A light-controlled shape memory microcapsule and its preparation method and application

Abstract

The present invention discloses a light-controlled shape memory microcapsule and its preparation method and application, which relate to the technical field of shape memory materials. The light-controlled shape memory microcapsule includes a capsule core and a capsule wall covering the capsule core, the capsule core includes a two-dimensional photothermal nanomaterial and a thermally responsive shape memory polymer material, and the capsule wall includes a water-soluble polymer material. The present invention is based on a thermally responsive shape memory polymer material. By adding a two-dimensional photothermal nanomaterial, the two-dimensional photothermal nanomaterial and the thermally responsive shape memory polymer material cooperate with each other. The two-dimensional photothermal nanomaterial has a photothermal effect. When a certain wavelength of light is used, the temperature rises, thereby promoting the shape memory effect of the thermally responsive shape memory polymer material, thereby giving the microcapsule a light-controlled shape memory ability, so that the microcapsule can be remotely regulated in vitro, and the controllability of the shape memory performance of the microcapsule is increased.

Description

Technical Field

[0001] This invention relates to the field of shape memory materials technology, and in particular to a light-controlled shape memory microcapsule, its preparation method, and its application. Background Technology

[0002] Shape memory polymers, as a novel type of smart material, have attracted widespread attention in recent years. They can sense and respond to changes in the environment, returning to a pre-set original shape to achieve specific effects. Currently, they are widely used in cardiovascular stents, smart sutures, tissue engineering, controlled drug release, and antibacterial materials, making them one of the hottest research areas in biomaterials. Compared to macroscopic scales, micro- and nano-scale shape memory polymers, due to their unique properties such as injectability, large specific surface area, customized biodistribution, and controllable interaction with cells, exhibit unique advantages in biological applications such as cell and tissue engineering, drug loading and release, cancer chemotherapy, and biosensing. In practical applications, shape memory polymers are often affected by the complex microenvironment within the body. Therefore, shape memory polymers with responsiveness to external stimuli and controllable deformation capabilities have attracted widespread attention from researchers. Commonly used response sources for shape memory polymers include heat, light, electricity, force, and magnetism. Among these, thermally responsive shape memory polymers, as implants, can respond to temperature changes before and after implantation and have been widely used in the biomedical field. However, due to the uncontrollable response process and the difficulty in achieving remote in vitro regulation, their application in certain specific biological applications is limited.

[0003] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0004] Based on the shortcomings of the prior art, the purpose of this invention is to provide a light-controlled shape memory microcapsule, its preparation method and application, in order to solve the problem that thermally responsive shape memory polymer materials are not easy to remotely control in vitro.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a light-controlled shape memory microcapsule, wherein the light-controlled shape memory microcapsule includes a capsule core and a capsule wall covering the capsule core, the capsule core includes a two-dimensional photothermal nanomaterial and a thermally responsive shape memory polymer material, and the capsule wall includes a water-soluble polymer material.

[0007] Optionally, the two-dimensional photothermal nanomaterial is a biodegradable two-dimensional photothermal nanomaterial.

[0008] Optionally, the biodegradable two-dimensional photothermal nanomaterial includes at least one of two-dimensional MXene nanosheets, two-dimensional niobium selenide nanosheets, and two-dimensional bismuth oxy selenide nanosheets.

[0009] Optionally, the thermally responsive shape memory polymer material includes at least one of poly(D,L-lactic acid), poly(D, lactide-trimethylene carbonate), polyurethane, and polylactic acid.

[0010] Optionally, the water-soluble polymer material includes at least one of polyvinyl alcohol, polyethylene glycol, and polyvinylpyrrolidone.

[0011] Optionally, the particle size of the light-controlled shape memory microcapsules is 5–55 μm.

[0012] A second aspect of the present invention provides a method for preparing the light-controlled shape memory microcapsules as described above, comprising the following steps:

[0013] Two-dimensional photothermal nanomaterials and thermally responsive shape memory polymer materials were added to an organic solvent and ultrasonically dispersed to obtain a dispersion.

[0014] A water-soluble polymer material solution is provided, and the water-soluble polymer material solution is mixed with the dispersion and stirred at a speed of 800-1200 rpm to obtain the light-controlled shape memory microcapsules.

[0015] Optionally, the mass ratio of the two-dimensional photothermal nanomaterial, the thermally responsive shape memory polymer material, and the water-soluble polymer material in the water-soluble polymer material solution is (0.5-2):(10-40):(37.5-150);

[0016] In the dispersion, the concentration of the two-dimensional photothermal nanomaterial is 0.5–2 mg / mL;

[0017] In the solution of the water-soluble polymer material, the concentration of the water-soluble polymer material is 1.25–5 mg / mL.

[0018] Optionally, the organic solvent includes at least one of dichloromethane and trichloromethane.

[0019] A third aspect of the present invention provides the application of the light-controlled shape memory microcapsules of the present invention as described above and / or the light-controlled shape memory microcapsules prepared by the preparation method of the present invention as described above in the preparation of tumor vascular embolization materials.

[0020] Beneficial effects: This invention is based on thermally responsive shape memory polymer materials. By adding two-dimensional photothermal nanomaterials, the two-dimensional photothermal nanomaterials and the thermally responsive shape memory polymer materials work together. The two-dimensional photothermal nanomaterials have a photothermal effect. When irradiated with light of a certain wavelength, the temperature rises, which in turn promotes the shape memory effect of the thermally responsive shape memory polymer materials. This endows the microcapsules with light-controlled shape memory capabilities, enabling the microcapsules to be remotely controlled in vitro and increasing the controllability of the shape memory performance of the microcapsules. Attached Figure Description

[0021] Figure 1 The image shows the UV-Vis-NIR absorption spectrum of the monolayer Ti3C2 nanosheets prepared in Example 1 of this invention in an aqueous solution.

[0022] Figure 2 This is a transmission electron microscope image of the monolayer Ti3C2 nanosheets prepared in Example 1 of the present invention.

[0023] Figure 3 This is a scanning electron microscope image of the MXene / PDLLA microcapsules prepared in Example 1 of the present invention.

[0024] Figure 4 This is a particle size distribution diagram of the MXene / PDLLA microcapsules prepared in Example 1 of the present invention.

[0025] Figure 5 The image shows the energy spectrum of the MXene / PDLLA microcapsules prepared in Example 1 of this invention.

[0026] Figure 6 The graph shows the photothermal performance test results of the MXene / PDLLA microcapsules prepared in Example 1 of this invention and the PDLLA microcapsules in Comparative Example 1.

[0027] Figure 7 The image shows the optically controlled shape memory performance of the MXene / PDLLA microcapsules prepared in Example 1 of this invention, as recorded by scanning electron microscopy. (a) shows the original morphology of the MXene / PDLLA microcapsules, (b) shows the morphology of the spindle-shaped MXene / PDLLA microcapsules formed after stretching, and (c) shows the original morphology restored to the spindle-shaped MXene / PDLLA microcapsules after near-infrared irradiation.

[0028] Figure 8 The figure shows the cytotoxicity test results of the MXene / PDLLA microcapsules prepared in Example 1 of this invention. Detailed Implementation

[0029] This invention provides a light-controlled shape memory microcapsule, its preparation method, and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0031] Tumor embolization therapy is a novel treatment widely used in clinical practice for cancer. It involves injecting embolic materials into the arteries supplying the tumor or into the tumor's blood vessels, blocking the blood supply to those arteries, cutting off the tumor's nutrient supply, and thus controlling, shrinking, or even eliminating the tumor. For most cancer patients in clinical practice, anti-tumor treatment targets already vascularized tumors. Therefore, tumor embolization therapy shows broad-spectrum and highly effective clinical application prospects. However, finding safe and effective embolization therapies remains a bottleneck in this research field. Thermally responsive shape memory polymers, as implants, can respond to temperature changes before and after implantation and have been widely used in the biomedical field. However, due to the uncontrollable response process and the difficulty in remotely controlling it in vitro, their application in certain specific biological applications is limited. However, compared to thermal response, photoresponse offers the significant advantage of controllable manipulation on both temporal and spatial scales. It allows for selective and orderly control of the material's shape recovery process through artificial means, possessing remote controllability and enabling point-to-point, time-based, speed-adjustable, and quantity-adjustable shape control. Based on this, embodiments of the present invention provide a light-controlled shape memory microcapsule, wherein the light-controlled shape memory microcapsule includes a capsule core and a capsule wall covering the capsule core, the capsule core includes a two-dimensional photothermal nanomaterial and a thermally responsive shape memory polymer material, and the capsule wall includes a water-soluble polymer material.

[0032] In this embodiment of the invention, a thermoresponsive shape memory polymer material is used as the base. By adding two-dimensional photothermal nanomaterials, the thermoresponsive shape memory polymer material is indirectly transformed into a photosensitive shape memory material. The excellent photothermal effect of the two-dimensional photothermal nanomaterials can enhance the shape memory performance of the microcapsules. That is, the two-dimensional photothermal nanomaterials and the thermoresponsive shape memory polymer material are used in combination. The two-dimensional photothermal nanomaterials have a photothermal effect; when irradiated with light of a certain wavelength, the temperature rises, thereby promoting the shape memory effect of the thermoresponsive shape memory polymer material, thus endowing the microcapsules with photosensitive shape memory capabilities. This allows the microcapsules to be remotely controlled in vitro, increasing the controllability of the shape memory performance of the microcapsules. The photosensitive shape memory microcapsules provided by this invention have important research and practical significance for tumor vascular embolization therapy.

[0033] In this embodiment of the invention, the light-controlled shape memory microcapsule includes a capsule core and a capsule wall covering the capsule core. It can also be understood that the light-controlled shape memory microcapsule has a core-shell structure, wherein the core material includes two-dimensional photothermal nanomaterials and thermally responsive shape memory polymer materials, and the shell includes water-soluble polymer materials.

[0034] Among numerous light sources of different wavelengths, near-infrared light is widely used as an excitation light due to its excellent tissue penetration ability (penetration depth up to approximately 10 cm) and minimal photodamage, making it widely applied in biomedical fields such as cancer photothermal therapy, controlled drug release, and bioimaging. However, single near-infrared light-responsive shape memory materials also suffer from drawbacks such as slow response, low response efficiency, difficulty in degrading the materials used, and a tendency to induce toxic reactions in the body. Therefore, developing a microcapsule with excellent biodegradable near-infrared light-controlled shape memory properties is of significant research and practical importance for tumor vascular embolization therapy. Therefore, in some embodiments, the two-dimensional photothermal nanomaterial is a biodegradable two-dimensional photothermal nanomaterial. This allows the light-controlled shape memory microcapsule to possess excellent biodegradability, reducing residues in the body, significantly lowering its biotoxicity, and thus ensuring high safety.

[0035] In some embodiments, the biodegradable two-dimensional photothermal nanomaterial includes at least one of two-dimensional MXene nanosheets, two-dimensional niobium selenide nanosheets (i.e., niobium diselenide nanosheets), and two-dimensional bismuth oxyselenide nanosheets. MXene typically comprises a MAX phase (which is a chemical formula M... n+1 AX n A non-van der Waals layered compound, where M is a transition metal, A is a main group element, and X is carbon or nitrogen. It is obtained by etching away the A-layer atoms in the material.

[0036] In some embodiments, the two-dimensional MXene nanosheets include at least one of Ti3C2 nanosheets, Ta4C3 nanosheets, Ti3CN nanosheets, Nb2C nanosheets, and Mo2C nanosheets, but are not limited thereto.

[0037] Taking the preparation of Ti3C2 nanosheets as an example, the preparation method of Ti3C2 nanosheets includes the following steps:

[0038] After mixing LiF and hydrochloric acid, Ti3AlC2 was added to obtain a suspension;

[0039] The suspension was placed at a preset temperature, stirred, etched for a preset time, washed, filtered, and freeze-dried to obtain multilayer Ti3C2 nanosheets.

[0040] Furthermore, multilayer Ti3C2 nanosheets can be ultrasonically processed to obtain single-layer Ti3C2 nanosheets.

[0041] In some embodiments, the thermally responsive shape memory polymer material includes, but is not limited to, at least one of poly(D,L-lactic acid), poly(D, lactide-trimethylene carbonate), polyurethane, and polylactic acid.

[0042] In some embodiments, the water-soluble polymer material includes at least one of polyvinyl alcohol, polyethylene glycol, and polyvinylpyrrolidone, but is not limited thereto.

[0043] In some embodiments, the particle size of the light-controlled shape memory microcapsules is 5–55 μm (e.g., 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or 55 μm). This micron-scale particle size makes the light-controlled shape memory microcapsules more suitable for in vivo applications.

[0044] This invention also provides a method for preparing the light-controlled shape memory microcapsules as described above, comprising the following steps:

[0045] S1. Two-dimensional photothermal nanomaterials and thermally responsive shape memory polymer materials are added to an organic solvent and ultrasonically dispersed to obtain a dispersion.

[0046] S2. Provide a water-soluble polymer material solution, mix the water-soluble polymer material solution with the dispersion, and stir at a speed of 800-1200 rpm to obtain the light-controlled shape memory microcapsule.

[0047] In this embodiment of the invention, two-dimensional photothermal nanomaterials and thermally responsive shape memory polymer materials are added to an organic solvent and ultrasonically dispersed. The resulting dispersion is used as the oil phase, and the water-soluble polymer material solution is used as the aqueous phase. Using the oil-in-water emulsion evaporation method, the oil phase and the water-soluble polymer material solution are dispersed by high-speed magnetic stirring to form oil-in-water droplets. On the other hand, the solvent of the oil phase (i.e., the aforementioned organic solvent) is evaporated as much as possible through high-speed stirring. Finally, the water-soluble polymer material coats the two-dimensional photothermal nanomaterials and the thermally responsive shape memory polymer material to form photo-controlled shape memory microcapsules.

[0048] The preparation method provided in this invention is simple and controllable, and the resulting microcapsules have relatively uniform and adjustable particle sizes. The addition of two-dimensional photothermal nanomaterials indirectly transforms the thermally responsive shape memory polymer material into a photosensitive shape memory material, thereby realizing the photosensitive shape memory characteristics of the microcapsules and their highly efficient in vitro remote control properties. Furthermore, due to the advantages of the microscale, the microcapsules are easier to use in vivo.

[0049] In this embodiment, the specific selection of the two-dimensional photothermal nanomaterial, thermally responsive shape memory polymer material, and water-soluble polymer material is as described above and will not be repeated here.

[0050] In some embodiments, the mass ratio of the two-dimensional photothermal nanomaterial, the thermally responsive shape memory polymer material, to the water-soluble polymer material in the water-soluble polymer material solution is (0.5–2):(10–40):

[0051] (37.5~150), for example, it can be 0.5:10:37.5, 0.5:25:78, 0.5:40:150, 1:10:37.5, 1:25:78, 1:40:150, 2:10:37.5, 2:25:78 or 2:40:150, etc.

[0052] In some embodiments, the concentration of the two-dimensional photothermal nanomaterial in the dispersion is 0.5 to 2 mg / mL, for example, it can be 0.5 mg / mL, 1 mg / mL, 1.2 mg / mL, 1.5 mg / mL, 1.8 mg / mL or 2 mg / mL, etc.

[0053] In some embodiments, the concentration of the water-soluble polymer material in the solution is 1.25 to 5 mg / mL, for example, it can be 1.25 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.5 mg / mL, 4 mg / mL, 4.5 mg / mL or 5 mg / mL, etc.

[0054] In some embodiments, the organic solvent includes at least one of dichloromethane and trichloromethane, but is not limited thereto.

[0055] In step S2, the water-soluble polymer material solution is mixed with the dispersion, stirred at a speed of 800-1200 rpm, and then collected by centrifugation to obtain the light-controlled shape memory microcapsules.

[0056] This invention also provides the application of the light-controlled shape memory microcapsules described above in the present invention in the preparation of tumor vascular embolization materials. This invention further provides the application of the light-controlled shape memory microcapsules prepared by the preparation method described above in the present invention in the preparation of tumor vascular embolization materials. This invention also provides the application of the light-controlled shape memory microcapsules described above in the present invention and the light-controlled shape memory microcapsules prepared by the preparation method described above in the present invention in the preparation of tumor vascular embolization materials. The light-controlled shape memory microcapsules provided by this invention have excellent light-controlled shape memory properties and can be used as embolization materials for tumor vascular embolization therapy.

[0057] The present invention will be further described below through specific embodiments.

[0058] Example 1

[0059] This embodiment provides a method for preparing light-controlled shape memory microcapsules, including the following steps:

[0060] (1) Preparation of MXene nanosheets (by in-situ etching away the Al atomic layer in Ti3AlC2 using a mixture of HCl and LiF)

[0061] Dissolve 3.2g of LiF in 40mL of hydrochloric acid (HCl concentration of 9mol / L), then slowly add 2g of Ti3AlC2 powder (addition process takes about 15 minutes) to obtain a suspension.

[0062] The suspension was placed at 40°C and stirred at 600 rpm for 35 hours. After etching, the suspension was washed with deionized water and centrifuged three times (3500 rpm for 5 minutes each time) until the pH of the supernatant was 6. Then, it was vacuum filtered (using a 0.22 μm cellulose membrane) and freeze-dried to obtain multilayer MXene nanosheets (i.e., multilayer Ti3C2 nanosheets).

[0063] 400 mg of multilayer Ti3C2 nanosheets were dispersed in 100 mL of deionized water and sonicated at 300 W for 4 hours in an ice-water bath under argon protection. Then, the mixture was centrifuged at 3500 rpm for 60 minutes to obtain a monolayer MXene colloidal solution, which is the monolayer Ti3C2 nanosheet.

[0064] (2) Preparation of light-controlled shape memory microcapsules

[0065] 100 mg of poly(D,L-lactic acid) (PDLLA, glass transition temperature Tg = 41 °C) was dissolved in 5 mL of dichloromethane by magnetic stirring. Then, 1 mL of the above solution was taken, and 1 mg of monolayer Ti3C2 nanosheets were added to it. The solution was then ultrasonically dispersed using a 130 W probe to obtain a dispersion.

[0066] The above dispersion was added to 30 mL of a 0.25 wt% polyvinyl alcohol aqueous solution (i.e., the concentration of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is about 2.506 mg / mL), and the mixture was magnetically stirred at a speed of 1200 rpm (the purpose of high-speed magnetic stirring is, on the one hand, to form oil-in-water droplets, and on the other hand, to volatilize dichloromethane as much as possible through stirring). After stirring overnight, the mixture was centrifuged at a speed of 2000 rpm, and the light-controlled shape memory microcapsules (denoted as MXene / PDLLA microcapsules) were collected and washed twice with water.

[0067] Comparative Example 1

[0068] This embodiment provides a method for preparing microcapsules (without Ti3C2 nanosheets), comprising the following steps:

[0069] 100 mg of PDLLA was dissolved in 5 mL of dichloromethane using magnetic stirring to obtain a dispersion.

[0070] Take 1 mL of the above dispersion and add it to 30 mL of a 0.25 wt% polyvinyl alcohol aqueous solution. Stir the mixture at 1200 rpm using a high-speed magnetic stirrer. After stirring overnight, centrifuge at 2000 rpm to collect the microcapsules (denoted as PDLLA microcapsules) and wash them twice with water.

[0071] test:

[0072] (1) The UV-Vis-NIR absorption spectrum of the monolayer Ti3C2 nanosheets prepared in Example 1 in aqueous solution is shown below. Figure 1 As shown, it exhibits a distinct absorption peak near the 808nm region, thus proving its excellent light absorption characteristics for near-infrared light.

[0073] (2) Transmission electron microscopy image of the monolayer Ti3C2 nanosheets prepared in Example 1 is shown below. Figure 2 As shown, the small-sized monolayer Ti3C2 nanosheets exhibit good monodispersity and uniform size, with a lateral dimension of approximately 100 nm.

[0074] (3) The MXene / PDLLA microcapsules prepared in Example 1 were subjected to scanning electron microscopy (SEM) testing, and the results are as follows: Figure 3 As shown, the prepared microcapsules exhibit a relatively uniform spherical shape and good dispersibility.

[0075] (4) The particle size analysis of the MXene / PDLLA microcapsules prepared in Example 1 was performed, and the results are as follows: Figure 4 As shown, the average size of the prepared microcapsules is 26 μm.

[0076] (5) Energy dispersive spectroscopy (EDS) was performed on the MXene / PDLLA microcapsules prepared in Example 1, and the results are as follows: Figure 5 As shown, it can be seen that it contains a high Ti element content, thus proving the successful encapsulation of Ti3C2 nanosheets.

[0077] (6) Photothermal performance test

[0078] The MXene / PDLLA microcapsules prepared in Example 1 were added to ultrapure water to prepare an MXene / PDLLA microcapsule solution with a concentration of 50 μg / mL.

[0079] Take 1 mL of MXene / PDLLA microcapsule solution with a concentration of 50 μg / mL, and use a power density of 1.0 W / cm². 2 The sample was irradiated with an 808nm laser for 5 minutes. Simultaneously, the PDLLA microcapsules and water from Comparative Example 1 were used as control groups and subjected to the same irradiation conditions. Temperature was recorded in real-time using an infrared camera (Fotric 220). Results are as follows: Figure 6 As shown, compared with PDLLA microcapsules and pure water, MXene / PDLLA microcapsules have a significant photothermal heating effect, increasing from room temperature to 63.2℃ in 10 minutes.

[0080] (7) Test of light-controlled shape memory performance

[0081] The shape memory process utilizes SEM to capture the memory morphology of the microcapsules. The specific process is as follows:

[0082] The MXene / PDLLA microcapsules prepared in Example 1 (the SEM image of which is shown below) Figure 7As shown in (a), spherical MXene / PDLLA microcapsules are uniformly dispersed in a mixed solution of polyvinyl alcohol and glycerol (polyvinyl alcohol content is 10% by mass and glycerol content is 2% by mass). After coating, the microcapsules are air-dried at room temperature. The resulting film is then stretched to twice its original size using an automatic film stretching machine. The stretched film is then dissolved in an aqueous solution and finally centrifuged to obtain spindle-shaped MXene / PDLLA microcapsules (the SEM images are shown in Figure 1). Figure 7 As shown in (b) in the figure, it serves as a temporary shape for shape memory.

[0083] Spindle-shaped MXene / PDLLA microcapsules were added to ultrapure water to prepare a 50 μg / mL solution of spindle-shaped MXene / PDLLA microcapsules. 1 mL of this 50 μg / mL solution was placed in a container with a power density of 1.0 W / cm². 2 Irradiation with an 808nm laser for 5 minutes resulted in the spindle-shaped MXene / PDLLA microcapsules returning to their original spherical shape (as shown in the SEM image). Figure 7 (as shown in (c)).

[0084] As can be seen, the MXene / PDLLA microcapsules prepared in Example 1 can be stretched from their original form to a temporary form, and can gradually return to their original form under near-infrared light irradiation, exhibiting excellent light-controlled shape memory properties, and can be used in the embolization treatment of tumor vessels.

[0085] (8) Cytotoxicity test

[0086] Mouse mononuclear macrophage leukemia cells (RAW 264.7) were seeded into 96-well plates at a density of 1 × 10⁶ cells per well. 4 Cells were cultured at 37°C in a 5% CO2 incubator for 24 hours. Subsequently, the original medium was replaced with 200 μL of fresh medium containing different concentrations (0 μg / mL, 1.25 μg / mL, 2.5 μg / mL, 5 μg / mL, 10 μg / mL, 20 μg / mL, 50 μg / mL, and 100 μg / mL) of MXene / PDLLA microcapsules. After 24 hours of incubation, the medium was replaced with 10% CCK-8 medium and incubated for another 60 minutes. Cell viability was measured using an absorbance reader (FilterMax F5, Molecular Devices, USA) at 450 nm. Results are shown below. Figure 8 As shown, the MXene / PDLLA microcapsules maintained over 90% cell viability even at a high concentration of 100 μg / mL, demonstrating the excellent biocompatibility of the MXene / PDLL microcapsules provided by this invention, which can be used for embolization therapy of tumor vessels.

[0087] In summary, this invention provides a light-controlled shape memory microcapsule, its preparation method, and its application. Based on a thermally responsive shape memory polymer material, this invention adds a two-dimensional photothermal nanomaterial, enabling the two-dimensional photothermal nanomaterial and the thermally responsive shape memory polymer material to work synergistically. The two-dimensional photothermal nanomaterial exhibits a photothermal effect; when illuminated with light of a certain wavelength, its temperature rises, thereby promoting the shape memory effect of the thermally responsive shape memory polymer material. This endows the microcapsule with light-controlled shape memory capability, allowing for remote in vitro control of the microcapsule and increasing the controllability of its shape memory performance.

[0088] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing light-controlled shape memory microcapsules, characterized in that, The light-controlled shape memory microcapsule comprises a capsule core and a capsule wall covering the capsule core. The capsule core comprises a two-dimensional photothermal nanomaterial and a thermally responsive shape memory polymer material, and the capsule wall comprises a water-soluble polymer material. The preparation method of the light-controlled shape memory microcapsule includes the following steps: Two-dimensional photothermal nanomaterials and thermally responsive shape memory polymer materials were added to an organic solvent and ultrasonically dispersed to obtain a dispersion. A water-soluble polymer material solution is provided, and the water-soluble polymer material solution is mixed with the dispersion and stirred at a speed of 800~1200 rpm to obtain the light-controlled shape memory microcapsules; The two-dimensional photothermal nanomaterial is a biodegradable two-dimensional photothermal nanomaterial, which includes at least one of two-dimensional MXene nanosheets, two-dimensional niobium selenide nanosheets, and two-dimensional bismuth oxy selenide nanosheets. The thermally responsive shape memory polymer material includes at least one of poly(D,L-lactic acid), poly(D, lactide-trimethylene carbonate), and polyurethane.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the two-dimensional photothermal nanomaterial, the thermally responsive shape memory polymer material, and the water-soluble polymer material in the water-soluble polymer material solution is (0.5~2):(10~40):(37.5~150). In the dispersion, the concentration of the two-dimensional photothermal nanomaterial is 0.5~2 mg / mL; In the solution of the water-soluble polymer material, the concentration of the water-soluble polymer material is 1.25~5 mg / mL.

3. The preparation method according to claim 1, characterized in that, The organic solvent includes at least one of dichloromethane and trichloromethane.

4. The preparation method according to claim 1, characterized in that, The water-soluble polymer material includes at least one of polyvinyl alcohol, polyethylene glycol, and polyvinylpyrrolidone.

5. The preparation method according to claim 1, characterized in that, The particle size of the light-controlled shape memory microcapsules is 5~55 μm.

6. The application of a light-controlled shape memory microcapsule prepared by the preparation method according to any one of claims 1-5 in the preparation of tumor vascular embolization materials.

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