Iron-based nanomotor loaded with antitumor drugs, its preparation method and application

Abstract

This invention discloses a photo-driven iron-based nanomotor loaded with the antitumor drug dihydroporphyrin E6, its preparation method, and its application. First, hemispherical hollow nanoparticles are formed by the coordination self-assembly of ferrous ions and organic hydrazide molecules. Then, these nanoparticles are modified with dopamine-modified hyaluronic acid to impart suspension stability in aqueous solution. Finally, dihydroporphyrin E6 is loaded onto the nanoparticles to form a nanomotor with a drug loading rate of 5-20%, a particle size of 80-200 nm, a zeta potential of -10.8 mV, and photoresponsive motion characteristics. The iron-based nanomotor of this invention exhibits good biocompatibility, a simple preparation process, good suspension stability, high drug loading rate, and strong photoresponsive motion capability, making it suitable for combined photothermal and photodynamic therapy of tumors.

Description

Technical Field

[0001] This invention relates to the preparation and application of an iron-based nanomotor loaded with an antitumor drug, belonging to the field of biomaterials. Background Technology

[0002] Cancer has become a leading cause of death and reduced life expectancy. Current cancer treatments mainly include surgery, chemotherapy, and radiotherapy. These methods have made significant progress and effectively extended the survival time of cancer patients. However, they still have some problems, such as postoperative recurrence, incomplete treatment, or side effects. Reactive oxygen species (ROS) refer to the collective term for oxygen-containing free radicals and peroxides that are related to oxygen metabolism in organisms, mainly including peroxides, superoxides, hydroxyl radicals, and singlet oxygen. Recent research has found that a large amount of ROS in cells can lead to oxidative damage and induce tumor cell death. Currently, anti-tumor therapies based on ROS include chemodynamic, sonodynamic, and photodynamic therapies, the efficacy of which is heavily dependent on acidic pH (e.g., pH=2-4), hydrogen peroxide levels, and tissue oxygen content. Among these, phototherapy is an emerging anti-tumor treatment method. Its principle is to use near-infrared light to irradiate a photothermal agent to generate high temperatures or irradiate a photosensitizer to generate ROS, thereby killing tumor cells. Phototherapy has advantages such as strong controllability and good targeted killing effect. However, the tumor microenvironment not only exhibits properties such as hypoxia, weak acidity, and high reducing properties, but also features high internal pressure and dense extracellular matrix, which seriously hinders the delivery effect of nanomedicines and the actual treatment efficiency.

[0003] Recent studies have shown that asymmetric nanoparticles with photothermal properties generate a thermal gradient field around them under near-infrared light irradiation, exhibiting a "thermophoresis" phenomenon, meaning that the directional movement of nanoparticles accelerates. Nanoparticles utilizing this property are called nanomotors, and using them as drug carriers can significantly improve the accumulation of nanomedicine systems at tumor sites and the penetration ability of drugs into tumor tissues, thus facilitating drug uptake by tumor cells and improving therapeutic efficacy.

[0004] Dihydroporphyrin E6 is a photosensitizer with excellent overall performance. Under 660 nm laser irradiation, it can generate a large amount of reactive oxygen species, effectively killing tumor cells. Loading dihydroporphyrin E6 onto nanomotors could further enhance its tumor-killing effect. Recent studies have shown that by constructing carrier materials to load dihydroporphyrin E6 into the tumor microenvironment, tumor cells can better absorb the drug, achieving tumor cell killing. However, this method suffers from problems such as a single carrier function, a simple treatment modality, lack of targeting, and low efficiency of tumor cell drug absorption, and therefore cannot effectively inhibit tumor growth. Summary of the Invention

[0005] To address the technical problem of poor tumor-inhibiting effects of existing nanomotors loaded with dihydroporphyrin E6, this invention provides an iron-based nanomotor loaded with anti-tumor drugs, its preparation method, and its applications. This nanomotor can be loaded with the photosensitizer dihydroporphyrin E6, exhibiting a prominent "thermophoresis" phenomenon under near-infrared light irradiation. It not only possesses photothermal therapy, chemodynamic therapy, photodynamic therapy, and ferroptosis therapy capabilities, but also enhances its enrichment and penetration into tumor tissue under near-infrared light irradiation, significantly improving the tumor cell killing effect. This invention utilizes the ferrous ions contained in the nanomotor to induce ferroptosis in tumor cells, thereby achieving a combined ferroptosis-photodynamic-photothermal therapy. Simultaneously, the iron-based nanomotor is modified with a hyaluronic acid derivative to enhance its targeting ability. Its photo-driven directional movement enhances the ability of the iron-based nanomotor to penetrate tumor cells and enter their interior.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a photosensitizer-loaded, light-driven iron-based nanomotor includes the following steps:

[0008] Prepare hemispherical hollow vesicle-like iron-based nanomotors by metal-hydrazide coordination self-assembly;

[0009] Dopamined hyaluronic acid was modified with hemispherical hollow vesicle-like iron-based nanomotors coordinated by metal-hydrazide, and then loaded with dihydroporphyrin E6 to form a photodriven iron-based nanomotor loaded with a photosensitizer.

[0010] Furthermore, the hemispherical hollow vesicle-like iron-based nanomotors, coordinated by metal-hydrazide, were prepared via the following process:

[0011] An ethanol solution of ferrous chloride tetrahydrate was mixed with an ethanol solution of small organic molecules containing hydrazide groups. The mixture was then placed in a shaker at 20-50°C and reacted for 10-16 hours to obtain a metal-hydrazide coordinated self-assembled hemispherical hollow vesicle-like iron-based nanomotor.

[0012] Furthermore, the small organic molecule containing the hydrazide group is 3,3'-dithiodipropionylhydrazide.

[0013] Furthermore, the molar ratio of ferrous ions to 3,3'-dithiodipropionylhydrazine is 0.3-3:1.

[0014] Furthermore, dopamine-modified hyaluronic acid is prepared through the following process:

[0015] Sodium periodate was added to an aqueous solution of sodium hyaluronate, followed by reaction and then ethylene glycol. After stirring, the mixture was dialyzed and freeze-dried to obtain aldehyde-modified hyaluronic acid.

[0016] Add dopamine hydrochloride to an aqueous solution of aldehyde-modified hyaluronic acid, and react in a shaker at 20-50°C for 5-60 minutes. After dialysis and freeze-drying, dopamine-modified hyaluronic acid is obtained.

[0017] Furthermore, the ratio of sodium hyaluronate, sodium periodate, and ethylene glycol is 1g:0.1-1.0g:2mL, the reaction temperature for aldehyde-modified hyaluronic acid is 30℃, and the reaction time is 8 hours.

[0018] Furthermore, the mass concentration of the aldehyde-modified hyaluronic acid aqueous solution is 0.1-10%, and the amount of aldehyde-modified hyaluronic acid aqueous solution to dopamine hydrochloride is 10 ml: 0.1-10 mg.

[0019] Furthermore, dopamined hyaluronic acid was modified with hemispherical hollow vesicle-like iron-based nanomotors coordinated by metal-hydrazide, and then loaded with dihydroporphyrin E6 to form a photodriven iron-based nanomotor loaded with a photosensitizer, including the following steps:

[0020] Under ultrasound, an ethanol suspension of hemispherical hollow vesicle iron-based nanomotors coordinated with metal-hydrazide was added to an aqueous solution of dopamine-modified hyaluronic acid and reacted for 10-60 minutes to obtain a photodriven iron-based nanomotor loaded with a photosensitizer.

[0021] A photosensitive-loaded, photodriven iron-based nanomotor was dispersed in a saturated dihydroporphyrin E6 ethanol solution and reacted for 48 hours to obtain a photosensitive-loaded, photodriven iron-based nanomotor.

[0022] A photosensitizer-loaded photodriven iron-based nanomotor, wherein the loading rate of dihydroporphyrin E6 in the photosensitizer-loaded photodriven iron-based nanomotor is 5%-20%, the particle size of the photosensitizer-loaded photodriven iron-based nanomotor is 80-200 nm, the zeta potential is -10.8 mV, the loading is 5-20%, and the 808 nm laser at a power of 2 W / cm² is used. 2 Under irradiation, the mean square displacement velocity of the photodriven iron-based nanomotor loaded with photosensitizer is 40 μm. 2 / s.

[0023] Application of a photosensitizer-loaded, light-driven iron-based nanomotor in the preparation of antitumor drugs.

[0024] Furthermore, the anti-tumor drugs are anti-liver cancer drugs.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] In this invention, a metal ion alcohol solution is uniformly mixed with small organic molecules containing hydrazide groups in ethanol, reacted in a shaker, centrifuged, and washed to obtain metal-hydrazide self-assembled asymmetric nanoparticles. This method offers strong controllability of particle size, solving the problems of complex preparation methods for spherical nanoparticles, uneven particle size distribution, and the inability of nanoparticles to achieve directional movement. Antitumor drugs are loaded onto hemispherical hollow nanoparticles to form iron-based nanomotors. These iron-based nanomotors possess photothermal, photodynamic, and ferroptosis-inducing effects, achieving an organic integration of multiple treatment modalities and significantly improving antitumor therapeutic effects. The iron-based nanomotors of this invention feature a simple preparation process, mild reaction conditions, high photosensitizer loading, and good stability in the aqueous phase, significantly enhancing the killing effect of photosensitizer-loaded, light-driven iron-based nanomotors on tumor cells.

[0027] In this invention, a hyaluronic acid shell with tumor-targeting function is modified onto a nanomotor through hydrazide-iron coordination. This not only maintains stability in the circulatory system, preventing premature drug leakage, but also actively targets tumor tissue and rapidly removes it from the tumor, facilitating the thermophoretic ability of the internal nanomotor. The prepared iron-based nanomotor exhibits dissociation and drug release behaviors that are responsive to both acidic pH and reduced glutathione, enabling it to better exert therapeutic effects in response to both weakly acidic and reduced tumor microenvironments. Furthermore, it undergoes a photothermal effect under near-infrared light irradiation, stimulating the nanomotor to perform directional movement, enhancing the absorption of anti-tumor drugs by tumor cells, and achieving a combined ferroptosis-photodynamic-photothermal therapy for tumor cells, which can be applied in the preparation of anti-tumor drugs. Attached Figure Description

[0028] Figure 1 These are scanning electron microscope (SEM) and transmission electron microscope (TEM) images of the hemispherical hollow nanoparticles of Example 2. (a) is a TEM image of the hemispherical hollow nanoparticles; (b) is a SEM image of the hemispherical hollow nanoparticles.

[0029] Figure 2 These are comparison graphs of photothermal heating curves of nanoparticles with different morphologies in Examples 2 and 4. (a) is the photothermal heating curve of the hemispherical hollow nanoparticles in Example 2; (b) is the photothermal heating curve of the solid spherical nanoparticles in Example 4.

[0030] Figure 3 This is the thermophoresis phenomenon under near-infrared light irradiation in Example 6, where (a) is the motion trajectory of the iron-based nanomotor under different laser irradiation powers, and (b) is the mean square displacement of the iron-based nanomotor over time under different laser irradiation powers.

[0031] Figure 4 This is a transmission electron microscope image of the nanomotor in Example 6.

[0032] Figure 5 The particle size distributions of nanoparticles at each stage in Examples 1 and 6 are shown, where (a) is the particle size distribution of hemispherical hollow nanoparticles; (b) is the particle size of hyaluronic acid-oxidized hemispherical hollow nanoparticles; and (c) is the particle size of iron-based nanomotors.

[0033] Figure 6 The zeta potential of the hemispherical hollow nanoparticles, hyaluronic acidified hemispherical hollow nanoparticles, and iron-based nanomotors in Example 6 is shown.

[0034] Figure 7 This is the ultraviolet absorption spectrum of the iron-based nanomotor in Example 6.

[0035] Figure 8 This refers to the changes in particle size and zeta potential of the iron-based nanomotor in water over time, obtained in Example 6.

[0036] Figure 9 The photothermal heating curves of dopamine-modified hyaluronic acid-modified hemispherical hollow nanoparticles and hyaluronic acid-modified hemispherical hollow nanoparticles in Example 6 are shown.

[0037] Figure 10 The photodynamic test of the iron-based nanomotor in Example 6 is shown in (a) for the change of absorbance of 1,3-diphenylisobenzofuran with light exposure time; and (b) for the change of absorbance of 1,3-diphenylisobenzofuran with light exposure time after the addition of the iron-based nanomotor.

[0038] Figure 11 This is the electron paramagnetic resonance test of the nanomotor in Example 6.

[0039] Figure 12 This is the killing effect of different concentrations of iron-based nanomotors on Hepa1-6 cells (mouse liver cancer cells) in vitro in Example 6. Detailed Implementation

[0040] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0041] The method for preparing a photosensitizer-loaded, light-driven iron-based nanomotor of the present invention includes the following steps:

[0042] An ethanol solution of ferrous chloride tetrahydrate with a concentration of 0.2-0.6 mol / L was mixed with an ethanol solution of a small organic molecule (3,3'-dithiodipropionylhydrazine) containing an acylhydrazine group with a concentration of 0.002-0.006 mol / L. The molar ratio of ferrous ions to 3,3'-dithiodipropionylhydrazine was 0.3-3:1. The mixture was placed in a shaker at 20-50°C and reacted for 10-16 hours. After centrifugation at 8000-13000 rpm for 5-20 minutes, the mixture was washed once and centrifuged again to obtain hemispherical hollow nanoparticles, namely metal-acylhydrazine coordinated self-assembled hemispherical hollow vesicle-like iron-based nanomotors. The hemispherical hollow nanoparticles had a particle size of about 80-200 nm, were uniform in size, and had good dispersibility. They can be used to prepare antitumor drugs and contrast agents.

[0043] The preparation process of dopamined hyaluronic acid is as follows: 1 gram of sodium hyaluronate (the molecular weight of hyaluronic acid in sodium hyaluronate is in the range of 10-200 kDa) is dissolved in 100 ml of water, followed by the addition of 0.1-1.0 gram of sodium periodate. After reacting at 30°C for 8 hours, 2 ml of ethylene glycol is added, and after stirring for 1 hour, the reaction system is dialyzed and freeze-dried to obtain aldehyde-modified hyaluronic acid (aldehyde degree 10%-40%). 10 ml of aldehyde-modified hyaluronic acid aqueous solution with a mass concentration of 0.1-10% is prepared, followed by the addition of 0.1-10 mg of dopamine hydrochloride. The mixture is placed in a shaker at 20-50°C and reacted for 5-60 minutes. After dialyzing through a dialysis bag with a molecular weight cutoff of 1 kDa and freeze-drying, dopamined hyaluronic acid with a dopamine degree of 5%-50% is obtained.

[0044] Hemispherical hollow nanoparticles were sequentially modified with a hyaluronic acid derivative (dopamined hyaluronic acid) and loaded with dihydroporphyrin E6 to form a photosensitizer-loaded, light-driven iron-based nanomotor. Specifically, the modification process of dopamined hyaluronic acid was as follows: under ultrasonication, 300 μL of an ethanol suspension of nanomotors (hemispherical hollow nanoparticles) with a concentration of 4 mg / mL was added to 4 mL of a 0.1% (w / w) aqueous solution of dopamined hyaluronic acid. After reacting for 10-60 minutes, hollow nanoparticles modified with dopamined hyaluronic acid were obtained, which are the photosensitizer-loaded, light-driven iron-based nanomotors.

[0045] Hollow nanoparticles modified with dopamine-modified hyaluronic acid were dispersed in a saturated solution of dihydroporphyrin E6 in ethanol. After reacting for 48 hours, dihydroporphyrin E6-loaded nanomotors, i.e., photosensitizer-loaded photodriven iron-based nanomotors, were obtained. The dihydroporphyrin E6 loading rate (the mass percentage of dihydroporphyrin E6 in the photosensitizer-loaded photodriven iron-based nanomotors) was 5%-20%. The nanomotors had a particle size of 80-200 nm, a zeta potential of -10.8 mV, and were supported by an 808 nm laser at a power of 2 W / cm². 2Under irradiation, the mean square displacement velocity of the nanoparticles was 40 μm. 2 / s.

[0046] The photo-driven iron-based nanomotor loaded with photosensitizer prepared in this invention can be used for combined photothermal, photodynamic, and ferroptosis therapy of tumors.

[0047] Example 1

[0048] A 0.4 mol / L ferrous chloride tetrahydrate ethanol solution and a 0.004 mol / L 3,3'-dithiodipropionylhydrazine ethanol solution were mixed, with a molar ratio of ferrous chloride to 3,3'-dithiodipropionylhydrazine of 1:1. The mixture was reacted in a shaker at 37°C for 12 hours, followed by centrifugation at 13,000 rpm for 13 minutes to obtain poorly dispersed iron-hydrazine coordinated self-assembled hemispherical hollow nanoparticles. The particle size distribution was measured to be 120-140 nm, and a large number of nanoparticles were observed to aggregate under transmission electron microscopy.

[0049] Example 2

[0050] A 0.4 mol / L ferrous chloride tetrahydrate ethanol solution and a 0.003 mol / L 3,3'-dithiodipropionylhydrazine ethanol solution were mixed, with a molar ratio of ferrous chloride to 3,3'-dithiodipropionylhydrazine of 1:1. The mixture was reacted in a shaker at 37°C for 12 hours, followed by centrifugation at 13,000 rpm for 13 minutes to obtain hemispherical hollow nanoparticles (Fe-TPH) with improved dispersibility. The particle size distribution was measured to be 90-100 nm, and a small amount of nanoparticle aggregation was observed under transmission electron microscopy.

[0051] from Figure 1 As can be seen in (a) and (b), the obtained hemispherical hollow nanoparticles have uniform size, complete morphology, and good dispersibility, with a size of about 100 nanometers.

[0052] Example 3

[0053] A 0.4 mol / L ferrous chloride tetrahydrate ethanol solution and a 0.002 mol / L 3,3'-dithiodipropionylhydrazine ethanol solution were mixed, with a molar ratio of ferrous chloride to 3,3'-dithiodipropionylhydrazine of 1:1. The mixture was reacted in a shaker at 37 °C for 12 hours, followed by centrifugation at 13,000 rpm for 13 minutes to obtain iron-hydrazine coordinated self-assembled hemispherical hollow / solid spherical nanoparticles.

[0054] Example 4

[0055] A 0.4 mol / L ferrous chloride tetrahydrate ethanol solution and a 0.003 mol / L 3,3'-dithiodipropionylhydrazine ethanol solution were mixed, with a molar ratio of ferrous chloride to 3,3'-dithiodipropionylhydrazine of 1:2. The mixture was reacted in a shaker at 37°C for 12 hours, followed by centrifugation at 13,000 rpm for 13 minutes to obtain solid spherical nanoparticles of iron-hydrazine coordination self-assembly.

[0056] See Figure 2 As shown in (a) and (b), when nanoparticles are irradiated with an 808nm laser, the intensity of the photothermal effect of metal-hydrazide coordinated nanoparticles changes with their morphology, indicating that there is a driving force for the movement of nanoparticles. The photothermal effect of hemispherical hollow nanoparticles is much stronger than that of spherical solid nanoparticles.

[0057] Example 5

[0058] A 0.4 mol / L ferrous chloride tetrahydrate ethanol solution and a 0.003 mol / L 3,3'-dithiodipropionylhydrazine ethanol solution were mixed, with a molar ratio of ferrous chloride to 3,3'-dithiodipropionylhydrazine of 2:1. The mixture was reacted in a shaker at 37 °C for 12 hours, followed by centrifugation at 13,000 rpm for 13 minutes to obtain solid spherical nanoparticles with iron-hydrazine coordination self-assembly.

[0059] Example 6

[0060] 1) Preparation of hemispherical hollow nanoparticles: A 0.4 mol / L ferrous chloride tetrahydrate ethanol solution and a 0.003 mol / L 3,3'-dithiodipropionylhydrazine ethanol solution were mixed, with a molar ratio of ferrous chloride to 3,3'-dithiodipropionylhydrazine of 1:1. The mixture was reacted in a shaker at 37°C for 12 hours, followed by centrifugation at 13,000 rpm for 13 minutes to obtain hemispherical hollow nanoparticles with improved dispersibility and coordination with iron-hydrazine. The particle size distribution was measured to be 80-200 nm. A small amount of nanoparticle aggregation was observed under transmission electron microscopy.

[0061] 2) Preparation of hyaluronic acid-modified hemispherical hollow nanoparticles: First, prepare hyaluronic acid derivatives: Dissolve 1g of sodium hyaluronate in 100ml of water and add 0.535g of sodium periodate. After reacting at 30℃ for 8 hours, add 2ml of ethylene glycol to neutralize excess unreacted sodium periodate, stir for about 1 hour, and then dialyze the reaction mixture in a dialysis bag. After lyophilization, weigh the mixture to obtain aldehyde-modified hyaluronic acid. Then, prepare 10ml of 1wt% aldehyde-modified hyaluronic acid aqueous solution and add 5mg of dopamine hydrochloride to obtain a dopamine-modified aldehyde-modified hyaluronic acid solution.

[0062] 3) Prepare a 0.1wt% dopamine / aldehyde-modified hyaluronic acid aqueous solution. Disperse the hemispherical hollow nanoparticles prepared in the above steps in 300μl ethanol by ultrasonication. Then add 4ml of the above dopamine-modified aldehyde-modified hyaluronic acid aqueous solution and react in a shaker for 30min to obtain hyaluronic acid-modified hemispherical hollow nanoparticles.

[0063] Preparation of photosensitizer-loaded photodriven iron-based nanomotors: Hyaluronic acid-oxidized hemispherical hollow nanoparticles were dispersed in a saturated dihydroporphyrin E6 ethanol solution. Dihydroporphyrin E6 was loaded onto the hyaluronic acid-oxidized hemispherical hollow nanoparticles by electrostatic adsorption. After reacting for 48 h, the photosensitizer-loaded photodriven iron-based nanomotors were collected.

[0064] Comparative Example 1

[0065] Similar to Example 6, except that in step 2), dopamine hydrochloride is not added, and the resulting product is denoted as Fe-TPH-Ce6.

[0066] from Figure 3 As can be seen from (a) and (b), when irradiated with an 808nm laser, a significant thermophoretic phenomenon of the iron-based nanomotor was observed under an optical microscope. In the absence of light, the iron-based nanomotor only undergoes Brownian motion. When laser irradiation begins, the iron-based nanomotor immediately changes its motion state, and the speed of motion increases with the increase of laser power.

[0067] from Figure 4 It can be seen that dispersing hyaluronic acid-oxidized hemispherical hollow nanoparticles in an ethanol solution of dihydroporphyrin E6 for 48 hours ( Figure 4 (a)), and then aldehyde-modified hyaluronic acid is coated on its surface ( Figure 4 (b) Finally, in a Tris solution at pH 8.5, polydopamine was encapsulated. Figure 4 In (c), the obtained nanoparticles still maintained good dispersibility, and their size did not change significantly. Figure 1 Compared to the hemispherical hollow nanoparticles in (a), the surface is rougher, proving that polydopamine is synthesized on the surface of the iron-based nanomotor.

[0068] from Figure 5 As can be seen from (a), (b) and (c), compared with hemispherical hollow nanoparticles, hyaluronic acid-treated hemispherical hollow nanoparticles and iron-based nanomotors, the particle size difference is small. After the formation of iron-based nanomotors, the particle size increases, but overall it still remains less than 300 nm.

[0069] from Figure 6As can be seen, compared with hemispherical hollow nanoparticles, hyaluronic acid-treated hemispherical hollow nanoparticles and iron-based nanomotors, the potentials also show significant changes, confirming that hyaluronic acid derivatives are coated on the surface of hemispherical hollow nanoparticles, and dihydroporphyrin E6 is loaded on hyaluronic acid-treated hemispherical hollow nanoparticles, ultimately forming iron-based nanomotors.

[0070] from Figure 7 As can be seen from the ultraviolet absorption spectrum, there are obvious absorption peaks at 407 nm and 667 nm, proving that dihydroporphyrin E6 was successfully loaded onto hyaluronic acid-oxidized hemispherical hollow nanoparticles to form iron-based nanomotors with a drug loading rate of 10%.

[0071] from Figure 8 It can be seen that the changes in particle size and potential of iron-based nanomotors recorded over 60 hours show that the iron-based nanomotors have good stability in water and do not aggregate or degrade.

[0072] from Figure 9 Figures (a), (b), and (c) show that photodriven iron-based nanomotors loaded with photosensitizers were added to water to form suspensions with concentrations of 50 μg / mL, 150 μg / mL, and 300 μg / mL, respectively. Figure (a) shows that the addition of PDA (polydopamine) significantly enhanced the photothermal performance of the iron-based nanomotors. The iron-based nanomotors exhibit good photothermal performance; Figure (b) shows a positive correlation between the photothermal effect and light intensity, and Figure (c) shows a positive correlation between the photothermal effect and the concentration of the iron-based nanomotors.

[0073] from Figure 10 As shown in (a) and (b), after adding iron-based nanomotors to an aqueous solution of 1,3-diphenylisobenzofuran, the intensity of the characteristic peak at 413 nm changed after laser irradiation (635 nm). This indicates that the iron-based nanomotors generate reactive oxygen species, thus verifying the photodynamic properties of Ce6.

[0074] from Figure 11 It can be seen that the iron-based nanomotors exhibit significant photodynamic performance under laser (635nm) irradiation conditions and demonstrate the generation of singlet oxygen.

[0075] Figure 12 It can be seen that singlet oxygen cannot be detected in the iron-based nanomotors without light exposure, but after light exposure, a significant killing effect of iron-hydrazine self-assembled nanospheres on tumor cells can be detected. The cell viability assay kit (CCK-8) was used to detect the killing effect of iron-hydrazine self-assembled nanospheres on mouse hepatocellular carcinoma Hepa 1-6 cells. Hepa 1-6 cells were incubated at 5 × 10⁻⁶ cells / year. 3Cells were seeded at a density of 100 cells / well in 96-well plates. After 24 hours of routine culture, different concentrations of nanoparticles were added to each well and cultured for another 24 hours. Then, 10 μL of CCK-8 reagent was added to each well and cultured for another hour. The absorbance at 450 nm for each well was measured using a microplate reader. The percentage of absorbance of the experimental group relative to the control group (iron-based nanomotor concentration of 0) represents cell viability. Hepa 1-6 cell viability gradually decreased with increasing iron-based nanomotor concentration. When the iron-based nanomotor concentration was 100 μg / mL, after irradiation with 635 nm and 808 nm lasers, respectively, the viability of Hepa 1-6 cells was 20%, indicating that iron-based nanomotors can effectively kill tumor cells.

[0076] Example 7

[0077] A 0.2 mol / L ethanol solution of ferrous chloride tetrahydrate was mixed with a 0.002 mol / L ethanol solution of an organic small molecule (3,3'-dithiodipropionylhydrazine) containing an acylhydrazine group, wherein the molar ratio of ferrous ions to 3,3'-dithiodipropionylhydrazine was 0.3:1. The mixture was placed in a shaker at 20°C and reacted for 16 hours. After centrifugation at 8000 rpm for 20 minutes, the mixture was washed once and centrifuged again to obtain hemispherical hollow nanoparticles, namely metal-acylhydrazine coordinated self-assembled hemispherical hollow vesicle-like iron-based nanomotors.

[0078] The preparation process of dopamine-modified hyaluronic acid is as follows: 1 gram of sodium hyaluronate (the molecular weight of hyaluronic acid in sodium hyaluronate is in the range of 10-200 kDa) is dissolved in 100 ml of water, followed by the addition of 0.1 gram of sodium periodate. After reacting at 30°C for 8 hours, 2 ml of ethylene glycol is added. After stirring for 1 hour, the reaction system is dialyzed and freeze-dried to obtain aldehyde-modified hyaluronic acid.

[0079] Prepare 10 mL of 0.1% aqueous solution of aldehyde-modified hyaluronic acid, then add 4 mg of dopamine hydrochloride, and react in a shaker at 20 °C for 60 minutes. After dialyzing through a dialysis bag with a molecular weight cutoff of 1 kDa and freeze-drying, dopamine-modified hyaluronic acid is obtained.

[0080] Hemispherical hollow nanoparticles were sequentially modified with a hyaluronic acid derivative (dopamined hyaluronic acid) and loaded with dihydroporphyrin E6 to form a photosensitizer-loaded, light-driven iron-based nanomotor. Specifically, the modification process of dopamined hyaluronic acid was as follows: under ultrasonication, 300 μL of an ethanol suspension of nanomotors (hemispherical hollow nanoparticles) with a concentration of 4 mg / mL was added to 4 mL of a 0.1% (w / w) aqueous solution of dopamined hyaluronic acid. After reacting for 60 minutes, hollow nanoparticles modified with dopamined hyaluronic acid were obtained, which are the photosensitizer-loaded, light-driven iron-based nanomotors.

[0081] Hollow nanoparticles modified with dopamine-modified hyaluronic acid were dispersed in a saturated dihydroporphyrin E6 ethanol solution. After reacting for 48 hours, a dihydroporphyrin E6-loaded nanomotor, i.e., a photodriven iron-based nanomotor loaded with a photosensitizer, was obtained.

[0082] Example 8

[0083] A 0.5 mol / L ethanol solution of ferrous chloride tetrahydrate was mixed with a 0.006 mol / L ethanol solution of an organic small molecule (3,3'-dithiodipropionylhydrazine) containing an acylhydrazine group, wherein the molar ratio of ferrous ions to 3,3'-dithiodipropionylhydrazine was 3:1. The mixture was placed in a shaker at 50 °C and reacted for 10 hours. After centrifugation at 10,000 rpm for 10 minutes, the mixture was washed once and centrifuged again to obtain hemispherical hollow nanoparticles, namely metal-acylhydrazine coordinated self-assembled hemispherical hollow vesicle-like iron-based nanomotors.

[0084] The preparation process of dopamine-modified hyaluronic acid is as follows: 1 gram of sodium hyaluronate (the molecular weight of hyaluronic acid in sodium hyaluronate is in the range of 10-200 kDa) is dissolved in 100 ml of water, followed by the addition of 0.5 gram of sodium periodate. After reacting at 30°C for 8 hours, 2 ml of ethylene glycol is added. After stirring for 1 hour, the reaction system is dialyzed and freeze-dried to obtain aldehyde-modified hyaluronic acid.

[0085] Prepare 10 mL of 10% aldehyde-modified hyaluronic acid aqueous solution, then add 0.1 mg of dopamine hydrochloride, and react in a shaker at 30 °C for 20 minutes. After dialyzing through a dialysis bag with a molecular weight cutoff of 1 kDa and freeze-drying, dopamine-modified hyaluronic acid is obtained.

[0086] Hemispherical hollow nanoparticles were sequentially modified with a hyaluronic acid derivative (dopamined hyaluronic acid) and loaded with dihydroporphyrin E6 to form a photosensitizer-loaded, light-driven iron-based nanomotor. Specifically, the modification process of dopamined hyaluronic acid was as follows: under ultrasonication, 300 μL of an ethanol suspension of nanomotors (hemispherical hollow nanoparticles) with a concentration of 4 mg / mL was added to 4 mL of a 0.1% (w / w) aqueous solution of dopamined hyaluronic acid. After reacting for 40 minutes, hollow nanoparticles modified with dopamined hyaluronic acid were obtained, which are the photosensitizer-loaded, light-driven iron-based nanomotors.

[0087] Hollow nanoparticles modified with dopamine-modified hyaluronic acid were dispersed in a saturated dihydroporphyrin E6 ethanol solution. After reacting for 48 hours, a dihydroporphyrin E6-loaded nanomotor, i.e., a photodriven iron-based nanomotor loaded with a photosensitizer, was obtained.

[0088] Example 9

[0089] A 0.6 mol / L ethanol solution of ferrous chloride tetrahydrate was mixed with a 0.004 mol / L ethanol solution of an organic small molecule (3,3'-dithiodipropionylhydrazine) containing an acylhydrazine group, wherein the molar ratio of ferrous ions to 3,3'-dithiodipropionylhydrazine was 0.7:1. The mixture was placed in a shaker at 40 °C and reacted for 12 hours. After centrifugation at 12,000 rpm for 5 minutes, the mixture was washed once and centrifuged again to obtain hemispherical hollow nanoparticles, namely metal-acylhydrazine coordinated self-assembled hemispherical hollow vesicle-like iron-based nanomotors.

[0090] The preparation process of dopamine-modified hyaluronic acid is as follows: 1 gram of sodium hyaluronate (the molecular weight of hyaluronic acid in sodium hyaluronate is in the range of 10-200 kDa) is dissolved in 100 ml of water, followed by the addition of 0.1 gram of sodium periodate. After reacting at 30°C for 8 hours, 2 ml of ethylene glycol is added. After stirring for 1 hour, the reaction system is dialyzed and freeze-dried to obtain aldehyde-modified hyaluronic acid.

[0091] Prepare 10 mL of 5% (w / w) aldehyde-modified hyaluronic acid aqueous solution, then add 10 mg of dopamine hydrochloride, and react in a shaker at 50 °C for 5 minutes. After dialyzing through a dialysis bag with a molecular weight cutoff of 1 kDa and freeze-drying, dopamine-modified hyaluronic acid is obtained.

[0092] Hemispherical hollow nanoparticles were sequentially modified with a hyaluronic acid derivative (dopamined hyaluronic acid) and loaded with dihydroporphyrin E6 to form a photosensitizer-loaded, light-driven iron-based nanomotor. Specifically, the modification process of dopamined hyaluronic acid was as follows: under ultrasonication, 300 μL of an ethanol suspension of nanomotors (hemispherical hollow nanoparticles) with a concentration of 4 mg / mL was added to 4 mL of a 0.1% (w / w) aqueous solution of dopamined hyaluronic acid. After reacting for 10 minutes, hollow nanoparticles modified with dopamined hyaluronic acid were obtained, which are the photosensitizer-loaded, light-driven iron-based nanomotors.

[0093] Hollow nanoparticles modified with dopamine-modified hyaluronic acid were dispersed in a saturated dihydroporphyrin E6 ethanol solution. After reacting for 48 hours, a dihydroporphyrin E6-loaded nanomotor, i.e., a photodriven iron-based nanomotor loaded with a photosensitizer, was obtained.

[0094] The preparation method of hemispherical hollow nanoparticles in this invention is a metal-hydrazide self-assembly nanoparticle preparation method. A metal ion alcohol solution is uniformly mixed with small organic molecules containing hydrazide groups in ethanol, reacted in a shaker, centrifuged, and washed to obtain metal-hydrazide self-assembled nanoparticles. By adjusting the reaction conditions, such as the concentration of hydrazide groups and ferrous ions, nanoparticles with different morphologies can be obtained. Under appropriate conditions, hollow hemispherical vesicle-like nanoparticles, i.e., nanoparticles with asymmetric structures, can be obtained. This invention, based on the metal-hydrazide coordination self-assembly method, obtains nanoparticles with asymmetric structures, solving the problems of complex preparation methods for spherical nanoparticles, uneven particle size distribution, and the inability of nanoparticles to achieve directional movement. Antitumor drugs are loaded onto hemispherical hollow nanoparticles to form iron-based nanomotors. Under near-infrared light irradiation, a photothermal effect occurs, exciting the nanomotors to perform directional movement, enhancing the absorption of antitumor drugs by tumor cells, and realizing combined ferroptosis-photodynamic-photothermal therapy of tumor cells. This method can be applied in the preparation of antitumor drugs.

[0095] The advantages of this invention are as follows:

[0096] (1) The hemispherical hollow nanoparticles in this invention are formed by the infinite coordination of iron ions and small organic hydrazide molecules through metal-hydrazide, and the particle size is highly controllable.

[0097] (2) The nanomotor in this invention has photothermal effect, photodynamic effect and ferroptosis induction ability, realizing the organic integration of multiple treatment modes and significantly improving the anti-tumor treatment effect;

[0098] (3) The nanomotor in this invention has dissociation and drug release behavior that are responsive to both acidic pH and reduced glutathione, and can better exert therapeutic effects in response to weakly acidic and reduced tumor microenvironment;

[0099] (4) The hyaluronic acid shell with tumor-targeting function is modified onto the nanomotor through hydrazide-iron coordination. It can maintain stability in the circulatory system and prevent premature drug leakage, and can actively target tumor tissue and be quickly removed from the tumor, which is conducive to the thermophoretic ability of the internal nanomotor.

[0100] (5) The iron-based nanomotor of the present invention has the advantages of simple preparation process, mild reaction conditions, high photosensitizer loading and good stability in aqueous phase, which significantly enhances the killing effect of the photosensitizer-loaded light-driven iron-based nanomotor on tumor cells.

[0101] The above description is only of the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0102] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A method for preparing a light-driven iron-based nanomotor loaded with a photosensitizer, characterized in that, Includes the following steps: Prepare hemispherical hollow vesicle-like iron-based nanomotors by metal-hydrazide coordination self-assembly; Dopamined hyaluronic acid was modified with metal-hydrazide coordinated self-assembled hemispherical hollow vesicle iron-based nanomotors, and then loaded with dihydroporphyrin E6 to form a photodriven iron-based nanomotor loaded with photosensitizer. Among them, the hemispherical hollow vesicle-like iron-based nanomotors with metal-hydrazide coordination self-assembly were prepared through the following process: A 0.4 mol / L ethanol solution of ferrous chloride tetrahydrate and a 0.003 mol / L ethanol solution of an organic small molecule containing an acylhydrazine group were mixed thoroughly and reacted in a shaker at 20-50°C for 10-16 hours to obtain a hemispherical hollow vesicle-like iron-based nanomotor with metal-acylhydrazine coordination self-assembly; the molar ratio of ferrous ions to 3,3'-dithiodipropionylhydrazine was 1:1; the organic small molecule containing the acylhydrazine group was 3,3'-dithiodipropionylhydrazine. Dopamined hyaluronic acid was modified with hemispherical hollow vesicle-like iron-based nanomotors coordinated by metal-hydrazide, and then loaded with dihydroporphyrin E6 to form a photodriven iron-based nanomotor loaded with a photosensitizer, including the following steps: Under the action of ultrasound, an ethanol suspension of hemispherical hollow vesicle iron-based nanomotors coordinated and self-assembled by metal-hydrazide coordination was added to an aqueous solution of dopamine-modified hyaluronic acid and reacted for 10-60 minutes to obtain a light-driven iron-based nanomotor. A photo-driven iron-based nanomotor was dispersed in a saturated dihydroporphyrin E6 ethanol solution and reacted for 48 hours to obtain a photo-driven iron-based nanomotor loaded with a photosensitizer.

2. The method for preparing a photodriven iron-based nanomotor loaded with a photosensitizer according to claim 1, characterized in that, Dopamine-modified hyaluronic acid is prepared through the following process: Sodium periodate was added to an aqueous solution of sodium hyaluronate, followed by reaction and then ethylene glycol. After stirring, the mixture was dialyzed and freeze-dried to obtain aldehyde-modified hyaluronic acid. Add dopamine hydrochloride to an aqueous solution of aldehyde-modified hyaluronic acid, and react in a shaker at 20-50°C for 5-60 minutes. After dialysis and freeze-drying, dopamine-modified hyaluronic acid is obtained.

3. The method for preparing a photodriven iron-based nanomotor loaded with a photosensitizer according to claim 2, characterized in that, The ratio of sodium hyaluronate, sodium periodate, and ethylene glycol is 1g:0.1-1.0g:2mL. The reaction temperature for aldehyde-modified hyaluronic acid is 30℃, and the reaction time is 8 hours.

4. The method for preparing a photodriven iron-based nanomotor loaded with a photosensitizer according to claim 2, characterized in that, The mass concentration of the aldehyde-modified hyaluronic acid aqueous solution is 0.1-10%, and the ratio of the aldehyde-modified hyaluronic acid aqueous solution to dopamine hydrochloride is 0.1-10 mg per 10 ml.

5. A photodriven iron-based nanomotor loaded with a photosensitizer, prepared by the method according to any one of claims 1-4, characterized in that, The photosensitizer-loaded photodriven iron-based nanomotors have a dihydroporphyrin (e6) loading rate of 5%-20%, a particle size of 80-200 nm, a zeta potential of -10.8 mV, a drug loading of 5-20%, and are operated by 808 nm laser at a power of 2 W / cm². 2 Under irradiation, the mean square displacement velocity of the photodriven iron-based nanomotor loaded with photosensitizer is 40 μm. 2 / s.

6. The application of a photosensitizer-loaded photodriven iron-based nanomotor prepared by the method according to any one of claims 1-4 in the preparation of antitumor drugs.

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