Three-dimensional printing photo-thermal immune scaffold for postoperative treatment and repair of skin melanoma and preparation method of three-dimensional printing photo-thermal immune scaffold

Abstract

The invention discloses a three-dimensional printing photo-thermal immune scaffold for postoperative treatment and repair of skin melanoma and a preparation method of the three-dimensional printing photo-thermal immune scaffold. The preparation method comprises the following steps: S1, preparing manganese silicate nanospheres loaded with an immunologic adjuvant; and S2, mixing the composite nanoparticles obtained in the step S1 with a photo-crosslinking hydrogel precursor solution, a calcium ion source and a photoinitiator to obtain an internal phase slurry, and preparing a sodium alginate aqueous solution as an external phase slurry. According to the invention, a photo-thermal therapeutic agent (manganese silicate), an immunologic adjuvant (imiquimod) and a tissue regeneration promoting factor (manganese and silicon ions) are integrated on a three-dimensional scaffold platform for the first time, and through a precise preparation method, space-time synergy and function integration of local ablation-system immunity-tissue repair are realized.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials and tissue engineering technology, and particularly relates to a three-dimensional printed photothermal immune scaffold for postoperative treatment and repair of skin melanoma and its preparation method. Background Technology

[0002] Cutaneous melanoma is one of the most aggressive and deadliest malignant skin tumors, characterized by rapid progression, easy metastasis, and poor prognosis. Despite advancements in surgical resection, chemotherapy, and immunotherapy, the 5-year survival rate for advanced-stage patients remains unsatisfactory, primarily due to the high incidence of local recurrence and distant metastasis after surgery. Currently, surgery is the main treatment for localized melanoma, but it faces two key challenges: first, incomplete resection and recurrence caused by intraoperative dissemination of circulating tumor cells, a significant cause of melanoma-related mortality; second, extensive resection to ensure negative margins often results in large areas of skin defects, exceeding the body's self-repair capacity, easily leading to delayed healing, functional impairment, and various postoperative complications. Furthermore, the immunosuppressive tumor microenvironment of melanoma further restricts treatment efficacy, hindering the activation and function of anti-tumor immune cells, weakening the response to immunotherapy, and accelerating tumor progression and metastasis.

[0003] Tissue-engineered three-dimensional scaffolds provide a multifunctional platform for tissue repair, offering structural support, promoting cell adhesion and proliferation, and delivering bioactive components that promote angiogenesis and regulate extracellular matrix remodeling. Integrating photothermal agents into the scaffold allows for localized hyperthermia using near-infrared light, effectively eliminating residual tumor cells while minimizing damage to normal tissues. However, current research on photothermal scaffolds largely focuses on local tumor ablation, often neglecting the crucial role of systemic immune regulation in preventing metastasis and long-term recurrence.

[0004] Immunotherapy, as an adjuvant or neoadjuvant therapy, has shown clinical improvement potential in resectable melanoma; however, its response is heterogeneous, and recurrence remains a problem. Photothermal immunotherapy, by synergistically combining photothermal tumor killing and immune activation, holds significant promise for transforming local therapeutic effects into systemic anti-tumor immune protection. However, the clinical translation of this strategy still faces limitations such as insufficient immune stimulation and poor biocompatibility of photothermal materials.

[0005] Therefore, there is an urgent need to develop a comprehensive postoperative strategy that can simultaneously achieve residual tumor clearance, tumor immunosuppression reversal, recurrence and metastasis prevention, and wound tissue regeneration. Constructing a multifunctional biomaterial platform that can be controlled in real-time and integrates photothermal therapy, immune activation, and tissue repair functions is of great significance for improving the postoperative efficacy of melanoma surgery. Summary of the Invention

[0006] The purpose of this invention is to provide a three-dimensional printed photothermal immune scaffold for postoperative treatment and repair of skin melanoma and its preparation method, so as to solve the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the specific technical solution of the present invention is as follows: A method for preparing a three-dimensional printed photothermal immunoscaffold for postoperative treatment and repair of skin melanoma, comprising the following steps:

[0008] S1. Preparation of manganese silicate nanospheres loaded with immune adjuvants;

[0009] S2. Mix the composite nanoparticles obtained in step S1 with the photocrosslinking hydrogel precursor solution, calcium ion source and photoinitiator to make the inner phase slurry, and prepare sodium alginate aqueous solution as the outer phase slurry.

[0010] S3. Using a coaxial microfluidic 3D printing device, the inner phase slurry and the outer phase slurry are extruded simultaneously. During and after extrusion, the slurry is stacked layer by layer according to the preset 3D model through a dual curing mechanism of calcium ion crosslinking and ultraviolet light irradiation to form a 3D porous scaffold.

[0011] Preferably, in step S1, the manganese silicate nanospheres have a porous structure and are prepared by thermal reaction of manganese salt with mesoporous silica as a template and calcination; the immunoadjuvant is imiquimod.

[0012] Preferably, in step S2, the photocrosslinked hydrogel precursor is methacrylamide hyaluronic acid.

[0013] Preferably, in step S3, the core-shell structure size of the printed fiber is controlled by adjusting the flow rate ratio of the inner phase slurry to the outer phase slurry based on the coaxial microfluidic device.

[0014] Preferably, in step S3, the macroscopic three-dimensional structure, porosity, and pore size of the support are controlled by changing the three-dimensional printing path program.

[0015] The present invention also relates to a three-dimensional printed photothermal immune scaffold, the scaffold being a three-dimensional porous network composed of interwoven hydrogel fibers containing manganese silicate nanospheres loaded with immune adjuvants, the hydrogel fibers having a core-shell structure formed by coaxial microfluidic printing.

[0016] Preferably, the stent can generate a photothermal effect when irradiated with near-infrared light, and can controllably release manganese ions and the immune adjuvant under the stimulation of near-infrared light and an acidic microenvironment.

[0017] This invention also relates to the application of three-dimensional printed photothermal immune scaffolds in the preparation of products for postoperative treatment of cutaneous melanoma. The treatment includes inhibiting local tumor recurrence and / or distant metastasis. The mechanism of action is as follows: after the scaffold is implanted into the wound, the photothermal effect is triggered by near-infrared light irradiation to ablate residual tumor cells. At the same time, under the dual stimulation of photothermal and acidic tumor microenvironment, the controllable release of manganese ions can activate immune pathways such as cGAS-STING, and the released immune adjuvants can promote the maturation of immune cells such as dendritic cells, thereby synergistically stimulating a strong systemic anti-tumor immune response.

[0018] This invention also relates to the application of three-dimensional printed photothermal immune scaffolds in the preparation of products for promoting skin wound repair, wherein the repair is achieved by promoting angiogenesis and collagen deposition through the continuous release of bioactive ions (such as manganese ions and silicon ions) by the degradation of the scaffold, thereby accelerating wound healing and tissue function reconstruction.

[0019] This invention also relates to a three-dimensional printed photothermal immune scaffold for postoperative treatment and repair of skin melanoma, which is prepared using the preparation method described in any one of the preceding claims.

[0020] The three-dimensional printed photothermal immune scaffold for postoperative treatment and repair of cutaneous melanoma, and its preparation method, of the present invention have the following advantages:

[0021] 1. This invention is the first to integrate photothermal therapy agent (manganese silicate), immune adjuvant (imiquimod), and tissue regeneration promoting factors (manganese and silicon ions) into a three-dimensional scaffold platform. Through a precise preparation method, it achieves spatiotemporal synergy and functional integration of "local ablation-systemic immunity-tissue repair".

[0022] 2. This invention employs coaxial microfluidic 3D printing technology, combined with a dual curing mechanism of calcium ion crosslinking and ultraviolet light crosslinking, which not only enables the controllable preparation of the macroscopic shape and internal pore structure of the scaffold, but also endows the hydrogel fiber with a unique core-shell structure, which is beneficial to the spatial distribution and controllable release of functional components.

[0023] 3. This stent possesses dual response characteristics to near-infrared light and microenvironment pH. During the postoperative treatment phase, external near-infrared light irradiation and the acidic microenvironment at the tumor site can precisely trigger the rapid release of immune adjuvants and manganese ions to activate immunity; during the tissue repair phase, the stent slowly degrades and continuously releases bioactive ions, promoting long-term healing.

[0024] 4. This invention overcomes the limitations of traditional materials with their single function, and simultaneously solves the two major clinical problems of postoperative tumor control and tissue repair in one implant, significantly improving the comprehensive treatment effect after melanoma surgery, and has extremely high clinical translational value and application prospects. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram illustrating the preparation process and mechanism of action of the three-dimensional printed photothermal immune scaffold of the present invention.

[0027] Figure 2 The images show the morphology and phase characterization of the manganese silicate nanospheres prepared in Example 1.

[0028] Figure 3 Macroscopic photographs and core-shell structure diagrams of the scaffold prepared in Example 2.

[0029] Figure 4 The image shows the photothermal heating effect of the stent prepared in Example 2 under near-infrared light irradiation.

[0030] Figure 5 The drug and ion release curves of the scaffold prepared in Example 2 under different pH conditions and near-infrared light irradiation are shown.

[0031] Figure 6 This is a graph showing the results of photothermal antitumor therapy and immune activation of the scaffold in in vitro experiments.

[0032] Figure 7 This image shows the effect of photothermal immunosuppression of in situ tumor recurrence and metastasis by the scaffold in in vivo animal experiments.

[0033] Figure 8 This study analyzed the tumor immune response in each experimental group during in vivo animal experiments. Detailed Implementation

[0034] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0035] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.

[0038] The following disclosure provides many different implementations or examples for carrying out different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0039] To better understand the purpose, structure, and function of this invention, the following description, in conjunction with the accompanying drawings, provides a more detailed account of a three-dimensional printed photothermal immune scaffold for postoperative treatment and repair of skin melanoma and its preparation method.

[0040] Example 1. Preparation of manganese silicate (IMQ@MS) nanospheres loaded with imiquimod.

[0041] This invention utilizes microfluidic 3D printing to fabricate photothermal immune functional scaffolds, such as... Figure 1 As shown, the specific preparation process is as follows:

[0042] 1. Preparation of porous manganese silicate (MS) nanospheres:

[0043] 1) Weigh 25 mg of mesoporous silica nanospheres (MSN) with an average particle size of about 100 nm and 25 mg of manganese acetate tetrahydrate (Mn(CH3COO)2·4H2O), and add them to 40 mL of deionized water.

[0044] 2) Place the above mixture on a magnetic stirrer and stir at room temperature for 30 minutes to ensure thorough dispersion.

[0045] 3) Transfer the dispersion to a 50 mL stainless steel high-pressure reactor lined with polytetrafluoroethylene, seal it, and place it in an oven for hydrothermal reaction at 140°C for 24 hours.

[0046] 4) After the reaction is complete, allow the mixture to cool naturally to room temperature. Collect the product by centrifugation (10,000 rpm, 5 minutes) and wash it three times each with deionized water and anhydrous ethanol.

[0047] 5) Place the washed precipitate in a vacuum drying oven and dry at 60°C for 12 hours.

[0048] 6) Transfer the dried powder to a crucible, place it in a muffle furnace, raise the temperature to 600°C at a rate of 2°C / min, maintain the temperature for 6 hours for calcination, and cool it to room temperature with the furnace to obtain manganese silicate (MS) nanospheres.

[0049] 2. Imiquimod loading:

[0050] 1) Accurately weigh 5 mg of MS nanospheres and add them to 1 mL of dimethyl sulfoxide (DMSO) solution, which contains 2.5 mg of imiquimod (IMQ).

[0051] 2) Place the mixed solution in an ice-water bath and use an ultrasonic cell disruptor at 100 W power for 2 hours to ensure that IMQ is fully dispersed into the pores of the MS nanospheres.

[0052] 3) After ultrasonic treatment, centrifuge the solution at 10,000 rpm for 10 minutes and collect the precipitate.

[0053] 4) Wash the precipitate twice with phosphate buffered saline (PBS, pH 7.4) to remove the drug physically adsorbed on the surface.

[0054] 5) Freeze-dry the washed product for 24 hours to obtain IMQ@MS nanosphere powder.

[0055] 3. Material Characterization

[0056] 1) Transmission electron microscopy observation: A small amount of IMQ@MS nanospheres were dispersed in ethanol, dropped onto a copper grid, dried, and then observed using a transmission electron microscope. Figure 2 As shown in A and B, the nanospheres exhibit a uniform spherical structure with an average particle size of approximately 150 nm and obvious porous characteristics.

[0057] 2) Elemental analysis: Analysis using energy-dispersive X-ray spectroscopy (EDS) mapping ( Figure 2CF shows that manganese (Mn), silicon (Si), and oxygen (O) elements are uniformly distributed in the nanoparticles.

[0058] 3) Drug loading determination: The concentration of IMQ in the supernatant was determined by ultraviolet-visible spectrophotometry, and the drug loading rate was calculated.

[0059] 4) X-ray diffraction analysis: XRD pattern ( Figure 2 G) shows that the characteristic diffraction peaks match the standard card (JCPDS #41-1367), confirming the successful synthesis of the manganese silicate crystal structure.

[0060] 5) X-ray photoelectron spectroscopy analysis: XPS high-resolution Mn 2p spectrum ( Figure 2 H) shows that the atomic ratio of Mn(+3) / Mn(+2) is approximately 3.4.

[0061] Example 2. Fabrication of a 3D Printed Photothermal Immunosorbent Asher

[0062] 1. Printing ink preparation:

[0063] 1) Internal phase ink: The IMQ@MS nanoparticles prepared in Example 1 were dispersed at a concentration of 1.0 mg / mL in a PBS solution containing 4% (w / v) methacrylamide hyaluronic acid, 0.16% CaCl2 and 0.1% LAP photoinitiator. After thorough mixing, the mixture was stored in the dark.

[0064] 2) External phase ink: Weigh 25 mg of sodium alginate and dissolve it in 1 mL of deionized water to prepare a 2.5% (w / v) solution. Stir at room temperature until completely dissolved.

[0065] 2. Microfluidic printing device setup:

[0066] 1) Assemble the microfluidic printhead using coaxial glass capillaries (inner diameter: inner tube approximately 100 μm, outer tube approximately 500 μm).

[0067] 2) Inject the internal and external phase inks into 5 mL syringes and attach them to the dual-channel injection pump.

[0068] 3) Synchronize the motion control system with the injection pump to achieve precise coordination between hydrogel fiber extrusion and printhead movement.

[0069] 3. Bracket printing

[0070] 1) Set the internal phase flow rate to 1.0 mL / h and the external phase flow rate to 1.5 mL / h (flow rate ratio 1:1.5), and print the grid structure layer by layer on the receiving plate with a layer height of 0.5 mm, a line width of 0.5 mm, and a 90° staggered angle.

[0071] 2) During the printing process, the external phase sodium alginate reacts with Ca... 2+ Upon contact, an ionic cross-linked shell is formed immediately.

[0072] 3) After printing, the scaffold was transferred to a 2% CaCl2 solution and continuously irradiated with ultraviolet light for 30 minutes to induce photocrosslinking of the internal phase HAMA. It was then further immersed in the CaCl2 solution for 24 hours to enhance crosslinking.

[0073] 4) Finally, a three-dimensional porous scaffold with dimensions of 10×10×2 mm was obtained. Figure 3 ).

[0074] 4. Stent performance characterization

[0075] 1) Photothermal performance test: Scaffolds with different nanoparticle contents (0-2.5 mg / mL) were vertically irradiated for 5 minutes using an 808 nm near-infrared laser (power density 0.7-1.0 W / cm²), and the surface temperature change of the scaffolds was recorded in real time using an infrared thermal imager. Results ( Figure 4 The results showed that the MS-HF scaffold rapidly increased in temperature to ~45 °C within 5 minutes, while the HF scaffold without MS nanoparticles showed only a negligible temperature rise (~26 °C). Figure 4 A, B). These findings confirm that the incorporation of MS nanoparticles endows the MS-HF scaffold with strong photothermal conversion capabilities. Furthermore, the maximum photothermal temperature can be further increased by increasing the MS content or laser power density. Figure 4 C,D).

[0076] 2) Drug release performance: The stent was placed in PBS with different pH values ​​(pH 7.4, 6.5, 5.6) and shaken at 37℃ (100 rpm). Three parallel samples were set up for each group, and the IMQ concentration was measured at predetermined time points. The results showed ( Figure 5 A): Under physiological pH (7.4), IMQ release is slow and sustained, but significantly accelerated under acidic conditions (pH 5.6 and 6.5). Furthermore, short-duration NIR irradiation can induce a burst of IMQ release, indicating that drug release can be precisely regulated by microenvironmental acidity and external photothermal stimulation.

[0077] 3) Ion release behavior: The release of Mn and Si ions was determined by ICP-OES ( Figure 5 (B, C). NIR irradiation has minimal effect on the release of Mn and Si ions. Instead, pH is the dominant factor: Mn release is significantly accelerated under acidic conditions compared to neutral pH, while Si release shows no significant difference across different pH values.

[0078] Example 3. Evaluation of antitumor and immune activation effects in vitro and in vivo

[0079] 1. Evaluation of in vitro photothermal killing effect:

[0080] 1) Mouse melanoma cells B16F10 were injected at a rate of 5 × 10⁻⁶. 4 Cells / wells were seeded in 24-well plates, and scaffolds (HF, MS-HF, IMQ@MS-HF) were placed in Transwell chambers for co-culture with the cells.

[0081] 2) The experimental group was irradiated with NIR (808 nm, 0.8 W / cm², 15 minutes), while the control group was not irradiated.

[0082] 3) After irradiation, continue culturing for 24 hours, and evaluate cell viability using Calcein-AM / PI staining.

[0083] 4) Results ( Figure 6 (A, B) shows that under NIR irradiation (808 nm, 0.80 W / cm², 15 min), MS-containing scaffolds generated localized hyperthermia, leading to a significant decrease in cell viability in the MS-HF+NIR (23.8 ± 1.2%) and IMQ@MS-HF+NIR (22.2 ± 2.4%) groups. In contrast, scaffolds untreated with NIR irradiation or without MS nanoparticles showed negligible cytotoxicity, with cell viability similar to the untreated control group (~100%), confirming that MS-mediated photothermal heating was crucial for the observed antitumor effect.

[0084] 2. Evaluation of in vitro immune activation effect:

[0085] 1) Establishment of Transwell co-culture system: Mouse dendritic cells DC2.4 (1×10⁴) were inoculated in the lower chamber. 5 cells / well), upper chamber seeded with B16F10 cells (5 × 10⁶ cells / well), 4 (cells / wells) and place a support.

[0086] 2) After irradiating B16F10 cells with NIR, they were co-cultured for another 48 hours.

[0087] 3) DC2.4 cells were collected, and the expression of surface markers was detected by flow cytometry. We found that the expression levels of co-stimulatory molecules CD80 and CD86 on DCs in the IMQ@MS-HF+NIR group were significantly higher than those in other scaffold treatment groups, indicating that the proportion of mature DCs was the highest. Figure 6 C). Compared with unirradiated MS-HF and blank control, MS-HF+NIR also significantly promoted DC activation.

[0088] 4) ELISA detection of cytokines in supernatant ( Figure 6(D,E): Compared with other treatments, the levels of pro-inflammatory cytokines IL-6 and TNF-α in the supernatant of the IMQ@MS-HF+NIR group were significantly increased. These findings suggest that the IMQ@MS-HF scaffold promotes DC maturation and cytokine secretion through the synergistic effect of immunogenic tumor cell death and innate immune activation mediated by Mn ion and IMQ release.

[0089] 3. Postoperative management of melanoma in vivo

[0090] 1) Animal model establishment: Using 6-8 week old male C57BL / 6 mice (18-22 g), B16F10 cell suspension (1×10⁻⁶) was subcutaneously injected into the back of the mice. 6 (cells / 100 µL). When the tumor volume reaches 100 mm³ (approximately 7 days after tumor implantation), a simulated surgical resection is performed, removing approximately 90% of the tumor tissue and creating a full-thickness skin defect with a diameter of 10 mm.

[0091] 2) Experimental grouping and treatment: Mice were randomly divided into 6 groups (n=8):

[0092] ①Control group: Blank wound

[0093] ②HF group: implantation of pure hydrogel scaffold

[0094] ③MS-HF group: implantation of a stent containing MS but not IMQ

[0095] ④MS-HF + NIR group: MS-HF stent implantation + NIR irradiation 3 days postoperatively

[0096] ⑤IMQ@MS-HF group: Implantation of IMQ@MS-HF stent (no irradiation)

[0097] ⑥IMQ@MS-HF + NIR group: IMQ@MS-HF stent implantation + NIR irradiation 3 days postoperatively.

[0098] 3) Postoperative management and observation: After stent implantation, a transparent dressing was used for fixation. The NIR irradiation group received irradiation on postoperative days 0, 1, and 2 (808 nm, 0.8 W / cm², 15 minutes / day). Tumor volume was measured every 3 days postoperatively, and the wound site was photographed. Figure 7 A) Plot the tumor growth curve. On day 15, sacrifice the animals and collect tumor tissue, wound skin, and lung tissue.

[0099] 4. Analysis of the efficacy of photothermal immunotherapy for tumors in vivo

[0100] 1) Tumor recurrence inhibition ( Figure 7B): Tumors treated with NIR-irradiated MS scaffolds (MS-HF+NIR and IMQ@MS-HF+NIR) showed significant growth inhibition during the first three days of irradiation and no subsequent recurrence. Control group tumors, however, continued to grow. Furthermore, NIR-irradiated MS scaffolds accelerated wound healing, while control group wounds remained associated with abundant melanoma-like tissue.

[0101] 2) Distant metastasis inhibition ( Figure 7 C): H&E staining of lung tissue showed that lung metastases were significantly reduced in the IMQ@MS-HF+NIR group, manifested as a reduction in lung nodules and a decrease in tissue damage.

[0102] 3) Immune response analysis Figure 8 Flow cytometry analysis of tumor-infiltrating lymphocytes showed that elevated levels of pro-inflammatory cytokines (IL-6, TNF-α, IFN-γ, and IL-12p70) in the inguinal lymph nodes of mice in the IMQ@MS-HF + NIR group supported this systemic antitumor effect, reflecting downstream consequences of DC maturation and T cell initiation induced by photothermal-induced immunogenic cell death (ICD). In summary, these responses promoted cytotoxic T cell activity, contributing to the suppression of tumor recurrence and metastasis.

[0103] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A method for preparing a three-dimensional printed photothermal immunoscaffold for postoperative treatment and repair of cutaneous melanoma, characterized in that: Includes the following steps: S1. Preparation of manganese silicate nanospheres loaded with immune adjuvants; S2. Mix the composite nanoparticles obtained in step S1 with the photocrosslinking hydrogel precursor solution, calcium ion source and photoinitiator to make the inner phase slurry, and prepare sodium alginate aqueous solution as the outer phase slurry. S3. Using a coaxial microfluidic 3D printing device, the inner phase slurry and the outer phase slurry are extruded simultaneously. During and after extrusion, the slurry is stacked layer by layer according to the preset 3D model through a dual curing mechanism of calcium ion crosslinking and ultraviolet light irradiation to form a 3D porous scaffold.

2. The method for preparing a three-dimensional printed photothermal immunoscaffold for postoperative treatment and repair of cutaneous melanoma according to claim 1, characterized in that: In step S1, the manganese silicate nanospheres have a porous structure and are prepared by thermal reaction of manganese salt with mesoporous silica as a template and calcination; the immunoadjuvant is imiquimod.

3. The method for preparing a three-dimensional printed photothermal immune scaffold for postoperative treatment and repair of cutaneous melanoma according to claim 1, characterized in that: In step S2, the photocrosslinked hydrogel precursor is methacrylamide hyaluronic acid.

4. The method for preparing a three-dimensional printed photothermal immune scaffold for postoperative treatment and repair of cutaneous melanoma according to claim 1, characterized in that: In step S3, based on the coaxial microfluidic device, the core-shell structure size of the printed fiber is controlled by adjusting the flow rate ratio of the inner phase slurry to the outer phase slurry.

5. The method for preparing a three-dimensional printed photothermal immunoscaffold for postoperative treatment and repair of cutaneous melanoma according to claim 1, characterized in that: In step S3, the macroscopic three-dimensional structure, porosity, and pore size of the scaffold are controlled by changing the three-dimensional printing path program.

6. A three-dimensional printed photothermal immunoscaffold prepared by the method according to any one of claims 1-5, characterized in that: The scaffold is composed of a three-dimensional porous network of hydrogel fibers containing manganese silicate nanospheres loaded with immune adjuvants, the hydrogel fibers having a core-shell structure formed by coaxial microfluidic printing.

7. The three-dimensional printed photothermal immunoscaffold according to claim 6, characterized in that: The stent can generate a photothermal effect when irradiated with near-infrared light, and can controllably release manganese ions and the immune adjuvant under the stimulation of near-infrared light and an acidic microenvironment.

8. The application of the three-dimensional printed photothermal immunoscaffold according to claim 6 or 7 in the preparation of products for postoperative treatment of cutaneous melanoma, characterized in that: The treatment includes suppressing local tumor recurrence and / or distant metastasis.

9. The application of the three-dimensional printed photothermal immunoscaffold according to claim 6 or 7 in the preparation of products for promoting skin wound repair, characterized in that, The repair is achieved through the continuous release of bioactive ions from the degradation of the stent, which promotes angiogenesis and collagen deposition.

10. A three-dimensional printed photothermal immunoscaffold for postoperative treatment and repair of skin melanoma, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.

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