Fully-degradable arterial embolism microspheres as well as preparation method and application thereof

Abstract

The invention provides a fully-degradable arterial embolism microsphere as well as a preparation method and application thereof. The preparation method comprises the following steps: adding the degradable polymer into an organic solvent to prepare an oil phase; adding an emulsifier into water to prepare a water phase; fully emulsifying the oil phase and the water phase to form an emulsion; under a negative pressure condition, stirring the emulsion to solidify the emulsion, filtering to obtain a solid, cleaning the solid, and carrying out low-temperature vacuum drying to obtain microspheres; weighing polysaccharide and a cross-linking agent, adding the polysaccharide and the cross-linking agent into water, stirring and dissolving to obtain a polysaccharide polymer solution; and adding the microspheres into a polysaccharide polymer solution, fully infiltrating, filtering, heating and drying in vacuum to obtain the crosslinked polysaccharide shell coated microspheres. The microspheres provided by the invention can be completely degraded and metabolized in vivo, the embolism degradation effect can be maintained for 12 months, and the microspheres can be used for blood supply of embolism of prostatic artery by a minimally invasive intervention technology after carrying drugs, and can improve and treat prostate related diseases.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and specifically relates to a fully degradable arterial embolization microsphere and a preparation method and application thereof, and is particularly applicable to the preparation of drug-loaded microspheres for prostate-related diseases and for the treatment of prostate-related diseases. Background Art

[0003] At present, transurethral resection of the prostate is still the gold standard for surgical treatment of prostate hyperplasia. However, transurethral resection of the prostate requires general anesthesia, and the surgical trauma is relatively large. Because elderly patients often have heart, lung, and kidney dysfunction, general anesthesia and invasive surgery will significantly increase perioperative risks. Some elderly patients are even unable to undergo this surgery because of poor anesthesia evaluation. Not only that, the incidence of complications such as retrograde ejaculation, bleeding, and urinary tract infection after surgery is still high.

[0004] In 2000, Demeritt et al. reported a case of hematuria caused by polyvinyl alcohol particle embolization for the treatment of prostatic hyperplasia. The hematuria disappeared immediately after the operation, and in the subsequent 5-month and 12-month follow-up, it was found that the patient's prostate volume was reduced by 52% and 62% respectively compared with the initial. Since then, scholars have found that by embolizing the artery, the blood supply of the prostate tissue is reduced, and the local microcirculation is blocked, which can cause ischemia, necrosis, and absorption of the prostate parenchyma tissue, reduce the volume of the prostate, and thus relieve the obstruction symptoms. In addition, due to the reduction in blood supply, the androgen entering the prostate is reduced, and its effect of stimulating prostate cell proliferation is weakened, delaying the process of prostatic hyperplasia; at the same time, the blood supply of the nerve tissue within the embolization range is reduced, the nerve excitability is reduced, the α-receptor excitability is reduced, and the prostate smooth muscle is in a relaxed state, improving the bladder outlet obstruction. At present, there are no fully degradable microspheres specifically for the prostate artery in clinical practice. The polyvinyl alcohol microspheres currently reported for embolization of the prostate cannot be degraded and metabolized in the body, and long-term retention in the body has a potential carcinogenic risk. At the same time, if you are not familiar with the vascular anatomy during the operation and mistakenly occlude blood vessels in other parts, it will cause permanent ischemia of other organs (penile ischemia, perianal ischemia, etc.).

[0005] Therefore, it is urgent to provide a fully degradable arterial embolization microsphere, which can be used to prepare drug-loaded microspheres for prostate-related diseases and to treat prostate-related diseases. Summary of the invention

[0006] Based on the defects of the prior art, the first purpose of the present invention is to provide a method for preparing fully degradable arterial embolization microspheres; the second purpose of the present invention is to provide fully degradable arterial embolization microspheres prepared by the method; the third purpose of the present invention is to provide a method for preparing fully degradable arterial embolization drug-loaded microspheres; the fourth purpose of the present invention is to provide fully degradable arterial embolization drug-loaded microspheres prepared by the method; the fifth purpose of the present invention is to provide the use of fully degradable arterial embolization drug-loaded microspheres in the preparation of drugs for treating prostate diseases; the sixth purpose of the present invention is to provide a method for treating prostate diseases using fully degradable arterial embolization drug-loaded microspheres.

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

[0008] In one aspect, the present invention provides a method for preparing fully degradable arterial embolic microspheres, the method comprising the following steps:

[0009] Step 1: weigh a degradable polymer, add it to an organic solvent, stir and dissolve it, and obtain an oil phase; weigh an emulsifier, add it to water, heat and stir to dissolve it, and obtain an aqueous phase; slowly add the oil phase to the aqueous phase, and use a high-speed and then low-speed stirring method to fully emulsify the oil phase in the aqueous phase to form an emulsion;

[0010] Step 2, under negative pressure, stirring the emulsion to volatilize the organic solvent, solidifying the emulsion, filtering and washing the solid obtained, and drying it under low temperature vacuum to obtain microspheres;

[0011] Step three, weighing polysaccharide and cross-linking agent, adding them into water, stirring and dissolving, and obtaining a polysaccharide polymer solution; adding microspheres into the polysaccharide polymer solution to fully soak them, filtering, and heating and vacuum drying, and obtaining microspheres coated with a cross-linked polysaccharide shell.

[0012] In the above method, preferably, in step one, the degradable polymer can be selected from one or more copolymers or blended combinations of poly (L-lactic acid) (PLLA), poly (hydroxyalkanoate) (PHA), poly (racemic) lactic acid (PDLLA), polycaprolactone (PCL), polytrimethylene carbonate (PTMC), polydioxanone (PPDO), polyethylene glycol (PEG), poly (butylene succinate) (PBS), polyglycolic acid (PGA) and poly (lactic acid-glycolic acid copolymer) (PLGA), but is not limited thereto.

[0013] In the above method, preferably, in step 1, the emulsifier is selected from one or more of polyvinyl alcohol (PVA), polyethylene glycol (PEG), didodecyl dimethyl ammonium bromide (DMAB), vinyl pyrrolidone (PVP), and carboxymethyl cellulose (CMC).

[0014] In the above method, preferably, the molecular weight of the degradable polymer is 50,000 to 500,000.

[0015] In the above method, preferably, the molecular weight of the degradable polymer is 50,000 to 500,000; for example: 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000, 200,000, 210,000, 220,000, 230,000, 240,000, 250,000, 260,000, 270,000, 280,000, 290,000, 300,000, 310,000, 320,000, 330,000, 340,000, 350,000, 360,000, 370,000, 380,000, 390,000, 400,000, 410,000, 420,000, 430,000, 440,000, 450,000, 460,000, 470,000, 480,000, 490,000, and 500,000.

[0016] In the above method, preferably, in step 1, the organic solvent can be selected from one or more combinations of dichloromethane, ethyl acetate, acetone, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, chloroform and cyclohexanone, but is not limited thereto.

[0017] In the above method, preferably, in step one, in the oil phase of step one, the mass concentration of the degradable polymer is 5% to 15%; for example: 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%.

[0018] In the above method, preferably, in step 1, the speed of stirring and dissolving is 10 to 100 rpm, and the stirring time is 12 to 24 hours.

[0019] In the above method, preferably, in the aqueous phase of step one, the mass concentration of the polyvinyl alcohol is 1% to 2%; for example: 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%.

[0020] In the above method, preferably, the heating and stirring temperature is 50 to 70° C., and the stirring time is 12 to 24 hours.

[0021] In the above method, preferably, in step one, the emulsification adopts a high-speed and then low-speed stirring method, wherein the high-speed stirring speed is 1000-1500rpm, for example: 1000rpm, 1100rpm, 1200rpm, 1300rpm, 1400rpm, 1500rpm; the stirring time is 15min; the low-speed stirring speed is 100rpm, and the stirring time is 12h.

[0022] In the above method, preferably, in step 1, the volume ratio of the oil phase to the water phase is 1:5 to 1:10; for example: 1:5, 1:6, 1:7, 1:8, 1:9, 1:10.

[0023] In the above method, preferably, in step 2, the negative pressure condition is: -100 kPa to -80 kPa. Specifically, the negative pressure condition needs to be adjustable, first low and then high, until the solvent is removed to a vacuum state (-100 kPa to -80 kPa).

[0024] In the above method, preferably, in step 2, low-temperature vacuum drying is performed by freezing and vacuum drying at -80°C to -20°C.

[0025] In the above method, preferably, in step 2, the microspheres are further sieved through a sieve to obtain microspheres with a particle size of 100 to 500 μm.

[0026] In the above method, preferably, in step three, the polysaccharide can be selected from one or more combinations of sodium hyaluronate (HA), chitosan (CS), gelatin, collagen, silk fibroin, agar, carrageenan, pectin, cellulose, xanthan gum, gum arabic, dextran, sodium alginate, starch and chitin, etc.; but not limited thereto.

[0027] In the above method, preferably, in step three, the molecular weight of the polysaccharide is 800,000 to 2.5 million; for example: 800,000, 900,000, 1 million, 1.1 million, 1.2 million, 1.3 million, 1.4 million, 1.5 million, 1.6 million, 1.7 million, 1.8 million, 1.9 million, 2 million, 2.1 million, 2.2 million, 2.3 million, 2.4 million, and 2.5 million.

[0028] In the above method, preferably, in step three, the cross-linking agent can be selected from one or more combinations of glutaraldehyde, 1,4-butanediol glycidyl ether (BDDGE), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), N-hydroxysuccinimide (NHS), genipin and a photosensitive cross-linking agent, but is not limited thereto.

[0029] In the above method, preferably, in step three, the mass concentration of the polysaccharide polymer solution is 1% to 20%; for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%.

[0030] In the above method, preferably, in step three, the mass ratio of the polysaccharide to the cross-linking agent is 2:1 to 10:1; for example: 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1.

[0031] In the above method, preferably, in step three, ultrasonic infiltration is used for sufficient infiltration.

[0032] In the above method, preferably, in step three, the heating vacuum drying is vacuum drying in an oven at a temperature of 40 to 70° C. and a drying time of 3 to 12 hours.

[0033] In the above method, preferably, in step three, the microspheres coated with the cross-linked polysaccharide shell are sieved through a sieve to obtain microspheres with a particle size of 100 to 500 μm.

[0034] On the other hand, the present invention also provides a fully degradable arterial embolic microsphere, which is prepared by the above-mentioned preparation method.

[0035] In another aspect, the present invention also provides a method for preparing fully degradable arterial embolization drug-loaded microspheres, the method comprising the following steps:

[0036] According to the above method for preparing fully degradable arterial embolization microspheres, in step three, drugs are further added during the preparation of the polysaccharide polymer solution, and the other steps remain unchanged; thereby, composite drug-loaded microspheres with a core-shell structure are prepared.

[0037] In the above method, preferably, the drug can be selected from one or more combinations of 5α-reductase inhibitors, α-receptor blockers, phosphodiesterase-5 inhibitors, anticholinergic drugs and plant extract natural supplements, but is not limited thereto.

[0038] In the above method, preferably, the 5α-reductase inhibitor can be selected from one or more combinations of finasteride, dutasteride and epristeride, but is not limited thereto.

[0039] In the above method, preferably, the α-receptor blocker can be selected from one or more combinations of terazosin, doxazosin, tamsulosin, alfuzosin and silodosin, but is not limited thereto.

[0040] In the above method, preferably, the phosphodiesterase-5 inhibitor can be selected from one or more combinations of tadalafil, sildenafil, vardenafil, udenafil, avanafil and milonafil, but is not limited thereto.

[0041] In the above method, preferably, the anticholinergic drug can be selected from one or more combinations of oxybutynin, tolterodine and solifenacin, but is not limited thereto.

[0042] In the above method, preferably, the plant extract natural supplement can be selected from one or more combinations of saw palmetto, pygeum africanum and pumpkin seed oil, but is not limited thereto.

[0043] In the above method, preferably, the mass ratio of the polysaccharide to the drug is 1:1 to 5:3; for example: 1:1, 5:3, 5:4.

[0044] In another aspect, the present invention further provides a fully degradable arterial embolization drug-loaded microsphere, which is prepared by the above-mentioned preparation method.

[0045] In another aspect, the present invention also provides the use of the above-mentioned fully degradable arterial embolization drug-loaded microspheres or the fully degradable arterial embolization drug-loaded microspheres prepared by the above-mentioned preparation method in the preparation of drugs for treating prostate diseases.

[0046] In the above application, preferably, the prostate disease includes one or more of benign prostatic hyperplasia, prostatitis, prostatic cyst, prostatic calculus and prostatic abscess, but is not limited thereto.

[0047] In another aspect, the present invention also provides a method for treating prostate diseases, which comprises administering the above-mentioned fully degradable arterial embolization drug-loaded microspheres by embolization.

[0048] In the above method, preferably, the prostate disease includes one or more of benign prostatic hyperplasia, prostatitis, prostatic cyst, prostatic calculus and prostatic abscess, but is not limited thereto.

[0049] Beneficial effects of the present invention:

[0050] In the present invention, adding a polysaccharide layer is beneficial to improving the suspension and dispersibility of the microspheres during injection, and is also beneficial to tissue adhesion and wrapping after the microspheres enter the embolization site; the adhesion between the polysaccharide layer and the microspheres is improved by cross-linking, and at the same time, the outer layer of polysaccharide material is prevented from being quickly dissolved by water during injection, thereby preventing the loss of suspension and dispersion effects.

[0051] The microspheres prepared by the present invention have good elasticity and can be compressed by 70% without breaking. They are suitable for the diameter and anatomical characteristics of the prostate artery. The microspheres can embolize the blood supply of the prostate artery through minimally invasive interventional technology, causing the prostate in the hyperplastic part to necrotize and atrophy, thereby reducing the volume of the prostate and improving the dysuria of patients with prostate hyperplasia. The canine benign prostate hyperplasia model shows that after the microspheres are used to embolize the prostate artery, part of the glands in the central area of ​​the prostate tissue are significantly reduced within one week, the acinus atrophies or disappears, the ducts are sparsely distributed, the interstitial fibrous tissue proliferates, a small amount of lymphocytes and plasma cells infiltrate, and focal lymphocytes gather to form a tertiary lymphoid follicle. A small amount of embolic agent is seen in an artery on the periphery of the prostate, the arterial endothelial cells are intact, the vascular cavity is unobstructed, no thrombosis is seen, and the vascular wall tissue structure is not abnormal. The intraprostate vein and capillary structure are not abnormal. Pathological tips: embolic material is seen in the lumen of individual prostate arteries, the vascular wall structure is not abnormal, the prostate tissue is partially atrophied, accompanied by interstitial fibrous tissue hyperplasia and mild chronic inflammation.

[0052] The microspheres of the present invention can be completely degraded and metabolized in vivo, without the risk of long-term retention in the body. The degradation time of the microspheres is controllable, and the embolization effect can be effectively maintained within 6 months, and gradually degraded 6 months after embolization, and completely degraded about 12 months after embolization.

[0053] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1 This is the SEM image of the PLLA microspheres prepared in Example 1.

[0056] Figure 2 This is the SEM image of the PLLA-HA composite microspheres prepared in Example 1.

[0057] Figure 3 This is a drug release curve of the PLLA-HA composite drug-loaded microspheres prepared in Example 4.

[0058] Figure 4 This is the drug release curve of the PLLA-HA composite drug-loaded microspheres prepared in Example 5.

[0059] Figure 5 This is the drug release curve of the PLLA-HA composite drug-loaded microspheres prepared in Example 6. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The process, conditions, reagents, experimental methods, etc. for implementing the present invention, except for the contents specifically mentioned below, are all common knowledge and common common sense in the art, and the present invention does not particularly limit the contents.

[0061] definition:

[0062] The term "arterial embolization microspheres" refers to a medical device used in interventional radiology and intravascular therapy, usually made of biocompatible materials, designed to be delivered to the target blood vessel through a catheter system to block or reduce blood flow. This treatment method is called arterial embolization, which is commonly used to control bleeding, treat tumors, eliminate arteriovenous malformations, etc. The arterial embolization microspheres of the present invention can be loaded with chemotherapeutic drugs or other therapeutic drugs to achieve local release of drugs, improve the therapeutic effect and reduce systemic toxicity.

[0063] The term "fully degradable" means that the material can be completely decomposed into harmless small molecules in the body or under specific environmental conditions, and finally absorbed or excreted from the body. In the present invention, fully degradable arterial embolization microspheres refer to those microspheres that can be completely degraded and metabolized by the body within a predetermined time.

[0064] The term "core-shell structure" refers to a composite material structure with a clear core and shell. In this structure, the core (core) is wrapped by one or more layers of different materials to form a complete microsphere or particle. This structure is very useful in a variety of applications because it can combine the advantages of different materials to achieve specific functions. The core-shell structure can be used for drug delivery, controlled release, and improved biocompatibility. In the present invention, microspheres are used as the core structure, and biocompatible degradable polysaccharides are used as the shell structure for drug delivery systems. The release rate of the drug is controlled by the shell material to achieve local or systemic treatment.

[0065] The term "degradable polymers" refers to a class of polymer materials that can be gradually decomposed in the human body through hydrolysis, enzymatic hydrolysis or other biochemical processes, and eventually completely absorbed or metabolized into harmless substances by the body. This type of material is designed to temporarily block or reduce blood supply to the lesion site, thereby achieving therapeutic purposes, such as controlling bleeding, treating tumors, eliminating inflammation, and eliminating arteriovenous malformations.

[0066] The term "emulsifier" refers to a substance that can improve the surface tension between various constituent phases in an emulsion to form a uniform and stable dispersion system or emulsion. They are surfactants, and have both hydrophilic and lipophilic groups in their molecules, which enables the emulsifier to aggregate at the oil-water interface, stabilize and increase the energy of the emulsion by reducing the interfacial tension and the energy required to form the emulsion. The polyvinyl alcohol (PVA) in the present invention is a medical excipient that has been certified by the U.S. FDA for clinical use. It has the characteristics of being non-toxic, harmless, biocompatible, and can be used as a drug carrier.

[0067] The term "emulsion" refers to a mixture of two immiscible liquids, one of which is dispersed in the other in the form of tiny droplets. In the present invention, emulsion refers to a mixture of oil and water, one of which is a dispersed phase (in the form of tiny droplets) and the other is a continuous phase (droplets surrounding the dispersed phase); in particular, an emulsion is a mixture of an oil phase in which a biodegradable polymer is dissolved in an organic solvent and a water phase in which polyvinyl alcohol is dissolved in water.

[0068] The term "polysaccharides" refers to an important class of biological macromolecules, which are high-molecular compounds composed of ten or more monosaccharide units connected by glycosidic bonds. These monosaccharide units can be the same (homopolysaccharides) or different (heteropolysaccharides). Polysaccharides are widely present in nature and are one of the main components of plant, animal and microbial cell walls. Polysaccharides play a variety of important physiological roles in organisms, including energy storage, structural support, and signal transduction. In the fields of medicine and biomaterials, polysaccharides are widely used due to their good biocompatibility, degradability and multiple functionalities.

[0069] The term "crosslinking" refers to the process of connecting two or more molecules together through chemical bonds to form a more complex network structure. In the present invention, the polysaccharide is crosslinked to the embolic microspheres to form a core-shell structure, and crosslinking refers to connecting specific groups between polysaccharide molecules or between polysaccharide molecules and other materials through chemical reactions to form a stable three-dimensional network structure.

[0070] The term "curing" refers to the process of converting a material from a liquid or semi-solid state to a solid state through a physical or chemical process. In the present invention, the emulsion is stirred under negative pressure to remove the liquid components (such as organic solvents) in the emulsion, thereby forming a stable solid structure of the solid components (such as polymers or cross-linked networks) in the emulsion.

[0071] The term "Low-Temperature Vacuum Drying" refers to a drying technique performed at low temperatures (usually -20°C or lower) and under vacuum conditions. This method removes moisture from the material by freezing it below freezing point and then allowing the ice to sublime directly into water vapor in a vacuum environment. This method is particularly suitable for heat-sensitive materials and can effectively preserve the structure and activity of the material.

[0072] The term "Benign Prostatic Hyperplasia (BPH), also known as benign prostatic hyperplasia (BPH), is a common male urinary system disease that mainly occurs in middle-aged and elderly men. It refers to the non-cancerous enlargement of prostate tissue, which leads to an increase in the size of the prostate, thereby compressing the urethra and causing a series of lower urinary tract symptoms (LUTS).

[0073] The term "prostatitis" refers to inflammation of the prostate tissue and is a common male urinary system disease. Prostatitis can be caused by a variety of reasons, including bacterial infection, non-bacterial factors (such as immune response, neuromuscular dysfunction, etc.) and other unknown causes. According to the different causes and clinical manifestations, prostatitis can be divided into acute bacterial prostatitis (Acute Bacterial Prostatitis, ABP), chronic bacterial prostatitis (Chronic Bacterial Prostatitis, CBP), chronic prostatitis / chronic pelvic pain syndrome (Chronic Prostatitis / Chronic Pelvic Pain Syndrome, CP / CPPS), asymptomatic inflammatory prostatitis (Asymptomatic Inflammatory Prostatitis, AIP) and other types.

[0074] The term "prostatic cysts" refers to fluid-filled cystic structures that form within the prostate gland. These cysts are usually benign and can be congenital (related to developmental abnormalities) or acquired (caused by inflammation, infection, or other factors). Prostatic cysts can be divided into congenital prostatic cysts and acquired prostatic cysts based on their formation and location.

[0075] The term "prostatic calculi" refers to calcifications that form in the prostate tissue or prostate ducts. These stones are usually small, hard particles composed mainly of calcium phosphate, calcium oxalate or other minerals. Prostatic stones can be single or multiple and are generally considered benign.

[0076] The term "prostatic abscess" refers to a pus-filled cystic structure that forms within the prostate tissue. This abscess is usually caused by bacterial infection, resulting in inflammation, necrosis, and accumulation of pus in the local tissue. Prostatic abscess is a relatively rare but serious condition that requires prompt diagnosis and treatment to avoid complications.

[0077] The term "5α-Reductase Inhibitors" refers to a class of drugs that reduce the conversion of testosterone to dihydrotestosterone (DHT) by inhibiting the activity of 5α-reductase. 5α-reductase is the key enzyme that catalyzes the conversion of testosterone to DHT, a potent androgen that plays an important role in prostate hyperplasia and androgenic alopecia. By inhibiting this conversion process, 5α-reductase inhibitors can reduce DHT levels, thereby slowing or reversing symptoms caused by DHT.

[0078] The term "alpha-blockers" refers to a class of drugs that relax blood vessel smooth muscle and the smooth muscle of the prostate and bladder neck by blocking alpha-adrenergic receptors of the adrenergic nervous system. This action can lead to vasodilation, lower blood pressure, and improve urine flow, alleviating lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH).

[0079] The term "Phosphodiesterase Type 5 Inhibitors (PDE5 Inhibitors)" refers to a class of drugs that increase the level of intracellular cyclic guanosine monophosphate (cGMP) by selectively inhibiting the activity of phosphodiesterase-5 (PDE5). cGMP is an important second messenger molecule that plays a key role in the smooth muscle relaxation process. PDE5 inhibitors inhibit the activity of PDE5 and prevent the decomposition of cGMP, thereby increasing the concentration of cGMP, promoting smooth muscle relaxation and vasodilation, enhancing the ability of blood flow to enter the corpus cavernosum of the penis, and helping to achieve and maintain an erection; in addition, they can be used to improve lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH).

[0080] The term "anticholinergic drugs" refers to a class of drugs that can block the effects of acetylcholine (ACh) in the nervous system. Acetylcholine is an important neurotransmitter that mainly plays a role in the central nervous system and peripheral nervous system. Anticholinergic drugs bind to acetylcholine receptors and prevent the interaction between acetylcholine and its receptors, thereby producing a series of pharmacological effects. They are used to treat overactive bladder (OAB) and reduce symptoms such as urgency, frequency and incontinence.

[0081] The term "Plant Extracts and Natural Supplements" refers to active ingredients or mixtures extracted from plants that are used to supplement diet, improve health or treat specific diseases. These supplements usually contain a variety of bioactive compounds, such as flavonoids, saponins, fatty acids, polyphenols, etc., and have multiple biological activities such as antioxidant, anti-inflammatory, and immunomodulatory. In the field of prostate health, saw palmetto, African pygeum and pumpkin seed oil are several common plant extract natural supplements. Saw palmetto extract is often used to treat benign prostatic hyperplasia (BPH), which can relieve symptoms such as frequent urination, urgency, and increased nocturia. It has a certain anti-inflammatory effect and helps relieve prostate inflammation. African pygeum extract is often used to treat BPH, which can improve urine flow and reduce prostate volume. It has anti-inflammatory and antioxidant effects and helps relieve prostate inflammation. Pumpkin seed oil is believed to help maintain prostate health and can relieve the symptoms of BPH.

[0082] Embodiment 1:

[0083] This embodiment provides a PLLA-HA composite microsphere with a core-shell structure and a preparation method thereof, and the specific steps are as follows:

[0084] (1) Weigh 10 g of poly (L-lactic acid) (PLLA) with a weight average molecular weight of 200,000, add it to 100 mL of dichloromethane, and stir and dissolve it at 100 rpm for 24 h until it is uniformly dissolved to obtain a PLLA organic solution with a mass concentration of 10% as the oil phase.

[0085] (2) Weigh 2 g of polyvinyl alcohol (PVA) and add it to 100 mL of water. Heat and stir at 70° C. for 24 h to dissolve the mixture, and obtain a uniform PVA aqueous solution with a mass concentration of 2%. After cooling, the solution is used as the aqueous phase.

[0086] (3) Emulsification and solidification: The oil phase in step (1) was slowly added to the stirred water phase, with the volume ratio of the oil phase to the water phase being 1:10. The mixture was first stirred at a high speed of 1000-1500 rpm for 15 min, and then stirred at a low speed of 100 rpm for 12 h. After standing, the PLLA microspheres were collected.

[0087] (4) Weigh 0.5 g of sodium hyaluronate with a molecular weight of 1 million to 1.5 million and add it to 10 mL of water. Stir for 2 h until it is completely dissolved. Then add 0.25 g of 1,4-butanediol glycidyl ether and stir for 15 min to obtain a mixed solution. Add PLLA microspheres to the mixed solution, and collect the composite microspheres after ultrasonic infiltration.

[0088] (5) The composite microspheres were placed in a 50° C. oven under vacuum and dried for 5 h until the mass remained unchanged, so that the sodium hyaluronate formed a cross-linked composite layer outside the PLLA microspheres. The PLLA-HA composite microspheres with a sodium hyaluronate core-shell structure were collected after being sieved through a 150-mesh sieve.

[0089] The PLLA microspheres and PLLA-HA composite microspheres prepared in Example 1 were subjected to scanning electron microscopy experiments. The experimental results are shown in FIG. Figure 1 and Figure 2 As shown, Figure 1 is a SEM image of the PLLA microspheres prepared in Example 1; Figure 2 This is the SEM image of the PLLA-HA composite microspheres prepared in Example 1.

[0090] Depend on Figure 1 and Figure 2 It can be seen that the surface of PLLA-HA composite microspheres is cross-linked with a polysaccharide shell, while the surface of PLLA microspheres is smooth.

[0091] The PLLA microspheres and PLLA-HA composite microspheres were subjected to sedimentation experiments, specifically:

[0092] Different microspheres were dispersed in physiological saline and their sedimentation time was tested using a multiple light scattering instrument at 25°C. The experimental results showed that the sedimentation time of ordinary microspheres was 15 seconds, and the sedimentation time of composite microspheres was 120 seconds.

[0093] It can be seen that the hydrophilicity of PLLA-HA composite microspheres is improved compared with ordinary PLLA microspheres. When added with physiological saline during clinical use, the composite microspheres are more conducive to dispersion and do not aggregate and clog the needle. The suspension of microspheres is improved: after being mixed evenly in physiological saline, the sedimentation time is increased from 15s to 120s.

[0094] Embodiment 2:

[0095] This embodiment provides a PLLA-CS composite microsphere with a core-shell structure and a preparation method thereof, and the specific steps are as follows:

[0096] (1) Weigh 10 g of poly (L-lactic acid) (PLLA) with a weight average molecular weight of 200,000, add it to 100 mL of dichloromethane, and stir and dissolve it at 100 rpm for 24 h until it is uniformly dissolved to obtain a PLLA organic solution with a mass concentration of 10% as the oil phase.

[0097] (2) Weigh 2 g of polyvinyl alcohol (PVA) and add it to 100 mL of water. Heat and stir at 70° C. for 24 h to dissolve the mixture, and obtain a uniform PVA aqueous solution with a mass concentration of 2%. After cooling, the solution is used as the aqueous phase.

[0098] (3) Emulsification and solidification: The oil phase in step (1) was slowly added to the stirred water phase, with the volume ratio of the oil phase to the water phase being 1:10. The mixture was first stirred at a high speed of 1000-1500 rpm for 15 min, and then stirred at a low speed of 100 rpm for 12 h. After standing, the PLLA microspheres were collected.

[0099] (4) Weigh 0.5 g of chitosan (CS) with a molecular weight of 1 million to 1.5 million and add it to 10 mL of 1% acetic acid aqueous solution, stir for 2 h until completely dissolved, then add 0.05 g of glutaraldehyde and stir for 15 min to obtain a mixed solution; add PLLA microspheres to the above mixed solution, and collect the composite microspheres after ultrasonic infiltration.

[0100] (5) The composite microspheres were placed in a 50°C oven and vacuum dried for 5 h until the mass remained unchanged, so that chitosan formed a cross-linked composite layer outside the PLLA microspheres. The PLLA-CS composite microspheres with a chitosan core-shell structure were collected after being sieved through a 150-mesh sieve.

[0101] Embodiment 3:

[0102] This embodiment provides a PLLA-gelatin composite microsphere with a core-shell structure and a preparation method thereof, and the specific steps are as follows:

[0103] (1) Weigh 10 g of poly (L-lactic acid) (PLLA) with a weight average molecular weight of 200,000, add it to 100 mL of dichloromethane, and stir and dissolve it at 100 rpm for 24 h until it is uniformly dissolved to obtain a PLLA organic solution with a mass concentration of 10% as the oil phase.

[0104] (2) Weigh 2 g of polyvinyl alcohol (PVA) and add it to 100 mL of water. Heat and stir at 70° C. for 24 h to dissolve the mixture, and obtain a uniform PVA aqueous solution with a mass concentration of 2%. After cooling, the solution is used as the aqueous phase.

[0105] (3) Emulsification and solidification: The oil phase in step (1) was slowly added to the stirred water phase, with the volume ratio of the oil phase to the water phase being 1:10. The mixture was first stirred at a high speed of 1000-1500 rpm for 15 min, and then stirred at a low speed of 100 rpm for 12 h. After standing, the PLLA microspheres were collected.

[0106] (4) Weigh 0.5 g of gelatin with a molecular weight of 100,000 and add it to 10 mL of water. Heat at 50° C. and stir for 2 h until completely dissolved. After cooling, add 0.05 g of glutaraldehyde and stir for 15 min to obtain a mixed solution. Add PLLA microspheres to the mixed solution, and collect the composite microspheres after ultrasonic infiltration.

[0107] (5) The composite microspheres were placed in a 50°C oven under vacuum drying for 5 h until the mass remained unchanged, so that gelatin formed a cross-linked composite layer outside the PLLA microspheres. The PLLA-gelatin composite microspheres with a gelatin core-shell structure were collected after being sieved through a 150-mesh sieve.

[0108] Embodiment 4:

[0109] This embodiment provides a core-shell structure of PLLA-HA drug-loaded composite microspheres and a preparation method thereof, and the specific steps are as follows:

[0110] (1) Weigh 10 g of poly (L-lactic acid) (PLLA) with a weight average molecular weight of 200,000, add it to 100 mL of dichloromethane, and stir and dissolve it at 100 rpm for 24 h until it is uniformly dissolved to obtain a PLLA organic solution with a mass concentration of 10% as the oil phase.

[0111] (2) Weigh 2 g of polyvinyl alcohol (PVA) and add it to 100 mL of water. Heat and stir at 70° C. for 24 h to dissolve the mixture, and obtain a uniform PVA aqueous solution with a mass concentration of 2%. After cooling, the solution is used as the aqueous phase.

[0112] (3) Emulsification and solidification: The oil phase in step (1) was slowly added to the stirred water phase, with the volume ratio of the oil phase to the water phase being 1:10. The mixture was first stirred at a high speed of 1000-1500 rpm for 15 min, and then stirred at a low speed of 100 rpm for 12 h. After standing, the PLLA microspheres were collected.

[0113] (4) Weigh 0.5 g of sodium hyaluronate with a molecular weight of 800,000 and add it to 10 mL of water. Stir for 2 h until it is completely dissolved. Add 0.3 g of tamsulosin, then add 0.15 g of 1,4-butanediol glycidyl ether and stir for 15 min to obtain a mixed solution. Add PLLA microspheres to the mixed solution, and collect the composite drug-loaded microspheres after ultrasonic infiltration.

[0114] (5) The composite drug-loaded microspheres were placed in a 50°C oven and vacuum dried for 5 h until the mass remained unchanged, so that sodium hyaluronate formed a cross-linked composite layer outside the PLLA microspheres. The PLLA-HA composite drug-loaded microspheres with a sodium hyaluronate core-shell structure were collected after being sieved through a 150-mesh sieve.

[0115] Weigh 2 g of the above-mentioned drug-loaded microspheres into a sample bottle, add 500 mL of phosphate buffer, and place it in a 37°C constant temperature inspection box. Take samples every day and use high performance liquid chromatography to test the drug concentration in the solution and calculate the drug release amount.

[0116] The drug release curve of the PLLA-HA composite drug-loaded microspheres is as follows Figure 3 As shown by Figure 3 It can be seen that in addition to increasing the hydrophilic suspension, the drug can be stably released for 7 days.

[0117] Embodiment 5:

[0118] This embodiment provides a core-shell structure of PLLA-HA drug-loaded composite microspheres and a preparation method thereof, and the specific steps are as follows:

[0119] (1) Weigh 10 g of poly (L-lactic acid) (PLLA) with a weight average molecular weight of 200,000, add it to 100 mL of dichloromethane, and stir and dissolve it at 100 rpm for 24 h until it is uniformly dissolved to obtain a PLLA organic solution with a mass concentration of 10% as the oil phase.

[0120] (2) Weigh 2 g of polyvinyl alcohol (PVA) and add it to 100 mL of water. Heat and stir at 70° C. for 24 h to dissolve the mixture, and obtain a uniform PVA aqueous solution with a mass concentration of 2%. After cooling, the solution is used as the aqueous phase.

[0121] (3) Emulsification and solidification: The oil phase in step (1) was slowly added to the stirred water phase, with the volume ratio of the oil phase to the water phase being 1:10. The mixture was first stirred at a high speed of 1000-1500 rpm for 15 min, and then stirred at a low speed of 100 rpm for 12 h. After standing, the PLLA microspheres were collected.

[0122] (4) Weigh 0.5 g of sodium hyaluronate with a molecular weight of 1 million to 1.5 million and add it to 10 mL of water. Stir for 2 h until it is completely dissolved. Add 0.5 g of finasteride, then add 0.25 g of 1,4-butanediol glycidyl ether and stir for 15 min to obtain a mixed solution. Add PLLA microspheres to the mixed solution, and collect the composite drug-loaded microspheres after ultrasonic infiltration.

[0123] (5) The composite drug-loaded microspheres were placed in a 50°C oven and vacuum dried for 5 h until the mass remained unchanged, so that sodium hyaluronate formed a cross-linked composite layer outside the PLLA microspheres. The PLLA-HA composite drug-loaded microspheres with a sodium hyaluronate core-shell structure were collected after being sieved through a 150-mesh sieve.

[0124] Weigh 2 g of the above-mentioned drug-loaded microspheres into a sample bottle, add 500 mL of phosphate buffer, and place it in a 37°C constant temperature inspection box. Take samples every day and use high performance liquid chromatography to test the drug concentration in the solution and calculate the drug release amount.

[0125] The drug release curve of the PLLA-HA composite drug-loaded microspheres is as follows Figure 4 As shown by Figure 4 It can be seen that in addition to increasing the hydrophilic suspension, the drug can be stably released for 15 days.

[0126] Embodiment 6:

[0127] This embodiment provides a core-shell structure of PLLA-HA drug-loaded composite microspheres and a preparation method thereof, and the specific steps are as follows:

[0128] (1) Weigh 10 g of poly (L-lactic acid) (PLLA) with a weight average molecular weight of 200,000, add it to 100 mL of dichloromethane, and stir and dissolve it at 100 rpm for 24 h until it is uniformly dissolved to obtain a PLLA organic solution with a mass concentration of 10% as the oil phase.

[0129] (2) Weigh 2 g of polyvinyl alcohol (PVA) and add it to 100 mL of water. Heat and stir at 70° C. for 24 h to dissolve the mixture, and obtain a uniform PVA aqueous solution with a mass concentration of 2%. After cooling, the solution is used as the aqueous phase.

[0130] (3) Emulsification and solidification: The oil phase in step (1) was slowly added to the stirred water phase, with the volume ratio of the oil phase to the water phase being 1:10. The mixture was first stirred at a high speed of 1000-1500 rpm for 15 min, and then stirred at a low speed of 100 rpm for 12 h. After standing, the PLLA microspheres were collected.

[0131] (4) Weigh 0.5 g of sodium hyaluronate with a molecular weight of 2 to 2.5 million and add it to 10 mL of water. Stir for 2 h until it is completely dissolved. Add 0.5 g of dutasteride, then add 0.45 g of 1,4-butanediol glycidyl ether and stir for 15 min to obtain a mixed solution. Add PLLA microspheres to the mixed solution, and collect the composite drug-loaded microspheres after ultrasonic infiltration.

[0132] (5) The composite drug-loaded microspheres were placed in a 50°C oven and vacuum dried for 5 h until the mass remained unchanged, so that sodium hyaluronate formed a cross-linked composite layer outside the PLLA microspheres. The PLLA-HA composite drug-loaded microspheres with a sodium hyaluronate core-shell structure were collected after being sieved through a 150-mesh sieve.

[0133] Weigh 2 g of the above-mentioned drug-loaded microspheres into a sample bottle, add 500 mL of phosphate buffer, and place it in a 37°C constant temperature inspection box. Take samples every day and use high performance liquid chromatography to test the drug concentration in the solution and calculate the drug release amount.

[0134] The drug release curve of the PLLA-HA composite drug-loaded microspheres is as follows Figure 5 As shown by Figure 5 It can be seen that:

[0135] In addition to increasing hydrophilic suspension, it can stably release drugs for 30 days.

[0136] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for preparing fully degradable arterial embolization microspheres, characterized in that: The steps include: Step 1: weigh a degradable polymer, add it to an organic solvent, stir and dissolve it, and obtain an oil phase; weigh an emulsifier, add it to water, heat and stir to dissolve it, and obtain an aqueous phase; slowly add the oil phase to the aqueous phase, and use a high-speed and then low-speed stirring method to fully emulsify the oil phase in the aqueous phase to form an emulsion; Step 2, under negative pressure, stirring the emulsion to volatilize the organic solvent, solidifying the emulsion, filtering and washing the solid obtained, and drying it under low temperature vacuum to obtain microspheres; Step three, weighing polysaccharide and cross-linking agent, adding them into water, stirring and dissolving, and obtaining a polysaccharide polymer solution; adding microspheres into the polysaccharide polymer solution to fully soak them, filtering, and heating and vacuum drying, and obtaining microspheres coated with a cross-linked polysaccharide shell.

2. The method according to claim 1, characterized in that: In step 1, the degradable polymer is selected from one or more copolymers or blends of poly (L-lactic acid) (PLLA), poly (hydroxyalkanoate) (PHA), poly (racemic) lactic acid (PDLLA), poly (caprolactone) (PCL), polytrimethylene carbonate (PTMC), poly (p-dioxanone) (PPDO), polyethylene glycol (PEG), poly (butylene succinate) (PBS), polyglycolic acid (PGA) and poly (lactic acid-co-glycolic acid) (PLGA); Preferably, the molecular weight of the degradable polymer is 50,000 to 500,000.

3. The method according to claim 1, characterized in that: In step one, the emulsifier is selected from one or more of polyvinyl alcohol (PVA), polyethylene glycol (PEG), didodecyl dimethyl ammonium bromide (DMAB), vinyl pyrrolidone (PVP), and carboxymethyl cellulose (CMC).

4. The method according to claim 1, characterized in that: In step 1, the organic solvent is selected from one or more combinations of dichloromethane, ethyl acetate, acetone, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, chloroform and cyclohexanone.

5. The method according to claim 1 or 2, characterized in that: In the oil phase of step 1, the mass concentration of the degradable polymer is 5% to 15%; Preferably, the rotation speed of stirring and dissolving is 10 to 100 rpm, and the stirring time is 12 to 24 hours.

6. The method according to claim 1, characterized in that: In the aqueous phase of step 1, the mass concentration of the polyvinyl alcohol is 1% to 2%; Preferably, the heating and stirring temperature is 50 to 70° C., and the stirring time is 12 to 24 hours.

7. The method according to claim 1, characterized in that: In step 1, emulsification is carried out by stirring at high speed first and then at low speed, wherein the high speed stirring speed is 1000-1500 rpm and the stirring time is 1-15 min; the low speed stirring speed is 10-100 rpm and the stirring time is 2-12 h.

8. The method according to claim 1, characterized in that: In step 1, the volume ratio of the oil phase to the water phase is 1:5 to 1:

10.

9. The method according to claim 1, characterized in that: In step 2, the negative pressure condition is: -100 kPa to -80 kPa.

10. The method according to claim 1, characterized in that: In step 2, low temperature vacuum drying is performed by freezing at -80°C to -20°C and vacuum drying.

11. The method according to claim 1, characterized in that: In step 2, the microspheres are further sieved through a sieve to obtain microspheres with a particle size of 100 to 500 μm.

12. The method according to claim 1, characterized in that: In step 3, the polysaccharide is selected from one or more combinations of sodium hyaluronate (HA), chitosan (CS), gelatin, collagen, silk fibroin, agar, carrageenan, pectin, cellulose, xanthan gum, gum arabic, dextran, sodium alginate, starch and chitin; Preferably, the molecular weight of the polysaccharide is 800,000 to 2.5 million.

13. The method according to claim 1, characterized in that: In step three, the crosslinking agent is selected from one or more combinations of glutaraldehyde, 1,4-butanediol glycidyl ether (BDDGE), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), N-hydroxysuccinimide (NHS), genipin and a photosensitive crosslinking agent.

14. The method according to claim 1 or 11, characterized in that: In step three, the mass concentration of the polysaccharide polymer solution is 1% to 20%.

15. The method according to claim 1, 12 or 13, characterized in that: In step three, the mass ratio of the polysaccharide to the cross-linking agent is 2:1 to 10:

1.

16. The method according to claim 1, characterized in that: In step three, ultrasonic infiltration is used for full infiltration.

17. The method according to claim 1, characterized in that: In step three, the heating vacuum drying is vacuum drying in an oven at a temperature of 40 to 70° C. for a drying time of 3 to 12 hours.

18. The method according to claim 1, characterized in that: In step three, the microspheres coated with the cross-linked polysaccharide shell are sieved through a sieve to obtain microspheres with a particle size of 100 to 500 μm.

19. A fully degradable arterial embolic microsphere prepared by the preparation method according to any one of claims 1 to 18.

20. Use of the fully degradable arterial embolic microspheres according to claim 19 or the fully degradable arterial embolic microspheres prepared by the preparation method according to any one of claims 1 to 18 in the preparation of drugs for treating prostate diseases.

21. The use according to claim 20, characterized in that: The prostate disease includes one or more of benign prostatic hyperplasia, prostatitis, prostatic cyst, prostatic calculus and prostatic abscess.

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