as Figure 7 , Figure 8 shown, Figure 7 As shown, almost no endothermic peak caused by water evaporation was observed in Example 1, Example 2, and Comparative Example 1. In addition, as the concentration of asymmetric Mg (magnesium) particles increased, the heat released by this reaction also increased. From Figure 8It can be seen that when the temperature rises from 100 °C to 200 °C, the masses of Example 1, Example 2, and Comparative Example 1 decreased by 26.88%, 35.84%, and 58.43% respectively. This is because as the concentration of asymmetric Mg (magnesium) particles increases, the reaction between the asymmetric Mg (magnesium) particles and the water in the hydrogel increases, resulting in a decrease in the content of free water and bound water in the asymmetric Mg (magnesium) particle-PVA after freeze-thaw cycles.

[0104] To test the mechanical properties of the asymmetric Mg (magnesium) particle-PVA scaffolds, tensile and compression tests were performed on Example 1, Example 2, Comparative Example 1, and Example 4 at room temperature using a DR-603A from Dongri Instrument Co., Ltd. (Taiwan Province, China). Axial tension was carried out at a rate of 100 mm / min until the material broke, and the tensile fracture curve, maximum tensile strength, and Young's modulus were measured. For the cyclic tensile test, the sample was stretched by 50 mm at a rate of 100 mm / min for ten cycles, and the tensile cycle time curve was plotted. Then, the hydrogel sample was compressed by 6 mm at a rate of 10 mm / min for ten cycles to obtain the compression test curve and the compression tangent modulus curve. The results are as Figure 9 shown. The mechanical strength of Example 4 only decreased slightly, indicating that the asymmetric Mg (magnesium) particle-PVA scaffold can maintain stable mechanical properties in the acidic environment of reflux esophagitis. At the same time, the excellent mechanical strength of Example 1, Example 2, and Comparative Example 1 shows that the asymmetric Mg (magnesium) particle-PVA scaffold has excellent robustness and high elasticity, can maintain its shape under external forces, and can return to its original state after deformation. In addition, a rheometer was also used to perform tests such as frequency scanning, stress scanning, and alternating scanning of large and small strains on Example 1, Example 2, and Comparative Example 1 to comprehensively evaluate their viscoelasticity and mechanical properties. The results are as Figure 10 shown, further indicating that the asymmetric Mg (magnesium) particle-PVA scaffold has good self-recovery ability and anti-deformation ability.

[0105] 1.5 mL of Example 1 was placed in 10 mL of simulated body fluid and 10 mL of simulated gastric acid solution with pH = 1.5, and its hydrogen release behavior was observed. The results are as Figure 11 shown. Compared with being placed in simulated body fluid, the scaffold placed in simulated gastric acid solution has faster hydrogen release, indicating that the asymmetric Mg (magnesium) particle-PVA scaffold, as a controlled release system, can accelerate hydrogen release during gastric acid reflux. Once the gastric acid is cleared, the hydrogen release slows down or stops, thus achieving precise control of hydrogen release and prolonging the therapeutic effect. 1.5 mL of Example 1 was placed in 50 mL of simulated body fluid, 50 mL of simulated gastric acid solution with pH = 1.5, and 50 mL of simulated gastric acid solution with pH = 4, and its Mg ion release behavior was measured. The results are as Figure 12As shown, the results indicate that in simulated gastric acid with pH = 1.5, the release rate of Mg ions is the fastest, followed by simulated gastric acid with pH = 4.0, and the slowest is PBS (pH = 7.4), indicating that the asymmetric Mg (magnesium) particle-PVA scaffold also exhibits sustained and controlled release characteristics for the release of Mg ions.

[0106] Put 1.5 mL of Example 5 (containing 0.3 mg of dexamethasone) and 1.5 mL of Comparative Example 3 (containing 0.3 mg of dexamethasone) into 50 mL of PBS, and put 1.5 mL of Example 5 (containing 0.3 mg of dexamethasone) into 50 mL of simulated gastric acid solution (pH = 1.5), and observe the drug release behavior of dexamethasone. The results are as Figure 13 As shown, the results show that in PBS with pH = 7.4, the drug release rate of 10Mg@PLGA-PVA is lower than that of DXM-PVA. And the cumulative release rate of 10Mg@PLGA-PVA is 56%, lower than 68% of DXM-PVA, which indicates that the asymmetric Mg (magnesium) particle-PVA scaffold shows good controlled release effect when loading drugs. In addition, in simulated gastric acid with pH = 1.5, the drug release rate is slower, indicating that the acidic environment of reflux esophagitis helps the asymmetric Mg (magnesium) particle-PVA scaffold to release drugs slowly and continuously.

[0107] Coculture Example 1 (mass concentration of 0.1 mg / mL), Example 2 (mass concentration of 0.1 mg / mL), Comparative Example 1 (mass concentration of 0.1 mg / mL), Example 3 (mass concentration of 0.1 mg / mL) and L-929 cells (1×10 4 cells / well) in a 96-well plate for 24 and 48 hours, detect their cell proliferation by CCK-8 ratio and live-dead cell staining, measure the absorbance value at 450 nm with an enzyme-labeled instrument, and study the cytotoxicity of the asymmetric Mg (magnesium) particle-PVA esophageal stent material. The results are as Figure 14 As shown, the results show that Example 1, Example 2 and Comparative Example 1 all exhibit good biocompatibility. Compared with the control group, the cell viability of the cocultured cells in the Example 1 group and the Example 2 group increases significantly with time, indicating that an appropriate concentration of asymmetric Mg (magnesium) particle-PVA can promote cell proliferation. However, the cell viability of the Example 3 group is lower than that of the control group, which may be due to the excessive release of Mg 2+ In addition, after coculturing Example 1 (mass concentration of 0.1 mg / mL), Example 2 (mass concentration of 0.1 mg / mL), Comparative Example 1 (mass concentration of 0.1 mg / mL), Example 3 (mass concentration of 0.1 mg / mL) and L-929 cells (5×10 4 cells / well) in a 6-well plate for 24 hours, perform live-dead cell staining. The results are as Figure 15As shown, it is consistent with the above data.

[0108] The prepared Mg (0.18 mg / mL), asymmetric Mg (magnesium) microparticles (0.2 mg / mL), Example 2 (containing asymmetric Mg (magnesium) microparticles with a mass concentration of 10 mg / mL), Comparative Example 1 and Comparative Example 2 (containing magnesium microparticles with a mass concentration of 9 mg / mL) and RAW267.5 (5×10 4 cells / well) cells were co-cultured in a 12-well plate for 6 hours. The levels of inflammatory factors TNF-α, IL-1β and IL-6 in LPS-induced RAW264.7 cells were quantitatively determined by enzyme-linked immunosorbent assay (ELISA). The results are as Figure 16 shown. Compared with the Mg treatment group, the levels of TNF-α, IL-1β and IL-6 in the asymmetric Mg (magnesium) microparticle group were significantly reduced (p < 0.05). This is attributed to the motility of the asymmetric Mg (magnesium) microparticles. Although only a small amount of H 2 was released within a few hours of co-incubation of Example 2 with RAW264.7 cells, the levels of TNF-α, IL-1β and IL-6 in Example 2 were lower than those in Comparative Example 1 (p < 0.05), indicating that even a small amount of H 2 can play a certain anti-inflammatory role. In addition, the expression levels of TNF-α, IL-1β and IL-6 in the asymmetric Mg (magnesium) microparticle group were significantly lower than those in Example 2 group (p < 0.05), which can prove that the asymmetric Mg (magnesium) microparticles loaded with PVA can slowly release H 2 . The expression levels of inflammatory factors in the Comparative Example 2 group were lower than those in the Example 2 group (p < 0.05), which further showed that the PLGA coating optimized the sustained-release effect of the entire drug delivery system.

[0109] Meanwhile, the effects on the expression levels of inflammatory factor messenger RNA (mRNA) were further studied by real-time fluorescence quantitative PCR method for Mg (0.18 mg / mL), asymmetric Mg (magnesium) microparticles (0.2 mg / mL), Example 2 (containing asymmetric Mg (magnesium) microparticles with a mass concentration of 10 mg / mL), Comparative Example 1 and Comparative Example 2 (containing magnesium microparticles with a mass concentration of 9 mg / mL) and RAW264.7 cells (5×10 4 cells / well) after co-culture in a 6-well plate for 24 hours. The results are as Figure 17 shown. Compared with the asymmetric Mg (magnesium) microparticle group, the mRNA expression levels of TNF-α, IL-1β and IL-6 in the Example 2 group were higher (p < 0.05). Compared with the Example 3 group, the mRNA expression levels of TNF-α, IL-1β and IL-6 in the Example 2 group were significantly reduced (p < 0.05). These results indicate that the asymmetric Mg (magnesium) microparticle-PVA has the ability to slowly release H 2capacity, and the released H 2 was able to down-regulate the mRNA expression of TNF-α, IL-1β and IL-6 in cells after LPS induction (p < 0.05).

[0110] To evaluate the in vivo effects of the asymmetric Mg (magnesium) particle-PVA scaffold, the constructed rats in the RE group were randomly divided into 4 groups, with 5 rats in each group: control group, RE group, REST (PVA) group, and REST (asymmetric Mg (magnesium) particle-PVA) group. Seven days after the surgery, the esophagi of the rats in the REST (PVA) group and the REST (asymmetric Mg (magnesium) particle-PVA) group were implanted with Comparative Example 1 and Example 2 (containing the mass concentration of asymmetric Mg (magnesium) particles of 10 mg / mL), respectively. Twenty-one days later, the rats were sacrificed, and after taking the esophagi of the rats, histological staining was performed, and then the treatment effects were detected by fluorescence real-time PCR analysis and immunofluorescence staining, respectively.

[0111] Figure 18 、 Figure 19 The histological staining pictures and esophageal pictures of the rats at each stage are shown. It can be seen that after the treatment with the esophageal stent, the rats with reflux esophagitis almost completely recovered to the state of normal esophagus, specifically manifested as the clear visibility of each layer of the esophagus and the reconstruction of the epithelium, without the infiltration of inflammatory cells. Figure 20 The results of fluorescence real-time PCR analysis are shown. It can be seen that after the treatment with the asymmetric Mg (magnesium) particle-PVA esophageal stent, the expression levels of TNF-α and IL-1β are lower, and the expression level of IL-10 is higher, which indicates the anti-inflammatory effect of the asymmetric Mg (magnesium) particle-PVA stent, while Figure 21 The staining results of immunohistochemistry shown further corroborate the anti-inflammatory effect of the asymmetric Mg (magnesium) particle-PVA stent.

[0112] In addition, in this test example, Dihydroethidium (DHE) was also used as a fluorescent probe to detect the reactive oxygen species in the esophageal tissue cells. As Figure 22As shown, the REST (asymmetric Mg (magnesium) particle-PVA) group showed the least reactive oxygen species expression, followed by the REST (PVA) group. This indicates the potential of the asymmetric Mg (magnesium) particle-PVA hydrogel scaffold to alleviate esophageal oxidative stress. At the same time, to observe the infiltration of inflammatory cells and the differentiation of macrophages, MPO staining and CD68 / CD206 double staining were performed on the esophagi of each group. MPO is used to label neutrophils. CD68 can label infiltrating macrophages, while CD206 can specifically label M2-type macrophages. The differentiation of macrophages into the M2 type can reduce inflammation and promote tissue repair. The MPO staining results showed that the RE group showed obvious infiltration of neutrophils. In contrast, almost no neutrophil infiltration was observed in the REST (asymmetric Mg (magnesium) particle-PVA) group. This proves that the H 2 and Mg 2 + released by the asymmetric Mg (magnesium) particle-PVA hydrogel scaffold can rapidly relieve the acute inflammation of the esophagus caused by reflux. The results of CD68 / CD206 double staining showed that the proportion of M2-type cells in the REST (asymmetric Mg (magnesium) particle-PVA) group was higher than that in the REST (PVA) group, suggesting that the asymmetric Mg (magnesium) particle-PVA hydrogel scaffold can promote the differentiation of macrophages into the M2 type and accelerate the healing of damaged esophageal mucosa.

[0113] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A composite hydrogel material, characterized in that: The invention comprises a high molecular polymer and asymmetric Mg particles dispersed in the high molecular polymer. The asymmetric Mg particles comprise Mg particles and biodegradable polyester coated on one side of the Mg particles.

2. The composite hydrogel material according to claim 1, characterized in that: The high molecular polymer includes at least one of polyvinyl alcohol, polyvinyl butyral, polyacrylic acid, polyethylene oxide, polyvinyl pyrrolidone, and sodium alginate; and / or the biodegradable polyester includes at least one of poly (D, L-lactic acid-CO-glycolic acid), polylactic acid, polyglycolic acid, polycaprolactone or polyhydroxybutyrate.

3. The composite hydrogel material according to claim 1, characterized in that: In the composite hydrogel material, the mass ratio of the high molecular weight polymer to the asymmetric Mg particles is 1:(0.5-3).

4. The composite hydrogel material according to claim 1, characterized in that: The mass proportion of Mg in the asymmetric Mg particles is 80-96 wt %.

5. The composite hydrogel material according to claim 1, characterized in that: The other side of the asymmetric Mg particle presents a concave hole structure, and the average diameter of the hole is 5 to 15 μm.

6. The composite hydrogel material according to claim 1, characterized in that: The average particle size of the asymmetric Mg particles is 18-28 μm.

7. The composite hydrogel material according to claim 1, characterized in that: The composite hydrogel material is a porous network structure, and the average diameter of the pores is 100-400 nm; and / or the composite hydrogel material is also loaded with drugs.

8. A method for preparing the composite hydrogel material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Biodegradable polyester is coated on one side of the Mg particles to obtain asymmetric Mg particles, and then the asymmetric Mg particles are added to a high molecular polymer solution, and freeze-dried to obtain the composite hydrogel material.

9. The method for preparing the composite hydrogel material according to claim 8, characterized in that: The freeze drying temperature is -40 to -10°C and the time is 20 to 168 hours.

10. A medical stent comprising the composite hydrogel material according to any one of claims 1 to 7.

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