Multifunctional biomaterial, preparation method and application thereof

Abstract

This invention provides a multifunctional biomaterial, its preparation method, and its application, relating to the field of biomaterials technology. The multifunctional biomaterial is characterized by comprising: a biocompatible polymer matrix; and a sonosensitive agent complex dispersed in the biocompatible polymer matrix. The sonosensitive agent complex comprises a metal-insulator phase change material and an MXene two-dimensional material, wherein the metal-insulator phase change material and the two-dimensional material form a heterostructure. The metal-insulator phase change material undergoes a phase transition under thermal stimulation to alter the band structure and built-in electric field of the heterostructure. The multifunctional biomaterial according to embodiments of this invention can achieve a significant synergistic improvement in carrier generation efficiency, separation efficiency, and migration efficiency, solving the problem of a fixed upper limit for carrier concentration in traditional static heterostructures, achieving a secondary amplification of ROS generation, and improving the efficiency of sonodynamic therapy.

Description

Technical Field

[0001] This invention relates to the field of biomaterials technology, and in particular to a multifunctional biomaterial, its preparation method, and its applications. Background Technology

[0002] Osteosarcoma is a primary bone cancer that commonly affects children and adolescents. Traditional treatment strategies primarily involve surgical resection combined with chemotherapy and radiotherapy. However, this approach has certain limitations, including incomplete removal of the lesion, the development of drug resistance leading to local tumor recurrence and metastasis, and the heavy burden on the body due to intrinsic toxicity. Furthermore, excessive tumor removal can result in large segments of bone loss. In addition, systemic chemotherapy and the tumor-associated microenvironment have been shown to significantly disrupt skeletal homeostasis and create an immunosuppressive microenvironment, hindering the body's immune system's suppression of the tumor and causing abnormalities in the bone immune microenvironment during bone regeneration. In summary, traditional osteosarcoma treatment strategies suffer from the limitation of failing to synergistically eliminate tumors and repair bone defects.

[0003] Sonodynamic therapy (SDT) is an emerging treatment for osteosarcoma. It induces tumor cell death by using ultrasound to stimulate a sonosensitive agent to generate reactive oxygen species (ROS). However, traditional sonosensitive agents have drawbacks such as low catalytic efficiency and poor biocompatibility.

[0004] While constructing Schottky heterostructures can improve carrier separation efficiency and enhance acoustic dynamics, their static band structure limits the gain of the ROS. Once the heterojunction is constructed, its built-in electric field and band structure become fixed, resulting in a fixed upper limit on the carrier concentration, making it difficult to increase the carrier concentration. Summary of the Invention

[0005] To address the problems existing in current osteosarcoma treatment technologies, this invention provides a multifunctional biomaterial, its preparation method, and its application, which can synergistically achieve anti-tumor and bone healing-promoting effects, thereby enhancing the treatment efficacy of osteosarcoma.

[0006] To address the aforementioned problems, the first aspect of this invention provides a multifunctional biomaterial comprising: a biocompatible polymer matrix; and a sound-sensitizing agent complex dispersed in the biocompatible polymer matrix; wherein the sound-sensitizing agent complex comprises a metal-insulator phase change material and a two-dimensional material, the metal-insulator phase change material and the two-dimensional material forming a heterostructure, and undergoing a phase change when the temperature rises to the phase change temperature, thereby altering the band structure and built-in electric field of the heterostructure.

[0007] In one embodiment of the present invention, the metal-insulator phase change material includes doped vanadium dioxide, wherein the doping element is selected from at least one of tungsten, aluminum, molybdenum, chromium and niobium.

[0008] In one embodiment of the present invention, the doped vanadium dioxide is tungsten-doped vanadium dioxide.

[0009] In one embodiment of the present invention, the two-dimensional material includes MXene material, which is selected from at least one of Nb2C, Ti3C2 and Mo2C.

[0010] In one embodiment of the present invention, the mass ratio of the metal-insulator phase change material to the two-dimensional material in the acoustic sensitizer composite is (0.2-1):1.

[0011] In one embodiment of the present invention, a phase transition is initiated by thermally stimulating the metal-insulator phase change material to a temperature above the phase transition temperature.

[0012] In one embodiment of the present invention, the biocompatible polymer matrix includes at least one of methacryloyl gelatin, chitosan, bioactive glass, collagen, polylactic acid-glycolic acid copolymer, and alginate.

[0013] The second invention also provides a method for preparing a multifunctional biomaterial, comprising:

[0014] Provide metal-insulator phase change materials and two-dimensional materials; form heterostructures of metal-insulator phase change materials and two-dimensional materials through self-assembly technology; mix the heterostructures with biocompatible polymers;

[0015] Solidify biocompatible polymers to form multifunctional biomaterials.

[0016] In one embodiment of the second aspect, a heterostructure is formed by self-assembly of a metal-insulator phase change material and a two-dimensional material, including:

[0017] The surface of metal-insulator phase change materials is modified using cationic surfactants to make them positively charged;

[0018] Surface-modified metal-insulator phase change materials are mixed with negatively charged two-dimensional material dispersions and assembled by Coulomb attraction.

[0019] The assembled materials are dried and annealed to obtain a heterogeneous structure.

[0020] Thirdly, the present invention also provides the application of a multifunctional biomaterial in the preparation of a medical device for treating osteosarcoma and promoting bone regeneration, wherein the multifunctional biomaterial is the multifunctional biomaterial for treating osteosarcoma and promoting bone regeneration described in the first aspect embodiment.

[0021] Due to the above technical solution, the present invention has at least the following beneficial effects:

[0022] According to embodiments of the present invention, a multifunctional biomaterial uses a biocompatible polymer matrix as a framework to provide three-dimensional structural support and a biocompatible environment. A sonosensitive agent complex is used as a functional module, forming a heterostructure with a bandgap width that can be dynamically adjusted by near-infrared laser by combining a metal-insulator phase change material with a two-dimensional material. This heterostructure possesses basic sonocatalytic capabilities. When an external stimulus, such as a near-infrared laser, is applied, the metal-insulator phase change material absorbs energy and heats up, subsequently undergoing a metal-insulator phase transition from its insulating state to a metallic state. This phase transition alters the band structure of the metal-insulator phase change material, resulting in a significant reduction in the bandgap. This dynamically reshapes the band alignment and built-in electric field strength of the entire heterojunction, resulting in a significant synergistic improvement in the concentration, separation, and migration efficiency of charge carriers (electron-hole pairs). This solves the problem of a fixed upper limit for charge carrier concentration in traditional static heterostructures, achieving a secondary amplification of ROS generation and improving the sonodynamic therapeutic effect. Attached Figure Description

[0023] Figure 1A This is a flowchart of a method for preparing multifunctional biomaterials according to an embodiment of the present invention;

[0024] Figure 1B This is another flowchart of the method for preparing multifunctional biomaterials according to an embodiment of the present invention;

[0025] Figure 2 These are the material morphology characterization results in Example 2 of this invention;

[0026] Figure 3 This is an elemental analysis diagram of WVM-0.5 according to an embodiment of the present invention;

[0027] Figure 4 These are the elemental content analysis spectra of W-VO2 and WVM-0.5 from an embodiment of the present invention;

[0028] Figure 5 These are the Zeta potential (A), XRD (B), and XPS (C) full spectra of Nb2C, W-VO2, and WVM-0.5 in embodiments of the present invention;

[0029] Figure 6 The electronic structure characterization (AE), absorption spectrum (F), photoelectric performance characterization (GI), band gap reduction performance of WVM with temperature rise (JK), and schematic diagram of band structure before and after W-VO2 phase transition (L) of Examples 1-3 of this invention are shown.

[0030] Figure 7 These are the DRS spectra of W-VO2 and Nb2C before and after integration in an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the Schottky barrier after integrating W-VO2 and Nb2C according to an embodiment of the present invention;

[0032] Figure 9 This is the external acoustic dynamic performance characterization result corresponding to S2 in this embodiment of the invention;

[0033] Figure 10 This is a bar graph showing the results of the in vitro tumor cell toxicity experiment of S2 in this embodiment of the invention.

[0034] Figure 11 This diagram illustrates photothermal-enhanced acoustic dynamics therapy during in vitro antitumor treatment, corresponding to Embodiment S2 of this application.

[0035] Figure 12 The results of K7M2 cell activity assessment under different treatments corresponding to Embodiment S2 of this application are shown;

[0036] Figure 13 This invention provides a confocal observation of the live / dead staining of K7M2 tumor cells after different treatments.

[0037] Figure 14 This is an in vitro osteogenic performance evaluation diagram of S2 and the comparative product of the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the application scenarios of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] To facilitate understanding of the technical solution of this invention, the technical problems of this application will be explained first.

[0040] As described in the background above, sonodynamic therapy utilizes ultrasound to excite sonosensitive agents, generating reactive oxygen species (ROS). Under ultrasound excitation, these sonosensitive agents exhibit unique catalytic activity, producing hot carriers (electron-hole pairs) that react with water molecules or solutes in the solution to generate ROS capable of killing tumor cells. However, the short lifetimes of these hot carriers, ranging from femtoseconds to nanoseconds, are a mismatch with the long timescales of chemical reactions, ranging from milliseconds to seconds, which is the fundamental reason for low catalytic efficiency. To address this technical problem, researchers have constructed metal-semiconductor (Schottky) heterostructures that can effectively separate electrons and holes, allowing hot electrons from the metal surface to cross the Schottky barrier with sufficient energy and be trapped within the conduction band of the semiconductor, thus extending the lifetime of hot electrons and improving catalytic efficiency. However, the potential biotoxicity of these metals limits their application in vivo.

[0041] Furthermore, in some embodiments, two-dimensional transition metal carbide or nitride (MXene) materials, due to their high electrical conductivity, are beneficial for the effective separation and migration of charge carriers. MXene also exhibits good biocompatibility and biodegradability, making it a good replacement for biotoxic metal materials. Therefore, MXene-based composite materials, such as Cu₂O / Ti₃C₂, Ag₂S / Ti₃C₂, and g-C₃N₄ / Ti₃C₂, have been developed to improve charge carrier separation. However, the gain on ROS generation from MXene-based heterostructures is still limited by the static band structure. Once the heterostructure is constructed, its built-in electric field and band arrangement are fixed, resulting in a fixed upper limit on the charge carrier concentration, thus limiting the therapeutic effect of sonodynamic therapy.

[0042] Experimental research has shown that since the band gap width directly affects the generation efficiency of electron-hole pairs, if the band gap of a material can be effectively reduced based on the Schottky structure, it can not only increase the carrier concentration but also effectively separate electron-hole pairs, thereby breaking through the fixed upper limit of carrier concentration in the static band structure and achieving a secondary amplification of ROS. Existing methods for reducing the band gap of materials (such as elemental doping and vacancy defects) can only construct static energy level structures. Although they can increase the upper limit of carrier concentration, they cannot precisely and dynamically adjust the ROS according to the different needs of different stages of tumor treatment.

[0043] Furthermore, composite or nanomaterials cannot provide mechanical strength for bone regeneration because the regeneration of large bone defects still requires necessary biomaterials to provide structural support in order to maintain the physiological and cellular activities that occur during new bone formation.

[0044] To address the aforementioned technical problems, this invention provides a multifunctional biomaterial. This multifunctional biomaterial uses a biocompatible polymer matrix as a framework to provide three-dimensional structural support and a biocompatible environment for the regeneration of large bone defects. Furthermore, the trace elements released during the degradation of the biomaterial promote bone healing. This multifunctional biomaterial is primarily made of a biomaterial formed by combining a metal-insulator phase change material (hereinafter referred to as phase change material) with a two-dimensional material. This biomaterial possesses a heterogeneous structure whose band gap width can be dynamically adjusted by near-infrared laser. The mixing of the biomaterial with the biocompatible polymer matrix yields the multifunctional biomaterial. Because the heterogeneous structure possesses basic acoustic catalytic capabilities, when external stimuli, such as near-infrared laser, are applied, the phase change material absorbs energy and heats up, undergoing a phase transition. This significantly reduces the band gap, resulting in a surge in carrier concentration, thereby dynamically increasing the carrier concentration and improving the efficacy of acoustic dynamic therapy.

[0045] The multifunctional biomaterials of the present invention will be described below with reference to specific embodiments.

[0046] The multifunctional biomaterial of this invention includes a biocompatible polymer matrix and a sound-sensitizing agent complex dispersed in the biocompatible polymer matrix. The sound-sensitizing agent complex comprises a phase change material and a two-dimensional material, the phase change material and the two-dimensional material forming a heterostructure. The phase change material is configured to undergo a phase transition upon external stimulation to alter the band structure and built-in electric field of the heterostructure.

[0047] This invention relates to a multifunctional biomaterial that uses a biocompatible polymer matrix as a framework, providing three-dimensional structural support and a biocompatible environment. A sonosensitive agent complex is used as a functional module, forming a heterostructure with a bandgap width that can be dynamically adjusted by near-infrared laser light, by combining a phase change material with a two-dimensional material. This heterostructure possesses basic sonocatalytic capabilities; when an external stimulus, such as near-infrared laser light, is applied, the phase change material absorbs energy and undergoes a metal-insulator phase transition, changing from its insulating state to a metallic state. This phase transition alters the band structure of the phase change material, resulting in a significant reduction in the bandgap, thereby dynamically reshaping the band alignment and built-in electric field strength of the entire heterojunction. This reshaping of the heterostructure significantly and synergistically improves carrier (electron-hole pair) concentration, separation, and migration efficiency. It breaks through the fixed upper limit of carrier concentration in traditional static heterojunctions, achieving a secondary amplification of ROS generation.

[0048] In one embodiment of the present invention, the phase change material includes doped vanadium dioxide (VO2), and the doping element is selected from at least one of tungsten, aluminum, molybdenum, chromium and niobium.

[0049] The phase transition of vanadium dioxide (VO2) is accompanied by significant changes in its optical and electrical properties. However, its phase transition temperature (e.g., 68°C) is much higher than the biological temperature (around 37°C), thus limiting the application of its phase transition mechanism in vivo. Extensive experimental studies have shown that doping with elements such as tungsten, aluminum, molybdenum, chromium, and niobium can increase the carrier concentration in vanadium dioxide or induce structural changes. The electron distribution and band gap of doped VO2 change, thereby significantly reducing its phase transition temperature. Furthermore, when the doping ratio is appropriate, tungsten-doped VO2 (W-VO2) can undergo a phase transition at near the human body temperature of 37°C, making the VO2 phase transition mechanism potentially applicable in vivo. Therefore, in embodiments of this invention, vanadium dioxide with doped elements is combined with two-dimensional materials to form a Schottky structure. This Schottky structure can improve the therapeutic efficiency of sonodynamic therapy.

[0050] In the embodiments of this application, the doped vanadium dioxide is tungsten-doped vanadium dioxide, wherein the tungsten doping ratio is 1.5%-2.0%. For example, this ratio can be 1.5%, 1.6%, 1.8%, or 2.0%, etc. Tungsten-doped VO2 (abbreviated as W-VO2) at this ratio can undergo a phase transition at a temperature close to the human body temperature of 37°C, making the phase transition mechanism of VO2 a promising candidate for application in biological systems. Furthermore, W-VO2 combines with two-dimensional materials, such as Nb2C, to form a Schottky structure (W-VO2 / Nb2C) composite material, which can improve the treatment efficiency of sonodynamic therapy. Moreover, both W-VO2 and Nb2C are excellent photothermal agents; near-infrared laser irradiation can easily induce a phase transition in W-VO2, significantly reducing the band gap and leading to a significant enhancement of the charge carrier effect. Compared to before the phase transition, ultrasonic irradiation under the same conditions can significantly increase the generated charge carrier concentration, achieving a secondary amplification of ROS generation.

[0051] In some embodiments, the two-dimensional material includes MXene material, which is selected from at least one of Nb2C, Ti3C2 and Mo2C.

[0052] Preferably, the MXene material is Nb2C. The W-VO2 / Nb2C structure not only possesses the property of photothermal enhancement of sonodynamic therapy, but also, the Nb element released during the degradation of Nb2C in vivo can open the Wnt signaling pathway of key cells controlling bone growth and repair, further promoting angiogenesis. Simultaneously, a large amount of nutrients, oxygen, and bone marrow mesenchymal stem cells are transported to the bone defect site through new blood vessels, promoting bone regeneration. From a biological perspective, vanadium is one of the essential trace elements in the human body, abundant in bones, and plays a certain regulatory role in energy metabolism and bone growth. Specifically, vanadium can affect the osteogenic differentiation of bone marrow mesenchymal stem cells by regulating the focal adhesion kinase (FAK) and mitogen-activated protein kinase (MAPK) signaling pathways, and exhibits anti-tumor activity.

[0053] In embodiments of the present invention, the mass ratio of phase change material to two-dimensional material in the acoustic sensitizer composite is (0.2-1):1. This range ensures optimal interfacial contact and the highest carrier separation efficiency of the heterojunction. If the ratio is too low, there will be insufficient phase change material and a weak modulation effect; if the ratio is too high, it may cover the MXene surface, affecting its conductivity and photothermal properties.

[0054] In some embodiments, a phase change is initiated by raising the temperature of the metal-insulator phase change material above the phase change temperature through thermal stimulation, which may include at least one of photothermal stimulation, thermal conduction, and thermal convection.

[0055] In one embodiment of the present invention, the biocompatible polymer matrix includes at least one of methacryloyl gelatin, chitosan, bioactive glass, collagen, polylactic acid-glycolic acid copolymer, and alginate.

[0056] Regeneration of large bone defects requires biomaterials to provide structural support to sustain the physiological and cellular activities that occur during new bone formation. Some biomaterials possess injectability and photocurability, making them well-suited for filling irregular bone defects. Biomaterials with high porosity promote cell adhesion and proliferation; their porous structure serves as an effective channel for oxygen and nutrient transport and provides the necessary space for the growth of new bone tissue.

[0057] In embodiments of the present invention, gelatin methacryloyl (GelMA) is preferred. GelMA is a material modified by adding methacrylate groups to amine-containing side groups on a gelatin base. It has injectability and photocurability, and can well meet the filling requirements of irregular bone defects. The high porosity of GelMA is more conducive to cell adhesion and proliferation. Its porous structure can serve as an effective channel for the transport of oxygen and nutrients, and provide the necessary space for the growth of new bone tissue. Furthermore, W-VO2 and Nb2C are both good photoacoustic imaging contrast agents, giving the scaffold prepared from this biomaterial the potential for non-invasive monitoring of tumor treatment and bone regeneration processes.

[0058] This invention also provides a bio-implantable scaffold made from the aforementioned multifunctional biomaterials. For example, a composite material of Schottky structure W-VO2 / Nb2C is combined with porous GelMA to form W-VO2 / Nb2C@GelMA (WVM@GM), which is then prepared as a bio-implantable scaffold that can be used for efficient osteosarcoma treatment and bone tissue regeneration.

[0059] The preparation method of the multifunctional biomaterial according to the embodiments of the present invention will be described below.

[0060] refer to Figure 1A , Figure 1A A flowchart illustrating a method for preparing multifunctional biomaterials according to an embodiment of this application is shown;

[0061] like Figure 1A As shown, the preparation method of the multifunctional biomaterial in this embodiment of the invention includes steps S10-S40.

[0062] S10 provides metal-insulator phase change materials and two-dimensional materials.

[0063] The metal-insulator phase change material includes doped vanadium dioxide, with the doping element selected from at least one of tungsten, molybdenum, aluminum, chromium, and niobium. The doped vanadium dioxide is tungsten-doped vanadium dioxide, wherein the doping ratio of tungsten is 1.5%-2.0%, for example, the doping ratio can be 1.6%, 1.7%, 1.8%, or 1.9%, etc.

[0064] Two-dimensional materials include MXene materials, which are at least one of Nb2C, Ti3C2, and Mo2C.

[0065] S20 uses self-assembly technology to form a heterostructure from phase change materials and two-dimensional materials.

[0066] The self-assembly technology may include at least one of electrostatic adsorption, ultrasonic treatment, and annealing.

[0067] For example, cationic surfactants can be used to modify the surface of phase change materials, giving them a positive charge. The surface-modified phase change material is then mixed with a negatively charged two-dimensional material dispersion and assembled using Coulomb attraction. The assembled material is then dried and annealed to form a material with a heterogeneous structure.

[0068] Among them, cationic surfactants may include hexadecyltrimethylammonium bromide.

[0069] Annealing can be performed in an inert or reducing atmosphere at a temperature of 400°C to 600°C for 4 to 10 hours.

[0070] S30 is a mixture of heterostructures and biocompatible polymers.

[0071] S40 is a solidified biocompatible polymer that forms a multifunctional biomaterial with a three-dimensional structure.

[0072] Combination Figure 1A And refer to Figure 1B , Figure 1B A flowchart illustrating a method for preparing multifunctional biomaterials according to an embodiment of the present invention is shown.

[0073] like Figure 1B As shown, a self-assembly technique is used to form a composite material with a Schottky structure (W-VO2 / Nb2C) by combining a phase change material, such as W-VO2, and a two-dimensional material, such as Nb2C (corresponding to steps S10 and S20 in Figure 1). This composite material is then reacted with GelMA to obtain the multifunctional biomaterial W-VO2 / Nb2C@GelMA (corresponding to S30 and S40 in Figure 1), which can serve as a multifunctional scaffold. When using this scaffold, a phase transition in W-VO2 can be induced by NIR-II laser irradiation, significantly reducing the band gap of the heterostructure at higher intensities (1.5 W / cm²). 2 Ultrasonic stimulation increases the carrier concentration, leading to a secondary amplification of reactive oxygen species (ROS) generation. This amplification is beneficial for the efficient treatment of osteosarcoma. Furthermore, this bio-scaffold, at a lower intensity (0.2 W / cm²), exhibits [efficacy / effectiveness]. 2 Ultrasound stimulation promotes the release of vitamins V and Nb, and facilitates angiogenesis and osteoblast differentiation, which can lead to the regeneration of bone defects.

[0074] According to the preparation method of the multifunctional biomaterial of the present invention, a multifunctional biomaterial can be prepared. The method is simple, and the multifunctional biomaterial can be used as a biological implant scaffold for the treatment of osteosarcoma. Its specific functional effects can be referred to the description of the multifunctional biomaterial in the above embodiments.

[0075] Furthermore, this invention also discloses the application of a multifunctional biomaterial in the preparation of medical devices for treating osteosarcoma and promoting bone regeneration, wherein the multifunctional biomaterial is the multifunctional biomaterial for treating osteosarcoma and promoting bone regeneration described in the above embodiments.

[0076] The multifunctional biomaterials of the present invention will be described in detail below with reference to specific embodiments.

[0077] Example 1

[0078] 1) Mix 1 g of Nb2C multilayer nanosheets with 15 mL of intercalation solution (tetrapropylammonium hydroxide), seal and protect from light, stir at room temperature (1000 r / min) for 72 hours, then wash three times alternately with anhydrous ethanol and deionized water, centrifuge and dry to obtain few-layer Nb2C NSs.

[0079] 2) The surface of W-VO2 powder (2% tungsten doped, purchased from Wuhu Jikang New Material Technology Co., Ltd.) was modified with hexadecyltrimethylammonium bromide to make it positively charged.

[0080] 3) Preparation of Schottky structure W-VO2 / Nb2C composite material.

[0081] 100 mg of W-VO2 and Nb2C powder (mass ratio 0.2:1) were completely dispersed in 5 ml of anhydrous ethanol. 10 mg of hexadecyltrimethylammonium bromide (Aladdin, 99%) was added and the mixture was stirred for 10 min. Then, 500 mg of prepared Nb2C NSs was added, and the mixture was sonicated for 1 h to obtain a suspension. The suspension was stirred at low speed (800 r / min) at room temperature for 12 h. The suspension was then centrifuged at 10,000 rpm, and the collected black precipitate (W-VO2 / Nb2C) was dried under vacuum at 70 °C for 12 h. W-VO2 and Nb2C were annealed in an Ar / H2 (95:5) atmosphere at 500 °C (2 °C / min) for 8 h to obtain the W-VO2 / Nb2C composite material, denoted as W-VO2 / Nb2C-0.2 or WVM-0.2.

[0082] 5) Mix 100 μg WVM-0.2 with 1 mL of porous methacryloyl gelatin (purchased from Suzhou Yongqinquan Intelligent Equipment Co., Ltd.) and sonicate at 37 ℃ for 15 min to obtain the multifunctional biomaterial WVM@GelMA (WVM@GM). This biomaterial can be used to make the corresponding scaffold sample S1.

[0083] Example 2

[0084] Compared with Example 1, except for the different mass ratio of W-VO2 / Nb2C (0.5:1), i.e. the composite material is W-VO2 / Nb2C-0.5 or WVM-0.5, the rest are the same, and the scaffold sample S2 corresponding to the multifunctional biomaterial is obtained.

[0085] Example 3

[0086] Compared with Example 1, except for the difference in the mass ratio of W-VO2 / Nb2C (1:1), i.e., the composite material is W-VO2 / Nb2C-1 or WVM-1, the rest are the same, and the scaffold sample S3 corresponding to the multifunctional biomaterial is obtained.

[0087] It should be noted that in the following embodiments, WVM can represent any one of WVM-0.2, WVM-0.5, and WVM-1 mentioned above. Furthermore, in the following embodiments, since the stent sample contains WVM, the stent sample exhibits the same effects as WVM. Correspondingly, the anti-tumor effects of the stent also indicate that WVM has the same effects.

[0088] The substances used in each step of Example 2 are characterized below.

[0089] refer to Figure 2 , Figure 2 The material morphology characterization results from Example 2 are shown. Figure 2 Image (A) is a few-layer Nb2C transmission electron microscope (TEM) image. Figure 2 (B) in the image is a transmission electron microscope (TEM) image of W-VO2 and Figure 2 Transmission electron microscopy (TEM) image of (C)WVM-0.5.

[0090] like Figure 2 Images A, B, and C in the figure are transmission electron microscopy (TEM) images of few-layer Nb₂C, W-VO₂, and WVM-0.5, respectively. The few-layer Nb₂C exhibits a translucent, sheet-like structure, indicating successful intercalation and separation of the multilayer nanosheets. Its surface contains hydrophilic functional groups such as fluorine atoms and hydroxyl groups, providing a possibility for the assembly of the MXene composite material. Based solely on the TEM results of WVM-0.5, it can be preliminarily determined that the two have been successfully integrated. To further determine the bonding status, we used EDX for elemental analysis.

[0091] refer to Figures 3-4 , Figure 3 The elemental analysis diagram of WVM-0.5 is shown. Figure 4 Spectra of elemental composition analysis for W-VO2 and WVM-0.5.

[0092] Figure 3 and Figure 4 (a) and Figure 4 Figure (b) shows the elemental analysis diagram and elemental content spectrum of WVM-0.5. It can be seen that W-VO2 does not contain Nb, C, or other elements, while the five main elements are clearly detected in WVM-0.5. Because the doping ratio of W is approximately 2%, it shows a low content both before and after integration. To further determine the changes in physical properties after successful integration of W-VO2 and Nb2C, we continued with relevant tests.

[0093] refer to Figure 5 , Figure 5 The zeta potential, XRD and XPS full spectra of Nb2C, W-VO2 and WVM-0.5 are shown.

[0094] Among them, such as Figure 5 As shown in (A), the Zeta potential test results show that the two material particles can be bonded together by electrostatic adsorption. After annealing, CTAB is removed, allowing the two to be tightly bonded together. Figure 5 The X-ray diffraction (XRD) corresponding to (B) in the diagram is the same as... Figure 5 The full X-ray photoelectron spectroscopy (XPS) spectrum corresponding to (C) in the figure shows characteristic peaks of both materials in WVM-0.5, proving that the two materials are successfully integrated. For WVM-0.5, the characteristic diffraction peaks at (100) and (110) are attributed to Nb2C NSs, indicating that the combination of W-VO2 and Nb2C NSs does not affect the crystal structure of W-VO2.

[0095] refer to Figures 6-8 , Figure 6 The electronic structure characterization (AE), absorption spectrum (F), photoelectric performance characterization (GI), and bandgap reduction of WVM with temperature rise are shown in Examples 1-3 of this invention (JK), along with a schematic diagram of the band structure of W-VO2 before and after the phase transition (L). Figure 7 The DRS spectra of W-VO2 and Nb2C before and after integration are shown in this embodiment of the invention. Figure 8 This is a schematic diagram of the Schottky barrier after integrating W-VO2 and Nb2C according to an embodiment of the present invention.

[0096] Among them, the comparison before and after material integration Figure 6 A in the diagram represents the 3d orbital of Nb. Figure 6 B in the diagram represents the 4f orbital of W. Figure 6 The value of C in the figure shows the variation of the binding energy of the 2p orbital electrons in V. Figure 6 D in the diagram represents the Tauc plot. Figure 6 E in the figure shows the valence band spectrum. Figure 6 F in the figure shows the ultraviolet-visible-near-infrared absorption spectrum. Figure 6G in the figure represents the PL spectrum. Figure 6 H in the figure shows the electrochemical impedance (EIS) plot of D. Figure 6 The value I in the figure represents the transient photocurrent response under ultrasonic irradiation conditions. Figure 6 J in the figure shows the DRS spectra of WVM at different temperatures (37℃, 40℃ and 43℃). Figure 6 K in the diagram represents the Tauc plot. Figure 6 The L in the diagram illustrates the band structure changes before and after the W-VO2 phase transition.

[0097] The following is about Figures 6-8 Analysis and explanation will follow. First, the XPS high-resolution spectra of Nb, W, and V elements will be analyzed, such as... Figure 6 As shown in A, B, and C, the changes in electron binding energy reveal that after the integration of the two materials, the peak of the 3d orbital of Nb shifts towards higher binding energies, while the peaks of the 4f orbital of W and the 2p orbital of V shift towards lower binding energies. This indicates an increase in electron density around W and V atoms, which is due to the formation of a Schottky heterojunction between W-VO2 and Nb2C, affecting the distribution of charge carriers.

[0098] Next, we used diffuse reflectance spectroscopy (DRS) to test W-VO2 and WVM-0.5 before and after integration, such as... Figure 7 The results showed that the absorption spectrum changed before and after integration, with WVM-0.5 showing an increase in absorbance, which may be due to the narrowing of the band gap after integration, leading to enhanced light absorption.

[0099] Then, the band gap E is estimated using the Tauc plot. g The magnitude is based on the equation αhυ=K(hυ- E g ) n / 2 Plot the graphs (K, α, υ, and E) g Given constants, absorption coefficients, optical frequency, and band gap energy, where n=1, we obtain... Figure 6 In the Tauc plot corresponding to D, the tangent line in the near-straight-line segment of the graph intersects the X-axis, and the energy at the intersection point is the band gap size E of the material. g (Using either α or the absorbance value A for plotting does not affect the band gap solution, so the absorbance value A is used instead of the absorption coefficient α for plotting in this paper.) The band gap has a significant impact on the ultrasonic catalytic ability. The calculation results before and after integration are 0.58 and 0.53 eV, respectively, indicating that the band gap decreases after WVM-0.5 integration, making it easier to generate charge carriers under US irradiation.

[0100] The valence band (E) before and after material integration was tested using XPS. v ) spectrum (corresponding) Figure 6 The decrease in the valence band (E) indicates that WVM-0.5 has a stronger reducing effect than W-VO2, and then, according to formula E...g = E c -E v Calculate the conduction band E c The energy and the energy level diagram and Schottky barrier diagram (e.g.) are drawn. Figure 8 ).

[0101] To investigate the optimal integration ratio of W-VO2 and Nb2C, a series of tests were conducted on materials with different integration ratios, WVM-0.2, WVM-0.5, and WVM-1.0, such as... Figure 6 As shown in F, the UV-Vis-NIR absorption spectra of the materials after integration at different ratios reveal that WVM-0.2 and WVM-0.5 retain the broad-spectrum absorption characteristics of Nb2C. Acoustocatalytic activity is crucial for the generation of ROS by the acoustic sensitizer. We explored the electron-hole recombination rate of the materials using photoluminescence (PL) spectroscopy. The results show that WVM-0.5 has the lowest PL intensity, indicating that binding with an appropriate amount of Nb2C NSs can effectively suppress the recombination of electron-hole pairs in W-VO2. Furthermore, the EIS (electron impedance spectroscopy) of WVM-0.5 shows that it has the fastest electron transfer rate and the lowest electron transfer resistance (corresponding to...). Figure 6 (H in the middle).

[0102] Furthermore, the nanoplatform at 1.5 W / cm² was measured using an electrochemical workstation. 2 The acoustic current response after eight repeated switching cycles under ultrasonic irradiation at 1 MHz and a 50% duty cycle was determined. The results show that the acoustic current intensity is significantly enhanced after material integration, indicating that more electrons can be effectively transferred under ultrasonic irradiation (e.g., ...). Figure 6 (As shown in I).

[0103] In summary, the charge separation efficiency of W-VO2 / Nb2C is enhanced, demonstrating that the built-in electric field created by the Schottky heterostructure cannot be ignored. Based on these results, it is inferred that WVM-0.5 (S2 corresponding to Example 2) exhibits the strongest sonocatalytic activity. In the following examples, this composite material ratio was selected for subsequent experiments and is denoted as S2.

[0104] Characterization tests were conducted on the external acoustic and dynamic performance of the S2.

[0105] refer to Figure 9 , Figure 9 The results of the external acoustic dynamic performance characterization corresponding to S2 in the embodiment of the present invention are shown.

[0106] in, Figure 9 In this context, A represents the radiation intensity under US irradiation (1.5 W / cm²). 2 Singlet oxygen was detected by DPBF absorption spectroscopy processed by WVM under conditions of 50% duty cycle and 1 MHz. 1O2. Figure 9 B in the figure represents the radiation from US (1.5 W / cm²). 2 Detection of superoxide radical · O2 by absorption spectroscopy of NBT treated with S2 under conditions of 50% duty cycle and 1 MHz. 2- . Figure 9 C in the figure represents the temperature after US irradiation (1.5 W / cm²). 2 Detection of hydroxyl radicals (·OH) by fluorescence spectroscopy of TA treated with S2 under conditions of 50% duty cycle and 1 MHz. Figure 9 In this context, D represents the radiation level in the US (1.5 W / cm²). 2 DPBF absorption spectrum detection after W-VO2 treatment under the conditions of 50% duty cycle and 1 MHz. 1 O2. Figure 9 E in the text is from Figure 9 The statistical results of the change of DPBF absorption intensity over time obtained from analysis of A and D in the data are shown. Figure 9 F in the middle is from Figure 9 The decrease rate of DPBF absorption intensity over time was obtained from the analysis of E in the study, to reflect the catalytic efficiency of W-VO2 and WVM. Figure 9 In this context, G represents WVM and W-VO2. 1 ESR measurement results of O2 free radicals Figure 9 H in O is · 2- Free radical ESR measurement results and Figure 9 The I in the figure represents the ESR measurement result of the ·OH free radical. Figure 9 J in the figure represents the ESR detection at different temperatures (27, 32, 37, 42℃). 1 O2. Figure 9 K and J in the figure represent amplitude statistics. Figure 9 L in the diagram represents the generation mechanism of Type I and Type II ROS under ultrasonic excitation.

[0107] Combination Figure 6 Description of the external acoustic dynamic performance characteristics of S2.

[0108] To detect ROS generation under US irradiation, 1,3-diphenylisobenzofuran (DPBF) was used as a singlet culture medium. 1 O2 probe. Mix 200 µL of DPBF (0.2 mg / mL, dissolved in ethanol) with 200 µL of WVM (0.6 mg / mL, dissolved in ethanol). Then, use US (1 MHz, 50% duty cycle, 1.5 W / cm²) separately. 2Irradiation was performed at 0, 3, 6, 9, and 12 min, and the changes in absorption intensity of DPBF at 410 nm were recorded using a UV-Vis-NIR spectrophotometer. Nitroblue tetrazolium (NBT, 2 μg / mL) in dimethyl sulfoxide (DMSO) was used as a probe molecule to detect ·O. 2- NBT and O 2- The reaction is therefore evaluated by observing the reduction of NBT. 2- The amount generated.

[0109] Subsequently, terephthalic acid (TA, 600 μg / mL) was used to detect ·OH. After ultrasonic treatment, the photoluminescence (PL) spectrum of TA oxide (excitation wavelength 312 nm) was recorded. Figure 9 In A, it can be clearly observed that the absorbance of DPBF decreases with increasing US irradiation time, indicating that it is generated... 1 O2 oxidation degradation. And Figure 9 As shown in Figure B, the absorbance of NBT increases significantly under US irradiation, therefore S2 can produce ·O under US irradiation. 2- .

[0110] Figure 9 The results in C showed an increase in the fluorescence intensity of TA, indicating that S2 produced ·OH under US irradiation. These results preliminarily confirm that US irradiation of S2 can effectively generate ROS. Figure 9 The D-cell image recorded the production of W-VO2 under the same ultrasound stimulation conditions. 1 In the case of O2, we can see that W-VO2 has the ability to generate ROS, but its catalytic efficiency is significantly lower than that of S2 at the same concentration.

[0111] Figure 9 The study statistically analyzed the changes in absorbance of DPBF at 410 nm after treatment with W-VO2 and S2 under the same conditions. Although both methods could generate ROS under ultrasonic catalysis, leading to a decrease in DPBF absorbance, the decrease rate of DPBF absorbance under S2 treatment within the same time period was approximately twice that of W-VO2 (e.g., ...). Figure 9 As shown in F), this indicates that under the same conditions, S2 generates ROS more efficiently than W-VO2. Subsequently, electron spin resonance (ESR) spectroscopy analysis further verified the sample's ability to generate the above three ROS. S2 exhibited the highest ROS signal peak, consistent with previous experimental results.

[0112] The above results indicate that S2 exhibits significantly higher ROS generation efficiency than W-VO2 due to its highest electron-hole separation rate. To verify that WVM after temperature-induced phase transition possesses a more efficient ability to generate ROS, we further tested the ESR signal peaks of S2 at different temperatures (27℃, 32℃, 37℃, 42℃) (e.g., Figure 9 (as shown in J) and statistically compared the signal amplitude at different temperatures (e.g. Figure 9 (As shown in K). The results show that the amplitude of ESR gradually increases with increasing temperature, with the amplitude at 42℃ being approximately 2.56 times that at 27℃ and approximately 1.37 times that at 37℃, and the amplitude shows an almost linear relationship with temperature increase. Figure 9 The diagram in L shows two different types of ROS generation mechanisms. Under the synergistic enhancement of photothermal activity, the acoustic catalytic activity of S2 is significantly improved, resulting in superior anti-tumor performance.

[0113] The in vitro antitumor activity of S2 is described below with reference to the attached diagram.

[0114] refer to Figure 10 , Figure 10 A bar graph showing the in vitro toxicity test results corresponding to embodiment S2 of the present invention is presented. Wherein, as... Figure 10 The results show the activity assessment of K7M2 mouse osteosarcoma cells after co-incubation with different concentrations (0 μg / mL, 50 μg / mL, 100 μg / mL, 200 μg / mL, 400 μg / mL) of S2 samples for 24 hours. The results indicate that WVM-0.5 (S2) possesses excellent sonodynamic properties and is expected to enable highly efficient sonodynamic therapy for osteosarcoma. Therefore, we evaluated its ability to inhibit K7M2 cell growth. First, the relative toxicity of S2 itself to K7M2 cells was assessed using the CCK8 assay. Figure 10 As shown in A), co-incubation with S2 at concentrations below 200 μg / mL did not produce a significant anti-tumor effect. When the concentration increased to 400 μg / mL, the activity of tumor cells remained above 70%, thus ruling out the possibility that S2 itself was biotoxic and could kill the cells.

[0115] refer to Figure 11 and Figure 12 , Figure 11 This diagram illustrates photothermal-enhanced acoustic dynamics therapy during in vitro antitumor treatment, corresponding to Embodiment S2 of this application. Figure 12 The results of K7M2 cell activity evaluation under different treatments corresponding to Example S2 of this application are shown.

[0116] like Figure 11As shown, S2 activated by NIR-II laser has stronger acoustic dynamic performance, and the temperature rise generated by photothermal effect also has a killing effect on tumor cells, thus achieving a therapeutic effect of 1+1>2.

[0117] Next, we evaluated the relative viability of K7M2 cells under different treatments (including I: control, II: light only, III: US only, IV: WVM only, V: WVM + light, VI: WVM + US, VII: WVM + light + US) using the standard CCK8 assay. Figure 12 Compared with the control group, cell activity in groups II-IV was almost unaffected, while cell activity in groups V and VI decreased significantly, with tumor cell inhibition rates of approximately 35% and 40%, respectively. This demonstrates that both light and ultrasound irradiation of S2 have certain anti-tumor effects. When light and ultrasound are used in combination, tumor cell activity further decreases, with an inhibition rate exceeding 85%, which is greater than the arithmetic sum of groups V and VI. This directly illustrates that photothermal therapy further enhances the acoustic therapeutic effect.

[0118] refer to Figure 13 , Figure 13 This embodiment of the invention illustrates confocal observation of the live / dead staining of K7M2 tumor cells after different treatments. For example... Figure 13 As shown, similar to the CCK8 test results, almost all cells in groups I-IV emitted green fluorescence, while a small number of cells in groups V and VI emitted red fluorescence, indicating that laser or ultrasound stimulation of VWM alone can have a certain impact on the activity of tumor cells. When laser and ultrasound are present simultaneously, a large number of cells in group VII emitted red fluorescence, indicating a significant enhancement in anti-tumor effect.

[0119] The following description, in conjunction with the accompanying drawings, explains the in vitro osteogenic performance evaluation of S2.

[0120] refer to Figure 14 , Figure 14 The diagram shows the in vitro osteogenic performance evaluation of embodiment S2 and the comparative product of the present invention. Figure 14 A in the image represents the alkaline phosphatase (ALP) staining of rat bone marrow mesenchymal stem cells. Figure 14 B in the image represents the Alizarin Red S (ARS) staining of rat bone marrow mesenchymal stem cells.

[0121] like Figure 14 As shown, the differentiation of rat bone marrow mesenchymal stem cells co-incubated with S2 was evaluated using ALP and ARS staining techniques in the US irradiation and non-irradiation groups. Figure 14 A and Figure 14 As shown in Figure B, there was no significant difference between the US group and the control group, indicating that US alone (1.0 MHz, 0.2 W / cm²) was not significantly different from the control group.2 Stimulation with 50% duty cycle (S2) did not significantly promote rBMSC differentiation. However, we found that S2 significantly promoted rBMSC differentiation regardless of whether the control group received ultrasound irradiation. Furthermore, WVMs receiving ultrasound irradiation showed superior efficacy in promoting rBMSC differentiation.

[0122] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multifunctional biomaterial, characterized in that, include: Biocompatible polymer matrix; and, A sound-sensitizing agent complex dispersed in the biocompatible polymer matrix; The acoustic sensitizer complex comprises a metal-insulator phase change material and a two-dimensional material. The metal-insulator phase change material and the two-dimensional material form a heterostructure. When the metal-insulator phase change material is heated above the phase change temperature, it undergoes a phase change to alter the band structure and built-in electric field of the heterostructure.

2. The multifunctional biomaterial according to claim 1, characterized in that, The metal-insulator phase change material includes doped vanadium dioxide, wherein the doping element is selected from at least one of tungsten, aluminum, molybdenum, chromium, and niobium.

3. The multifunctional biomaterial according to claim 2, characterized in that, The doped vanadium dioxide is tungsten-doped vanadium dioxide.

4. The multifunctional biomaterial according to claim 1, characterized in that, The two-dimensional material includes MXene material, which is selected from at least one of Nb2C, Ti3C2 and Mo2C.

5. The multifunctional biomaterial according to claim 1, characterized in that, The mass ratio of the metal-insulator phase change material to the two-dimensional material in the acoustic sensitizer composite is (0.2-1):

1.

6. The multifunctional biomaterial according to claim 1, characterized in that, The metal-insulator phase change material is heated to a temperature above its phase change temperature by thermal stimulation, and a phase change occurs.

7. The multifunctional biomaterial according to claim 1, characterized in that, The biocompatible polymer matrix includes at least one of methacryloyl gelatin, collagen, chitosan, bioactive glass, polylactic acid-glycolic acid copolymer, and alginate.

8. A method for preparing a multifunctional biomaterial, characterized in that, include: Provides metal-insulator phase change materials and two-dimensional materials; The metal-insulator phase change material and the two-dimensional material are formed into a heterostructure by self-assembly technology; The heterostructure is mixed with a biocompatible polymer; The biocompatible polymer is solidified to form the multifunctional biomaterial.

9. The method according to claim 8, characterized in that, The metal-insulator phase change material and the two-dimensional material are formed into a heterostructure using self-assembly technology, including: The surface of the metal-insulator phase change material is modified using a cationic surfactant to make it positively charged; Surface-modified metal-insulator phase change materials are mixed with negatively charged two-dimensional material dispersions and assembled by Coulomb attraction. The assembled material is dried and annealed to obtain the heterostructure.

10. The application of a multifunctional biomaterial in the preparation of medical devices for treating osteosarcoma and promoting bone regeneration, characterized in that, The multifunctional biomaterial is the multifunctional biomaterial according to any one of claims 1-7.

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