A gel material for reducing bladder stone formation and its preparation method and application

Abstract

A kind of gel material for reducing bladder stone formation and its preparation method and application, the raw materials of the gel material include temperature-sensitive component Pluronic F127, photo-crosslinking component methacrylated gelatin and active functional ingredient cerium dioxide nanoparticles.The gel material is liquid at low temperature, which is convenient for perfusion into bladder through catheter;It quickly changes into physical gel at body temperature, realizing in-situ forming;Then it occurs photo-crosslinking through ultraviolet irradiation, forming chemical crosslinking gel with high mechanical strength and good stability, which can resist urine flushing and realize long-term residence.Loaded cerium dioxide nanoparticles continuously remove reactive oxygen species in stone formation microenvironment by simulating catalase and superoxide dismutase activity, thereby inhibiting the nucleation, growth and aggregation of crystals.The material has excellent biocompatibility, simple preparation method, can significantly reduce bladder stone formation, and has broad application prospect in preventing postoperative recurrence of bladder stone and conservative treatment.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials and urological medical devices, specifically relating to a gel material that reduces the formation of bladder stones, its preparation method, and its application. Background Technology

[0002] Bladder stones are a common urinary system disease, and their formation is related to various factors such as urine supersaturation, reduced crystallization inhibitors, urinary tract infection, foreign body retention, and lower urinary tract obstruction. Currently, larger bladder stones are mainly treated surgically, such as transurethral lithotripsy. However, the recurrence rate after surgery is high, mainly because the microenvironment for stone formation (such as inflammation, oxidative stress, and residual microcrystal nuclei) is not effectively improved. In addition, for some special patients (such as those with neurogenic bladder or those with long-term indwelling catheters), there is an urgent need for a method that can inhibit stone formation in a long-term, safe, and effective manner.

[0003] Existing preventative measures mostly involve oral medications (such as citrate and allopurinol) or drinking plenty of water, which have poor adherence and lack strong systemic targeting, potentially leading to side effects. Research on locally infused drugs or materials is still in its early stages, with issues such as short retention time, poor biocompatibility, and a lack of ability to actively intervene in key aspects of stone formation (such as oxidative stress).

[0004] Cerium dioxide nanoparticles (CeO2 NPs) are unique due to their CeO2 content. 3+ / Ce 4+ Redox pairs, capable of mimicking the activities of catalase and superoxide dismutase, are highly effective antioxidants and reactive oxygen species (ROS) scavengers. Studies have shown that ROS play a crucial role in the formation of urinary tract stones, promoting stone matrix formation, damaging the urothelium, and promoting crystal adhesion. Therefore, if cerium dioxide nanoparticles can be delivered locally, long-term, and safely to the bladder, theoretically, the nucleation and growth of stones could be intervened at the source by scavenging free radicals in the lesion area.

[0005] However, delivering CeO2 NPs stably, sustainably, and safely to the bladder and securing them at the site of action remains a significant challenge. Simply infusing nanoparticles is easily flushed out by urine and cannot provide long-term retention. Therefore, a suitable carrier is needed. Summary of the Invention

[0006] Technical Problem Solved: Addressing the shortcomings of existing oral medications (poor targeting and significant side effects) and local treatments (short duration and uncertain efficacy), this invention provides a gel material for reducing bladder stone formation, its preparation method, and its applications. This material can form a highly stable gel coating in situ and continuously scavenge reactive oxygen species by releasing cerium dioxide nanoparticles, thereby effectively inhibiting the formation and recurrence of bladder stones.

[0007] Technical solution: The first objective of this invention is to provide a gel material for reducing the formation of bladder stones, the raw materials of which include a thermosensitive component, a photocrosslinking component, and an active functional component; the thermosensitive component is Pluronic F127, the photocrosslinking component is methacrylamide gelatin (GelMA), and the active functional component is cerium dioxide nanoparticles (CeO2NPs).

[0008] Preferably, the loading of cerium dioxide nanoparticles in the gel is 0.05% (w / v). This loading ensures effective free radical scavenging activity without affecting the basic physicochemical properties and biocompatibility of the gel material.

[0009] The gel material of this invention exhibits dual response characteristics of temperature sensitivity and photocrosslinking. At low temperatures (e.g., 4°C), it exists as a flowable sol, facilitating instillation via a catheter. After instillation into the bladder, it rapidly transforms into a physical gel at body temperature (e.g., 37°C), achieving initial localization. Subsequently, under irradiation with ultraviolet light of a specific wavelength (405 nm), the methacrylamide gelatin undergoes chemical crosslinking, forming a stable covalent network hydrogel, thereby firmly adhering to the bladder mucosa, resisting urine flushing, and achieving long-lasting retention.

[0010] A second objective of this invention is to provide a method for preparing the above-mentioned gel material for reducing bladder stone formation, comprising the following steps:

[0011] Step 1: Dissolve Pluronic F127 in pre-cooled sterile solvent under ice bath conditions to form reagent B;

[0012] Step 2: Cerium dioxide nanoparticles are uniformly dispersed in a solution containing methacrylamide gelatin. The mixture is then ultrasonically treated in an ice-water bath to form reagent A. The amount of cerium dioxide nanoparticles added is such that its loading in the final gel is 0.05% (w / v).

[0013] Step 3: Mix reagent A and reagent B under ice bath conditions, stir until homogeneous, and obtain a gel material, which is then stored under ice bath conditions.

[0014] Furthermore, the gel material is filled into a syringe or a specially designed infusion device and transported and stored under ice bath conditions. In clinical use, the precursor solution is infused into the bladder via a urethral catheter, where it rapidly transforms into a physical gel at body temperature. Subsequently, a miniature ultraviolet fiber is introduced through an endoscope, and the gel in the bladder is irradiated with 405 nm wavelength ultraviolet light, initiating GelMA cross-linking and forming a stable gel coating loaded with CeO2 NPs, covering the bladder mucosa surface.

[0015] As a preferred embodiment of the present invention, the solvent in step one is water or PBS buffer, and the concentration of Pluronic F127 in reagent B is 20% (w / v).

[0016] As a preferred embodiment of the present invention, in step two, the concentration of the solution containing methacrylamide gelatin is 10% (w / v), and the solvent is water or PBS buffer.

[0017] As a preferred embodiment of the present invention, the conditions for ultrasonic treatment in step two are: power 100 W, on for 2 seconds, off for 2 seconds, and treatment time of 30 minutes.

[0018] As a preferred embodiment of the present invention, the volume ratio of reagent A to reagent B in step three is 1:1.

[0019] A third objective of this invention is to provide the use of the above-described gel material for reducing bladder stone formation in the preparation of medicaments or medical devices for reducing or inhibiting bladder stone formation.

[0020] Preferably, the gel material needs to be photocured by ultraviolet light irradiation during use.

[0021] More preferably, the ultraviolet light irradiation conditions are: wavelength 405 nm, irradiation time 1 minute.

[0022] Beneficial effects:

[0023] (1) The gel provided by the present invention can provide targeted therapy with few side effects. The gel acts directly on the local bladder, which can achieve high concentration enrichment and long-term release of CeO2 NPs at the lesion site, avoiding the side effects of systemic administration and improving the targeting and safety of the treatment.

[0024] (2) This invention utilizes temperature-sensitive properties to achieve minimally invasive perfusion and in-situ physical gelation, and utilizes photocrosslinking properties to achieve on-demand chemical curing. The curing time, location and range are controllable, and the formed chemical crosslinked gel has high mechanical strength, good stability in the dynamic urine environment of the bladder, and is not easily flushed away.

[0025] (3) The cerium dioxide nanoparticles loaded in the gel provided by the present invention continuously remove reactive oxygen free radicals in the microenvironment of stone formation by simulating the activities of catalase and superoxide dismutase, thereby inhibiting the nucleation, growth and aggregation of crystals, and thus fundamentally reducing the risk of stone formation.

[0026] (4) The materials selected in this invention, Pluronic F127 and GelMA, are both biomedical materials that have been extensively studied and have excellent biocompatibility. CeO2 NPs also have good biosafety.

[0027] (5) The entire preparation process of this invention is carried out at low temperature, without the need for complex chemical reactions or harsh conditions, and is easy to operate, standardized in production and clinical translation. Attached Figure Description

[0028] Figure 1 The figure shows the characterization results of the thermosensitive-photocrosslinked hydrogel loaded with cerium dioxide nanoparticles prepared in the embodiments of the present invention; wherein, A is a photo of the gel without photocuring (No UV), B is a photo of the gel after photocuring (UV), C is a schematic diagram of the gel shear capacity test, D is a bar chart of the shear modulus test results (No UV and UV), E is the compression test curve (No UV and UV), F is the viscosity-shear rate curve of the uncured material; G is the viscosity-shear rate curve of the photocured material, H is the rheological frequency scan curve of the uncured material, I is the rheological frequency scan curve of the photocured material, and J is the degradation rate curve of the uncured and photocured gels in simulated urine.

[0029] Figure 2 Figure 1 shows the biosafety evaluation results of the gel material prepared in the embodiments of the present invention. Among them, A is the fluorescence image of SV-HUC-1 cell live / dead staining (Calcein-AM / PI) of different treatment groups (control, oxalate, oxalate + material, material), B is the hemolysis experiment photo of each group (positive control, negative control, F127, CNPs@Gel, CNPs@Gel-F127), C is the corresponding hemolysis rate statistical bar chart, and D is the histological staining image of the main organs (heart, liver, spleen, lung, kidney) of rats by the control group and the material group (BAIM+CNPs@Gel-F127).

[0030] Figure 3Figure 1 shows the results of the anti-inflammatory study of the gel material prepared in the embodiments of the present invention. Among them, A is the DCFH-DA fluorescence staining image of intracellular ROS levels in different treatment groups (control, oxalate, oxalate + material), B is the corresponding relative ROS level statistical bar chart, C is the statistical graph of IL-6 expression level in cell supernatant of each group, D is the statistical graph of TNF-α expression level in cell supernatant of each group, E is the histological image of bladder cell-free matrix (BAM) patch group and BAM + material group under HE and ARS staining, and F is the immunohistochemical staining image of MPO and CD68 in the two groups.

[0031] Figure 4 The images show the in vivo anti-stone formation effect of the gel material prepared in this embodiment of the invention; the images are gross bladder specimens of rats in the bladder cell-free matrix (BAM) group and the BAM+ material group, respectively, to show the stone formation. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the invention. Unless otherwise specified, the raw materials used in the embodiments of this specification are all from commercially available products.

[0033] Unless otherwise specified, the raw materials used in the embodiments of this specification are all from common commercially available products, including:

[0034] The Pluronic F127 was purchased from Aladdin, CAS No.: 9003-11-6;

[0035] Cerium dioxide nanoparticles were purchased from Aladdin, item number C1520773;

[0036] The methacrylamide gelatin was purchased from Aladdin, product number M39824.

[0037] Example 1: Preparation of thermosensitive-photocrosslinked hydrogels loaded with cerium dioxide nanoparticles

[0038] This embodiment provides a method for preparing the gel material for reducing bladder stone formation according to the present invention, and compares the performance differences between the gel before and after photocuring. The specific steps are as follows:

[0039] Step 1: Prepare reagent B (temperature-sensitive component solution):

[0040] Under ice bath conditions, 2 g of Pluronic F127 was dissolved in 8 mL of pre-chilled sterile PBS buffer (4°C) and gently stirred until completely dissolved to obtain a 20% (w / v) F127 solution. The solution was then placed in a 4°C refrigerator overnight to allow for full hydration, yielding a clear and transparent reagent B.

[0041] Step 2: Prepare reagent A (a mixture of photocrosslinking components and active ingredients):

[0042] Weigh 10 mg of cerium dioxide nanoparticles with a particle size of approximately 5 nm and add them to 10 mL of PBS solution containing 10% (w / v) methacrylamide gelatin (methacrylamide degree approximately 80%). Place the mixture in an ice-water bath and sonicate it using an ultrasonic cell disruptor (100 W power, 2 seconds on, 2 seconds off, total time 30 minutes) to ensure that the cerium dioxide nanoparticles are fully and uniformly dispersed, thus obtaining reagent A.

[0043] Step 3: Preparation of gel precursor:

[0044] Under ice bath conditions, 500 μL of reagent B was placed in a 1.5 mL centrifuge tube, followed by 500 μL of reagent A. The mixture was repeatedly pipetted or vortexed for 30 seconds to ensure thorough mixing, resulting in a homogeneous, slightly yellowish gel precursor solution. This precursor solution remained in a flowable liquid state under ice bath conditions, facilitating perfusion.

[0045] Step 4, Uncured Group (No UV, Temperature-Sensitive Gel Forming Only):

[0046] The above-mentioned gel precursor solution was injected into a mold or animal bladder and placed in an environment of 37°C. Within about 2 minutes, the solution was induced by body temperature to transform into a non-flowing, translucent physical gel, which was recorded as the non-UV-cured group. This group of gels formed a physical cross-linked network solely through the thermosensitive micellization of Pluronic F127, resulting in low mechanical strength, limited stability, and easy degradation in simulated urine.

[0047] Step 5, UV curing assembly (UV, temperature-sensitive gelation + photocrosslinking curing):

[0048] Inject the above-mentioned gel precursor solution into a mold or animal bladder, and let it stand at 37°C for 2 minutes to form a physical gel. Then, use a 405 nm wavelength ultraviolet lamp (light intensity approximately 10 mW / cm²) to form the gel. 2 Irradiate the sample at a distance of 1 cm for 60 seconds to perform photocrosslinking and curing. During this process, the double bonds in the methacrylamide gelatin undergo free radical polymerization to form a covalent crosslinking network, which interpenetrates with the original physical network to form a more dense and stable chemically crosslinked hydrogel, denoted as the photocuring group (UV).

[0049] Step Six: Performance Comparison of Uncured and Cured Gels

[0050] The performance of the two groups of gels was tested, and the results are as follows: Figure 1 As shown:

[0051] Macro-morphology ( Figure 1 A, B): The uncured group (A) is a translucent, soft physical gel; the cured group (B) retains its shape and has significantly improved transparency and structural strength after being irradiated with ultraviolet light.

[0052] shear modulus ( Figure 1 C, D): Rheological tests showed that the storage modulus (G') of the UV-cured group was significantly higher than that of the non-UV group (P<0.01), indicating that photocrosslinking greatly enhanced the mechanical strength and deformation resistance of the gel.

[0053] Viscosity and rheological properties Figure 1 E, F, G, H, I): Viscosity-shear rate curves and frequency scanning results all confirm that the precursor solution has good temperature-sensitive gelation properties, and the mechanical properties of the gel are further enhanced after photocuring.

[0054] Degradation behavior ( Figure 1 J): The two groups of gels were placed in simulated urine and observed continuously at 37°C. The results showed that the uncured group (No UV) underwent significant degradation within 1 day due to only physical cross-linking; while the UV-cured group, due to the formation of a stable chemical covalent network, experienced a significantly slower degradation rate and maintained structural integrity for 2 days, indicating that it could achieve a longer residence time in the bladder.

[0055] In summary, uncured gels (No UV) mainly rely on temperature-sensitive physical cross-linking and are suitable for short-term residence scenarios; while photocured gels (UV) significantly improve mechanical strength and anti-degradation properties through subsequent ultraviolet light cross-linking, making them more suitable for clinical applications that require long-term inhibition of stone formation.

[0056] Example 2: In vivo anti-calculi effect of a cell-free bladder matrix patch loaded with the gel of the present invention in a rat bladder stone model.

[0057] To facilitate localized localization and long-term efficacy evaluation in a rodent bladder model, this embodiment uses a bladder acellular matrix patch (BAM) as a temporary carrier for the gel of this invention. The patch itself does not possess anti-stone activity; it is only used to fix the gel in a specific area of ​​the bladder wall to simulate the situation where the gel covers the mucosal surface after clinical instillation. Those skilled in the art will understand that, based on the thermosensitive gelling properties, photocrosslinking-enhanced mechanical properties, and anti-degradation ability verified in Example 1, directly instilling the gel precursor of this invention into the bladder via a catheter can also achieve in-situ formation at body temperature and form a stable gel coating through photocrosslinking, achieving resistance to urine flushing and long-term retention. Its principle of inhibiting stone formation is exactly the same as that of patch loading. Therefore, the following patch model is a simplified verification model of the efficacy of the gel material of this invention, and not a limitation on its use.

[0058] This embodiment evaluates the inhibitory effect of a cell-free bladder matrix patch (BAM+ material) loaded with the photocurable gel in Example 1 of this invention on the formation of bladder stones by establishing a rat bladder stone model, and compares it with the simple BAM patch.

[0059] 1. Preparation of experimental materials

[0060] Preparation of BAM patch: Rat bladder acellular matrix (BAM) was prepared according to the method in the literature, and then freeze-dried after decellularization for later use.

[0061] Material-loaded patch (BAM + material): Under aseptic conditions, the gel precursor solution prepared in Example 1 was uniformly coated onto the surface of the BAM patch (200 μL per square centimeter). The patch was then incubated at 37°C for 5 minutes to allow preliminary gel solidification, followed by photocrosslinking under 405 nm UV light for 1 minute to obtain the composite patch loaded with the gel of this invention. The control group consisted of BAM patches from the same batch without any material loading.

[0062] 2. Animal model establishment and grouping

[0063] SPF-grade male SD rats weighing 180-220 g were selected and randomly divided into two groups of eight rats each after one week of acclimatization.

[0064] BAM group (control group): Only blank BAM patches were implanted.

[0065] BAM+ material group (experimental group): implanted BAM patch loaded with the gel of this invention.

[0066] All rats were anesthetized by intraperitoneal injection of sodium pentobarbital (40 mg / kg), and a midline incision was made in the lower abdomen to expose the bladder. A 5 mm incision was made in the anterior wall of the bladder, and a BAM patch or a BAM+ material patch was sutured to the bladder incision with 5-0 absorbable sutures. The abdomen was closed routinely after surgery.

[0067] 3. Postoperative management and stone induction

[0068] Starting from the third day after surgery, rats were given drinking water containing 1% (w / v) ethylene glycol and 1% (w / v) ammonium chloride daily to induce stone formation for four consecutive weeks. During this period, they had free access to standard feed. The rats' mental state, activity, food intake, abdominal wound healing, and urination were observed daily. All rats successfully completed the experiment without death or serious infection, and no rats were discarded.

[0069] 4. Observation Indicators

[0070] Four weeks later, all rats were sacrificed, and their bladders were completely removed. The gross morphology, number, and size of the stones in the bladder were observed and photographed. Subsequently, the bladder tissue was fixed in 4% paraformaldehyde and histologically stained (HE staining and ARS alizarin red staining) to assess calcium salt deposition.

[0071] 5. Experimental Results

[0072] 5.1 Biosafety Assessment

[0073] 5.1.1 Cell compatibility and cell protection

[0074] To evaluate the cell compatibility and antioxidant stress protection of the gel material of this invention, the following four groups were set up:

[0075] Control group: SV-HUC-1 cells were cultured in normal culture medium without any treatment;

[0076] Material group (CNPs@Gel-F127): The photocurable gel material (CNPs@Gel-F127) prepared in Example 1 of this invention was added to the cell culture medium (1 mL of CNPs@Gel-F127 was evenly spread on the bottom of a six-well plate and cured under ultraviolet light before cell plating).

[0077] Oxalate group: Sodium oxalate (0.75 mM) was added to the cell culture medium to induce oxidative stress damage in cells;

[0078] Oxalate + material group (Ox + CNPs@Gel-F127): Sodium oxalate and the photocurable gel material of this invention were added to the cell culture medium at the same time (1 mL of CNPs@Gel-F127 was evenly spread on the bottom of a six-well plate, cured under UV light, and then the cells were plated. Sodium oxalate was added to the cell culture medium, with a final concentration of 0.75 mM).

[0079] Cell viability staining results ( Figure 2 A) The results showed that in the control group and the material-only group (CNPs@Gel-F127), the vast majority of SV-HUC-1 cells exhibited green fluorescence (Calcein-AM labeled live cells), while very little red fluorescence (PI labeled dead cells) was observed, indicating that the material itself has good biocompatibility. The oxalate-treated group showed a significant increase in red fluorescence and a significant decrease in green fluorescence, suggesting that oxalate has significant toxicity to cells. In contrast, the oxalate + material group showed a significant decrease in red fluorescence and a significant increase in green fluorescence compared to the oxalate group, indicating that the gel material of this invention can not only effectively reduce oxalate-induced cell damage, but also has good cell compatibility.

[0080] 5.1.2 Hemolysis test

[0081] The following groups were set up: positive control (pure water), negative control (PBS), F127 group, CNPs@Gel group and CNPs@Gel-F127 (the complete gel material of this invention).

[0082] The hemolysis experiment is as follows:

[0083] 1. Lubricate the tubing with heparin to prepare heparin anticoagulant tubing;

[0084] 2. Blood was collected from the eyeballs of rats after anesthesia, centrifuged at 3000 rpm for 15 minutes, and the supernatant was discarded to obtain blood cells;

[0085] 3. Take 1 mL of dd H2O, PBS, CNPs@Gel, F127, and CNPs@Gel-F127 respectively, add 20 μL of blood cells to each, incubate at 37°C for 4 hours, then centrifuge at 3000 rpm for 15 minutes and take a picture;

[0086] 4. Take the supernatant of the positive control group, negative control group, F127 group, CNPs@Gel group and CNPs@Gel-F127 group respectively, measure the absorbance at a wavelength of 542nm, and set up three duplicate wells;

[0087] 5. Calculate the hemolysis rate = [OD(sample) - OD(PBS)] / [OD(ddH2O) - OD(PBS)] * 100%.

[0088] Results of hemolysis test ( Figure 2B) shows that the positive control group exhibited significant hemolysis, with the solution appearing red; the negative control group, F127 group, CNPs@Gel group, and CNPs@Gel-F127 group all showed no visible hemolysis, with the solutions remaining clear and transparent; the hemolysis rate statistics ( Figure 2 C) indicates that the hemolysis rate of each material group is less than 5%, which meets the blood compatibility standard for medical biomaterials.

[0089] 5.1.3 Histological staining of major organs

[0090] Histological staining was performed on the major organs (heart, liver, spleen, lung, and kidney tissues) of rats in both the experimental group (BAM+ material) and the control group (BAM). The results showed ( Figure 2 (D) The heart, liver, spleen, lung, and kidney tissues implanted with the gel material of this invention and the control group showed intact morphology and structure, with no obvious inflammatory cell infiltration, tissue necrosis, or other pathological changes, further confirming that the gel material of this invention has excellent in vivo biocompatibility.

[0091] 5.2 Anti-inflammatory and antioxidant stress effects

[0092] 5.2.1 Intracellular reactive oxygen species levels

[0093] The following three groups were set up: control group, oxalate group, and oxalate + material group. Intracellular ROS levels were detected using the DCFH-DA fluorescent probe; results are shown below. Figure 3 .

[0094] Results of in vitro antioxidant stress ( Figure 3 A) showed that the intensity of DCFH-DA green fluorescence in cells of the oxalate-treated group was significantly enhanced compared with that of the control group, and the relative ROS level was significantly increased. Figure 3 B) indicates that oxalate successfully induced intracellular oxidative stress; while the green fluorescence of the oxalate + material group was significantly weaker than that of the oxalate group, and the relative ROS level was significantly lower, indicating that the cerium dioxide nanoparticles loaded in the gel material of this invention can effectively scavenge intracellular reactive oxygen free radicals.

[0095] 5.2.2 Inflammatory Factors

[0096] The expression levels of IL-6 and TNF-α in the cell supernatants of the above three groups were detected. The results of inflammatory factor detection in the cell supernatants showed ( Figure 3 (C, D) The expression levels of IL-6 and TNF-α in the oxalate group were significantly higher than those in the control group; the levels of IL-6 and TNF-α in the oxalate + material group were significantly lower than those in the oxalate group, indicating that the gel material of the present invention can significantly inhibit the release of inflammatory factors and has a good anti-inflammatory effect.

[0097] 5.2.3 Histological staining and immunohistochemistry

[0098] Bladder tissues from rats in the experimental group (BAM+ material) and the control group (BAM) were stained.

[0099] Histological staining ( Figure 3 E): HE staining revealed numerous deeply stained calcifications in the submucosal region of the bladder in the BAM group; ARS staining further confirmed extensive calcium salt deposition. In contrast, almost no positive staining areas were observed in the bladder tissue of the BAM+ material group, indicating that calcium salt deposition was effectively inhibited. In vivo immunohistochemical results ( Figure 3 F) showed that the BAM group had strong positive immunohistochemical staining for MPO (neutrophil marker) and CD68 (macrophage marker), indicating significant local infiltration of neutrophils and macrophages and a severe inflammatory response; while the BAM+ material group showed significantly reduced positive expression of MPO and CD68 and significantly reduced inflammatory cell infiltration.

[0100] 5.3 In vivo anti-stone formation effect

[0101] Experimental results are as follows Figure 4 As shown:

[0102] Gross observation: In the BAM group, numerous diffusely distributed yellowish-white stones were observed in the bladders of rats. The stones were numerous and large, with some fused into clumps. In contrast, the number of stones in the bladders of rats in the BAM+ material group was significantly reduced, with only scattered tiny crystalline particles and no clearly formed stones observed.

[0103] The results of this embodiment demonstrate that the thermosensitive-photocrosslinked hydrogel loaded with cerium dioxide nanoparticles prepared in this invention can significantly inhibit the formation of bladder stones. When this gel is loaded onto a BAM patch and implanted into the bladder, it effectively prevents the nucleation and aggregation of calcium oxalate crystals by continuously scavenging reactive oxygen free radicals in the local microenvironment and reducing inflammatory responses, thereby verifying the stone-preventing efficacy of the material of this invention at the animal level.

[0104] It should be noted that although this embodiment verified the in vivo anti-stone effect of the gel of the present invention using a patch model, based on the excellent thermosensitive gelation, photocrosslinking curing, and mechanical properties of the gel, those skilled in the art can directly and without doubt expect that after the gel is directly instilled into the bladder via a catheter, a stable gel coating can also be formed in situ, and the formation of bladder stones can be inhibited by scavenging reactive oxygen species and suppressing inflammation. Therefore, direct instillation application also falls within the scope of protection of the present invention. This material is expected to be used for stone prevention in the reconstructed area after bladder surgery and for related clinical indications.

[0105] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A gel material for reducing the formation of bladder stones, characterized in that, Its raw materials include a temperature-sensitive component, a photocrosslinking component, and an active functional component; the temperature-sensitive component is Pluronic F127, the photocrosslinking component is methacrylamide gelatin, and the active functional component is cerium dioxide nanoparticles.

2. The gel material for reducing bladder stone formation according to claim 1, characterized in that, The loading of cerium dioxide nanoparticles in the gel is 0.05% w / v.

3. A method for preparing a gel material for reducing bladder stone formation as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1: Dissolve Pluronic F127 in pre-cooled sterile solvent under ice bath conditions to form reagent B; Step 2: Cerium dioxide nanoparticles are uniformly dispersed in a solution containing methacrylamide gelatin. The mixture is then ultrasonically treated in an ice-water bath to form reagent A. The amount of cerium dioxide nanoparticles added is such that its loading in the final gel is 0.05% w / v. Step 3: Mix reagent A and reagent B under ice bath conditions, stir until homogeneous, and obtain a gel material, which is then stored under ice bath conditions.

4. The preparation method according to claim 3, characterized in that, In step one, the solvent is water or PBS buffer, and the concentration of Pluronic F127 in reagent B is 20% w / v.

5. The preparation method according to claim 3, characterized in that, In step two, the concentration of the solution containing methacrylamide gelatin is 10% w / v, and the solvent is water or PBS buffer.

6. The preparation method according to claim 3, characterized in that, In step two, the conditions for ultrasonic treatment are: power 100 W, on for 2 seconds, off for 2 seconds, and treatment time 30 minutes.

7. The preparation method according to claim 3, characterized in that, In step three, the volume ratio of reagent A to reagent B is 1:

1.

8. The use of the gel material for reducing bladder stone formation as described in claim 1 or 2 in the preparation of a medicament or medical device for reducing or inhibiting bladder stone formation.

9. The application according to claim 8, characterized in that, The gel material is used in conjunction with ultraviolet light irradiation.

10. The application according to claim 9, characterized in that, The conditions for ultraviolet light irradiation are: wavelength 405 nm, irradiation time 1 minute.

Images