阅读说明：本技术 一种用于光热治疗联合化疗的介孔二氧化硅前药纳米粒子及其制备方法和应用 (Mesoporous silica prodrug nanoparticle for photothermal therapy and chemotherapy and preparation method and application thereof ) 是由 章莉娟 彭诗元 张富盛 于 2021-07-08 设计创作，主要内容包括：本发明属于生物医药纳米材料技术领域,公开了一种具有pH响应性的联合近红外染料分子光热治疗和阿霉素化疗作用的介孔二氧化硅前药纳米粒子及其制备方法和应用。本发明纳米粒子由包括介孔二氧化硅纳米粒子、键合在介孔二氧化硅纳米粒子表面的药物、修饰在介孔二氧化硅纳米粒子表面的聚合物及装载在介孔二氧化硅纳米粒子孔道中的有机光热小分子构成。本发明纳米粒子材料利用酸敏感的顺式乌头酸酐键实现药物的可控释放：药物在正常细胞周围几乎不释放,而在肿瘤细胞的微酸性环境下快速释放,实现对肿瘤的靶向治疗。近红外辐射不仅造成局部温度的提高,并且加速药物的释放,有助于药物迅速达到血药浓度,实现光热/化疗的协同作用。(The invention belongs to the technical field of biomedical nano materials, and discloses mesoporous silica prodrug nanoparticles with pH responsiveness and combined near-infrared dye molecule photothermal therapy and adriamycin chemotherapy effects, and a preparation method and application thereof. The nano-particles comprise mesoporous silica nano-particles, a drug bonded on the surfaces of the mesoporous silica nano-particles, a polymer modified on the surfaces of the mesoporous silica nano-particles and organic photo-thermal micromolecules loaded in pore channels of the mesoporous silica nano-particles. The nano particle material realizes the controllable release of the medicine by utilizing the acid-sensitive cis-aconitic anhydride bond: the drug is hardly released around normal cells, and is quickly released in the slightly acidic environment of tumor cells, so that the targeted therapy of tumors is realized. Near infrared radiation not only causes the increase of local temperature, but also accelerates the release of the medicine, is beneficial to the medicine to quickly reach blood concentration, and realizes the synergistic action of photo-thermal/chemotherapy.)

1. A preparation method of mesoporous silica prodrug nanoparticles for photothermal therapy and chemotherapy is characterized by comprising the following steps:

(1) reacting the ordered mesoporous silica nano particles with a silane coupling agent to obtain mesoporous silica with aminated surface;

(2) mixing the obtained mesoporous silica with aminated surface with acyl bromide to carry out acylation reaction to obtain a silica initiator; mixing the mesoporous silica with a polymer containing a hydroxyl block, and carrying out surface polymerization reaction to obtain mesoporous silica modified with the hydroxyl polymer;

(3) carrying out condensation reaction on cis-aconitic anhydride and adriamycin to obtain a small molecular prodrug, which is named as CA-DOX; then anchoring the small molecule prodrug on the surface of the mesoporous silica modified with hydroxyl polymer through esterification reaction; the product is named MSN-cis-DOX;

(4) and mixing and dispersing the obtained MSN-cis-DOX and indocyanine green to obtain the mesoporous silica prodrug nano particle for photothermal therapy and chemotherapy, which is named as MSN-cis-DOX/ICG.

2. The method according to claim 1, characterized by comprising the steps of:

(1) mixing the ordered mesoporous silica nanoparticles with a silane coupling agent and an organic solvent, and drying to obtain MSN-NH after the reaction is finished₂；

(2) The MSN-NH obtained in the step (1)₂Dispersing in an organic solvent, adding an acid-binding agent and acyl bromide under an ice-bath condition, carrying out amidation reaction, filtering, washing and drying after the reaction is finished to obtain MSN-Br;

(3) mixing the MSN-Br obtained in the step (2), monomethoxypolyethylene glycol methacrylate, hydroxyethyl methacrylate, hexamethyltriethylenetetramine and copper bromide with a solvent, stirring, adding ascorbic acid, and centrifuging, washing and vacuum drying the product after the reaction is finished to obtain an MSN-polymer;

(4) mixing the drug DOX, cis-aconitic anhydride, acid-binding agent and organic solvent, carrying out condensation reaction, washing and drying the product after the reaction is finished, and obtaining prodrug micromolecule CA-DOX;

(5) dispersing the MSN-polymer obtained in the step (3), the CA-DOX obtained in the step (4) and a catalytic system in an organic solvent, carrying out esterification reaction, and washing and drying an obtained reaction product to obtain MSN-cis-DOX;

(6) and (4) dispersing the MSN-cis-DOX and ICG obtained in the step (5) in a solvent, and drying after the reaction is finished to obtain the MSN-cis-DOX/ICG.

3. The method of claim 2, wherein:

the mass ratio of the ordered mesoporous silica nanoparticles to the silane coupling agent in the step (1) is 69-103: 97 to 129;

the silane coupling agent in the step (1) is at least one of aminopropyltriethoxysilane and aminopropyltrimethoxysilane; the organic solvent is at least one of anhydrous toluene and anhydrous ethanol.

4. The method according to claim 2, wherein the MSN-NH of step (2)₂The mass ratio of the acid-binding agent to the acyl bromide is 39-51: 78-150: 45-79 parts of;

the acyl bromide in the step (2) is 2-bromine isobutyryl bromide; the organic solvent is at least one of anhydrous tetrahydrofuran and anhydrous dichloromethane.

5. The method of claim 2, wherein:

the mass ratio of MSN-Br, PEGMA, HEMA, hexamethyltriethylenetetramine, copper bromide to ascorbic acid in the step (3) is 10-30: 10-30: 10-30: 1-15: 1-5: 10 to 46;

the solvent in the step (3) is a mixed solution of methanol and water;

in the step (3) and the step (5), the acid-binding agents are the same or different and are at least one of triethylamine and pyridine respectively;

the mass ratio of the medicine DOX, the cis-aconitic anhydride and the acid-binding agent in the step (4) is 1-8: 1-8: 2-30;

the organic solvent in the step (4) is at least one of dimethylformamide, dichloromethane, N-dimethyl pyridine and dimethyl sulfoxide.

6. The method of claim 2, wherein:

in the step (5), the mass ratio of the MSN-polymer to the CA-DOX is 10-30: 1-3; the catalyst system is a catalytic amount;

in the step (5), the catalyst system is N-3- (dimethylaminopropyl) -N' -ethylcarbodiimide hydrochloride and N-hydroxysuccinimide;

the organic solvent in the step (5) is at least one of dichloromethane, N-dimethyl pyridine and dimethyl sulfoxide;

the mass ratio of MSN-cis-DOX to ICG in the step (6) is 10-30: 1-3;

and (4) the solvent in the step (6) is methanol.

7. The method of claim 2, wherein:

the reaction temperature in the step (1) is 80-100, and the reaction time is 24-48 h;

the amidation reaction in the step (2) is specifically a reaction at ice bath for 2-3 h and then at room temperature for 24-48 h;

stirring for 2-3 h in the step (3), adding ascorbic acid, and reacting at 40-80 ℃ for 20-24 h;

the condensation reaction in the step (4) is specifically stirred for reaction for 12-24 hours under the condition of keeping out of the sun;

the esterification reaction in the step (5) is carried out at room temperature for 24-48 h;

the reaction in the step (6) is specifically carried out at room temperature for 24-48 h.

8. The method of claim 2, wherein: the ordered mesoporous silica nano particles in the step (1) are prepared by a sol-gel method, and the method comprises the following steps: dissolving a template agent, an alkali source and an auxiliary agent in water, stirring for 0.5-1 h at 70-80 ℃, adding a silicon source, and reacting for 0.5-4.0 h to obtain the mesoporous silica containing the template agent.

9. Mesoporous silica prodrug nanoparticles for photothermal therapy in combination with chemotherapy, prepared by the method of any one of claims 1 to 8.

10. The use of the mesoporous silica prodrug nanoparticles for photothermal therapy in combination with chemotherapy according to claim 9 in the preparation of controlled release drugs and photothermal/chemotherapy synergistic materials.

Technical Field

The invention belongs to the technical field of biomedical nano materials, and particularly relates to mesoporous silica prodrug nanoparticles for photothermal therapy and chemotherapy, and a preparation method and application thereof.

Background

Among the various cancer treatments currently available, conventional chemotherapy is the oral or intravenous injection of anti-cancer drugs through the blood circulation system to the tumor site to kill cancer cells. Although chemotherapy is not the optimal treatment option, it is still the most common option for most patients. However, simple chemotherapy has certain limitations in clinical application, for example, anticancer drugs often have strong cytotoxicity and lack of specific recognition capability for cancer cells, resulting in serious toxic and side effects; cancer cells have low drug intake efficiency, require repeated administration, and easily induce drug resistance in the body. Therefore, many anticancer drug delivery systems are researched and developed, wherein the Mesoporous Silica Nanoparticle (MSN) has the advantages of large specific surface area and internal pore volume, adjustable pore size, highly ordered structure, easy modification of surface rich active hydroxyl groups, good biocompatibility, low cost and the like, and is particularly suitable for being used as a drug delivery material. Besides the development of nano-carriers with controlled release effect, the combined application of chemotherapy and other treatment methods is also one of effective ways to improve the tumor treatment effect.

In recent years, photothermal therapy (PTT) induces local tissue to be heated to a high-heat state (> 42 ℃) by irradiation with near-infrared light, thereby causing tumor cell death, and PTT has been attracting attention as an adjuvant therapy for tumors. The multi-mode treatment combining photothermal treatment and chemotherapy generally generates photothermal effect through photothermal molecules, and chemotherapy drugs generate synergistic effect when the temperature is increased, so that tumor cells are effectively killed. Compared with single chemotherapy, the multi-mode treatment has better anti-tumor activity. Zhang et al [ ACS biomateer, Sci. Eng.4(2018) 2424-2434 ] designs and prepares liposome-coated poly (N-isopropylacrylamide-acrylamide) (P (NIPAM-co-AAM)) nanogel, the gel can effectively encapsulate NIR dyes indocyanine green (ICG) and adriamycin (DOX), and the phase change is generated when the temperature of a medicine carrying system is increased under near infrared light radiation to trigger the release of DOX, so that the synergistic effect of photothermal-chemotherapy is realized. However, this method releases DOX only triggered by the thermal effect of NIR radiation, and in the absence of significant temperature increase, it may result in incomplete release of DOX by the drug-loaded particles, thereby reducing the synergy of photothermal and chemotherapy treatments.

Patent application CN106727274A discloses a preparation method of a polypyrrole/mesoporous silica/graphene quantum dot nanocomposite with a core-shell structure, which has excellent photo-thermal conversion performance, converts light into heat under the irradiation of near-infrared light, and controls the opening of a pore channel of encapsulated mesoporous silica. But the heat generated by the material is not sufficient to obtain high temperatures that can cause cell damage. Patent CN109793710A discloses a multifunctional nanoparticle which uses PLGA nanoparticles as carriers, and has chemotherapy, photo-thermal and immunotherapy drugs wrapped inside and targeting molecules connected on the surface. However, the drug is not covalently bonded to the material, and the force is weak, so that the drug is likely to be released suddenly.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention provides a preparation method of mesoporous silica prodrug nanoparticles for photothermal therapy and chemotherapy.

The invention also aims to provide the mesoporous silica prodrug nanoparticles prepared by the method. The reversible covalent bond of the nano particles connecting the drug and the carrier particles is broken in an acidic environment, so that the controlled release of the drug is realized; the small molecular organic dye entrapped in the mesoporous pore canal has good photo-thermal conversion performance, and can increase the local temperature, thereby realizing the synergistic effect of photo-thermal treatment and chemotherapy.

The invention further aims to provide application of the mesoporous silica prodrug nanoparticles for photothermal therapy and chemotherapy in the field of preparation of controlled release drugs and photothermal/chemotherapy synergistic materials.

The purpose of the invention is realized by the following scheme:

a preparation method of mesoporous silica prodrug nanoparticles for photothermal therapy and chemotherapy comprises the following steps:

(1) reacting the ordered mesoporous silica nano particles with a silane coupling agent to obtain mesoporous silica (MSN-NH) with aminated surface₂)；

(2) Mixing the obtained mesoporous silica with aminated surface with acyl bromide to carry out acylation reaction to obtain a silica initiator (MSN-Br); mixing the mesoporous silica with a polymer containing a hydroxyl block, and carrying out surface polymerization reaction to obtain mesoporous silica (MSN-polymer) modified with the hydroxyl polymer;

(3) carrying out condensation reaction on cis-aconitic anhydride and adriamycin (DOX) to obtain a micromolecule prodrug, which is named as CA-DOX; then anchoring the small molecule prodrug on the surface of the mesoporous silica modified with hydroxyl polymer through esterification reaction; the product is named MSN-cis-DOX;

(4) and mixing and dispersing the obtained MSN-cis-DOX and indocyanine green (ICG) to obtain mesoporous silica prodrug nanoparticles (MSN-cis-DOX/ICG) for photothermal therapy and chemotherapy.

Preferably, the preparation method of the mesoporous silica prodrug nanoparticle for photothermal therapy and chemotherapy comprises the following steps:

(1) mixing the ordered mesoporous silica nano particles with a silane coupling agent and an organic solvent,after the reaction is finished, drying to obtain MSN-NH₂。

(2) The MSN-NH obtained in the step (1)₂Dispersing in an organic solvent, adding an acid-binding agent and acyl bromide under an ice-bath condition, carrying out amidation reaction, filtering, washing and drying after the reaction is finished to obtain MSN-Br;

(3) mixing the MSN-Br obtained in the step (2), monomethoxy polyethylene glycol methacrylate (PEGMA), hydroxyethyl methacrylate (HEMA), hexamethyl triethylene tetramine and copper bromide with a solvent, stirring, adding ascorbic acid, and centrifuging, washing and vacuum drying the product after the reaction is finished to obtain an MSN-polymer;

(4) mixing the drug DOX, cis-aconitic anhydride (CA), an acid-binding agent and an organic solvent, carrying out condensation reaction, washing and drying the obtained product after the reaction is finished, and obtaining prodrug micromolecules (CA-DOX);

(5) dispersing the MSN-polymer obtained in the step (3), the CA-DOX obtained in the step (4) and a catalytic system in an organic solvent, carrying out esterification reaction, and washing and drying an obtained reaction product to obtain MSN-cis-DOX;

(6) and (4) dispersing the MSN-cis-DOX and ICG obtained in the step (5) in a solvent, and drying after the reaction is finished to obtain the MSN-cis-DOX/ICG.

The ordered mesoporous silica nano particles in the step (1) are prepared by a sol-gel method, and the method comprises the following steps: dissolving a template agent, an alkali source and an auxiliary agent in water, stirring for 0.5-1 h at 70-80 ℃, adding a silicon source, and reacting for 0.5-4.0 h to obtain the mesoporous silica containing the template agent.

Preferably, the mass ratio of the template agent, the auxiliary agent, the alkali source and the silicon source is 10-25: 10-25: 0.5-6: 95 to 96. The template agent is at least one of Cetyl Trimethyl Ammonium Bromide (CTAB), cetyl trimethyl ammonium p-toluenesulfonate (CTAT) and Cetyl Trimethyl Ammonium Chloride (CTAC), preferably CTAB. The auxiliary agent is sodium trifluoroacetate. The silicon source is at least one of methyl orthosilicate, tetraethyl orthosilicate (TEOS), propyl orthosilicate and sodium silicate, and preferably tetraethyl orthosilicate (TEOS). The alkali source can be at least one of sodium hydroxide, triethanolamine and ammonia water. The particle size of the obtained mesoporous silica nanoparticles is preferably 50-150nm, and the pore diameter is preferably 3-5 nm.

The mass ratio of the ordered mesoporous silica nanoparticles to the silane coupling agent in the step (1) is 69-103: 97 to 129.

The silane coupling agent in the step (1) can be at least one of aminopropyltriethoxysilane and aminopropyltrimethoxysilane. The organic solvent is at least one of anhydrous toluene and anhydrous ethanol.

The reaction temperature in the step (1) is 80-100, and the reaction time is 24-48 h;

after the reaction in the step (1) is finished, the method also comprises a step of removing the template agent, wherein the step of removing the template agent means that the product is dispersed in NH₄NO₃Refluxing the mixture in an ethanol solution or a hydrochloric acid-methanol solution at 80-90 ℃ for 24h, and repeating the refluxing for 2 times, wherein the hydrochloric acid-methanol solution is preferred.

The MSN-NH in the step (2)₂The mass ratio of the acid-binding agent to the acyl bromide is 39-51: 78-150: 45-79.

The acyl bromide in the step (2) is preferably 2-bromoisobutyryl bromide (BIBB); the organic solvent is at least one of anhydrous tetrahydrofuran and anhydrous dichloromethane.

And (3) performing amidation reaction in the step (2), namely reacting for 2-3 h in ice bath, and then reacting for 24-48 h at room temperature.

The mass ratio of MSN-Br, PEGMA, HEMA, hexamethyltriethylenetetramine, copper bromide to ascorbic acid in the step (3) is 10-30: 10-30: 10-30: 1-15: 1-5: 10 to 46.

The solvent in the step (3) is preferably a mixed solution of methanol and water; preferably, the volume ratio is 1/1.

The stirring time in the step (3) is 2-3 h, the reaction temperature is 40-80 ℃ after the ascorbic acid is added, and the reaction time is 20-24 h.

The mass ratio of the medicine DOX, the cis-aconitic anhydride and the acid-binding agent in the step (4) is 1-8: 1-8: 2 to 30.

The organic solvent in the step (4) is at least one of dimethylformamide, dichloromethane, N-dimethyl pyridine and dimethyl sulfoxide.

And (4) the condensation reaction is specifically a stirring reaction for 12-24 hours under a light-shielding condition.

And (4) the washing specifically comprises diluting the obtained product ethyl glacial acetate, and washing with a saturated sodium chloride aqueous solution.

In the step (5), the mass ratio of the MSN-polymer to the CA-DOX is 10-30: 1-3; the catalyst system is a catalytic amount.

In the step (5), the catalyst system is N-3- (dimethylaminopropyl) -N' -ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) in a mass ratio of about 4: 3-2: 1.

The organic solvent in the step (5) is at least one of dichloromethane, N-dimethyl pyridine and dimethyl sulfoxide.

The esterification reaction in the step (5) is carried out at room temperature for 24-48 h;

the mass ratio of MSN-cis-DOX to ICG in the step (6) is 10-30: 1-3;

the solvent in step (6) is preferably methanol.

The reaction in the step (6) is specifically carried out at room temperature for 24-48 h;

in the step (3) and the step (5), the acid-binding agents are the same or different and are at least one of triethylamine and pyridine respectively, and triethylamine is preferred.

The HEMA in the step (3) is used as a traditional bio-based monomer, the water solubility is good, the terminal containing hydroxyl can be bonded with cis-aconitic anhydride, PEGMA can play a role in stabilizing nanoparticles as a widely used hydrophilic block, and the modification amount is 10-30 wt%.

And (4) connecting the drug and the hydroxyl at the end of HEMA by a pH sensitive cis-aconitic anhydride bond grafting method so as to bond the drug and the hydroxyl on the surface of the mesoporous silica nano particle, thereby not only reducing the side effect of the drug on normal cells, but also accumulating in cell nuclei, and further improving the anti-tumor effect. The drug loading is 5-20 wt%.

The ICG used in the step (6) is a tricarbocyanine near-infrared dye with good water solubility, and can be clinically used after being approved by the FDA in the United states. ICG has strong absorption to 800nm near infrared light, can convert most of light energy into heat energy, and is a widely used PTT reagent. The organic dye micromolecules are loaded inside mesoporous silica nanoparticle pore channels, and the loading amount is 8-13 wt%.

Mesoporous silica prodrug nanoparticles for photothermal therapy and chemotherapy are prepared by the method. The dye-sensitized solar cell comprises mesoporous silica nanoparticles, organic dye micromolecules loaded in the mesoporous silica nanoparticles, polymers modified on the surfaces of the mesoporous silica nanoparticles and drugs bonded on polymer chains.

The mesoporous silica prodrug nano particle for photothermal therapy and chemotherapy is applied to the field of preparation of controlled release drugs and the field of photothermal/chemotherapy synergistic material. The prepared nano-particles can realize DOX release by reversible covalent bond breakage in a weak acid pH microenvironment. Near-infrared laser irradiation realizes photothermal conversion, thereby achieving the purpose of synergistic effect.

In the invention, mesoporous silica-polymer composite nano-particles containing functional group hydroxyl are obtained by surface Atom Transfer Radical Polymerization (ATRP); the polymer chain modifies DOX on the surface of mesoporous silica through a pH-sensitive cis-aconitic anhydride bond, then loads photo-thermal micromolecules into a mesoporous pore channel, the cis-aconitic anhydride bond is broken in a weak acid pH microenvironment, and the medicine shows the release of the falling medicine from MSN.

The nano particle material has good biocompatibility, and realizes the controllable release of the medicine by utilizing the acid-sensitive cis-form aconitic anhydride bond: the drug is hardly released around normal cells, and is quickly released in the slightly acidic environment of tumor cells, so that the targeted therapy of tumors is realized. The near infrared radiation can not only cause the increase of local temperature, but also accelerate the release of the medicine, is beneficial to the medicine to quickly reach the blood concentration, and realizes the synergistic effect of photo-thermal/chemotherapy.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the mesoporous silica nano particle is used as a drug carrier, and has good drug loading capacity and biocompatibility; the cis-aconitic anhydride bond which can be broken in a pH environment endows the system with good pH response release performance, so that the burst release of the drug can be improved, and the requirement of the drug-loaded system on quick release in a specific pH range can be met; the photo-thermal micromolecules are loaded in the mesoporous pore canal, so that the synergistic treatment effect is realized, and the medicine release is promoted.

Drawings

FIG. 1 is a reaction equation for the synthesis of prodrug small molecule (CA-DOX) in example 1.

FIG. 2 shows MSN-NH in example 1₂Scanning Electron Microscopy (SEM) images of nanoparticles.

FIG. 3 is a Transmission Electron Microscopy (TEM) image of Polymer @ MSN nanoparticles of example 1.

FIG. 4 shows MSN-NH in example 1₂Particle size distribution of nanoparticles.

FIG. 5 shows MSN @ CTAB and MSN-NH in example 1₂Comparison graph of infrared spectra of MSN-Br and MSN-polymer.

FIG. 6 shows MSN-NH in example 1₂N of MSN-polymer and MSN-cis-DOX/ICG nanoparticles₂Comparison of adsorption and desorption curves.

FIG. 7 shows MSN-NH in example 1₂A comparison of the pore sizes of MSN-polymer and MSN-cis-DOX/ICG.

FIG. 8 shows MSN-NH in example 1₂TGA comparison of MSN-Br and MSN-polymer and MSN-cis-DOX nanoparticles.

FIG. 9 shows DOX, MSN-NH in example 1₂UV-VIS comparison of MSN-cis-DOX, ICG and MSN-cis-DOX/ICG.

FIG. 10 shows the sum of the spectra of the prodrug small molecule CA-DOXFT-IR of example 1¹H NMR spectrum with CDCl as solvent₃。

FIG. 11 is the in vitro drug release profile of the MSN-cis-DOX/ICG nanoparticles of example 7.

FIG. 12 is a graph showing the photothermal properties of the MSN-cis-DOX/ICG nanoparticle nanoparticles of example 8.

FIG. 13 is the in vitro cytotoxicity of the MSN-cis-DOX/ICG nanoparticle nanoparticles of example 9.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto. The preferred number average molecular weight of the PEGMA used in the present invention is Mn ═ 500 Da.

The materials referred to in the following examples are commercially available. The using amount of each component is calculated by mass volume portion, g/mL. Some abbreviations used in the examples are compared as follows:

example 1

(1) Preparation of mesoporous silica containing surfactant: taking 0.2 parts by mass of CTAB and 0.2 parts by mass of FC₂0.018 mass portion of NaOH and 96 volume portions of water are mechanically stirred for 0.5 hour, then 1.0 volume portion of ethyl orthosilicate is rapidly added, the temperature is raised to 80 ℃, and the reaction is continued for 2 hours. After the reaction is finished, the mixture is naturally cooled to room temperature, centrifugally separated at 10000rpm, washed by water for a plurality of times and dried in vacuum at 30 ℃ for 24 hours to obtain white powder (MSN @ CTAB).

The weight parts of reactants in the step (1) are as follows: 0.20 parts of CTAB; 0.2 part of FC₂(ii) a 0.018 parts of sodium hydroxide; 0.96 part of TEOS; 98.78 parts of water.

(2) Preparation of surface aminated mesoporous silica: 0.5 part by mass of MSN @ CTAB is dispersed in 20 parts by volume of anhydrous toluene, N₂Refluxing at 80 deg.C for 2h, adding 0.75 volume part of APTES into the solution dropwise with a syringe, and adding N₂Refluxing at 80 deg.C for 24 h. After completion of the reaction, it was cooled to room temperature and centrifuged (1)0000rpm, 10min) and washed twice with toluene and ethanol, respectively. Then stirring with 60 volume parts of methanol and 3.8 volume parts of concentrated HCl at 70 ℃ for 24h to remove a template CTAB, centrifuging, washing with methanol for three times, and vacuum drying at 40 ℃ and 35mbar for 24h to obtain white powder, namely amino-modified mesoporous silica (MSN-NH)₂)。

The weight parts of reactants in the step (2) are as follows: 41.34 parts of mesoporous silica containing a template agent; 58.66 parts of APTES.

(3) Preparation of initiator MSN-Br: 0.3 part by mass of MSN-NH is taken₂Dispersing the components in 20 parts by volume of anhydrous tetrahydrofuran, adding 1.4 parts by volume of triethylamine under the ice bath condition, dropwise adding 5 parts by volume of THF solution containing 1.2 parts by volume of BIBB into the reaction solution under the slow stirring condition, continuing stirring for reaction for 2 hours after the dropwise adding is finished, removing the ice bath, and continuing the reaction for 48 hours at room temperature. Filtering to obtain a solid, fully washing the solid with THF, ethanol and deionized water, and drying the solid in vacuum at the temperature of 30 ℃ to obtain an initiator MSN-Br.

The weight parts of reactants in the step (3) are as follows: 3 parts of MSN-NH₂(ii) a 10.1 parts of TEA; 6.2 parts of BIBB.

(4) Preparation of mesoporous silica nanoparticles (MSN-polymers) with surface modified polymers: 0.2 part by mass of MSN-Br and 0.02 part by mass of CuBr₂Mixing, sealing, vacuumizing and introducing nitrogen for three times, then sequentially adding 0.12 part by mass of PEGMA, 0.15 part by mass of HEMA, 18 parts by volume of methanol/water (1/1, v/v) and 0.047 part by mass of HMTETA, and stirring for 10min to form the catalyst complex Cu/HMTETA. Then 0.15 parts by mass of ascorbic acid was dissolved in 2 parts by volume of methanol/water and added to a reaction flask, stirred for 10min and then transferred to a 50 ℃ oil bath for reaction for 24h, cooled to room temperature, and the reaction solution was exposed to air, 50 parts by volume of THF was added, the crude product was ultrasonically dispersed in 100 parts by volume of acetylacetone/ethanol (5/1, v/v), stirred for 24h at room temperature, centrifuged and the precipitate was washed with a large amount of water and ethanol, collected and vacuum-dried for 24h to obtain a white product, MSN-polymer.

The weight parts of reactants in the step (4) are as follows: 2 parts of CuBr₂(ii) a 12 parts of PEGMA; 15 parts of HEMA; 4.7 parts HMTETA; 15 portions of antAscorbic acid; 20 parts of MSN-Br.

(5) Preparation of prodrug small molecule (CA-DOX) with pH sensitivity (reaction equation shown in FIG. 1): mixing 0.08 mass part of DOX & HCl and 0.08 mass part of cis-aconitic anhydride (CA), sealing, vacuumizing and introducing nitrogen for three times, adding 10 volume parts of anhydrous DMF and 0.12 mass part of Triethylamine (TEA), reacting at room temperature in a dark place for 24 hours, diluting the mixture with ethyl glacial acetate, washing with a saturated sodium chloride aqueous solution, and drying to obtain the prodrug small molecule (CA-DOX).

The weight parts of reactants in the step (5) are as follows: 8 parts of DOX & HCl; 8 parts of CA; 12 parts of TEA.

(6) Preparation of prodrug nanoparticles: dispersing 10 parts by mass of MSN-polymer in 20 parts by volume of anhydrous dichloromethane, dissolving 2 parts by mass of CA-DOX in 3 parts by volume of anhydrous DCM, adding the mixture into a reaction system, reacting for 24 hours in a dark place, centrifuging, washing the precipitate with a large amount of water, removing unreacted CA-DOX, collecting the precipitate, and freeze-drying to obtain MSN-cis-DOX.

The weight parts of reactants in the step (6) are as follows: 10 parts of an MSN-polymer; 2 parts of CA-DOX.

(7) Preparing photo-thermal/chemotherapy synergistic nanoparticles: 3 parts by mass of MSN-cis-DOX are dispersed in 5 parts by volume of methanol, then 3 parts by mass of ICG are added, stirring is carried out for 24 hours at room temperature, photo-thermal/synergistic nanoparticles (MSN-cis-DOX/ICG) are obtained, thoroughly washed with water and centrifuged, and vacuum drying is carried out for 24 hours at 25 ℃ and under 35 mbar.

FIG. 2 shows MSN-NH in example 1₂Scanning Electron Microscopy (SEM) images of nanoparticles.

FIG. 3 is a Transmission Electron Microscopy (TEM) image of Polymer @ MSN nanoparticles of example 1.

FIG. 4 shows MSN-NH in example 1₂Particle size distribution of nanoparticles.

FIG. 5 shows MSN @ CTAB and MSN-NH in example 1₂Comparison graph of infrared spectra of MSN-Br and MSN-polymer.

FIG. 6 shows MSN-NH in example 1₂N of MSN-polymer and MSN-cis-DOX/ICG nanoparticles₂Comparison of adsorption and desorption curves.

FIG. 7 shows an embodiment1 MSN-NH₂A comparison of the pore sizes of MSN-polymer and MSN-cis-DOX/ICG.

FIG. 8 shows MSN-NH in example 1₂TGA comparison of MSN-Br and MSN-polymer and MSN-cis-DOX nanoparticles.

FIG. 9 shows DOX, MSN-NH in example 1₂UV-VIS comparison of MSN-cis-DOX, ICG and MSN-cis-DOX/ICG.

FIG. 10 shows the sum of the spectra of the prodrug small molecule CA-DOXFT-IR of example 1¹H NMR spectrum with CDCl as solvent₃。

Example 2

(1) Preparation of mesoporous silica containing surfactant: taking 0.15 mass part of CTAB and 0.15 mass part of FC₂3.75 parts by volume of TEOA solution and 96 parts by volume of water are mechanically stirred for 0.5h, then 1.0 part by volume of ethyl orthosilicate is rapidly added, the temperature is raised to 80 ℃, and the reaction is continued for 2 h. After the reaction is finished, the mixture is naturally cooled to room temperature, centrifugally separated at 10000rpm, washed by water for a plurality of times and dried in vacuum at 30 ℃ for 24 hours to obtain white powder (MSN @ CTAB).

The weight parts of reactants in the step (1) are as follows: 0.15 parts of CTAB; 0.15 part of FC₂(ii) a 0.06 parts TEOA; 0.95 part of TEOS; 98.78 parts of water.

(2) Preparation of surface aminated mesoporous silica: 0.6 part by mass of MSN @ CTAB is dispersed in 20 parts by volume of anhydrous toluene, and N₂Refluxing at 80 deg.C for 2h, adding 0.5 volume parts of APS into the solution dropwise by using a syringe, and adding N₂Refluxing at 80 deg.C for 24 h. After completion of the reaction, it was cooled to room temperature, separated by centrifugation (10000rpm, 10min), and washed twice with toluene and ethanol, respectively. Then stirring with 60 volume parts of methanol and 3.8 volume parts of concentrated HCl at 70 ℃ for 24h to remove a template CTAB, centrifuging, washing with methanol for three times, and vacuum drying at 40 ℃ and 35mbar for 24h to obtain white powder, namely amino-modified mesoporous silica (MSN-NH)₂)。

The weight parts of reactants in the step (2) are as follows: 51.39 parts of mesoporous silica containing a template agent; 48.61 parts APS.

(3) Preparation of initiator MSN-Br: 0.5 part by mass of MSN-NH is taken₂The parts are dispersed in 20 parts by volume of anhydrous tetrahydroAdding 1.5 volume parts of triethylamine into furan under an ice bath condition, dropwise adding 5 volume parts of THF solution containing 1.2 volume parts of BIBB into the reaction solution under the condition of slow stirring, continuously stirring for reaction for 2 hours after the dropwise addition is finished, removing the ice water bath, and continuously reacting for 48 hours at room temperature. Filtering to obtain a solid, fully washing the solid with THF, ethanol and deionized water, and drying the solid in vacuum at the temperature of 30 ℃ to obtain an initiator MSN-Br.

The weight parts of reactants in the step (3) are as follows: 5 parts of MSN-NH₂(ii) a 10.8 parts of TEA; 6.2 parts of BIBB.

(4) Preparation of mesoporous silica nanoparticles (MSN-polymers) with surface modified polymers: 0.2 part by mass of MSN-Br and 0.01 part by mass of CuBr are taken₂Mixing, sealing, vacuumizing and introducing nitrogen for three times, then sequentially adding 0.15 parts by mass of PEGMA, 0.2 parts by mass of HEMA, 18 parts by volume of methanol/water (1/1, v/v) and 0.047 part by mass of HMTETA, and stirring for 10min to form the catalyst complex Cu/HMTETA. Then 0.15 parts by mass of ascorbic acid was dissolved in 2 parts by volume of methanol/water and added to a reaction flask, stirred for 10min and then transferred to a 50 ℃ oil bath for reaction for 24h, cooled to room temperature, and the reaction solution was exposed to air, 50 parts by volume of THF was added, the crude product was ultrasonically dispersed in 100 parts by volume of acetylacetone/ethanol (5/1, v/v), stirred for 24h at room temperature, centrifuged and the precipitate was washed with a large amount of water and ethanol, collected and vacuum-dried for 24h to obtain a white product, MSN-polymer.

The weight parts of reactants in the step (4) are as follows: 1 part of CuBr₂(ii) a 15 parts of PEGMA; 20 parts of HEMA; 4.7 parts HMTETA; 15 parts of ascorbic acid; 20 parts of MSN-Br.

(5) Preparation of prodrug small molecule (CA-DOX) with pH sensitivity (reaction equation shown in FIG. 1): 0.05 part by mass of DOX & HCl and 0.05 part by mass of cis-aconitic anhydride (CA) are mixed, vacuum-pumping is carried out for three times after sealing, 10 parts by volume of anhydrous DMF and 0.10 part by mass of Triethylamine (TEA) are added, the mixture is reacted for 24 hours in a dark place at room temperature, then the mixture is diluted by ethyl glacial acetate, and the mixture is washed by saturated sodium chloride aqueous solution and dried to obtain prodrug small molecule (CA-DOX).

The weight parts of reactants in the step (5) are as follows: 5 parts of DOX & HCl; 5 parts of CA; 10 parts of TEA.

(6) Preparation of prodrug nanoparticles: dispersing 10 parts by mass of MSN-polymer in 20 parts by volume of anhydrous dichloromethane, dissolving 2 parts by mass of CA-DOX in 3 parts by volume of anhydrous DCM, adding the mixture into a reaction system, reacting for 24 hours in a dark place, centrifuging, washing the precipitate with a large amount of water, removing unreacted CA-DOX, collecting the precipitate, and freeze-drying to obtain MSN-cis-DOX.

The weight parts of reactants in the step (6) are as follows: 10 parts of an MSN-polymer; 2 parts of CA-DOX.

(7) Preparing photo-thermal/chemotherapy synergistic nanoparticles: 3 parts by mass of MSN-cis-DOX are dispersed in 5 parts by volume of methanol, then 3 parts by mass of ICG are added, stirring is carried out for 24 hours at room temperature, photo-thermal/synergistic nanoparticles (MSN-cis-DOX/ICG) are obtained, thoroughly washed with water and centrifuged, and vacuum drying is carried out for 24 hours at 25 ℃ and under 35 mbar.

Example 3

(1) Preparation of mesoporous silica containing surfactant: taking 0.25 mass part of CTAB and 0.25 mass part of FC₂After mechanically stirring 2.5 parts by volume of ammonia water and 96 parts by volume of water for 0.5h, quickly adding 1.0 part by volume of tetraethoxysilane, heating to 80 ℃, and continuously reacting for 2 h. After the reaction is finished, the mixture is naturally cooled to room temperature, centrifugally separated at 10000rpm, washed by water for a plurality of times and dried in vacuum at 30 ℃ for 24 hours to obtain white powder (MSN @ CTAB).

The weight parts of reactants in the step (1) are as follows: 0.25 parts of CTAB; 0.25 part of FC₂(ii) a 0.10 part of ammonia water; 0.95 part of TEOS; 98.78 parts of water.

(2) Preparation of surface aminated mesoporous silica: 0.5 part by mass of MSN @ CTAB is dispersed in 20 parts by volume of anhydrous toluene, N₂Refluxing at 80 deg.C for 2h, adding 1.0 volume part of APTES into the solution dropwise with syringe, and adding N₂Refluxing at 80 deg.C for 24 h. After completion of the reaction, it was cooled to room temperature, separated by centrifugation (10000rpm, 10min), and washed twice with toluene and ethanol, respectively. Then stirring with 60 volume parts of methanol and 3.8 volume parts of concentrated HCl at 70 ℃ for 24h to remove a template CTAB, centrifuging, washing with methanol for three times, and vacuum drying at 40 ℃ and 35mbar for 24h to obtain white powder, namely amino-modified mesoporous silica (MSN-NH)₂)。

The weight parts of reactants in the step (2) are as follows: 34.58 parts of mesoporous silica containing a template agent; 65.42 parts of APTES.

(3) Preparation of initiator MSN-Br: 0.5 part by mass of MSN-NH is taken₂Dispersing the components in 20 parts by volume of anhydrous tetrahydrofuran, adding 1.5 parts by volume of triethylamine under the ice bath condition, dropwise adding 5 parts by volume of THF solution containing 1.5 parts by volume of BIBB into the reaction solution under the slow stirring condition, continuing stirring for reaction for 2 hours after the dropwise adding is finished, removing the ice bath, and continuing the reaction for 48 hours at room temperature. Filtering to obtain a solid, fully washing the solid with THF, ethanol and deionized water, and drying the solid in vacuum at the temperature of 30 ℃ to obtain an initiator MSN-Br.

The weight parts of reactants in the step (3) are as follows: 5 parts of MSN-NH₂(ii) a 10.8 parts of TEA; 7.75 parts of BIBB.

(4) Preparation of mesoporous silica nanoparticles (MSN-polymers) with surface modified polymers: 0.5 part by mass of MSN-Br and 0.01 part by mass of CuBr are taken₂Mixing, sealing, vacuumizing and introducing nitrogen for three times, then sequentially adding 0.15 parts by mass of PEGMA, 0.2 parts by mass of HEMA, 18 parts by volume of methanol/water (1/1, v/v) and 0.067 part by mass of HMTETA, and stirring for 10min to form the catalyst complex Cu/HMTETA. Then 0.15 parts by mass of ascorbic acid was dissolved in 2 parts by volume of methanol/water and added to a reaction flask, stirred for 10min and then transferred to a 50 ℃ oil bath for reaction for 24h, cooled to room temperature, and the reaction solution was exposed to air, 50 parts by volume of THF was added, the crude product was ultrasonically dispersed in 100 parts by volume of acetylacetone/ethanol (5/1, v/v), stirred for 24h at room temperature, centrifuged and the precipitate was washed with a large amount of water and ethanol, collected and vacuum-dried for 24h to obtain a white product, MSN-polymer.

The weight parts of reactants in the step (4) are as follows: 1 part of CuBr₂(ii) a 15 parts of PEGMA; 20 parts of HEMA; 6.7 parts HMTETA; 15 parts of ascorbic acid; 50 parts of MSN-Br.

(5) Preparation of prodrug small molecule (CA-DOX) with pH sensitivity (reaction equation shown in FIG. 1): mixing 0.08 mass part of DOX & HCl and 0.08 mass part of cis-aconitic anhydride (CA), sealing, vacuumizing and introducing nitrogen for three times, adding 10 volume parts of anhydrous DMF and 0.12 mass part of Triethylamine (TEA), reacting at room temperature in a dark place for 24 hours, diluting the mixture with ethyl glacial acetate, washing with a saturated sodium chloride aqueous solution, and drying to obtain the prodrug small molecule (CA-DOX).

The weight parts of reactants in the step (5) are as follows: 8 parts of DOX & HCl; 8 parts of CA; 12 parts of TEA.

(6) Preparation of prodrug nanoparticles: dispersing 10 parts by mass of MSN-polymer in 20 parts by volume of anhydrous dichloromethane, dissolving 2 parts by mass of CA-DOX in 3 parts by volume of anhydrous DCM, adding the mixture into a reaction system, reacting for 24 hours in a dark place, centrifuging, washing the precipitate with a large amount of water, removing unreacted CA-DOX, collecting the precipitate, and freeze-drying to obtain MSN-cis-DOX.

The weight parts of reactants in the step (6) are as follows: 10 parts of an MSN-polymer; 2 parts of CA-DOX.

(7) Preparing photo-thermal/chemotherapy synergistic nanoparticles: 4.5 parts by mass of MSN-cis-DOX are dispersed in 5 parts by volume of methanol, 4.5 parts by mass of ICG are then added and stirred at room temperature for 24 hours to obtain photothermal/synergistic nanoparticles (MSN-cis-DOX/ICG), which are thoroughly washed with water and centrifuged, and dried under vacuum at 25 ℃ and 35mbar for 24 hours.

Example 4

(1) Preparation of mesoporous silica containing surfactant: taking 0.2 mass part of CTAB and 0.25 mass part of FC₂And after mechanically stirring 0.7 volume part of NaOH solution (2M) and 96 volume parts of water for 0.5h, quickly adding 1.0 volume part of tetraethoxysilane, heating to 80 ℃, and continuously reacting for 2 h. After the reaction is finished, the mixture is naturally cooled to room temperature, centrifugally separated at 10000rpm, washed by water for a plurality of times and dried in vacuum at 30 ℃ for 24 hours to obtain white powder (MSN @ CTAB).

The weight parts of reactants in the step (1) are as follows: 0.2 part of CTAB; 0.25 part of FC₂(ii) a 0.06 part of NaOH; 0.96 part of TEOS; 98.78 parts of water.

(2) Preparation of surface aminated mesoporous silica: 0.5 part by mass of MSN @ CTAB is dispersed in 20 parts by volume of anhydrous toluene, N₂Refluxing at 80 deg.C for 2h, adding 0.75 volume part of APTES into the solution dropwise with a syringe, and adding N₂Refluxing at 80 deg.C for 24 h. After completion of the reaction, it was cooled to room temperature, centrifuged (10000rpm, 10min), and separated with toluene andthe ethanol was washed twice each. Then stirring with 60 volume parts of methanol and 3.8 volume parts of concentrated HCl at 70 ℃ for 24h to remove a template CTAB, centrifuging, washing with methanol for three times, and vacuum drying at 40 ℃ and 35mbar for 24h to obtain white powder, namely amino-modified mesoporous silica (MSN-NH)₂)。

The weight parts of reactants in the step (2) are as follows: 41.34 parts of mesoporous silica containing a template agent; 58.66 parts of APTES.

(3) Preparation of initiator MSN-Br: 0.5 part by mass of MSN-NH is taken₂Dispersing the components in 20 parts by volume of anhydrous tetrahydrofuran, adding 1.5 parts by volume of triethylamine under the ice bath condition, dropwise adding 5 parts by volume of THF solution containing 1.5 parts by volume of BIBB into the reaction solution under the slow stirring condition, continuing stirring for reaction for 2 hours after the dropwise adding is finished, removing the ice bath, and continuing the reaction for 48 hours at room temperature. Filtering to obtain a solid, fully washing the solid with THF, ethanol and deionized water, and drying the solid in vacuum at the temperature of 30 ℃ to obtain an initiator MSN-Br.

The weight parts of reactants in the step (3) are as follows: 5 parts of MSN-NH₂(ii) a 10.8 parts of TEA; 7.75 parts of BIBB.

(4) Preparation of mesoporous silica nanoparticles (MSN-polymers) with surface modified polymers: 0.5 part by mass of MSN-Br and 0.01 part by mass of CuBr are taken₂Mixing, sealing, vacuumizing and introducing nitrogen for three times, then sequentially adding 0.15 parts by mass of PEGMA, 0.2 parts by mass of HEMA, 18 parts by volume of methanol/water (1/1, v/v) and 0.067 part by mass of HMTETA, and stirring for 10min to form the catalyst complex Cu/HMTETA. Then 0.15 parts by mass of ascorbic acid was dissolved in 2 parts by volume of methanol/water and added to a reaction flask, stirred for 10min and then transferred to a 50 ℃ oil bath for reaction for 24h, cooled to room temperature, and the reaction solution was exposed to air, 50 parts by volume of THF was added, the crude product was ultrasonically dispersed in 100 parts by volume of acetylacetone/ethanol (5/1, v/v), stirred for 24h at room temperature, centrifuged and the precipitate was washed with a large amount of water and ethanol, collected and vacuum-dried for 24h to obtain a white product, MSN-polymer.

The weight parts of reactants in the step (4) are as follows: 1 part of CuBr₂(ii) a 15 parts of PEGMA; 20 parts of HEMA; 6.7 parts HMTETA; 15 parts of ascorbic acid; 50 parts of MSN-Br.

(5) Preparation of prodrug small molecule (CA-DOX) with pH sensitivity (reaction equation shown in FIG. 1): mixing 0.08 mass part of DOX & HCl and 0.08 mass part of cis-aconitic anhydride (CA), sealing, vacuumizing and introducing nitrogen for three times, adding 10 volume parts of anhydrous DMF and 0.12 mass part of Triethylamine (TEA), reacting at room temperature in a dark place for 24 hours, diluting the mixture with ethyl glacial acetate, washing with a saturated sodium chloride aqueous solution, and drying to obtain the prodrug small molecule (CA-DOX).

The weight parts of reactants in the step (5) are as follows: 8 parts of DOX & HCl; 8 parts of CA; 12 parts of TEA.

(6) Preparation of prodrug nanoparticles: dispersing 15 parts by mass of MSN-polymer in 20 parts by volume of anhydrous dichloromethane, dissolving 5 parts by mass of CA-DOX in 3 parts by volume of anhydrous DCM, adding the mixture into a reaction system, reacting for 24 hours in a dark place, centrifuging, washing the precipitate with a large amount of water, removing unreacted CA-DOX, collecting the precipitate, and freeze-drying to obtain MSN-cis-DOX.

The weight parts of reactants in the step (6) are as follows: 15 parts of an MSN-polymer; 5 parts of CA-DOX.

(7) Preparing photo-thermal/chemotherapy synergistic nanoparticles: 4.5 parts by mass of MSN-cis-DOX are dispersed in 5 parts by volume of methanol, 4.5 parts by mass of ICG are then added and stirred at room temperature for 24 hours to obtain photothermal/synergistic nanoparticles (MSN-cis-DOX/ICG), which are thoroughly washed with water and centrifuged, and dried under vacuum at 25 ℃ and 35mbar for 24 hours.

Example 5

(1) Preparation of mesoporous silica containing surfactant: taking 0.2 mass part of CTAB and 0.7 mass part of FC₂And after mechanically stirring 0.7 volume part of NaOH solution (2M) and 96 volume parts of water for 0.5h, quickly adding 1.0 volume part of tetraethoxysilane, heating to 80 ℃, and continuously reacting for 2 h. After the reaction is finished, the mixture is naturally cooled to room temperature, centrifugally separated at 10000rpm, washed by water for a plurality of times and dried in vacuum at 30 ℃ for 24 hours to obtain white powder (MSN @ CTAB).

The weight parts of reactants in the step (1) are as follows: 0.20 parts of CTAB; 0.7 part of FC₂(ii) a 0.06 part of sodium hydroxide; 0.96 part of TEOS; 98.78 parts of water.

(2) Surface aminated mesoporous dioxidePreparation of silicon: 0.5 part by mass of MSN @ CTAB is dispersed in 20 parts by volume of anhydrous toluene, N₂Refluxing at 80 deg.C for 2h, adding 0.75 volume part of APTES into the solution dropwise with a syringe, and adding N₂Refluxing at 80 deg.C for 24 h. After completion of the reaction, it was cooled to room temperature, separated by centrifugation (10000rpm, 10min), and washed twice with toluene and ethanol, respectively. Then stirring with 60 volume parts of methanol and 3.8 volume parts of concentrated HCl at 70 ℃ for 24h to remove a template CTAB, centrifuging, washing with methanol for three times, and vacuum drying at 40 ℃ and 35mbar for 24h to obtain white powder, namely amino-modified mesoporous silica (MSN-NH)₂)。

The weight parts of reactants in the step (2) are as follows: 41.34 parts of mesoporous silica containing a template agent; 58.66 parts of APTES.

(3) Preparation of initiator MSN-Br: 0.5 part by mass of MSN-NH is taken₂Dispersing the components in 20 parts by volume of anhydrous tetrahydrofuran, adding 1.5 parts by volume of triethylamine under the ice bath condition, dropwise adding 5 parts by volume of THF solution containing 1.5 parts by volume of BIBB into the reaction solution under the slow stirring condition, continuing stirring for reaction for 2 hours after the dropwise adding is finished, removing the ice bath, and continuing the reaction for 48 hours at room temperature. Filtering to obtain a solid, fully washing the solid with THF, ethanol and deionized water, and drying the solid in vacuum at the temperature of 30 ℃ to obtain an initiator MSN-Br.

The weight parts of reactants in the step (3) are as follows: 5 parts of MSN-NH₂(ii) a 10.8 parts of TEA; 7.75 parts of BIBB.

(4) Preparation of mesoporous silica nanoparticles (MSN-polymers) with surface modified polymers: 0.5 part by mass of MSN-Br and 0.01 part by mass of CuBr are taken₂Mixing, sealing, vacuumizing and introducing nitrogen for three times, then sequentially adding 0.15 parts by mass of PEGMA, 0.2 parts by mass of HEMA, 18 parts by volume of methanol/water (1/1, v/v) and 0.067 part by mass of HMTETA, and stirring for 10min to form the catalyst complex Cu/HMTETA. Then 0.15 part by mass of ascorbic acid was dissolved in 2 parts by volume of methanol/water and added to a reaction flask, stirred for 10min and then transferred to a 50 ℃ oil bath for reaction for 24h, cooled to room temperature, and the reaction solution was exposed to air, 50 parts by volume of THF was added, the crude product was ultrasonically dispersed in 100 parts by volume of acetylacetone/ethanol (5/1, v/v), stirred for 24h at room temperature, centrifuged and concentrated with a large amount of waterAnd washing the precipitate with ethanol, collecting the precipitate, and drying in vacuum for 24h to obtain a white product MSN-polymer.

The weight parts of reactants in the step (4) are as follows: 1 part of CuBr₂(ii) a 15 parts of PEGMA; 20 parts of HEMA; 6.7 parts HMTETA; 15 parts of ascorbic acid; 50 parts of MSN-Br.

(5) Preparation of prodrug small molecule (CA-DOX) with pH sensitivity (reaction equation shown in FIG. 1): mixing 0.08 mass part of DOX & HCl and 0.08 mass part of cis-aconitic anhydride (CA), sealing, vacuumizing and introducing nitrogen for three times, adding 10 volume parts of anhydrous DMF and 0.12 mass part of Triethylamine (TEA), reacting at room temperature in a dark place for 24 hours, diluting the mixture with ethyl glacial acetate, washing with a saturated sodium chloride aqueous solution, and drying to obtain the prodrug small molecule (CA-DOX).

The weight parts of reactants in the step (5) are as follows: 8 parts of DOX & HCl; 8 parts of CA; 12 parts of TEA.

(6) Preparation of prodrug nanoparticles: dispersing 15 parts by mass of MSN-polymer in 20 parts by volume of anhydrous dichloromethane, dissolving 5 parts by mass of CA-DOX in 3 parts by volume of anhydrous DCM, adding the mixture into a reaction system, reacting for 24 hours in a dark place, centrifuging, washing the precipitate with a large amount of water, removing unreacted CA-DOX, collecting the precipitate, and freeze-drying to obtain MSN-cis-DOX.

The weight parts of reactants in the step (6) are as follows: 15 parts of an MSN-polymer; 5 parts of CA-DOX.

(7) Preparing photo-thermal/chemotherapy synergistic nanoparticles: 4.5 parts by mass of MSN-cis-DOX are dispersed in 5 parts by volume of methanol, 4.5 parts by mass of ICG are then added and stirred at room temperature for 24 hours to obtain photothermal/synergistic nanoparticles (MSN-cis-DOX/ICG), which are thoroughly washed with water and centrifuged, and dried under vacuum at 25 ℃ and 35mbar for 24 hours.

Example 6

(1) Preparation of mesoporous silica containing surfactant: taking 0.15 mass part of CTAB and 0.15 mass part of FC₂3.75 parts by volume of TEOA solution and 96 parts by volume of water are mechanically stirred for 0.5h, then 1.0 part by volume of ethyl orthosilicate is rapidly added, the temperature is raised to 70 ℃, and the reaction is continued for 1.5 h. After the reaction is finished, the mixture is naturally cooled to room temperature, centrifugally separated at 10000rpm, washed by water for a plurality of times at 30 DEG CVacuum drying for 24h to obtain white powder (MSN @ CTAB).

The weight parts of reactants in the step (1) are as follows: 0.15 parts of CTAB; 0.15 part of FC₂(ii) a 0.06 parts TEOA; 0.95 part of TEOS; 98.78 parts of water.

(2) Preparation of surface aminated mesoporous silica: 0.6 part by mass of MSN @ CTAB is dispersed in 20 parts by volume of anhydrous toluene, and N₂Refluxing at 80 deg.C for 2h, adding 0.5 volume parts of APS into the solution dropwise by using a syringe, and adding N₂Refluxing at 80 deg.C for 24 h. After completion of the reaction, it was cooled to room temperature, separated by centrifugation (10000rpm, 10min), and washed twice with toluene and ethanol, respectively. Then stirring with 60 volume parts of methanol and 3.8 volume parts of concentrated HCl at 60 ℃ for 24h to remove template CTAB, centrifuging, washing with methanol for three times, and vacuum drying at 40 ℃ and 35mbar for 24h to obtain white powder, i.e. amino-modified mesoporous silica (MSN-NH)₂)。

The weight parts of reactants in the step (2) are as follows: 51.39 parts of mesoporous silica containing a template agent; 48.61 parts APS.

(3) Preparation of initiator MSN-Br: 0.5 part by mass of MSN-NH is taken₂Dispersing the components in 20 parts by volume of anhydrous tetrahydrofuran, adding 1.5 parts by volume of triethylamine under the ice bath condition, dropwise adding 5 parts by volume of THF solution containing 1.5 parts by volume of BIBB into the reaction solution under the slow stirring condition, continuing stirring for reaction for 2 hours after the dropwise adding is finished, removing the ice bath, and continuing the reaction for 48 hours at room temperature. Filtering to obtain a solid, fully washing the solid with THF, ethanol and deionized water, and drying the solid in vacuum at the temperature of 30 ℃ to obtain an initiator MSN-Br.

The weight parts of reactants in the step (3) are as follows: 5 parts of MSN-NH₂(ii) a 10.8 parts of TEA; 7.75 parts of BIBB.

(4) Preparation of mesoporous silica nanoparticles (MSN-polymers) with surface modified polymers: 0.5 part by mass of MSN-Br and 0.06 part by mass of CuBr are taken₂Mixing, sealing, vacuumizing and introducing nitrogen for three times, then sequentially adding 0.15 parts by mass of PEGMA, 0.2 parts by mass of HEMA, 18 parts by volume of methanol/water (1/1, v/v) and 0.067 part by mass of HMTETA, and stirring for 10min to form the catalyst complex Cu/HMTETA. Then, 0.15 part by mass of ascorbic acid was dissolved in 2-mer solutionAdding the product of methanol/water into a reaction bottle, stirring for 10min, transferring into 50 ℃ oil bath for reaction for 24h, cooling to room temperature, exposing the reaction solution to air, adding 50 volume parts of THF, ultrasonically dispersing the crude product in 100 volume parts of acetylacetone/ethanol (5/1, v/v), stirring for 24h at room temperature, centrifuging, washing the precipitate with a large amount of water and ethanol, collecting the precipitate, and vacuum-drying for 24h to obtain a white product MSN-polymer.

The weight parts of reactants in the step (4) are as follows: 6 parts of CuBr₂(ii) a 15 parts of PEGMA; 20 parts of HEMA; 6.7 parts HMTETA; 15 parts of ascorbic acid; 50 parts of MSN-Br.

(5) Preparation of prodrug small molecule (CA-DOX) with pH sensitivity (reaction equation shown in FIG. 1): mixing 0.08 mass part of DOX & HCl and 0.08 mass part of cis-aconitic anhydride (CA), sealing, vacuumizing and introducing nitrogen for three times, adding 10 volume parts of anhydrous DMF and 0.12 mass part of Triethylamine (TEA), reacting at room temperature in a dark place for 24 hours, diluting the mixture with ethyl glacial acetate, washing with a saturated sodium chloride aqueous solution, and drying to obtain the prodrug small molecule (CA-DOX).

The weight parts of reactants in the step (5) are as follows: 8 parts of DOX & HCl; 8 parts of CA; 12 parts of TEA.

(6) Preparation of prodrug nanoparticles: dispersing 15 parts by mass of MSN-polymer in 20 parts by volume of anhydrous dichloromethane, dissolving 5 parts by mass of CA-DOX in 3 parts by volume of anhydrous DCM, adding the mixture into a reaction system, reacting for 24 hours in a dark place, centrifuging, washing the precipitate with a large amount of water, removing unreacted CA-DOX, collecting the precipitate, and freeze-drying to obtain MSN-cis-DOX.

The weight parts of reactants in the step (6) are as follows: 15 parts of an MSN-polymer; 5 parts of CA-DOX.

(7) Preparing photo-thermal/chemotherapy synergistic nanoparticles: 4.5 parts by mass of MSN-cis-DOX are dispersed in 5 parts by volume of methanol, 4.5 parts by mass of ICG are then added and stirred at room temperature for 24 hours to obtain photothermal/synergistic nanoparticles (MSN-cis-DOX/ICG), which are thoroughly washed with water and centrifuged, and dried under vacuum at 25 ℃ and 35mbar for 24 hours.

Example 7

And (3) measuring the in-vitro release performance of the composite nano particles under the photo-thermal/chemotherapy synergistic effect.

3mg of the prodrug granules prepared in example 1 were dispersed in 3mL of PBS (pH 7.4, 6.5) or acetate buffer (pH 5.0), transferred into a dialysis bag (MWCO3000), and the dialysis bag was filled with 47mL of PBS or acetate buffer (V)₀50mL) and then placed in a drug dissolution instrument, and subjected to in vitro release at 37 ℃ and 100rpm, and 4mL (V) was sampled at fixed time_e4mL) and 4mL of fresh buffer was added to calculate the concentration of doxorubicin in the release solution at different times. The release curves were plotted by averaging 3 replicates at each pH, see figure 11.

As can be seen in FIG. 11, at pH 7.4, less than 20% of the DOX was released from the carrier after 50h, since cis-rooftop anhydride is a dynamic chemical bond sensitive to acidic environments and is therefore relatively more stable in neutral environments and less prone to cleavage, thereby reducing the burst of drug. With decreasing pH, the release of DOX was 64.6% (pH 6.5) and 84.3% (pH 5.0) well above physiological conditions, respectively, under similar incubation conditions (about 50h), showing a clear pH-responsive controlled release behavior.

Example 8

And measuring the photothermal performance of the composite nano-particles with the photothermal/chemotherapy synergistic effect.

To investigate the photothermal heating effect, a series of concentrations (100, 200 and 500ug/mL) of the MSN-cis-DOX/ICG nanocarriers obtained in example 1 were prepared. A volume of 100uL of the solution was placed in a 96-well plate and then irradiated with an NIR laser (wavelength 980 nm; power 2W; laser spot diameter 3 mm). Immediately after irradiation, the solution temperature was monitored with a digital thermometer. Control experiments with negative samples (PBS solution and MSN-cis-DOX) were also measured under the same conditions, see FIG. 12.

As shown in FIG. 12, in the NIR laser (808nm, 2W/cm)²) After continuous irradiation for 6min, the temperature changes of the PBS solution and the system without loading ICG are not obvious, which shows that NIR laser with wavelength of 808nm has no damage to normal tissues; while MSN-cis-DOX/ICG produced a significant temperature increase. After continuous irradiation for 6min, the temperature is raised by about 12.7 ℃ and 17.5 ℃ at the concentration of 0.2mg/ml and 0.5mg/ml, which shows that the medicine carrying system has better photo-thermal conversion performance and can be used for carrying out photo-thermal conversionThe purposes of killing tumor cells by high heat (the temperature is higher than 42 ℃, the tumor cells can generate irreversible damage) and accelerating the breakage of acid sensitive bonds are achieved.

Example 9

Cytotoxicity test of photothermal/chemotherapeutic synergistic composite nanoparticles.

Cytotoxicity experiments were performed with HepG2 cells. The cancer cells HepG2 were cultured in DMEM medium containing 10% heat-inactivated Fetal Bovine Serum (FBS) and 1% double antibody (100. mu.L/mL penicillin and 0.1mg/mL streptomycin) and inoculated into 96-well plates (1X 10 concentration)⁴Cells/well), the well plate was placed at 37 ℃ with saturated humidity, 5% CO₂Culturing in an incubator for 24 h. The old medium was replaced with fresh medium containing different concentrations of the drug-loaded particles obtained in example 1, incubated for 48h, washed with PBS, and incubated for 4h with addition of MTT diluted with DMEM. The non-reduced MTT solution was aspirated, washed with PBS and then DMSO (200. mu.L) was added to dissolve MTT crystals. The 96-well plate was placed in a shaker at 37 ℃ and shaken for 10min, and the absorbance of each well at 570nm was measured by a microplate reader, and the results of calculating the cell survival rate are shown in FIG. 13.

As can be seen from FIG. 13, both MSN-cis-DOX/ICG and free DOX had significant inhibitory effects on the growth and proliferation of HepG2 cells. After 48h of culture, Polymer @ MSN-DOX showed obvious cytotoxicity, and the cell survival rate was further reduced under the irradiation of near-infrared laser. Therefore, the MSN-cis-DOX/ICG can achieve good photo-thermal/chemotherapy synergistic effect.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.