Nanometer material suitable for multi-mode diagnostic imaging and targeted photodynamic and photo-thermal cancer therapy as well as preparation and application of nanometer material

Abstract

The invention provides a nano material suitable for multi-mode diagnostic imaging and targeted photodynamic (PDT) and photo-thermal (PTT) cancer therapy, and belongs to the field of nano biomedicine. According to the invention, an upconversion material (NaYF4: Yb / Er / Gd) and a photo-thermal material (Bi2Se3) are taken as a core, mesoporous silica is taken as a shell, and a photosensitizer (Ce6) and lipid / PEG and acidity-triggered membrane (ATRAM) peptide coated on the surface of the shell are loaded. The PDT and PTT synergistic anticancer effect achieved through near-infrared laser induction is achieved, magnetic resonance imaging, thermal imaging and fluorescence imaging of tumors can be achieved, and the requirement for diagnosis and treatment integration is met. In addition, the in-vivo lifetime of the nano-carrier is effectively prolonged through lipid / PEG, and aggregation and premature degradation of the nano-carrier are prevented; and the pH-mediated acidity-triggered membrane peptide is utilized to improve the uptake of cancer cells to the nano-carrier, so that the effect of the nano-carrier and the cancer cells is enhanced.

Description

Technical Field

[0001] The present invention belongs to the field of nano-biomedicine, and specifically relates to a nano-material suitable for multi-modal diagnostic imaging and targeted photodynamic and photothermal cancer therapy, as well as the preparation and application thereof. Background Art

[0002] Photodynamic therapy (PDT) and photothermal therapy (PTT) are emerging cancer treatment methods following the three traditional methods of surgery, radiotherapy, and chemotherapy. PDT uses laser irradiation to activate photosensitizers (PS), which then produce cytotoxic reactive oxygen species (ROS) through a series of photochemical reactions to induce apoptosis of cancer cells. PTT uses photothermal agents (PTA) to convert absorbed light into thermal energy, and uses thermal therapy to partially or completely ablate tumor tissue. Currently, nanocarriers can simultaneously deliver PS and PTA to combine the two phototherapies of PDT and PTT to enhance their anti-tumor effects. The advantage of this method is that PTT-induced thermal therapy can promote local blood flow to increase the accumulation of PS molecules and molecular oxygen in tumor tissues, thereby improving the effectiveness of PDT; while the ROS produced by PDT can inactivate heat shock proteins, thereby reducing the heat resistance of cancer cells and increasing their susceptibility to PTT.

[0003] After searching, it was found that the Chinese patent document number CN104800846B discloses a core-shell gold nanomaterial and its preparation method and application. It consists of gold nanorods, mesoporous silica coated on the gold nanorods, photosensitizer adsorbed inside the mesoporous silica, and liposomes adsorbed on the surface of the mesoporous silica. The invention effectively combines gold nanoparticles with photothermal therapy effects with photosensitizers with absorption in the near-infrared region, which can not only accumulate rapidly in cancer cells; but also realize the preparation and application of combined drugs for photothermal therapy and photodynamic therapy under two-photon irradiation. Chinese patent document No. CN106806905A discloses a rare earth upconversion nano drug carrier that integrates fluorescence imaging and drug loading. The nano drug carrier includes rare earth upconversion nanoparticles with fluorescence imaging function, anti-tumor drugs loaded on the surface of the upconversion nanoparticles, and amphiphilic polymer molecules distearoylphosphatidylethanolamine-polyethylene glycol (DSPEPEG) coated on the surface of the nanoparticles. The surface structure of the nano drug is conducive to enriching it in tumor tissue through the EPR effect, thereby realizing passive drug targeting. However, the above method still has the following shortcomings: (1) The accumulation of nanocarriers in tumor tissues is small (<1%), which is attributed to the fact that serum proteins will be adsorbed to the surface of nanocarriers in the circulation, resulting in the destruction of the stability of nanocarriers and the triggering of immune responses, resulting in the rapid clearance of nanocarriers. (2) The small number of nanocarriers that reach the tumor tissue are difficult to be taken up by cancer cells. The reason is that most nanocarriers enter cancer cells through endocytosis, but most of the endocytosed nanocarriers are trapped in the degraded acidic endocytic compartment or undergo exocytosis. The efficiency of escaping from the cell is very low, which makes it difficult for nanocarriers to reach the deep layer of the tumor. (3) With the demand for integrated diagnosis and treatment, tumor targeted therapy combined with multimodal diagnostic imaging is of great significance. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems and provide a nanomaterial suitable for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy and its preparation and application.

[0005] To achieve the above purpose, the present invention adopts the following technical solution:

[0006] A nanomaterial suitable for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy, wherein the nanomaterial is a core-shell structured liposome, and an acid-triggered membrane peptide is attached to the surface of the liposome; wherein the core is an upconversion nanosphere core, and the shell is mesoporous silica loaded with a photosensitizer, and the upconversion nanosphere core is an upconversion nanosphere doped with a photothermal agent.

[0007] The up-conversion nanosphere core is NaYF4:Yb / Er / Gd,Bi2Se3.

[0008] A method for preparing nanomaterials suitable for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy:

[0009] 1) Mixing the synthesized upconversion nanosphere NaYF4:Yb / Er / Gd with a photothermal agent to obtain an upconversion nanosphere core (NaYF4:Yb / Er / Gd, Bi2Se3);

[0010] 2) coating the above-obtained upconversion nanosphere core with mesoporous silica, and then mixing it with a dimethyl sulfoxide solution containing a photosensitizer to obtain a core-shell structure material;

[0011] 3) The core-shell structure material is mixed with a liposome solution, and after mixing, the mixture is dispersed in an acid-triggered membrane peptide solution to obtain a nanomaterial.

[0012] The upconversion nanosphere core in step 1) is composed of sodium yttrium fluoride doped with lanthanide elements (ytterbium, erbium, gadolinium) and photothermal agent bismuth selenide, wherein the mass ratio of NaYF4:Yb / Er / Gd to bismuth selenide is 0.1-0.32:0.01-0.05.

[0013] The synthesized upconversion nanospheres NaYF4:Yb / Er / Gd are diluted in a mixture of HCl and anhydrous ethanol (1:1, v / v), and ultrasonically treated. After treatment, they are repeatedly washed with anhydrous ethanol, and then dispersed in ultrapure water for standby use. Mannitol is dissolved in 10 mL of ultrapure water, and the aqueous solution of the synthesized upconversion nanospheres, Bi(NO3)3·5H2O, PVP and selenium precursor are added in sequence, mixed and stirred evenly, and the product is collected by centrifugation.

[0014] Furthermore, the synthesis of upconversion nanosphere cores (NaYF4:Yb / Er / Gd,Bi2Se3)

[0015] (1) Synthesis of NaYF4:Yb / Er / Gd: In an Ar atmosphere, YCl3·6H2O (0.99 mmol), YbCl3·6H2O (0.34 mmol), ErCl3·6H2O (0.06 mmol) and GdCl3·6H2O (0.61 mmol) were dissolved in oleic acid (13.4 g) / octadecene (35 mL) and heated to 140°C to obtain a yellow solution. Subsequently, the solution was cooled to 45°C, sodium hydroxide (150 mg) and ammonium fluoride (300 mg) were added to the reaction mixture, and stirred until the solution became clear. At this time, the solution was heated to 300°C and maintained for 90 minutes, and the color of the mixture turned yellow-brown. Then 8 mL of anhydrous ethanol was added, the product was collected by centrifugation, and purified by multiple centrifugation in anhydrous ethanol. Finally, the obtained upconversion nanosphere core was stored in cyclohexane.

[0016] (2) Synthesis of NaYF4:Yb / Er / Gd,Bi2Se3: 5 mL of the upconversion nanosphere core synthesized in step 1 was diluted in a mixture of 15 mL HCl (2M) and anhydrous ethanol (1:1, v / v) and sonicated at 60°C for 5 h. It was rinsed with anhydrous ethanol several times and then dispersed in ultrapure water to facilitate the subsequent addition of Bi2Se3. Selenium (3.6 g, 40 mmol) was reduced using NaBH4 in a N2 atmosphere to synthesize a selenium precursor. Mannitol (1 g) was dissolved in 10 mL of ultrapure water, and an aqueous solution of upconversion nanosphere core (2 mL, 0.125 mM), Bi(NO3)3·5H2O (0.1 g) and PVP (0.1 g) and a previously synthesized selenium precursor (0.3 mmol) were added in sequence. After continuous stirring for 8 h, the product was collected by centrifugation and washed with ultrapure water, and finally the obtained NaYF4:Yb / Er / Gd,Bi2Se3 was stored in cyclohexane.

[0017] The step 2) fully mixes the upconversion nanosphere core with the solution, adds ethyl silicate and trimethoxy(octadecyl)silane and reacts under stirring, extracts with acetone after the reaction to obtain the coated mesoporous silica upconversion nanosphere core, and then disperses it in ultrapure water to obtain a uniform colloidal solution, and then adds dimethyl sulfoxide containing Ce6 to the colloidal solution, stirs, mixes and separates to obtain a core-shell structure material; wherein the ratio of the coated mesoporous silica upconversion nanosphere core to Ce6 is 0.05-0.1:0.15-0.3.

[0018] Furthermore, the synthesis of mesoporous silica-coated upconverted nanosphere cores (UMSNs)

[0019] (1) Encapsulating the upconversion core in a mesoporous silica shell to produce upconversion mesoporous silica nanospheres (UMSNs) was completed as described above. Take 5 mL of the product synthesized in step 2 (1 mg / mL) and mix it thoroughly with 1 mL of ammonia (28%) and 50 mL of cyclohexane. Subsequently, 200 mL of TEOS and 80 μL of trimethoxy(octadecyl)silane were added to the mixture and stirred for 48 h. After the reaction was completed, 10 mL of acetone was added to the solution to extract the UMSNs, the product was collected by centrifugation, and washed several times with anhydrous ethanol. Finally, to remove the surfactant, the synthesized UMSNs were refluxed in 10 mL of HCl (2 M) and 160 mL of methanol for 12 h, the product was collected by centrifugation, washed several times with ultrapure water, and then freeze-dried.

[0020] (2) Synthesis of upconversion mesoporous silica nanospheres loaded with photosensitizer (Ce6-UMSNs)

[0021] 5 mg UMSNs were ultrasonically dispersed in 0.8 mL ultrapure water to obtain a uniform colloidal solution; 0.2 mL Ce6 (0.5-10 mg) dispersed in DMSO was added to the above solution and stirred for 48 h. The obtained product was separated by centrifugation, washed with ultrapure water several times, and freeze-dried for later use.

[0022] In the step 3), the core-shell structure material is uniformly dispersed in physiological saline, and the core-shell structure material is uniformly mixed with the liposome membrane by ultrasonication at a mass ratio of 1:1.2-1:2, and the product is separated and collected. The separated and collected product and the acid-triggered membrane peptide are dispersed in methanol, stirred and mixed, and then centrifuged. The collected product is the nanomaterial; wherein the ratio of the separated and collected product to the acid-triggered membrane peptide is 0.5-0.8:0.8-0.1.5.

[0023] The liposome is a mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), cholesterol and DSPE-PEG 2000 Dissolved in a mixture of chloroform-ethanol in proportion, then evaporated the solvent under a nitrogen atmosphere to form a liposome membrane; wherein 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), cholesterol and DSPE-PEG in the mixture 2000 The total concentration was 0.15mg / mL-1.2mg / mL, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), cholesterol and DSPE-PEG 2000 The molar ratio is 77.5:20:2.5, chloroform-ethanol is 0.15-0.5:0.5-0.85.

[0024] Furthermore, synthetic lipid / PEG-encapsulated UMSNs (LUMSNs)

[0025] The double-coated nanospheres are coated with lipid / PEG membrane on the surface of UMSNs; the double coating is composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) / cholesterol / DSPE-PEG 2000 The composition (molar ratio is 77.5:20:2.5). The preparation method is as follows: 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) / cholesterol / DSPE-PEG 2000 Dissolved in a mixture of chloroform / ethanol in proportion. Then, under a nitrogen atmosphere, the solvent was evaporated to form a lipid / PEG membrane. 10 mg Ce6-UMSNs were uniformly dispersed in 3 mL of normal saline. The resulting suspension and lipid / PEG membrane were ultrasonically mixed at a mass ratio of 1:1.2. Finally, the solid and liquid were separated using a centrifuge and washed multiple times with normal saline and ultrapure water. The resulting product was LUMSNs. Synthesis of acid-triggered membrane peptide (ATRAM) functionalized LUMSNs (ALUMSNs)

[0026] 0.6 mmol ATRAM and 1 mg LUMSN were dispersed in 200 μL methanol, and the mixture was stirred for 12 h under N2 atmosphere. The obtained product was separated by centrifugation, washed with ultrapure water for several times, and freeze-dried for use.

[0027] A use of the nanomaterial in the preparation of tumor treatment drugs, multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy drug carriers.

[0028] The multimodal imaging includes magnetic resonance imaging, thermal imaging and fluorescence imaging.

[0029] A medicine uses the nano material as a drug carrier.

[0030] The drugs are photothermal agents (NaYF4:Yb / Er / Gd, Bi2Se3), photosensitizers (Ce6) and acidity-triggered membrane (ATRAM) peptides.

[0031] The advantages of the present invention are:

[0032] The nanomaterial of the present invention has pH-mediated upconversion mesoporous silica nanospheres, which can be used for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer treatment. The upconversion nanosphere core is obtained by mixing upconversion material (NaYF4: Yb / Er / Gd) with a photothermal agent (Bi2Se3); its shell is composed of mesoporous silica-supported photosensitizer (Ce6) and lipid / PEG and acidity-triggered membrane (ATRAM) peptide coated on the shell surface. Among them, Yb / Er in the NaYF4 core can convert deeply penetrating near-infrared light into visible light, thereby stimulating the photosensitizer (Ce6) to produce cytotoxic reactive oxygen species, Gd can perform magnetic resonance imaging on the nanospheres, and Bi2Se3 can effectively convert near-infrared light into thermal energy. In addition, the lipid / PEG-coated mesoporous silica shell layer can prevent it from being adsorbed by serum proteins and recognized by macrophages, effectively protect the photothermal agent and photosensitizer, and increase their aggregation in tumor tissues. Finally, the shell is combined with the acidic triggering membrane peptide, which can effectively promote the efficient and specific internalization of nanomaterials into malignant cells in the weakly acidic microenvironment of the tumor. The present invention effectively improves the survival period of nanocarriers in the body, improves the uptake of nanocarriers by cancer cells, enhances the interaction between nanocarriers and cancer cells, and prevents their aggregation and protects them from premature degradation. Near-infrared laser induction achieves the synergistic anti-cancer effect of PDT and PTT, and can realize magnetic resonance imaging, thermal imaging and fluorescence imaging of tumors, meeting the needs of integrated diagnosis and treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A method flow chart of a nanomaterial suitable for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy of the present invention;

[0034] Figure 2 This is a transmission electron microscope image of the upconversion nanosphere core (NaYF4: Yb / Er / Gd, Bi2Se3) in Example 1 of the present invention;

[0035] Figure 3 This is a transmission electron microscopy image of mesoporous silica-coated upconversion nanosphere cores (UMSNs) in Example 1 of the present invention;

[0036] Figure 4 This is the nuclear magnetic resonance imaging image of the mesoporous silica nanospheres in Example 2 of the present invention;

[0037] Figure 5 TEM image of lipid / PEG coated UMSNs (LUMSNs) in Example 3 of the present invention;

[0038] Figure 6 A comparison diagram of the ROS generation capabilities of Ce6 and Ce6-LUMSNs in Example 3 of the present invention;

[0039] Figure 7 This is the photothermal response diagram of Ce6-LUMSNs in Example 3 of the present invention;

[0040] Figure 8 is a graph showing the percentage of Ce6 released by UMSNs and Ce6-LUMSNs in Example 3 of the present invention;

[0041] Fig. 9 is the normalized intensity ratio of LUMSNs and ALUMSNs taken up in 4T1 cells at different pH in Example 4 of the present invention; Fig.10 This is a confocal fluorescence microscopy image of Ce6-ALUMSNs in 4T1 cells at pH 6.5 in Example 4 of the present invention; Fig.11 In Example 4 of the present invention, Ce6-ALUMSNs (0.05-5 μg / mL Ce6) were exposed to an optical power of 1.5 W / cm 2 The survival rate of 4T1 cells at different treatment times (3min and 5min), pH ~ 7.4 in the left figure, pH ~ 6.5 in the right figure; Fig.12 Example 4 of the present invention shows the concentration of Ce6 in mouse 4T1 tumor 8 hours after a single intravenous injection (left) and the concentration of Ce6 in mouse 4T1 tumor cells under near-infrared laser irradiation (1.0 W / cm 2 ) under thermal imaging (right); DETAILED DESCRIPTION

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation modes, but the present invention is not limited thereto.

[0043] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0044] Example 1

[0045] 1. Synthesis of upconversion nanosphere cores (NaYF4: Yb / Er / Gd, Bi2Se3)

[0046] The nanosphere core is composed of sodium yttrium fluoride and bismuth selenide doped with lanthanide elements (ytterbium, erbium, gadolinium) (NaYF4: Yb / Er / Gd, Bi2Se3).

[0047] (1) Synthesis of NaYF4:Yb / Er / Gd: In an Ar atmosphere, YCl3·6H2O (0.99 mmol), YbCl3·6H2O (0.34 mmol), ErCl3·6H2O (0.06 mmol) and GdCl3·6H2O (0.3 mmol) were dissolved in oleic acid (13.4 g) / octadecene (35 mL) and heated to 140°C to obtain a yellow solution. Subsequently, the solution was cooled to 45°C, sodium hydroxide (150 mg) and ammonium fluoride (300 mg) were added to the reaction mixture, and stirred until the solution became clear. At this time, the solution was heated to 300°C and maintained for 90 minutes, and the color of the mixture turned yellow-brown. Then 8 mL of anhydrous ethanol was added, the product was collected by centrifugation, and purified by multiple centrifugation in anhydrous ethanol. Finally, the obtained upconversion nanosphere core was stored in cyclohexane.

[0048] (2) Synthesis of NaYF4:Yb / Er / Gd,Bi2Se3: 5 mL of the upconversion nanosphere core synthesized in step 1 was diluted in a mixture of 15 mL of HCl (2 M) and anhydrous ethanol (1:1, v / v) and sonicated at 60 °C for 5 h. Rinse with anhydrous ethanol several times and then disperse in ultrapure water to facilitate the subsequent addition of Bi2Se3. In a N2 atmosphere, selenium (3.6 g, 40 mmol) was reduced using NaBH4 to synthesize a selenium precursor. Mannitol (1 g) was dissolved in 10 mL of ultrapure water, and an aqueous solution of upconversion nanosphere core (2 mL, 0.125 mM), Bi(NO3)3·5H2O (0.1 g) and PVP (0.1 g) and a pre-synthesized selenium precursor (0.3 mmol) were added in sequence. After continuous stirring for 8 hours, the product was collected by centrifugation and washed with ultrapure water. Finally, the obtained NaYF4:Yb / Er / Gd,Bi2Se3 was stored in cyclohexane (see Figure 1 ).

[0049] Depend on Figure 1 The particle size of NaYF4:Yb / Er / Gd,Bi2Se3 is shown to be 60-80nm.

[0050] 2 Synthesis of upconversion mesoporous silica nanospheres (UMSNs)

[0051] (1) Encapsulating the upconversion core in a mesoporous silica shell to produce upconversion mesoporous silica nanospheres (UMSNs) was completed as described above. Take 5 mL of the product synthesized in step 2 (1 mg / mL) and mix it thoroughly with 1 mL of ammonia (28%) and 50 mL of cyclohexane. Subsequently, 200 mL of TEOS and 80 μL of trimethoxy(octadecyl)silane were added to the mixture and stirred for 48 h. After the reaction was completed, 10 mL of acetone was added to the solution to extract the UMSNs, the product was collected by centrifugation, and washed several times with anhydrous ethanol. Finally, to remove the surfactant, the synthesized UMSNs were refluxed in 10 mL of HCl (2 M) and 160 mL of methanol for 12 h, the product was collected by centrifugation, washed several times with ultrapure water, and then freeze-dried.

[0052] (2) Synthesis of upconversion mesoporous silica nanospheres loaded with photosensitizer (Ce6-UMSNs)

[0053] 5 mg UMSNs were ultrasonically dispersed in 0.8 mL ultrapure water to obtain a uniform colloidal solution; 0.2 mL Ce6 (dihydrochlorin) (0.5-10 mg) dispersed in DMSO was added to the above solution and stirred for 48 h. The obtained product was separated by centrifugation, washed with ultrapure water several times, and freeze-dried for later use (see Figure 2 ).

[0054] Depend on Figure 2 The core-shell structure is clearly shown in the figure, confirming that silica encapsulates the upconversion nanosphere core.

[0055] Example 2

[0056] The UMSNs prepared according to Example 1 are different in that the amount of GdCl3·6H2O added is different, that is, the amount added is 0.0215-0.9516 mM. The NMR imaging image of the obtained mesoporous silica nanospheres is as follows: Figure 4 As can be seen from the figure, different amounts of Gd have different color development times, and 0.9516mM has the fastest color development time. (The technical effects reflected in the figure are clearly described).

[0057] Example 3

[0058] The UMSNs obtained in Example 1 were encapsulated by liposomes, specifically:

[0059] Synthetic lipid / PEG coated UMSNs (LUMSNs): Double-coated nanospheres are composed of lipid / PEG membranes coated on the surface of UMSNs; the double coating is composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) / cholesterol / DSPE-PEG 2000 The composition (molar ratio is 77.5:20:2.5). The preparation method is as follows: 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) / cholesterol / DSPE-PEG 2000 Dissolved in a 1:1 chloroform / ethanol mixture. Then, the solvent was evaporated under nitrogen atmosphere to form a lipid / PEG membrane. 10 mg Ce6-UMSNs were evenly dispersed in 3 mL saline. The resulting suspension and lipid / PEG membrane were ultrasonically mixed at a mass ratio of 1:1.2. Finally, the solid and liquid were separated using a centrifuge and washed multiple times with saline and ultrapure water. The resulting product was LUMSNs (see Figure 3 ).

[0060] Figure 3 The successful encapsulation of LUMSNs by lipid / PEG is shown in FIG.

[0061] The LUMSNs and free Ce6 were prepared as described above to obtain Ce6-LUMSNs under the conditions (0.5 W / cm 2 )Near-infrared laser irradiation, see Figure 5 , under near-infrared light irradiation (0.5W / cm 2 ), the ROS detected in the presence of Ce6-LUMSNs was significantly higher than that in free Ce6. Under near-infrared laser irradiation (1.5W / cm), the photothermal response curve of Ce6-LUMSNs showed that the temperature increased with time, and at 600s, the temperature rose to 55°C, showing an excellent photothermal effect. (The effect is clearly described in the figure).

[0062] To further evaluate the ability of nanocarriers as a cancer therapy delivery platform, 50 μg / mL of nanomaterials were measured without 980 nm laser irradiation to test the release of Ce6. Fig. 7 compares the amount of Ce6 released from UMSNs and Ce6-LUMSNs. The test results showed that the coating of nanospheres (Ce6-LUMSNs) with lipid / PEG coating produced highly stable nanocarriers, which is essential for preventing premature release and delivering therapeutic efficacy to malignant cells.

[0063] Example 4

[0064] In order to further facilitate the uptake of nanocarriers by cancer cells, LUMSNs (ALUMSNs) functionalized with acid-triggered membrane peptide (ATRAM) were used to change the pathway of nanocarriers entering cancer cells from endocytosis to pH regulation, thereby enhancing the interaction between nanocarriers and cancer cells. The steps are as follows: 0.6mmol ATRAM and 1mg LUMSN were dispersed in 200μL methanol, and the mixture was stirred continuously for 12h under N2 atmosphere. The obtained product was separated by centrifugation and washed with ultrapure water several times, and freeze-dried for use.

[0065] Then, the above method was used to obtain the effects of LUMSNs (ALUMSNs) on 4T1 cells at different pH, specifically, 4T1 cells were incubated at physiological or acidic pH for 4 hours. Figure 8 The relative intensity ratio of LUMSNs and ALUMSNs taken up by 4T1 cells at different pH values ​​is shown. Compared with LUMSNs, ALUMSNs were taken up by cells in greater amounts. Fig. 9 Shown are confocal fluorescence microscopy images of Ce6-ALUMSNs in 4T1 cells.

[0066] To further demonstrate the effect of the nanomaterial on the activity of tumor cells, the nanomaterial Ce6-ALUMSNs (0.05-5 μg / mL Ce6) was used to generate a photon with a light power of 1.5 W / cm 2 Under the condition of 4T1 cells, the survival rate of tumor cells was observed by treating 4T1 cells for different time periods (3min and 5min). Fig.10 As shown, at pH 7.4, Ce6-ALUMSNs did not adversely affect the viability of 4T1 cells (left figure); in contrast, at pH 6.5, Ce6-ALUMSNs significantly reduced the viability of 4T1 cells (right figure). This further indicates that acid-triggered membrane peptides are beneficial for binding to tumor cells and increase the uptake of nanocarriers by cancer cells.

[0067] Finally, the prepared nanomaterials were intravenously injected into 4T1 tumors of mice, and the concentration of Ce6 was observed after 8 hours. Fig.11 As shown, Ce6-ALUMSNs showed the highest Ce6 concentration (left). In addition, Ce6-ALUMSNs showed the highest Ce6 concentration in mouse 4T1 tumor cells under near-infrared laser irradiation (1.0 W / cm 2 ), Ce6-ALUMSNs induced a rapid and significant increase in temperature in the tumor (right), highlighting the high in vivo photothermal conversion efficiency and photostability of Ce6-ALUMSNs.

Claims

1. A nanomaterial suitable for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy, characterized in that: The nanomaterial is a core-shell structured liposome, and an acid-triggered membrane peptide is attached to the surface of the liposome; wherein the core is an upconversion nanosphere core, the shell is mesoporous silica loaded with a photosensitizer, and the upconversion nanosphere core is an upconversion nanosphere doped with a photothermal agent.

2. The nanomaterial suitable for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy according to claim 1, characterized in that: The up-conversion nanosphere core is NaYF4:Yb / Er / Gd,Bi2Se3.

3. A method for preparing a nanomaterial suitable for multimodal diagnostic imaging and targeted photodynamic and photothermal cancer therapy as claimed in claim 1, characterized in that: 1) Mixing the synthesized upconversion nanosphere NaYF4:Yb / Er / Gd with a photothermal agent to obtain an upconversion nanosphere core (NaYF4:Yb / Er / Gd, Bi2Se3); 2) coating the above-obtained upconversion nanosphere core with mesoporous silica, and then mixing it with a dimethyl sulfoxide solution containing a photosensitizer to obtain a core-shell structure material; 3) The core-shell structure material is mixed with a liposome solution, and after mixing, the mixture is dispersed in an acid-triggered membrane peptide solution to obtain a nanomaterial.

4. The method according to claim 3, characterized in that: The upconversion nanosphere core in step 1) is composed of sodium yttrium fluoride doped with lanthanide elements (ytterbium, erbium, gadolinium) and photothermal agent bismuth selenide, wherein the mass ratio of NaYF4:Yb / Er / Gd to bismuth selenide is 0.1-0.32:0.01-0.

05.

5. The method according to claim 4, characterized in that: The synthesized upconversion nanospheres NaYF4:Yb / Er / Gd are diluted in a mixture of HCl and anhydrous ethanol (1:1, v / v), and ultrasonically treated. After treatment, they are repeatedly washed with anhydrous ethanol, and then dispersed in ultrapure water for standby use. Mannitol is dissolved in 10 mL of ultrapure water, and the aqueous solution of the synthesized upconversion nanospheres, Bi(NO3)3·5H2O, PVP and selenium precursor are added in sequence, mixed and stirred evenly, and the product is collected by centrifugation.

6. The method according to claim 3, characterized in that: The step 2) mixes the upconversion nanosphere core with the solution thoroughly, adds ethyl silicate and trimethoxy(octadecyl)silane and reacts under stirring, extracts with acetone after the reaction to obtain the coated mesoporous silica upconversion nanosphere core, and then disperses it in ultrapure water to obtain a uniform colloidal solution, and then adds dimethyl sulfoxide containing dihydrochlorin (Ce6) to the colloidal solution, stirs, mixes and separates to obtain a core-shell structure material; wherein the ratio of the coated mesoporous silica upconversion nanosphere core to Ce6 is 0.05-0.1:0.15-0.

3.

7. The method according to claim 3, characterized in that: In the step 3), the core-shell structure material is uniformly dispersed in physiological saline, and the core-shell structure material is uniformly mixed with the liposome membrane by ultrasonication at a mass ratio of 1:1.2-1:2, and the product is separated and collected. The separated and collected product and the acid-triggered membrane peptide are dispersed in methanol, stirred and mixed, and then centrifuged. The collected product is the nanomaterial; wherein the ratio of the separated and collected product to the acid-triggered membrane peptide is 0.5-0.8:0.8-0.1.

5.

8. The method according to claim 7, characterized in that: The liposome is a mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), cholesterol and DSPE-PEG 2000 Dissolved in a mixture of chloroform-ethanol in proportion, then evaporated the solvent under a nitrogen atmosphere to form a liposome membrane; wherein 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), cholesterol and DSPE-PEG in the mixture 2000 The total volume is 1-15 ml, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), cholesterol and DSPE-PEG 2000 The molar ratio was 77.5:20:2.5, chloroform-ethanol was 0.15-0.5:0.5-0.85-1.

1.

9. Use of the nanomaterial according to claim 1 in the preparation of drugs for treating tumors, multimodal diagnostic imaging, and targeted photodynamic and photothermal cancer therapy drug carriers.

10. A drug, characterized in that: The drug uses the nano material described in claim 1 as a drug carrier.

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