Acid response conjugated polymer ZnO composite nanomaterial as well as preparation method and application thereof

Abstract

The invention discloses an acid response conjugated polymer ZnO composite nanomaterial as well as a preparation method and application thereof, and belongs to the technical field of organic-inorganic hybrid nanomaterials. The acid response conjugated polymer ZnO composite nanomaterial can be used for fluorescence imaging and sonodynamic therapy of tumors. The ZnO quantum dots can quench the fluorescence and acoustic dynamic performance of the conjugated polymer through charge transfer, in the normal environment, the fluorescence emission and acoustic dynamic performance of the conjugated polymer in the acid response conjugated polymer ZnO composite nanomaterial is inhibited, but activation response is achieved in the tumor acid environment, and the tumor response is inhibited. ZnO is decomposed, so that the fluorescence and sonodynamic performance of the conjugated polymer is recovered, meanwhile, released Zn < 2 + > can induce pyroptosis, and the tumor treatment effect is improved to a certain extent.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of organic-inorganic hybrid nanomaterials, in particular to an acid-responsive conjugated polymer ZnO composite nanomaterial and a preparation method and application thereof. Background Art

[0002] Sonodynamic therapy is a technology that uses sonosensitizers under ultrasound to generate reactive oxygen free radicals, which oxidatively destroy various biomacromolecules in tissues and cells, causing irreversible damage to abnormal cells to achieve the purpose of treatment. It has the advantages of deep tissue penetration and the ability to reduce systemic toxic reactions. Conjugated polymers are an emerging class of sonosensitizers for sonodynamic therapy, and can achieve near-infrared second-zone luminescence for high-resolution bioimaging. However, most of the sonosensitizers reported so far, including conjugated polymers, are of the "always-on" type and cannot be specifically activated in the tumor microenvironment.

[0003] ZnO quantum dots are easy to synthesize, inexpensive, and have acid responsiveness, and can be effectively degraded in the acidic microenvironment of tumors. ZnO quantum dots themselves have good biocompatibility, but the Zn 2+ It can interfere with the mitochondrial function of cancer cells and activate the caspase-3 / gasderminD (GSDMD)-dependent cell pyroptosis pathway. Zinc itself supports immune cell function (such as T cell activation), which may enhance the body's anti-tumor immune response. In addition, ZnO quantum dots can quench the fluorescence of conjugated polymers through a light-induced electron transfer mechanism and affect the sonodynamic properties of polymers.

[0004] Therefore, after compounding a suitable conjugated polymer with ZnO, a composite material with significantly suppressed fluorescence and sonodynamic therapy effects can be obtained. This composite material needs to remain suppressed in normal tissues, but in the acidic environment of tumors, the ZnO structure can be destroyed, its conduction band energy level disappears or the electron transmission path is interrupted, and the conjugated polymer restores its original performance. This "quenching-recovery" property can be designed as an intelligent diagnostic and therapeutic agent for fluorescence imaging and sonodynamic therapy of diseases such as tumors. Summary of the invention

[0005] In order to provide a composite material that can be used for fluorescence imaging and sonodynamic therapy of diseases such as tumors, the present invention provides an acid-responsive conjugated polymer ZnO composite nanomaterial and a preparation method and application thereof.

[0006] The present invention first mixes ZnO quantum dots with conjugated polymers, and then uses an amphiphilic surfactant to modify the mixture to obtain an acid-responsive conjugated polymer ZnO composite nanomaterial, wherein the surfactant is coated on the surface of the conjugated polymer ZnO nanoaggregate. The acid-responsive conjugated polymer ZnO composite nanomaterial is a water-soluble material. Under normal conditions, the fluorescence emission and sonodynamic properties of the conjugated polymer are suppressed. However, under the acidic environment of the tumor, ZnO decomposes, thereby restoring the near-infrared second-zone imaging capability and sonodynamic properties of the conjugated polymer, and the released ZnO is released. 2+ It can induce cell pyroptosis and improve the therapeutic effect to a certain extent.

[0007] The method for preparing the acid-responsive conjugated polymer ZnO composite nanomaterial provided by the present invention specifically comprises the following steps:

[0008] Step 1, dissolving the conjugated polymer PCPDTBT in an organic solvent to obtain a solution A, dissolving the ZnO quantum dots in an organic solvent to obtain a solution B, and mixing the solution A and the solution B to obtain a mixed solution containing the conjugated polymer and ZnO;

[0009] Step 2, preparing an amphiphilic surfactant aqueous solution;

[0010] Step 3: Under ultrasonic conditions, the mixed solution containing the conjugated polymer and ZnO is quickly injected into the aqueous solution of the amphiphilic surfactant, and the organic solvent is removed after mixing evenly, and then ultrafiltration is performed for purification to obtain the acid-responsive conjugated polymer ZnO composite nanomaterial.

[0011] Furthermore, in the preparation method:

[0012] In step 1, the concentrations of solution A and solution B are both 1 mg / mL, and the volume ratio of solution A to solution B is (1-6):1; solution A and solution B are mixed and stirred for 2 hours to obtain a mixed solution containing a conjugated polymer and ZnO.

[0013] In step 2, the concentration of the aqueous solution of the amphiphilic surfactant is 2-8 mg / mL;

[0014] In step 3, the volume ratio of the mixed solution containing the conjugated polymer and ZnO to the aqueous solution of the amphiphilic surfactant is (1-2): (25-45); the mixing method is ultrasound.

[0015] Furthermore, the organic solvent is chloroform or tetrahydrofuran.

[0016] Furthermore, the ZnO quantum dots are hydrophobic ZnO quantum dots, which are synthesized by reacting zinc acetate, magnesium acetate and sodium hydroxide, and then modified by using butylamine and octadecyltrimethoxysilane.

[0017] Furthermore, when the organic solvent is chloroform, solution B is a ZnO quantum dot chloroform solution, and the preparation method is:

[0018] Dissolve zinc acetate dihydrate and magnesium acetate dihydrate in anhydrous ethanol; prepare an ethanol solution of NaOH by reflux heating; cool the two solutions in an ice bath; slowly drop the ethanol solution of NaOH into the anhydrous ethanol of zinc acetate and magnesium acetate; stir the mixture of the two for a period of time at room temperature; after the reaction is completed, precipitate with cyclohexane, centrifuge, and wash with ethanol to obtain ZnO quantum dots; disperse the ZnO quantum dots in a mixed solution of toluene-ethanol, and add butylamine and octadecyltrimethoxysilane; add ethanol for precipitation after ultrasonic treatment, and disperse in chloroform after washing to obtain a chloroform solution of ZnO quantum dots.

[0019] When the organic solvent is tetrahydrofuran, chloroform is replaced with tetrahydrofuran, and the remaining steps are the same as those of the ZnO quantum dot chloroform solution.

[0020] Furthermore, the amphiphilic surfactant is selected from any one of PSMA-PEG (resulted from the reaction of polystyrene maleic anhydride copolymer PSMA with polyethylene glycol PEG and oleylamine), F127 (polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer), DSPE-PEG (distearoylphosphatidylethanolamine-polyethylene glycol), and CTAB (hexadecyltrimethylammonium bromide).

[0021] Conjugated polymer PCPDTBT (poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopentadienyl[2,1-b;3,4-b′]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)]) and ZnO quantum dots are hydrophobic materials and need to be modified by amphiphilic surfactants to achieve water solubility for biomedical applications. Preferably, the amphiphilic surfactant is PSMA-PEG. The preparation method of the PSMA-PEG aqueous solution is as follows:

[0022] Add amino-polyethylene glycol to the tetrahydrofuran solution of polystyrene maleic anhydride copolymer, stir at 60°C for a period of time, add oleylamine tetrahydrofuran solution, stir for a period of time, and then rotary evaporate and dissolve in chloroform to obtain an amphiphilic surfactant PSMA-PEG chloroform solution; rotary evaporate the PSMA-PEG chloroform solution to remove chloroform, add pure water, and heat at 80°C for a period of time to obtain a PSMA-PEG aqueous solution;

[0023] The structural formula of PSMA-PEG is as follows:

[0024]

[0025] Furthermore, when the organic solvent in step 1 is chloroform and the amphiphilic surfactant aqueous solution in step 2 is a PSMA-PEG aqueous solution, the method for preparing the acid-responsive conjugated polymer ZnO composite nanomaterial comprises the following steps:

[0026] Step 1: 1 mg / mL of conjugated polymer PCPDTBT and 1 mg / mL of ZnO quantum dots in chloroform solution were mixed at a volume ratio of (1-6):1 and stirred for 2 hours.

[0027] Step 2: Prepare a PSMA-PEG aqueous solution with a concentration of 2 mg / mL;

[0028] Step 3: Under ultrasonic conditions, the mixed solution of PCPDTBT and ZnO quantum dots is quickly injected into the PSMA-PEG aqueous solution, wherein the volume ratio of the mixed solution of PCPDTBT and ZnO quantum dots to the PSMA-PEG aqueous solution is (1-2) : 25. After ultrasonic homogenization, the chloroform is removed by heating at 80°C, and the polymer composite nanomaterial is obtained after purification by ultrafiltration.

[0029] Furthermore, when the organic solvent in step 1 is tetrahydrofuran and the amphiphilic surfactant in step 2 is F127 or DSPE-PEG, the method for preparing the acid-responsive conjugated polymer ZnO composite nanomaterial comprises the following steps:

[0030] Step 1: prepare 1 mg / mL of conjugated polymer tetrahydrofuran solution and 1 mg / mL of ZnO tetrahydrofuran solution, mix them in a volume ratio of (1-6):1 and stir for 2 hours.

[0031] Step 2, preparing a 2 mg / mL F127 or DSPE-PEG aqueous solution;

[0032] Step 2: Under ultrasonic conditions, the mixed solution of PCPDTBT and ZnO is quickly injected into the F127 or DSPE-PEG aqueous solution, the volume ratio of the mixed solution of PCPDTBT and ZnO to the F127 or DSPE-PEG aqueous solution is (1-2):45, and the ultrasound is maintained for 3 minutes; the tetrahydrofuran in the aqueous solution is blown away with nitrogen, and the polymer composite nanomaterial is obtained after ultrafiltration purification.

[0033] Furthermore, when the organic solvent in step 1 is chloroform and the amphiphilic surfactant in step 2 is CTAB, the method for preparing the acid-responsive conjugated polymer ZnO composite nanomaterial comprises the following steps:

[0034] Step 1: prepare 1 mg / mL of conjugated polymer chloroform solution and 1 mg / mL of ZnO chloroform solution, mix them in a volume ratio of (1-6):1 and stir for 2 hours.

[0035] Step 2: prepare 8 mg / mL CTAB aqueous solution;

[0036] Step 3: Rapidly inject the mixed solution of PCPDTBT and ZnO into the CTAB aqueous solution under ultrasonic conditions, wherein the configuration volume ratio of the mixed solution of PCPDTBT and ZnO to the CTAB aqueous solution is (1-2):25. After ultrasonic homogenization, the chloroform is removed by heating at 60°C, and the polymer composite nanomaterial is obtained after purification by ultrafiltration.

[0037] Beneficial effects:

[0038] (1) The present invention obtains a novel acid-responsive conjugated polymer ZnO composite nanomaterial by screening a suitable conjugated polymer and combining it with ZnO quantum dots. The novel acid-responsive conjugated polymer ZnO composite nanomaterial can be used in the field of acid-activated optical imaging and sonodynamic therapy. As an acid-activated optical probe and sonodynamic therapeutic agent, the invention can realize integrated diagnosis and treatment and minimize the side effects of the integrated diagnosis and treatment nano-diagnostic and therapeutic agents on the organism.

[0039] The acid-responsive conjugated polymer ZnO composite nanomaterial prepared by the present invention can realize specific sonodynamic therapy and near-infrared second-zone fluorescence imaging excited by 808nm. ZnO quantum dots can quench the fluorescence and sonodynamic properties of conjugated polymers by charge transfer. Under normal conditions (non-acidic), the fluorescence emission and sonodynamic properties of the conjugated polymers in the acid-responsive conjugated polymer ZnO composite nanomaterial are suppressed, but an activation response is achieved in the acidic environment of the tumor, and the ZnO decomposition restores the fluorescence and sonodynamic properties of the conjugated polymer, has good near-infrared second-zone fluorescence emission, and can be at 1.5W / cm 2 The singlet oxygen produced after ultrasound excitation is used for sonodynamic therapy of tumors. It is a new type of optical and acoustic integrated diagnostic and therapeutic agent. 2+ It can induce cell pyroptosis and improve the therapeutic effect of tumors to a certain extent.

[0040] (2) In the present invention, the amphiphilic surfactant PSMA-PEG is preferred. As a new type of polymer surfactant, PSMA-PEG is different from other amphiphilic surfactants. In addition to the hydrophobic oleylamine group and the hydrophilic polyethylene glycol chain, the molecule also has a large number of benzene rings. The hydrophobic structure can wrap the copolymer and ZnO in the surfactant micelles through hydrophobic interactions to prevent the dissociation of the composite material. The benzene ring structure can interact with the conjugated polymer to further improve the stability of the composite material, so that the conjugated polymer ZnO composite nanomaterial exhibits good water solubility.

[0041] (3) In the present invention, the volume ratio of the conjugated polymer PCPBTDT to the ZnO quantum dot solution is preferably (1-6): 1. ZnO quantum dots quench the fluorescence of the conjugated polymer through a light-induced electron transfer mechanism, so that the electrons in the excited state of the polymer are rapidly transferred to ZnO. In order to enhance the specific tumor treatment of conjugated polymer ZnO composite nanomaterials and reduce the singlet oxygen yield of the conjugated polymer as a sonosensitizer in normal cells under ultrasound, therefore, adding ZnO quantum dots to the polymer composite nanomaterial can significantly quench the fluorescence and sonodynamic therapeutic properties of the polymer, but too high a concentration will affect the quenching effect of the sonodynamic properties.

[0042] (4) The preparation method of the acid-responsive conjugated polymer ZnO composite nanomaterial proposed in the present invention is simple to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a transmission electron microscope image of the material obtained in Example 1;

[0044] Figure 2 This is a transmission electron microscope image of the material obtained in Example 1 under a slightly acidic environment;

[0045] Figure 3 The near-infrared second-region fluorescence intensity diagram of the materials obtained in Example 1 and Comparative Example 1;

[0046] Figure 4 The acoustic dynamic performance diagram of the materials obtained in Example 1 and Comparative Example 1;

[0047] Figure 5 The graphs of fluorescence intensity changes of the materials obtained in Example 1 and Comparative Example 1 after intratumoral injection;

[0048] Figure 6 The cytotoxicity graphs of the materials obtained in Example 1 and Comparative Example 1 under neutral conditions;

[0049] Figure 7 The cytotoxicity graphs of the materials obtained in Example 1 and Comparative Example 1 under acidic conditions are shown. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is described in detail below through specific embodiments and drawings, but the protection scope of the present invention is not limited to the embodiments.

[0051] (i) In the following examples, the sonodynamic effect of the material is evaluated by detecting whether the prepared material can generate singlet oxygen. The detection method is to use diphenylbenzofuran DPBF as a singlet oxygen probe and judge whether singlet oxygen is generated based on the change in its absorbance at 417nm. The specific test process is: prepare an aqueous solution of the composite nanomaterial to be tested, mix DPBF with the aqueous solution of the composite nanomaterial, and test the absorption of DPBF using a Mepta UV-1800 UV-visible spectrophotometer at 1.5W / cm 2 After ultrasound, the absorption spectrum was tested immediately, and the generation of singlet oxygen was characterized by the decrease in the absorbance of DPBF at 417 nm.

[0052] (ii) The preparation method of the PCPDTBT conjugated polymer used in the following examples is described in the open literature [Lu F, Li L, Zhang M, et al. Confined semiconducting polymers with boosted NIR light-triggered H 2 O 2 [J]. Chemical Science, 2024, 15(30): 12086-12097.] The synthesis steps of the conjugated polymer disclosed in the invention. PCPDTBT is a common hydrophobic conjugated polymer. Its highly delocalized π-electron conjugated skeleton makes its optical band gap (about 1.4-1.6 eV) narrow, which can achieve long-wavelength (such as 1000-1300 nm) fluorescence emission, and can be used as a near-infrared second-zone fluorescent probe for high-resolution optical imaging. At the same time, the polymer can also produce reactive oxygen species under ultrasound conditions and can be used for sonodynamic therapy. Therefore, in order to achieve specific fluorescence imaging and treatment of tumors, the present invention mixes the conjugated polymer with ZnO to prepare an acid-responsive composite nanomaterial, and ZnO can inhibit the fluorescence and sonodynamic properties of the conjugated polymer. At the tumor site, due to its acidic microenvironment, ZnO decomposes, and the fluorescence and sonodynamic properties of the conjugated polymer are activated, which can be used for specific fluorescence imaging and treatment of tumors. The zinc ions produced by the decomposition can also induce tumor cell pyroptosis, thereby further improving the therapeutic effect. In addition, the composite material can avoid activation in non-tumor sites, produce unnecessary singlet oxygen under ultrasound, and reduce side effects on normal tissues. Therefore, the acid-activated conjugated polymer ZnO composite nanomaterial provided by the present invention has significantly suppressed fluorescence and sonodynamic properties in normal tissues as a nano-diagnostic agent, and can generate near-infrared second-zone luminescence under 808nm laser irradiation in the tumor microenvironment, and can also generate near-infrared second-zone luminescence at 1.5W / cm 2, singlet oxygen is efficiently generated under 1MHz ultrasound for sonodynamic therapy, and Zn released in the tumor microenvironment 2+ It can also coordinately activate the caspase-1 / gasderminD (GSDMD)-dependent cell pyroptosis pathway to improve the therapeutic effect.

[0053] (III) Preparation steps of the ZnO quantum dot chloroform solution used in the following examples:

[0054] Dissolve zinc acetate dihydrate and magnesium acetate dihydrate in anhydrous ethanol in a mass ratio of 44:4.4:3000; at the same time, prepare an ethanol solution of NaOH by reflux heating, with a concentration of 10 mg / mL; after cooling the two solutions in an ice bath, slowly add the ethanol solution of NaOH to the anhydrous ethanol solution of zinc acetate and magnesium acetate in a volume ratio of 1:3; stir the mixture at room temperature for 6 hours; after the reaction is completed, precipitate with cyclohexane, centrifuge, and wash with ethanol 2-3 times to obtain Z nO quantum dots; the obtained ZnO quantum dots are dispersed in a mixed solution of toluene and ethanol (the volume ratio of toluene to ethanol is 1:5 to 5:1), and butylamine and octadecyltrimethoxysilane are continuously added; the concentrations of ZnO quantum dots, butylamine and octadecyltrimethoxysilane are 10 mg / mL, 12 mg / mL and 5.9 mg / mL, respectively; after ultrasonic treatment for 6 hours, ethanol is added for precipitation, and the mixture is washed with ethanol and dispersed in chloroform to obtain a 1 mg / mL ZnO quantum dot chloroform solution.

[0055] (IV) Preparation steps of the amphiphilic surfactant PSMA-PEG aqueous solution used in the following examples:

[0056] Amino-polyethylene glycol (mPEG-NH 2 , Mw 5000, purchased from Shanghai Pengshuo Biotechnology Co., Ltd.), stirred at 60°C for 3h, added 34mg / mL oleylamine tetrahydrofuran solution, stirred for 12h, then rotary evaporated and dissolved in chloroform to obtain a chloroform solution of the amphiphilic surfactant PSMA-PEG with a concentration of 50mg / mL; wherein the mass ratio of the polystyrene maleic anhydride copolymer, amino-polyethylene glycol and oleylamine is 1:12.68:0.71. The PSMA-PEG chloroform solution was rotary evaporated to remove chloroform, and then pure water was added and heated at 80°C for 1 hour to obtain a PSMA-PEG aqueous solution;

[0057] Example 1

[0058] This embodiment provides a specific preparation method of an acid-responsive conjugated polymer ZnO composite nanomaterial, comprising the following steps:

[0059] In the first step, 1 mg / mL PCPDTBT chloroform solution and 1 mg / mL ZnO chloroform solution were mixed and stirred for 2 hours to obtain a mixed solution containing a conjugated polymer and ZnO; wherein the volume ratio of the PCPDTBT chloroform solution to the ZnO chloroform solution was 4:1.

[0060] The second step is to take 50 mg / mL of PSMA-PEG chloroform solution, remove chloroform by rotary evaporation, add deionized water, and heat at 80°C for 1 hour to obtain a PSMA-PEG aqueous solution; wherein the volume ratio of the PSMA-PEG chloroform solution to the added deionized water is 1:25, and the concentration of the PSMA-PEG aqueous solution is 2 mg / mL.

[0061] The third step is to quickly inject 200uL of the mixed solution of PCPDTBT and ZnO quantum dots into 2.5mL of PSMA-PEG aqueous solution under ultrasonic conditions, and heat at 80°C to remove chloroform after ultrasonic homogenization, and obtain the conjugated polymer ZnO composite nanomaterial after purification by ultrafiltration.

[0062] The transmission electron microscopy images of the conjugated polymer ZnO composite nanomaterial obtained in Example 1 and the transmission electron microscopy images in a slightly acidic environment are as follows: Figure 1 and Figure 2 As shown. Figure 1 As shown in Figure 2, the particle size of the conjugated polymer ZnO composite nanomaterial is about 30 nm. Figure 2 As shown, under weakly acidic conditions, ZnO in the conjugated polymer ZnO composite nanomaterials was degraded, resulting in more low-contrast pores.

[0063] Comparative Example 1

[0064] The difference between Comparative Example 1 and Example 1 is that an equal volume of chloroform solution is used to replace the chloroform solution of ZnO quantum dots in Example 1, and other conditions remain unchanged to prepare conjugated polymer nanomaterials as nanoprobes.

[0065] The materials prepared in Example 1 and Comparative Example 1 were tested for near-infrared second-region fluorescence intensity, sonodynamic properties, fluorescence intensity after intratumoral injection, and cytotoxicity. The results are as follows: Figure 3-Figure 7 shown.

[0066] Figure 3The near-infrared second-zone fluorescence intensity diagram of the materials prepared in Example 1 and Comparative Example 1. In Example 1, the fluorescence intensity of PCPDTBT after mixing with ZnO decreased significantly, and the intensity was about half of that without ZnO (Comparative Example 1). However, under the condition of pH 5.5, the fluorescence intensity of the solution was quickly restored, proving that the nanomaterial can achieve fluorescence recovery under weakly acidic conditions. The fluorescence intensity of the material prepared in Comparative Example 1 did not change significantly at different pH values.

[0067] Figure 4 The sonodynamic performance of the materials prepared in Example 1 and Comparative Example 1 is shown in Figure 1. In Example 1, the sonodynamic performance of the composite nanomaterial prepared after the addition of ZnO has a significant decrease, and its sonodynamic therapeutic performance can be effectively restored under weak acid conditions. 2 Singlet oxygen is obviously generated under ultrasound, indicating that the conjugated polymer nanomaterial prepared in Comparative Example 1 has good sonodynamic properties, but changing pH has little effect on its properties.

[0068] Figure 5 The fluorescence intensity changes of the materials prepared in Example 1 and Comparative Example 1 after intratumoral injection are shown in FIG. Figure 5 As shown, after the material prepared in Example 1 was injected in situ into the mouse tumor model, the fluorescence intensity in the tumor was greatly increased, proving that the material prepared in Example 1 can be effectively activated in the tumor environment. After the material prepared in Comparative Example 1 was injected into the tumor, the fluorescence intensity value changed little.

[0069] Figure 6 The cytotoxicity graphs of the materials prepared in Example 1 and Comparative Example 1 under neutral conditions are shown. Figure 6 As shown, at normal pH, the material prepared in Example 1 has good biocompatibility, and the cell activity does not decrease significantly after ultrasonic treatment, indicating that the sonodynamic therapeutic effect is inhibited. Comparative Example 1 also has good biocompatibility, but can significantly inhibit tumor cell growth under ultrasound, indicating that the modified conjugated polymer has a good sonodynamic therapeutic effect.

[0070] Figure 7 The cytotoxicity graphs of the materials prepared in Example 1 and Comparative Example 1 under acidic conditions are shown. Figure 7 As shown, under weakly acidic conditions, the conjugated polymer ZnO composite nanomaterial prepared in Example 1 has a high tumor cell inhibition ability under ultrasound, indicating that its sonodynamic therapy ability is restored. Therefore, the composite material can be used for fluorescence imaging and sonodynamic therapy activated by tumor microenvironment. The material prepared in Comparative Example 1 can inhibit tumor cell activity at different pH values.

[0071] The above results indicate that the conjugated polymer PCPDTBT has good fluorescence imaging and sonodynamic properties, but does not have acid response ability.

[0072] Example 2

[0073] The only difference between Example 2 and Example 1 is that the conjugated polymer PCPDTBT and the ZnO chloroform solution are mixed in a volume ratio of 6:1, and other conditions remain unchanged to prepare an acid-responsive conjugated polymer ZnO composite nanomaterial.

[0074] Since the material prepared in Example 2 has fewer ZnO quantum dots and the interaction with the conjugated polymer is weakened, no significant fluorescence quenching effect is observed, and the sonodynamic performance is slightly lower than that of Comparative Example 1, but the quenching effect is significantly less than that of Example 1.

[0075] Example 3

[0076] The only difference between Example 3 and Example 1 is that the conjugated polymer PCPDTBT and the ZnO chloroform solution are mixed in a volume ratio of 1:1, and other conditions remain unchanged to prepare an acid-responsive conjugated polymer ZnO composite nanomaterial.

[0077] The material prepared in Example 3 has average stability in aqueous solution, and precipitation will occur when left to stand. The fluorescence quenching effect is similar to that of Example 1, and the quenching effect of the sonodynamic performance is less than that of Example 1, which is not the optimal ratio.

[0078] Example 4

[0079] The difference between Example 4 and Example 1 is that the amphiphilic surfactant is CTAB, and the preparation steps are as follows:

[0080] Step 1: prepare 1 mg / mL of conjugated polymer chloroform solution and 1 mg / mL of ZnO chloroform solution, mix them in a volume ratio of 4:1 and stir for 2 hours.

[0081] Step 2: prepare 8 mg / mL CTAB aqueous solution;

[0082] Step 3: Under ultrasonic conditions, 200 μL of the mixed solution of PCPDTBT and ZnO was quickly injected into 2.5 mL of CTAB aqueous solution. After ultrasonic homogenization, the chloroform was removed by heating at 60° C., and the polymer composite nanomaterial was obtained after purification by ultrafiltration.

[0083] The material prepared in Example 4 is almost the same as that in Example 1 in terms of fluorescence performance, and the acoustic dynamic inhibition and recovery effects are also significant. However, since CTAB cannot be used directly in vivo, further modification is required later.

[0084] Example 5

[0085] The difference between Example 5 and Example 1 is that the amphiphilic surfactant is F127, and the preparation steps are as follows:

[0086] Step 1: Prepare 1 mg / mL of conjugated polymer tetrahydrofuran solution and 1 mg / mL of ZnO tetrahydrofuran solution, mix them in a volume ratio of 4:1 and stir for 2 hours.

[0087] Step 2: prepare a 2 mg / mL F127 aqueous solution;

[0088] Step 2: Under ultrasonic conditions, 200 μL of the mixed solution of PCPDTBT and ZnO was quickly injected into 9 mL of F127 aqueous solution, and the ultrasonic treatment was maintained for 3 minutes; tetrahydrofuran in the aqueous solution was blown away with nitrogen, and the polymer composite nanomaterial was obtained after purification by ultrafiltration.

[0089] The material prepared in Example 5 has poor precipitation stability and exhibits lower fluorescence quenching and sonodynamic performance inhibition effects.

[0090] The specific preparation method of the acid-responsive conjugated polymer ZnO composite nanomaterial proposed in the present invention is simple to operate, and the obtained nanoparticles have good near-infrared second-zone fluorescence emission in the tumor microenvironment, and can also emit fluorescence at 1.5W / cm 2 Singlet oxygen is produced after ultrasound excitation and can be used for sonodynamic therapy of tumors.

[0091] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to the form and details without departing from the spirit and scope of the present invention.

Claims

1. A method for preparing an acid-responsive conjugated polymer ZnO composite nanomaterial, characterized in that: The preparation method comprises the following steps: Step 1, dissolving the conjugated polymer PCPDTBT in an organic solvent to obtain a solution A, dissolving the ZnO quantum dots in an organic solvent to obtain a solution B, and mixing the solution A and the solution B to obtain a mixed solution containing the conjugated polymer and ZnO; Step 2, preparing an amphiphilic surfactant aqueous solution; Step 3: Under ultrasonic conditions, inject the mixed solution containing the conjugated polymer and ZnO into the aqueous solution of the amphiphilic surfactant, remove the organic solvent after mixing evenly, and then perform ultrafiltration purification to obtain the acid-responsive conjugated polymer ZnO composite nanomaterial.

2. The preparation method according to claim 1, characterized in that: In step 1, the concentrations of solution A and solution B are both 1 mg / mL, and the volume ratio of solution A to solution B is (1-6):1; In step 2, the concentration of the aqueous solution of the amphiphilic surfactant is 2-8 mg / mL; In step 3, the volume ratio of the mixed solution containing the conjugated polymer and ZnO to the aqueous solution of the amphiphilic surfactant is (1-2): (25-45).

3. The preparation method according to claim 1, characterized in that: The ZnO quantum dots are hydrophobic ZnO quantum dots; the hydrophobic ZnO quantum dots are synthesized by reacting zinc acetate, magnesium acetate and sodium hydroxide, and then modified with butylamine and octadecyltrimethoxysilane.

4. The preparation method according to claim 1, characterized in that , the organic solvent is chloroform or tetrahydrofuran.

5. The preparation method according to claim 1, characterized in that When the organic solvent is chloroform, solution B is a ZnO quantum dot chloroform solution, and the configuration method is: Zinc acetate dihydrate and magnesium acetate dihydrate are dissolved in anhydrous ethanol, and an ethanol solution of NaOH is prepared by reflux heating. After cooling in an ice bath, the ethanol solution of NaOH is slowly added dropwise to the anhydrous ethanol of zinc acetate and magnesium acetate; the mixture of the two is stirred at room temperature for a period of time; after the reaction is completed, cyclohexane is used for precipitation, centrifugation, and ethanol washing is performed to obtain ZnO quantum dots; ZnO quantum dots are dispersed in a mixed solution of toluene-ethanol, and butylamine and octadecyltrimethoxysilane are added; after ultrasonic treatment, ethanol is added for precipitation and washing, and then dispersed in chloroform to obtain a chloroform solution of ZnO quantum dots.

6. The preparation method according to claim 1, characterized in that , the amphiphilic surfactant is selected from any one of PSMA-PEG, F127, DSPE-PEG, and CTAB.

7. The preparation method according to claim 1, characterized in that , the amphiphilic surfactant is PSMA-PEG, and the preparation method of the PSMA-PEG aqueous solution is as follows: Amino-polyethylene glycol was added to the tetrahydrofuran solution of polystyrene maleic anhydride copolymer, stirred at 60°C for a period of time, and oleylamine tetrahydrofuran solution was added. After stirring for a period of time, the solution was dissolved in chloroform by rotary evaporation to obtain the amphiphilic surfactant PSMA-PEG chloroform solution; the PSMA-PEG chloroform solution was rotary evaporated to remove the chloroform, and pure water was added, and heated at 80°C for a period of time to obtain the PSMA-PEG aqueous solution.

8. Acid-responsive conjugated polymer ZnO composite nanomaterial prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the acid-responsive conjugated polymer ZnO composite nanomaterial prepared by the preparation method according to any one of claims 1 to 7 as an acid-activated optical probe or sonodynamic therapeutic agent.

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