Self-driven micromotor system for treating helicobacter pylori gastritis and preparation method thereof

Abstract

The invention belongs to the technical field of biological medicines and micro-nano motors, and particularly relates to a self-driven micro-motor system for treating helicobacter pylori gastritis and a preparation method of the self-driven micro-motor system. A self-driven micro-motor system with an active targeting function is constructed, the drug coated on the PLGA layer can be any substance with antibacterial activity or capable of promoting gastric mucosa repair, and the drug loading capacity and the sustained release time can be adjusted by adjusting the thickness of the PLGA interlayer. The selection of the enteric coating layer mainly considers the good electrostatic targeting property and pH response release property of the enteric coating layer, and various types of enteric coatings can be selected to adjust pH nodes released by the shell.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine and micro-nano motor technology, and specifically relates to a self-driven micro-motor system for treating Helicobacter pylori gastritis and a preparation method thereof. Background Art

[0002] Helicobacter pylori H. pylori ) is a Gram-negative spiral bacterium and one of the most common chronic pathogens in humans, with an infection rate of more than half of the world's population. A large number of studies have shown that H. pylori Infection is one of the main risk factors for gastric diseases such as chronic gastritis, peptic ulcer and gastric cancer, and has been listed as a Class I carcinogen. H. pylori By adhering to the gastric submucosa, it releases a variety of toxic factors, inducing epithelial cells and immune cells to secrete a large number of inflammatory chemokines, thereby triggering severe gastric mucosal inflammation. At the same time, activated inflammatory cells produce excessive oxygen free radicals through respiratory burst, leading to mitochondrial dysfunction, protein denaturation and oxidative stress, aggravating mucosal damage and promoting the progression of chronic gastritis to ulcers and even cancer. Therefore, eradication of H. pylori Infection has important clinical significance for the prevention and treatment of stomach-related diseases.

[0003] Currently, the standard treatment options for Helicobacter pylori mainly include triple therapy and quadruple therapy, among which quadruple therapy consisting of bismuth, proton pump inhibitors (PPIs) and two broad-spectrum antibiotics is widely recommended as the first-line treatment strategy. However, this treatment option has many limitations: (1) Low drug delivery efficiency: The drug lacks specific targeting effect on Helicobacter pylori, and the drug's short residence time in the stomach (normal human gastric emptying time is usually 2-4 hours) leads to excessive use of broad-spectrum antibiotics, which not only causes bacterial resistance problems, but also may have long-term negative effects on the intestinal microbiome; (2) Insufficient inflammation and repair: It is unable to effectively inhibit excessive inflammation and it is difficult to promote the repair of damaged mucosa; (3) Large toxic side effects: The degradation of the drug by gastric acid significantly affects its antibacterial activity, and long-term use of PPIs may cause a series of adverse reactions, such as gastric acid secretion inhibition, electrolyte imbalance, Clostridium difficile infection, bacterial gastroenteritis, intestinal flora imbalance, and even increase the risk of gastric cancer.

[0004] Recent advances in smart drug delivery systems (DDS), particularly micro- / nanorobotics, offer promising solutions for the treatment of gastrointestinal diseases. These micro- / nanorobotics are generally categorized as externally driven or self-propelled systems. While externally driven robots require complex equipment (e.g., magnetic fields or ultrasound) for operation, self-propelled micro- / nanorobotics utilize intrinsic stimuli (e.g., gastric acid or redox conditions) to generate propulsion, offering superior adaptability and practicality. Their autonomous motility, active targeting, high drug loading capacity, and deep tissue penetration hold great potential for addressing the limitations of traditional Helicobacter pylori therapies.

[0005] The present invention constructs a self-propelled micromotor system with active targeting function. The drug coated in the PLGA layer can be any substance with antibacterial activity or promoting gastric mucosal repair, and the drug loading and sustained release time can be adjusted by adjusting the thickness of the PLGA interlayer. The selection of the enteric coating layer is mainly based on its good electrostatic targeting properties and pH-responsive release properties. Various types of enteric coatings can be selected to adjust the pH node of the shell release. Summary of the Invention

[0006] In a first aspect, the present invention provides a self-driven micromotor system for treating gastritis, characterized in that it consists of a magnesium microsphere core layer, an antibacterial layer of a copolymer loaded with inorganic compound nanoparticles and other active drugs, and an enteric coating layer.

[0007] Furthermore, the core of the magnesium microspheres is between 10-20 μm, preferably 15 μm.

[0008] Furthermore, the loaded size of the inorganic compound nanoparticles is about 50-60 nm, preferably 57 nm.

[0009] Furthermore, the enteric coating is negatively charged.

[0010] Furthermore, the inorganic compound nanoparticles are selected from one or more of bismuth nanoparticles, bismuth citrate, bismuth subsalicylate, ranitidine bismuth citrate, and bismuth pectin.

[0011] Furthermore, the other active drugs can be any substances that have antibacterial activity or promote gastric mucosal repair.

[0012] Furthermore, the active drug is selected from one or more of Weifuchun tablets, amoxicillin, metronidazole, clarithromycin, doxycycline, furazolidone, organic colloidal bismuth, Weidere, and Ledewei.

[0013] Furthermore, the copolymer is selected from polylactic acid-glycolic acid copolymer, which can control the degradation rate.

[0014] Furthermore, the adjustment ratio of the polylactic acid and glycolic acid is selected from one of 90:10, 80:20, and 70:30.

[0015] Furthermore, the molecular weight for controlling the degradation rate is 50,000-150,000.

[0016] Furthermore, the enteric coating is selected from one or more of the classic enteric coatings such as methacrylic acid copolymer type A, methacrylic acid copolymer type B, methacrylic acid copolymer type C, quaternary amino methacrylate copolymer type A, and quaternary amino methacrylate copolymer type B.

[0017] Furthermore, the antibacterial copolymer layer loaded with inorganic compound nanoparticles and other active drugs can adjust the drug loading amount and sustained release time by adjusting the thickness of the copolymer interlayer.

[0018] Furthermore, the enteric coating layer can adjust the pH point at which the shell releases.

[0019] Furthermore, the gastritis is caused by bacterial infection, specifically Helicobacter pylori infection.

[0020] In a second aspect, the present invention provides a method for preparing a self-driven micromotor system for treating gastritis, the method comprising the following steps: S1. The inorganic compound was added to a three-necked flask, and the organic compound was added. The resulting pale yellow mixture was purged with nitrogen and then heated to black using an electric heating mantle. After cooling, the product 1 was collected by centrifugation and washed with ethanol. S2. The product 1 obtained in step 1 was added to the configured copolymer solution to obtain a mixed solution; S3. After pre-treating the magnesium microspheres, the treated magnesium microspheres were evenly dispersed on a glass slide, coated with the mixed solution obtained in step 2, and then coated with an enteric coating. The microspheres were air-dried at room temperature and collected by gently scraping.

[0021] Furthermore, in step 1, the inorganic compound nanoparticles are selected from one or more of bismuth nanoparticles, bismuth citrate, bismuth subsalicylate, ranitidine bismuth citrate, and bismuth pectin.

[0022] Furthermore, in step 2, the copolymer is selected from polylactic acid-glycolic acid copolymer, which can control the degradation rate.

[0023] Furthermore, the adjustment ratio of the polylactic acid and glycolic acid is selected from one of 90:10, 80:20, and 70:30.

[0024] Furthermore, the molecular weight for controlling the degradation rate is 50,000-150,000.

[0025] Furthermore, in step 3, the enteric coating is selected from one or more of classic enteric coatings such as methacrylic acid copolymer type A, methacrylic acid copolymer type B, methacrylic acid copolymer type C, quaternary amino methacrylate copolymer type A, and quaternary amino methacrylate copolymer type B.

[0026] Furthermore, the gastritis is caused by bacterial infection, specifically Helicobacter pylori infection.

[0027] In a third aspect, the present invention provides an application of the self-driven micromotor system as described in the first aspect in the preparation of drugs for treating gastritis and other auxiliary medical products, characterized in that the drugs prepared for treating gastritis contain the self-driven micromotor system and other active drugs.

[0028] Furthermore, the other active drugs may be any substance having antibacterial activity or promoting gastric mucosal repair.

[0029] Furthermore, the active drug is selected from one or more of Weifuchun tablets, amoxicillin, metronidazole, clarithromycin, doxycycline, furazolidone, organic colloidal bismuth, Weidere, and Ledewei.

[0030] Furthermore, the other auxiliary medical products are selected from one or more of a drug delivery system, a Helicobacter pylori infection detection kit, a combined medication adjuvant, and a capsule coating agent.

[0031] Furthermore, the gastritis is caused by bacterial infection, specifically Helicobacter pylori infection.

[0032] Beneficial effects of the present invention: The size of the magnesium core is selected to be between 15 and 25 microns. The drug coated in the middle PLGA layer can be any substance with antibacterial activity or that promotes gastric mucosal repair. The drug loading and sustained release time can be adjusted by adjusting the thickness of the PLGA interlayer. The selection of the surface enteric coating layer is mainly based on its good electrostatic targeting properties and pH-responsive release properties. Various types of enteric coatings can be selected to adjust the pH node of the shell release. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Electron micrographs of MBE-motor (a: Scanning electron microscope (SEM) image of MBE-motor; b: Particle size distribution of MBE-motor) Figure 2 a, b Colony plate images of Helicobacter pylori after incubation with different samples and statistics of their antibacterial efficiency Figure 3(a) Quantitative analysis of the fluorescence intensity of Rhodamine B (RhB)-labeled PBE / MBE-motor on Muc / Tf-coated plates to simulate normal and inflamed tissues; (b) Statistical analysis of the fluorescence intensity of mouse gastric tissue 8 hours after oral administration of DID-labeled MBE-motor and PBE Figure 4 Quantitative detection results of (a) tumor necrosis factor-α (TNF-α) and (b) interleukin-1-β (IL-1β) by enzyme-linked immunosorbent assay Figure 5 Detection of proliferation activity of gastric mucosal epithelial cells Figure 6 Bacterial survival rate in gastric tissue after different treatments Figure 7 Quantification of interleukin-6 (IL-6) (a) and interleukin-10 (IL-10) (b) in the serum of mice in different groups by enzyme-linked immunosorbent assay Figure 8 (a, b) Analysis of Chao1 richness and Shannon diversity index in fecal samples from different groups DETAILED DESCRIPTION Example 1 Preparation of magnesium-based motor Synthesis of BiNPs: Bi(NO₃)₃·5H₂O (970 mg) was added to 10 mL of 1-dodecanethiol in a three-necked flask under vigorous stirring. The resulting pale yellow mixture was purged with nitrogen for 10 minutes to remove dissolved oxygen and then heated to 178°C using an electric heating mantle. Upon reaching approximately 172°C, the solution gradually changed from dark brown to black. The reaction mixture was maintained at 178°C for 1 minute. A nitrogen atmosphere was maintained throughout the process to prevent oxidation. After cooling to 40°C, the BiNPs were collected by centrifugation (12,000 rpm, 10 minutes) and washed three times with ethanol to remove residual byproducts.

[0034] Fabrication of the MBE-motor: The fabrication process begins with pretreatment of magnesium microspheres, sequentially washing them with isopropyl alcohol and acetone to remove the native magnesium oxide layer. Following this cleaning step, the microspheres are dried under a stream of nitrogen. Approximately 2 mg of the treated microspheres are then evenly dispersed onto a glass slide, serving as a uniform substrate for subsequent coating. To prepare the MBE-motor, 2 mg / mL of BiNPs were added to a 1.5 w / v% poly(lactic-co-glycolic acid) solution in ethyl acetate. After being prepared in 50 mL, the BiNPs were coated onto the magnesium microspheres via a pull-down coating. The coated microspheres were air-dried at room temperature and collected by gentle scraping for downstream use. The M-motor and MB-motor were fabricated using the same steps as the MBE-motor, with the primary difference being that the MB-motor omits the EC-based electrostatic targeting layer. Instead, a 1 w / v% polyvinyl alcohol (PVA) treatment was used to neutralize surface charge. The difference between the M-motor and the MBE-motor lies in the incorporation of BiNPs: the PLGA layer of the M-motor does not contain BiNPs, while the MB-motor incorporates these nanoparticles.

[0035] Example 2: Structural morphology of MBE-motor Scanning electron microscopy imaging revealed open holes of approximately 4 μm on the surface of the MBE-motor, confirming the successful fabrication of the Janus structure ( Figure 1 a); Particle size statistical analysis shows that the average particle size of the complete MBE-motor is about 20 μm ( Figure 1 b).

[0036] Example 3: In vitro antibacterial performance of MBE-motor The plate count method was used to evaluate the bactericidal effect of each group of samples on H. pylori. 2+ The treatment group had almost no antibacterial effect, while the colony counts in the Mg group and the M-motor group decreased slightly, suggesting that H2 may have a certain degree of antibacterial ability ( Figure 2 a). In contrast, the MB-motor group and the MBE-motor group showed significant antibacterial effects, with the number of colonies significantly reduced and almost completely eliminated, indicating that the synergistic effect of H2 and BiNPs significantly enhanced the bactericidal efficacy ( Figure 2 b).

[0037] Example 4: Highly efficient targeted delivery of MBE-motor in vivo and in vitro The surface of the normal gastric mucosa is covered with a layer of negatively charged mucus. When inflammatory damage occurs, the mucus layer is destroyed, resulting in the exposure of positively charged transferrin (Tf), and the inflammatory tissue becomes positively charged. To this end, negatively charged gastric mucin (Muc) and positively charged transferrin (Tf) coated well plates were used to simulate normal tissue and inflammatory tissue, respectively, and a passive targeting group (PBE) with polystyrene (PS) as the core was set up as a control to evaluate the targeting ability of MBE-motor to inflammatory tissue. After incubation with rhodamine B (Rh B)-labeled MBE-motor and PBE for 20 minutes, respectively, the fluorescence intensity of MBE-motor and PBE in the Tf group was much higher than that in the Muc group, indicating that EC gives the material efficient targeting ability to inflammatory tissue. In addition, the fluorescence intensity of MBE-motor in the Tf group is nearly twice that of PBE, indicating that the motor's motion performance can significantly improve the targeting efficiency by enhancing the probability of collision contact ( Figure 3 Finally, the in vivo targeting function of MBE-motor was investigated using healthy mice and mice with H. pylori-induced gastritis as models. Eight hours after oral administration, in vivo imaging revealed greater fluorescence retention in mice with H. pylori gastritis than in healthy mice. Furthermore, the fluorescence retention in the MBE-motor group was 3.09 times greater than that in the PBE group in the H. pylori gastritis mouse model ( Figure 3 b).

[0038] Example 5: In vitro anti-inflammatory properties of MBE-motor A large number of macrophages infiltrate the gastritis area. Figure 4 The blank control (Control), positive control (ROS up), magnesium ion (Mg 2+ ), magnesium microspheres (Mg), M-motor, MB-motor and MBE-motor groups were used to treat macrophages colonized in the well plate and the expression of related inflammatory factors was quantified by enzyme-linked immunosorbent assay. The results showed that compared with ROSup, the expression of tumor necrosis factor-α ( Figure 4 a), interleukin 1-β ( Figure 4 b) The expression level of the mitochondrial kinase was significantly downregulated, basically close to that of the normal group.

[0039] Example 6: MBE-motor promotes cell proliferation in vitro First, calcein-AM fluorescence staining was used to examine the proliferation of gastric mucosal epithelial cells. 2+ The cell number in the Mg and M-motor treatment groups increased significantly, suggesting that Mg 2+It effectively promoted the proliferation of gastric epithelial cells. It is worth noting that the MB-motor and MBE-motor groups that provided sustained release of BiNPs showed more significant enhancement in cell proliferation. These findings indicate that Mg 2+ Both NPs and BiNPs may promote the growth of gastric epithelial cells through complementary or synergistic mechanisms ( Figure 5 ).

[0040] Example 6: Antibacterial performance of MBE-motor in vivo The persistent colonization of Helicobacter pylori in the gastric mucosa poses a significant challenge to effective treatment, so the antibacterial properties of MBE-motor were evaluated by quantifying the bacterial load in gastric tissue homogenates. The results showed that the bacterial colonies in the MB-motor group were significantly reduced, reflecting the synergistic antibacterial effect of H2 and BiNPs. Notably, the MBE-motor group had the highest bactericidal effect, emphasizing the enhanced targeting and gastric retention conferred by the EC shell. In addition, the antibacterial performance of MBE-motor was approximately twice that of conventional antibiotic treatment ( Figure 6 ).

[0041] Example 7: Anti-inflammatory properties of MBE-motor in vivo Then, blood was collected from mice in different treatment groups and enzyme-linked immunosorbent assay was used to quantify the inflammatory factor interleukin-6 and the anti-inflammatory factor interleukin-10. The results showed that interleukin-6 was significantly downregulated and interleukin-10 was significantly increased in the MBE-motor group, indicating a good anti-inflammatory effect ( Figure 7 ).

[0042] Example 8 MBE-motor maintains intestinal flora homeostasis To evaluate the effects of MBE-motor on intestinal microbial homeostasis, 16S rRNA high-throughput sequencing was performed on fecal samples collected after treatment. Mice treated with MBE-motor exhibited significantly higher α-diversity compared with the antibiotic group, as indicated by Chao1 and Shannon indices, but showed no statistical difference from the normal control group ( Figure 8 a, b).

Claims

1. A self-driven micromotor system for treating gastritis, characterized in that: It consists of a magnesium microsphere core layer, a copolymer antibacterial layer loaded with inorganic compound nanoparticles and other active drugs, and an enteric coating layer.

2. The self-driven micromotor system for treating gastritis according to claim 1, characterized in that: The core of the magnesium microspheres is between 10-20 μm, preferably 15 μm; the loaded size of the inorganic compound nanoparticles is about 50-60 nm, preferably 57 nm; and the enteric coating is negatively charged.

3. The self-driven micromotor system for treating gastritis according to claim 1, wherein: The other active drugs can be any substance with antibacterial activity or promoting gastric mucosal repair.

4. The self-driven micromotor system for treating gastritis according to claim 1, wherein: The copolymer is selected from polylactic acid-glycolic acid copolymer, and the copolymer selected from polylactic acid-glycolic acid copolymer can control the degradation rate; the adjustment ratio of polylactic acid and glycolic acid is selected from one of 90:10, 80:20, and 70:30; the molecular weight controlling the degradation rate is 50,000-150,000.

5. The self-driven micromotor system for treating gastritis according to claim 1, wherein: The antibacterial copolymer layer loaded with inorganic compound nanoparticles and other active drugs can adjust the drug loading amount and sustained release time by adjusting the thickness of the copolymer interlayer; the enteric coating layer can adjust the pH node of the shell release.

6. A method for preparing a self-driven micromotor system for treating gastritis, the method comprising the following steps: S1. The inorganic compound was added to a three-necked flask, and the organic compound was added. The resulting pale yellow mixture was purged with nitrogen and then heated to black using an electric heating mantle. After cooling, the product 1 was collected by centrifugation and washed with ethanol. S2. The product 1 obtained in step 1 was added to the configured copolymer solution to obtain a mixed solution; S3. After pre-treating the magnesium microspheres, the treated magnesium microspheres were evenly dispersed on a glass slide, coated with the mixed solution obtained in step 2, and then coated with an enteric coating. The microspheres were air-dried at room temperature and collected by gently scraping.

7. An application of the self-driven micromotor system according to claim 1 in the preparation of drugs for treating gastritis and other auxiliary medical products, characterized in that: The medicine for treating gastritis contains a self-driven micromotor system and other active drugs.

8. The use of the self-driven micromotor system according to claim 7 in the preparation of drugs for treating gastritis and other auxiliary medical products, characterized in that: The other active drugs can be any substance with antibacterial activity or promoting gastric mucosal repair.

9. The use of the self-driven micromotor system according to claim 7 in the preparation of drugs for treating gastritis and other auxiliary medical products, characterized in that: The active drug is selected from one or more of Weifuchun tablets, amoxicillin, metronidazole, clarithromycin, doxycycline, furazolidone, organic colloidal bismuth, Weidere, and Ledewei.

10. The use of the self-driven micromotor system according to claim 7 in the preparation of drugs for treating gastritis and other auxiliary medical products, characterized in that: The other auxiliary medical products are selected from one or more of a drug delivery system, a Helicobacter pylori infection detection kit, a combined medication adjuvant, and a capsule coating agent.

Images