Nanocomposite for early diagnosis and treatment of gastric cancer and preparation method thereof

Abstract

The invention relates to the technical field of biological medicine, in particular to a nano-composite for early diagnosis and treatment of gastric cancer and a preparation method of the nano-composite, and the nano-composite comprises a nano-carrier, a diagnosis function module connected to the surface of the nano-carrier, a treatment function module loaded on the nano-carrier and a targeted modification group modified on the surface of the nano-carrier. According to the invention, the antibody or the aptamer which is connected to the surface of the nano-composite and is used for specifically recognizing a gastric cancer cell surface marker is beneficial to early discovery of gastric cancer lesions; the nano-composite can deliver a therapeutic drug to gastric cancer tissues in a targeted manner, so that the concentration of the drug in a tumor site is improved, and the killing effect of the drug on gastric cancer cells is enhanced; the nano compound disclosed by the invention integrates diagnosis and treatment functions; the nano-carrier adopted by the nano-composite has good biocompatibility and degradability, does not cause obvious immune response in vivo, and can be gradually degraded and discharged out of the body after a treatment task is completed; the preparation method is simple and low in cost.

Description

Technical Field

[0001] The present invention relates to the field of biomedical technology, and in particular to a nanocomposite for early diagnosis and treatment of gastric cancer and a preparation method thereof. Background Art

[0002] Gastric cancer is one of the most common malignant tumors in the world and poses a serious threat to human life and health. Early diagnosis and effective treatment are the key to improving the survival rate and prognosis of gastric cancer patients. However, the early diagnosis of gastric cancer currently faces many challenges. Existing diagnostic methods such as gastroscopy and pathological biopsy have problems such as strong invasiveness and poor patient compliance, and the sensitivity of detecting early microlesions is limited; although serological marker detection has a certain degree of convenience, the diagnostic accuracy of a single marker is not ideal. In terms of treatment, traditional surgical treatment, chemotherapy, and radiotherapy have problems such as large trauma, obvious side effects, and easy development of drug resistance. The treatment effect for patients with advanced gastric cancer is often unsatisfactory.

[0003] With the rapid development of nanotechnology, nanomaterials have shown great application potential in the field of biomedicine. Nanomaterials have unique physical and chemical properties, such as small size effect, high specific surface area, good biocompatibility, etc., which can achieve efficient loading and targeted delivery of biomolecules. Applying nanotechnology to the diagnosis and treatment of gastric cancer is expected to develop a new and efficient integrated diagnosis and treatment strategy, bringing new hope to gastric cancer patients.

[0004] Therefore, those skilled in the art provide a nanocomposite for early diagnosis and treatment of gastric cancer and a preparation method thereof to solve the problems raised in the above background technology. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a nanocomposite for early diagnosis and treatment of gastric cancer and a preparation method thereof;

[0006] A nanocomposite for early diagnosis and treatment of gastric cancer, mainly composed of the following parts:

[0007] Nanocarrier: Nanomaterials with good biocompatibility and degradability are used as carriers;

[0008] Diagnostic function module: The diagnostic function module connected to the surface of the nanocarrier is used to achieve early diagnosis of gastric cancer;

[0009] Therapeutic functional module: The nanocomplex is loaded with therapeutic drugs with anti-tumor activity;

[0010] Targeting modification groups: In order to further improve the targeting of the nanocomplex to gastric cancer tissue, targeting modification groups were modified on the surface of the nanocarrier.

[0011] Preferably, the material of the nanocarrier is one or more of polylactic acid-co-glycolic acid (PLGA) nanoparticles and silicon dioxide nanoparticles.

[0012] Preferably, the diagnostic function module uses antibodies and aptamers that specifically recognize surface markers of gastric cancer cells, including anti-human epidermal growth factor receptor 2 (HER2) antibodies and aptamers for gastric cancer-related antigens.

[0013] Preferably, the targeting modification group is one or more of folic acid and cyclic peptide.

[0014] Preferably, the therapeutic function module is a therapeutic drug with anti-tumor activity, including one or more of chemotherapeutic drugs, small molecule inhibitors, and nucleic acid drugs.

[0015] A method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer comprises the following steps:

[0016] Step 1, preparing nanocarriers;

[0017] Step 2: Activate the surface of the nanocarrier, and then couple it with the diagnostic function module to obtain a nanocarrier with a surface modified with the diagnostic function module;

[0018] Step 3: Loading the therapeutic functional module onto the nanocarrier whose surface is modified with the diagnostic functional module;

[0019] Step 4: Activate the surface of the nanocarrier loaded with the therapeutic functional module, and then react with the targeting modification group to obtain a nanocomplex for early diagnosis and treatment of gastric cancer.

[0020] Preferably, when preparing the nanocarrier, PLGA nanoparticles are used as carriers, and the method for preparing the nanocarrier is one or more of an emulsification-solvent evaporation method and a chemical precipitation method. The steps for preparing PLGA nanoparticles by the emulsification-solvent evaporation method are as follows:

[0021] Preparation of PLGA nanoparticles: PLGA nanoparticles were prepared by emulsification-solvent evaporation method;

[0022] S11, dissolving PLGA in an organic solvent (such as dichloromethane) to form an oil phase;

[0023] S12, using an aqueous solution containing an emulsifier (such as polyvinyl alcohol, PVA) as the aqueous phase, and slowly dropping the oil phase into the aqueous phase under high-speed stirring or ultrasonic action to form an oil-in-water (O / W) emulsion;

[0024] S13, volatilizing the organic solvent from the emulsion under stirring conditions to solidify the PLGA nanoparticles;

[0025] S14, removing unreacted raw materials and impurities through centrifugation and washing steps to obtain pure PLGA nanoparticles.

[0026] Preferably, the operation steps of step 2 are as follows:

[0027] S21, performing surface activation treatment on the prepared PLGA nanoparticles using a carboxylation reagent and N-hydroxysuccinimide;

[0028] S22, coupling the antibody or aptamer that specifically recognizes the surface marker of gastric cancer cells with the activated PLGA nanoparticles under certain conditions, so that the antibody or aptamer is connected to the surface of the nanoparticles;

[0029] S23, after the reaction is completed, unbound antibodies or aptamers are removed by dialysis or ultrafiltration to obtain PLGA nanoparticles with surface modified with diagnostic functional modules.

[0030] Preferably, the operation steps of step three are as follows:

[0031] S31, classifies the methods of loading therapeutic drugs into physical adsorption and chemical bonding;

[0032] The physical adsorption method is to mix the prepared PLGA nanoparticles with the diagnostic function modules on the surface with the therapeutic drug solution, and load the therapeutic drug on the surface or inside of the nanoparticles through physical adsorption under certain temperature and stirring conditions;

[0033] The chemical bonding method is to introduce corresponding functional groups, such as amino and carboxyl groups, on the surface of therapeutic drugs and nanoparticles, and combine the therapeutic drugs and nanoparticles through chemical bonding under the action of cross-linking agents;

[0034] S32, after loading the drug, removing the unloaded drug through steps such as centrifugation and washing to obtain PLGA nanoparticles loaded with therapeutic drugs.

[0035] Preferably, the operation method of step 4 is as follows:

[0036] S41, activating the targeting modification group (such as folic acid) so that it can react with the functional groups on the surface of the nanoparticles;

[0037] S42, reacting the activated targeting modification group with the PLGA nanoparticles loaded with therapeutic drugs under certain conditions, so that the targeting modification group is modified on the surface of the nanoparticles;

[0038] S43, after the reaction is completed, unreacted targeting modification groups are removed by dialysis or ultrafiltration to obtain the final nanocomplex for early diagnosis and treatment of gastric cancer.

[0039] Applications of Nanocomposites

[0040] Early diagnosis of gastric cancer: The prepared nanocomplex is introduced into the body by intravenous injection or other methods. The diagnostic function module on the surface of the nanocomplex can specifically identify and bind to the markers on the surface of gastric cancer cells. Then, by using corresponding detection technologies, such as fluorescence imaging technology, the location and detection of gastric cancer cells can be achieved by detecting the fluorescent signal emitted by the nanocomplex. Since the nanocomplex has high sensitivity and specificity, it can detect early tiny gastric cancer lesions, providing a new and effective means for the early diagnosis of gastric cancer.

[0041] Gastric cancer treatment: Nanocomplexes are enriched in gastric cancer tissues in vivo through passive targeting and active targeting. Over time, the therapeutic drugs in the nanocomplexes are gradually released, playing a killing role on gastric cancer cells. Compared with traditional chemotherapy drugs, nanocomplexes can deliver drugs to gastric cancer tissues in a targeted manner, increase the concentration of drugs at the tumor site, and reduce toxic side effects on normal tissues, thereby improving the therapeutic effect. At the same time, nanocomplexes can also be combined with other treatment methods, such as photothermal therapy, immunotherapy, etc., to achieve comprehensive treatment of gastric cancer and further improve the therapeutic effect.

[0042] Technical effects and advantages of the present invention:

[0043] High sensitivity and specificity for early diagnosis: Antibodies or aptamers that specifically recognize surface markers of gastric cancer cells and are connected to the surface of the nanocomplex can specifically bind to gastric cancer cells. Through advanced detection technology, high-sensitivity detection and positioning of early gastric cancer cells can be achieved, which greatly improves the accuracy of early diagnosis of gastric cancer, helps to detect gastric cancer lesions at an early stage, and strives for the best treatment opportunity for patients.

[0044] High efficiency and low toxicity and side effects of treatment: Nanocomplexes can deliver therapeutic drugs to gastric cancer tissues in a targeted manner, increase the concentration of drugs in the tumor site, and enhance the killing effect of drugs on gastric cancer cells. At the same time, since the distribution of drugs in normal tissues is reduced, the toxicity and side effects on normal tissues are reduced, and the patient's tolerance and treatment effect are improved.

[0045] Integrated diagnosis and treatment: The nanocomposite of the present invention integrates diagnosis and treatment functions, realizing the integrated diagnosis and treatment of gastric cancer. Through a single administration, early diagnosis and treatment of gastric cancer can be achieved simultaneously, avoiding the multiple operations of traditional diagnosis and treatment methods, reducing the pain of patients and medical costs.

[0046] Good biocompatibility and degradability: The nanocarriers used in the nanocomplex have good biocompatibility and degradability, will not cause obvious immune response in the body, and can be gradually degraded and excreted from the body after completing the therapeutic task, without causing long-term adverse effects on the human body.

[0047] The preparation method is simple and low-cost: The nanocomposite preparation method of the present invention is easy to operate, and the raw materials and equipment used are conventional materials and equipment, with relatively low cost, and is suitable for large-scale production and clinical application. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the composition of a nanocomposite for early diagnosis and treatment of gastric cancer provided in an embodiment of the present application;

[0049] Figure 2 This is a flow chart of a method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer provided in an embodiment of the present application;

[0050] Figure 3 This is a flow chart of step 1 in a method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer provided in an embodiment of the present application;

[0051] Figure 4 This is a flow chart of step 2 in a method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer provided in an embodiment of the present application;

[0052] Figure 5 This is a flow chart of step 3 in a method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer provided in an embodiment of the present application;

[0053] Figure 6 This is a schematic flow chart of step 4 in a method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer provided in an embodiment of the present application; DETAILED DESCRIPTION

[0054] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0055] Example 1

[0056] See also Figures 1 to 6In this embodiment, a nanocomposite for early diagnosis and treatment of gastric cancer and a preparation method thereof are provided, comprising:

[0057] A nanocomposite for early diagnosis and treatment of gastric cancer, mainly composed of the following parts:

[0058] Nanocarrier: Nanomaterials with good biocompatibility and degradability are used as carriers;

[0059] Diagnostic function module: The diagnostic function module connected to the surface of the nanocarrier is used to achieve early diagnosis of gastric cancer;

[0060] Therapeutic functional module: The nanocomplex is loaded with therapeutic drugs with anti-tumor activity; Targeting modification group: In order to further improve the targeting of the nanocomplex to gastric cancer tissue, the surface of the nanocarrier is modified with a targeting modification group.

[0061] Preferably, the material of the nanocarrier is one or more of polylactic acid-co-glycolic acid (PLGA) nanoparticles and silicon dioxide (SiO2) nanoparticles; taking PLGA nanoparticles as an example, they have a suitable particle size distribution (generally between 100-500nm) and can be enriched in tumor tissues through passive targeting (enhanced penetration and retention effect, EPR effect). At the same time, the surface of PLGA nanoparticles can be modified in various ways to meet different functional requirements.

[0062] Preferably, the diagnostic function module uses antibodies and aptamers that specifically recognize surface markers of gastric cancer cells, including anti-human epidermal growth factor receptor 2 (HER2) antibodies and aptamers against gastric cancer-related antigens; these antibodies or aptamers can specifically bind to corresponding markers on the surface of gastric cancer cells, and achieve highly sensitive detection and positioning of gastric cancer cells through technical means such as immunofluorescence, magnetic resonance imaging (MRI), and fluorescence imaging.

[0063] Preferably, the targeting modification group is one or more of folic acid and cyclic peptide; these targeting modification groups can specifically bind to receptors overexpressed on the surface of gastric cancer cells, such as folate receptors, integrin receptors, etc., to achieve active targeted delivery of the nanocomplex and improve its enrichment efficiency in gastric cancer tissue.

[0064] Preferably, the therapeutic functional module is a therapeutic drug with anti-tumor activity, including one or more of chemotherapeutic drugs, small molecule inhibitors, and nucleic acid drugs; the therapeutic drug is loaded inside or on the surface of the nanocarrier by physical adsorption, chemical bonding, etc. When the nanocomplex reaches the gastric cancer tissue, the therapeutic drug can be slowly released to play a killing effect on gastric cancer cells.

[0065] A method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer comprises the following steps:

[0066] Step 1, preparing nanocarriers;

[0067] When preparing the nanocarrier, PLGA nanoparticles are used as carriers. The method for preparing the nanocarrier is one or more of an emulsification-solvent evaporation method and a chemical precipitation method. The steps for preparing PLGA nanoparticles by the emulsification-solvent evaporation method are as follows:

[0068] Preparation of PLGA nanoparticles: PLGA nanoparticles were prepared by emulsification-solvent evaporation method;

[0069] S11, dissolving PLGA in an organic solvent (such as dichloromethane) to form an oil phase;

[0070] S12, using an aqueous solution containing an emulsifier (such as polyvinyl alcohol, PVA) as the aqueous phase, and slowly dropping the oil phase into the aqueous phase under high-speed stirring or ultrasonic action to form an oil-in-water (O / W) emulsion;

[0071] S13, volatilizing the organic solvent from the emulsion under stirring conditions to solidify the PLGA nanoparticles;

[0072] S14, removing unreacted raw materials and impurities through centrifugation and washing steps to obtain pure PLGA nanoparticles;

[0073] Step 2: Activate the surface of the nanocarrier, and then couple it with the diagnostic function module to obtain a nanocarrier with a surface modified with the diagnostic function module;

[0074] S21, performing surface activation treatment on the prepared PLGA nanoparticles, such as using a carboxylation reagent (such as 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, EDC) and N-hydroxysuccinimide (NHS) to activate the carboxyl groups on the surface of the nanoparticles;

[0075] S22, coupling the antibody or aptamer that specifically recognizes the surface marker of gastric cancer cells with the activated PLGA nanoparticles under certain conditions, so that the antibody or aptamer is connected to the surface of the nanoparticles;

[0076] S23, after the reaction is completed, removing the unbound antibody or aptamer by dialysis or ultrafiltration to obtain PLGA nanoparticles with surface modified with diagnostic functional modules;

[0077] Step 3: Loading the therapeutic functional module onto the nanocarrier whose surface is modified with the diagnostic functional module;

[0078] S31, classifies the methods of loading therapeutic drugs into physical adsorption and chemical bonding;

[0079] The physical adsorption method is to mix the prepared PLGA nanoparticles with the diagnostic function modules on the surface with the therapeutic drug solution, and load the therapeutic drug on the surface or inside of the nanoparticles through physical adsorption under certain temperature and stirring conditions;

[0080] The chemical bonding method is to introduce corresponding functional groups, such as amino and carboxyl groups, on the surface of therapeutic drugs and nanoparticles, and combine the therapeutic drugs and nanoparticles through chemical bonding under the action of cross-linking agents;

[0081] S32, after loading the drug, removing the unloaded drug by centrifugation, washing, etc., to obtain PLGA nanoparticles loaded with therapeutic drugs;

[0082] Step 4: Surface activation treatment is performed on the nanocarrier loaded with the therapeutic functional module, and then reacts with the targeted modification group to obtain a nanocomposite for early diagnosis and treatment of gastric cancer:

[0083] S41, activating the targeting modification group (such as folic acid) so that it can react with the functional groups on the surface of the nanoparticles;

[0084] S42, reacting the activated targeting modification group with the PLGA nanoparticles loaded with therapeutic drugs under certain conditions, so that the targeting modification group is modified on the surface of the nanoparticles;

[0085] S43, after the reaction is completed, unreacted targeting modification groups are removed by dialysis or ultrafiltration to obtain the final nanocomplex for early diagnosis and treatment of gastric cancer.

[0086] Applications of Nanocomposites

[0087] Early diagnosis of gastric cancer: The prepared nanocomplex is introduced into the body by intravenous injection or other methods. The diagnostic function module on the surface of the nanocomplex can specifically identify and bind to the markers on the surface of gastric cancer cells. Then, by using corresponding detection technologies, such as fluorescence imaging technology, the location and detection of gastric cancer cells can be achieved by detecting the fluorescent signal emitted by the nanocomplex. Since the nanocomplex has high sensitivity and specificity, it can detect early tiny gastric cancer lesions, providing a new and effective means for the early diagnosis of gastric cancer.

[0088] Gastric cancer treatment: Nanocomplexes are enriched in gastric cancer tissues in vivo through passive targeting and active targeting. Over time, the therapeutic drugs in the nanocomplexes are gradually released, playing a killing role on gastric cancer cells. Compared with traditional chemotherapy drugs, nanocomplexes can deliver drugs to gastric cancer tissues in a targeted manner, increase the concentration of drugs at the tumor site, and reduce toxic side effects on normal tissues, thereby improving the therapeutic effect. At the same time, nanocomplexes can also be combined with other treatment methods, such as photothermal therapy, immunotherapy, etc., to achieve comprehensive treatment of gastric cancer and further improve the therapeutic effect.

[0089] Example 2: Preparation of Nanocomposites

[0090] Preparation of PLGA nanoparticles

[0091] S11, dissolving 100 mg of PLGA (molar ratio of lactic acid to glycolic acid is 50:50, molecular weight is 30000) in 5 mL of dichloromethane to form an oil phase;

[0092] S12, using 10 mL of an aqueous solution containing 1% (w / v) polyvinyl alcohol (PVA) as the aqueous phase, and slowly dropping the oil phase into the aqueous phase under high-speed stirring (10000 rpm) to form an oil-in-water (O / W) emulsion;

[0093] S13, continue stirring for 2 hours to volatilize the dichloromethane and solidify the PLGA nanoparticles;

[0094] S14, the emulsion was centrifuged at 12000 rpm for 15 minutes at 4°C, the supernatant was removed, and the precipitate was washed three times with deionized water to obtain pure PLGA nanoparticles.

[0095] Connection of diagnostic function modules

[0096] S21, taking 100 mg of the PLGA nanoparticles prepared above, adding them into 10 mL of MES buffer (pH=6.0) containing 10 mg EDC and 5 mg NHS, and stirring the mixture at room temperature for 30 minutes to activate the carboxyl groups on the surface of the PLGA nanoparticles.

[0097] S22, then, add 100 μg of anti-human epidermal growth factor receptor 2 (HER2) antibody, and stir at 4°C to react overnight.

[0098] S23, after the reaction is completed, the mixture is placed in a dialysis bag (molecular weight cutoff is 3500Da), and dialyzed in deionized water for 24 hours to remove unbound antibodies and impurities, thereby obtaining PLGA nanoparticles with surface modified with anti-HER2 antibodies.

[0099] Therapeutic drug load

[0100] Paclitaxel was loaded by physical adsorption;

[0101] S31, adding 100 mg of PLGA nanoparticles modified with anti-HER2 antibodies to 10 mL of anhydrous ethanol solution containing 10 mg of paclitaxel, and stirring the mixture at 37° C. for 6 hours.

[0102] S32, then, the mixture was centrifuged at 12000 rpm at 4°C for 15 minutes, the supernatant was removed, and the precipitate was washed three times with anhydrous ethanol to obtain paclitaxel-loaded PLGA nanoparticles.

[0103] Modification of targeted modifying groups

[0104] S41, 10 mg of folic acid was dissolved in 10 mL of MES buffer (pH=6.0) containing 10 mg of EDC and 5 mg of NHS, and the mixture was stirred at room temperature for 30 minutes to activate the folic acid.

[0105] S42, then, adding the activated folic acid solution to 100 mg of paclitaxel-loaded PLGA nanoparticles, and stirring the mixture at 4° C. to react overnight.

[0106] S43, after the reaction is completed, the mixture is placed in a dialysis bag (molecular weight cutoff is 3500Da), and dialyzed in deionized water for 24 hours to remove unreacted folic acid and impurities, thereby obtaining the final nanocomposite for early diagnosis and treatment of gastric cancer.

[0107] Example 3: Testing of the performance of nanocomplexes in early diagnosis of gastric cancer

[0108] Cell experiments

[0109] Human gastric cancer cells (such as AGS cells) and normal human gastric epithelial cells (such as GES-1 cells) were inoculated in 96-well plates, with 1×10 4 cells, cultured for 24 hours;

[0110] Then, the nanocomplex prepared in Example 1 was diluted to different concentrations with serum-free medium, added to a 96-well plate, and cultured for another 4 hours;

[0111] The cells were washed three times with PBS and fixed with 4% paraformaldehyde for 15 min;

[0112] The cells were then washed three times with PBS and DAPI was added to stain the nuclei for 5 min;

[0113] Finally, the cells were observed using a fluorescence microscope to detect the fluorescence signals of the nanocomplex in gastric cancer cells and normal cells.

[0114] The results showed that the nanocomplex could specifically bind to gastric cancer cells and emit a strong fluorescence signal in gastric cancer cells, while the fluorescence signal was weak in normal cells.

[0115] Animal experiments

[0116] Bal b / c nude mice were used to establish a subcutaneous transplanted tumor model of human gastric cancer;

[0117] Tumor-bearing nude mice were randomly divided into two groups, with 5 mice in each group;

[0118] The nanocomplex prepared in Example 2 and normal saline were injected through the tail vein, respectively;

[0119] 24 hours after injection, the nude mice were anesthetized and imaged using an in vivo fluorescence imager.

[0120] The results showed that nude mice injected with the nanocomplex had obvious fluorescent signals at the tumor site, while nude mice injected with normal saline had no obvious fluorescent signals at the tumor site; this indicates that the nanocomplex can be specifically enriched in gastric cancer tissues in vivo, enabling early diagnosis of gastric cancer.

[0121] Example 4: Testing of the Gastric Cancer Treatment Effect of Nanocomplexes

[0122] Cell experiments

[0123] Human gastric cancer cells (such as AGS cells) were inoculated in a 96-well plate, with 1×10 4 cells, cultured for 24 hours;

[0124] Then, the nanocomplex prepared in Example 2 was diluted to different concentrations with serum-free medium and added to a 96-well plate. A control group (with equal amounts of physiological saline and free paclitaxel solution) was set up and cultured for 48 hours.

[0125] Add 10 μL of CCK-8 reagent to each well and continue culturing for 4 h;

[0126] The absorbance was measured at a wavelength of 450 nm using an enzyme-labeled instrument to calculate the cell survival rate.

[0127] The results showed that the nanocomplex had a significant inhibitory effect on the growth of gastric cancer cells, and the inhibitory effect was better than that of free paclitaxel solution.

[0128] Animal experiments

[0129] Balb / c nude mice were used to establish a subcutaneous transplanted tumor model of human gastric cancer;

[0130] Tumor-bearing nude mice were randomly divided into three groups, with 5 mice in each group;

[0131] The nanocomplex prepared in Example 1, free paclitaxel solution and normal saline were injected through the tail vein respectively;

[0132] The tumor volume and body weight of nude mice were measured every 3 days for 21 consecutive days.

[0133] The results showed that the tumor growth of nude mice injected with nanocomplexes was significantly inhibited, and the tumor volume was significantly smaller than that of nude mice injected with free paclitaxel solution and saline; at the same time, the weight of nude mice injected with nanocomplexes changed less, indicating that the nanocomplexes had less toxic side effects on normal tissues. This shows that nanocomplexes can effectively treat gastric cancer with lower toxic side effects.

[0134] In the preparation process of the nanocomposite of the present invention, the reaction conditions, such as temperature, time, concentration of reactants, etc., should be strictly controlled to ensure the quality and performance of the nanocomposite.

[0135] During storage and transportation, care should be taken to maintain the stability of nanocomposites and avoid the influence of factors such as light, high temperature, and high humidity.

[0136] When conducting in vivo experiments on nanocomplexes, animal experiment ethics standards should be strictly followed to ensure the welfare and safety of experimental animals.

[0137] As a new type of biomedical material, nanocomposites need to undergo sufficient safety and effectiveness evaluation before clinical application to ensure their safety and reliability in the human body.

[0138] The electrical components appearing in this article are all electrically connected to an external main controller and 220V AC power, and the main controller can be a conventional known device that controls a computer, etc. The specific implementation method of the present disclosure omits the detailed description of known functions and known components. To ensure the compatibility of the equipment, the operating methods used are consistent with the parameters of marketed equipment.

[0139] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A nanocomposite for early diagnosis and treatment of gastric cancer, characterized in that: It includes a nanocarrier, a diagnostic function module connected to the surface of the nanocarrier, a therapeutic function module loaded on the nanocarrier, and a targeting modification group modified on the surface of the nanocarrier.

2. The nanocomposite for early diagnosis and treatment of gastric cancer according to claim 1, characterized in that: The nanocarrier is one or more of polylactic acid-glycolic acid copolymer nanoparticles and silicon dioxide nanoparticles.

3. The nanocomposite for early diagnosis and treatment of gastric cancer according to claim 1, characterized in that: The diagnostic function module is an antibody or aptamer that specifically recognizes surface markers of gastric cancer cells.

4. The nanocomposite for early diagnosis and treatment of gastric cancer and the preparation method thereof according to claim 1, characterized in that: The therapeutic function module is a therapeutic drug with anti-tumor activity, including one or more of chemotherapeutic drugs, small molecule inhibitors, and nucleic acid drugs.

5. The nanocomposite for early diagnosis and treatment of gastric cancer according to claim 1, characterized in that: The targeting modification group is one or more of folic acid and cyclic peptide.

6. The method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1, preparing nanocarriers; Step 2: Activate the surface of the nanocarrier, and then couple it with the diagnostic function module to obtain a nanocarrier with a surface modified with the diagnostic function module; Step 3: Loading the therapeutic functional module onto the nanocarrier whose surface is modified with the diagnostic functional module; Step 4: Activate the surface of the nanocarrier loaded with the therapeutic functional module, and then react with the targeting modification group to obtain a nanocomplex for early diagnosis and treatment of gastric cancer.

7. The method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer according to claim 6, characterized in that: The method for preparing the nanocarrier in step 1 is one or more of the emulsification-solvent evaporation method and the chemical precipitation method. The steps for preparing PLGA nanoparticles by the emulsification-solvent evaporation method are as follows: S11, dissolving PLGA in an organic solvent to form an oil phase; S12, using an aqueous solution containing an emulsifier as the aqueous phase, and slowly dropping the oil phase into the aqueous phase under high-speed stirring or ultrasonic action to form an oil-in-water emulsion; S13, volatilizing the organic solvent from the emulsion under stirring conditions to solidify the PLGA nanoparticles; S14, removing unreacted raw materials and impurities through centrifugation and washing steps to obtain pure PLGA nanoparticles.

8. The method for preparing a nanocomposite for early diagnosis and treatment of gastric cancer according to claim 6, characterized in that: The operation steps in step 2 are as follows: S21, performing surface activation treatment on the prepared PLGA nanoparticles using a carboxylation reagent and N-hydroxysuccinimide; S22, coupling the antibody or aptamer that specifically recognizes the surface marker of gastric cancer cells with the activated PLGA nanoparticles under certain conditions, so that the antibody or aptamer is connected to the surface of the nanoparticles; S23, after the reaction is completed, unbound antibodies or aptamers are removed by dialysis or ultrafiltration to obtain PLGA nanoparticles with surface modified with diagnostic functional modules.

9. The nanocomposite for early diagnosis and treatment of gastric cancer and the preparation method thereof according to claim 6, characterized in that: The operation steps of step three are as follows: S31, loading the therapeutic function module onto the nanocarrier with the diagnostic function module modified on the surface, specifically by one or more of physical adsorption method and chemical bonding method; The physical adsorption method is to mix the prepared PLGA nanoparticles with the diagnostic function modules on the surface with the therapeutic drug solution, and load the therapeutic drug on the surface or inside of the nanoparticles through physical adsorption under certain temperature and stirring conditions; The chemical bonding method is to introduce corresponding functional groups, such as amino and carboxyl groups, on the surface of therapeutic drugs and nanoparticles, and combine the therapeutic drugs and nanoparticles through chemical bonding under the action of cross-linking agents; S32, after loading the drug, removing the unloaded drug through steps such as centrifugation and washing to obtain PLGA nanoparticles loaded with therapeutic drugs.

10. The nanocomposite for early diagnosis and treatment of gastric cancer and the preparation method thereof according to claim 6, characterized in that: The operation steps of step 4 are as follows: S41, activating the targeting modification group so that it can react with the functional groups on the surface of the nanoparticles; S42, reacting the activated targeting modification group with the PLGA nanoparticles loaded with therapeutic drugs under certain conditions, so that the targeting modification group is modified on the surface of the nanoparticles; S43, after the reaction is completed, unreacted targeting modification groups are removed by dialysis or ultrafiltration to obtain the final nanocomplex for early diagnosis and treatment of gastric cancer.

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