A photothermal-chemotherapy synergistic double-crosslinked drug-loaded hydrogel and a preparation method and application thereof

Abstract

This invention belongs to the field of pharmaceutical technology, and particularly relates to a photothermal-chemotherapy synergistic dual-crosslinked drug-loaded hydrogel, its preparation method, and its application. Compared with the prior art, the photothermal-chemotherapy synergistic dual-crosslinked drug-loaded hydrogel provided by this invention has a dual-crosslinked network that enhances the mechanical stability and drug sustained-release performance of the hydrogel; furthermore, under near-infrared light irradiation, the coordination complex generates local heat, which can be used for direct thermotherapy and can also precisely trigger the release of chemotherapeutic drugs from thermosensitive liposomes at their phase transition temperature, thereby synergistically eliminating residual tumor cells after surgery; in addition, it also provides an effective postoperative treatment option for high-risk patients through the synergistic effects of photothermal antibacterial, chemotherapeutic antitumor, and healing-promoting functions.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology, and particularly relates to a photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel, its preparation method and application. Background Technology

[0002] Melanoma is the most malignant skin tumor, and surgical excision is the preferred clinical treatment. However, the postoperative local recurrence rate remains high, and the surgical wound often faces the risk of bacterial infection. The inflammatory microenvironment caused by infection further promotes tumor cell proliferation and invasion, and the combined effect makes postoperative treatment particularly challenging. Of particular concern is the case for melanoma patients with diabetes, whose postoperative treatment is even more difficult. The wound microenvironment in diabetic patients is characterized by high glucose levels, susceptibility to infection, microcirculatory disturbances, and delayed healing. The incidence of postoperative wound infection is significantly higher in diabetic patients than in non-diabetic patients, and once infection occurs, it is more difficult to control, further exacerbating the risk of local recurrence. Clinical treatment faces a vicious cycle of "infection-non-healing-recurrence." Therefore, there is an urgent need to develop a multifunctional hydrogel formulation that combines anti-tumor, anti-infection, and healing-promoting functions to address the postoperative treatment needs of these special patients.

[0003] Existing literature reports researchers have attempted to use hydrogels as postoperative local drug delivery carriers for local treatment via peritumoral injection or wound coverage, but the following problems remain: 1) Single-crosslinked network hydrogels lack sufficient mechanical strength and degrade too quickly in the physiological environment, making it difficult to maintain effective drug concentration and structural integrity postoperatively; 2) Existing photothermal hydrogels mostly disperse photothermal agents directly in the gel matrix, and the local heat generated is only used for thermotherapy itself, failing to convert the heat signal into a "trigger switch" for drug release, resulting in a temporal and spatial disconnect between photothermal therapy and chemotherapy, failing to achieve true synergistic effects; 3) Some protocols carry... Drug nanoparticles are combined with hydrogels to achieve sustained release, but the drug release behavior lacks active regulation and is still a passive diffusion-type drug release, making it difficult to achieve pulsed high-concentration release at the tumor site; 4) Although some existing systems mention antibacterial function, most schemes fail to organically integrate the three functions of anti-tumor, anti-infection and healing promotion into the same system, making it difficult to meet the multiple treatment needs of the complex microenvironment after melanoma surgery; 5) Existing schemes are mostly designed based on ordinary physiological conditions and have not been specifically optimized for the special microenvironment (high sugar, easy infection, slow healing) of patients with underlying diseases such as diabetes, and cannot meet the postoperative treatment needs of this high-risk group.

[0004] For example, Chinese patent application number CN202310227787.4 discloses a polyaniline-based photothermal framework hydrogel. This hydrogel is obtained by in-situ polymerizing aniline onto sulfonated chitosan and then dynamically cross-linking it with a protocatechuic aldehyde-iron chelate, resulting in a hydrogel possessing both photothermal conversion properties and antibacterial activity, suitable for postoperative wound management in melanoma surgery. Furthermore, Chinese patent application number CN202610170839.2 discloses a synergistic treatment of melanoma using an oridonin-magnesium ion composite gel formulation, its preparation method, and its application in the preparation of postoperative adjuvant therapy drugs for melanoma. This formulation co-loads oridonin and magnesium ions into a carboxymethyl chitosan-sodium alginate composite hydrogel, achieving continuous and controllable release of synergistic active ingredients through a three-dimensional hydrogel network, suitable for postoperative adjuvant therapy in melanoma surgery. A further approach is to combine temperature-sensitive liposomes with hydrogels. For example, Chinese patent CN115887381A discloses a temperature-sensitive liposome hydrogel for targeted and controllable release of drugs, its preparation method and application. It combines liposome emulsion with polysaccharide-polyvinyl alcohol physically crosslinked hydrogel to achieve a high drug release at 42°C.

[0005] Chinese patent CN119770413A discloses a pH / GSH programmed responsive photothermal nanocomposite hydrogel co-loaded drug system. This scheme embeds hyaluronic acid-encapsulated GSH-responsive drug-loaded nanoparticles and indocyanine green into a pH-sensitive chitosan hydrogel. It utilizes the photothermal effect of indocyanine green under near-infrared light irradiation for thermal ablation, while the drug-loaded nanoparticles release chemotherapeutic drugs in response to high concentrations of GSH in tumor cells, achieving synergistic chemotherapy-photothermal therapy. However, it uses indocyanine green as the photothermal agent, which has poor stability in aqueous solution, and its photothermal conversion efficiency has limited matching with the temperature required for tumor hyperthermia. Its drug release depends on the chemical signals (pH, GSH) of the tumor microenvironment, rather than the temperature signal of the hyperthermia itself. Therefore, the timing synergy between photothermal therapy and chemotherapy lacks precise control. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel that can undergo photothermal conversion under near-infrared light irradiation and use the heat to trigger liposome phase transition locally (about 41°C), thereby achieving a "photothermal-chemotherapy" synergistic effect in situ, as well as its preparation method and application.

[0007] This invention provides a photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel, formed by crosslinking a mixture; the mixture includes macromolecules with amino groups, macromolecules with aldehyde groups, coordination complexes, and thermosensitive liposomes; The coordination complex is formed by polyphenolic compounds and transition metal ions; The thermosensitive liposome comprises a phospholipid bilayer and an antitumor drug; the antitumor drug is encapsulated inside the phospholipid bilayer.

[0008] Preferably, the amino-containing macromolecular substance is selected from one or more of gelatin, methacrylamide gelatin, silk fibroin, polyethyleneimine, polylysine, amino-modified hyaluronic acid, and quaternary ammonium chitosan. And / or, the macromolecule with an aldehyde group is selected from one or more of oxidized dextran, aldehyde-modified hyaluronic acid, and aldehyde-modified PF127; And / or, the polyphenolic compound is selected from one or more of protocatechuic aldehyde, tannic acid, protocatechuic acid and epigallocatechin gallate; And / or, the transition metal ion is selected from Fe 3+ Au 3+ With Mn 2+ One or more of the following; And / or, the phospholipid bilayer membrane comprises phospholipids and cholesterol; the phospholipids comprise dipalmitoylphosphatidylcholine; And / or, the antitumor drug is selected from paclitaxel.

[0009] Preferably, the phospholipids further include one or more of hydrogenated soybean phospholipids, distearyl phosphatidylcholine, monopalmitoyl phosphatidylcholine, and PEGylated phospholipid derivatives.

[0010] Preferably, the mass ratio of phospholipids to cholesterol is (3~8):1; And / or, the mass ratio of one or more of the hydrogenated soybean phospholipids, distearyl phosphatidylcholine, monopalmitoyl phosphatidylcholine and PEGylated phospholipid derivatives to distearyl phosphatidylcholine is 1:(2~6).

[0011] Preferably, the mass ratio of the macromolecule with amino groups to the macromolecule with aldehyde groups is (1~3):1.

[0012] Preferably, the mass of the coordination complex is 0.5% to 3% of the mass of the photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel; And / or, the mass of the thermosensitive liposome is 0.0005% to 0.5% of the mass of the photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel.

[0013] Preferably, the particle size of the thermosensitive liposomes is 100~300 nm.

[0014] This invention also provides a method for preparing the above-mentioned photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel, comprising the following steps: The first solution and the second solution are mixed to obtain a photothermal-chemotherapy synergistic dual cross-linked drug-loaded hydrogel; the first solution includes macromolecules with aldehyde groups and coordination complexes; the second solution includes macromolecules with amino groups and thermosensitive liposomes.

[0015] Preferably, the coordination complex is prepared according to the following method: A polyphenol compound is mixed with a metal salt in water, and then the pH is adjusted to alkaline to obtain a coordination complex; the metal salt includes transition metal ions. And / or, the thermosensitive liposomes are prepared according to the following method: A1) Phospholipids, cholesterol, and antitumor drugs are mixed in a solvent, the solvent is removed, and a lipid film is obtained; A2) The lipid film was hydrated with a buffer solution and then sonicated under ice bath conditions to obtain thermosensitive liposomes.

[0016] The present invention also provides the application of the above-mentioned photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel in the preparation of drugs for treating skin tumors.

[0017] Compared with existing technologies, the photothermal-chemotherapy synergistic dual-crosslinked drug-loaded hydrogel provided by this invention has a dual-crosslinked network that enhances the mechanical stability and drug sustained-release performance of the hydrogel. Furthermore, under near-infrared light irradiation, the coordination complex generates local heat, which can directly provide thermotherapy and precisely trigger the release of chemotherapeutic drugs from thermosensitive liposomes at their phase transition temperature, thereby synergistically eliminating residual tumor cells after surgery. In addition, through the synergistic effects of photothermal antibacterial, chemotherapy antitumor, and healing-promoting functions, it provides an effective postoperative treatment option for high-risk patients. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the preparation and application of the photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel provided by the present invention. Figure 2 The infrared spectrum of the oxidized dextran prepared in Example 1 of this invention; Figure 3 The 1H NMR spectrum of the oxidized dextran prepared in Example 1 of this invention; Figure 4 The UV-Vis spectrum of PA (protocatechuic aldehyde)@Fe nanoparticles prepared in Example 1 of this invention; Figure 5 This is a particle size distribution diagram of the DPPC (dispalmitoylphosphatidylcholine)-PTX (paclitaxel) liposomes prepared in Example 1 of the present invention; Figure 6 This is a diagram showing the amount of TPF complex in the hydrogel prepared in Example 1 of the present invention; Figure 7This is a graph showing the adhesive strength test results of the hydrogel prepared in Example 1 of this invention; Figure 8 This is a graph showing the photothermal performance test results of the hydrogel prepared in Example 1 of this invention; Figure 9 This is a graph showing the photothermal performance test results of the hydrogel prepared in Example 1 of this invention embedded in the body surface and subcutaneous tissue of mice; Figure 10 This is a graph showing the antibacterial properties of the hydrogel prepared in Example 1 of this invention; Figure 11 The graph shows the results of testing the healing and antibacterial properties of the hydrogel prepared in Example 1 of this invention on infected skin wounds in mice. Figure 12 This is a diagram illustrating the antitumor effect of the drug-loaded hydrogel prepared in Example 1 of the present invention. Figure 13 This is a diagram showing the in vitro drug release experiment results of the drug-loaded hydrogel prepared in Example 1 of this invention; Figure 14 This is a graph showing the 24-hour CCK-8 cell proliferation inhibition experiment results of the drug-loaded hydrogel prepared in Example 1 of this invention; Figure 15 This is a diagram showing the results of a 24-hour live and dead cell fluorescence staining experiment on the drug-loaded hydrogel prepared in Example 1 of this invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention provides a photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel, formed by crosslinking a mixture; the mixture includes macromolecules with amino groups, macromolecules with aldehyde groups, coordination complexes, and thermosensitive liposomes; the coordination complexes are formed by polyphenolic compounds and transition metal ions; the thermosensitive liposomes include a phospholipid bilayer membrane and an antitumor drug; the antitumor drug is encapsulated inside the phospholipid bilayer membrane.

[0021] This invention achieves in-situ temporal synergy between photothermal and chemotherapy by coupling the photothermal effect of coordination complexes with the thermosensitive drug release function of thermosensitive liposomes. It integrates these effects into a double-crosslinked hydrogel platform formed by macromolecules with amino groups and macromolecules with aldehyde groups, thereby enabling simultaneous thermotherapy and triggered drug release using the same photothermal signal, forming a "one-time irradiation, dual-response" treatment mode.

[0022] In the hydrogel provided by this invention, macromolecules with amino groups and macromolecules with aldehyde groups form a first cross-linking network through Schiff base reaction. The catechol structure of the polyphenol compound and its aldehyde group participate in transition metal ion coordination cross-linking and Schiff base cross-linking, respectively, to form a second cross-linking network.

[0023] In one specific embodiment of the present invention, the amino-containing macromolecule is any amino-containing macromolecule known to those skilled in the art that can crosslink with aldehyde-containing macromolecules to form hydrogels, and there are no special limitations. In the present invention, one or more of gelatin, methacrylamide gelatin, silk fibroin, polyethyleneimine, polylysine, amino-modified hyaluronic acid, and quaternary ammonium salt chitosan are preferred.

[0024] In one specific embodiment of the present invention, the mass content of aldehyde groups in the macromolecule containing aldehyde groups is preferably 30% to 70%; optionally, the mass content of aldehyde groups in the macromolecule containing aldehyde groups is 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 57%, 57.5%, 58%, 60%, 62%, 65%, 68%, 70%, or any two of the above values.

[0025] In one specific embodiment of the present invention, the weight-average molecular weight of the macromolecule containing the aldehyde group is preferably 1 × 10⁻⁶. 4 ~1×10 9 Optionally, the weight-average molecular weight of the dextran is 1×10⁻⁶. 4 5×10 4 1×10 5 5×10 5 1×10 6 5×10 6 1×10 7 1.1×10 7 5×10 7 1×10 8 5×10 8 1×10 9 Or the range between any two of the above values.

[0026] In one specific embodiment of the present invention, the macromolecular substance with aldehyde group is preferably one or more of oxidized dextran, aldehyde-modified hyaluronic acid, and aldehyde-modified PF127.

[0027] In a specific embodiment of the present invention, the macromolecular substance with aldehyde groups is preferably oxidized dextran; the oxidized dextran is preferably formed by reacting dextran with sodium periodate in a solvent; the weight-average molecular weight of the dextran is preferably 1×10⁻⁶. 4 ~1×10 9 Optionally, the weight-average molecular weight of the dextran is 1×10⁻⁶. 4 5×10 4 1×10 5 5×10 5 1×10 6 5×10 6 1×10 7 1.1×10 7 5×10 7 1×10 8 5×10 8 1×10 9 Or any two of the above values; the molar ratio of the dextran to sodium periodate is preferably 1:(1.2~2), more preferably 1:(1.2~1.8), and even more preferably 1:1.5; the solvent is preferably water; the reaction is preferably carried out under light-protected conditions; the reaction time is preferably 15~30 min, more preferably 20~30 min, and even more preferably 24 h; after the reaction is completed, ethylene glycol is preferably added to terminate the reaction, followed by dialysis and freeze-drying to obtain oxidized dextran; the molecular weight cutoff of the dialysis bag used for dialysis is preferably 3~4 kDa, more preferably 3.2~3.8 kDa, and even more preferably 3.5 kDa; the dialysis is preferably carried out using deionized water, and the dialysis solution is preferably changed every 4~8 h during the dialysis process; the dialysis time is preferably 2~3 days.

[0028] In one specific embodiment of the present invention, the mass ratio of the macromolecule with amino groups to the macromolecule with aldehyde groups is preferably (1~3):1; optionally, the mass ratio of the macromolecule with amino groups to the macromolecule with aldehyde groups is 1:1, 1.5:1, 2:1, 2.5:1, 3:1 or any two of the above ratios.

[0029] In one specific embodiment of the present invention, the polyphenolic compound is any polyphenolic compound known to those skilled in the art that has photothermal conversion activity when forming coordination complexes with permetal ions, and there are no special limitations. Preferably, it contains a catechol structure and / or a pyrogallol structure. Specifically, the polyphenolic compound is one or more of protocatechuic aldehyde (PA), tannic acid, protocatechuic acid and epigallocatechin gallate (EGCG).

[0030] In one specific embodiment of the present invention, the polyphenol compound is preferably protocatechuic aldehyde, which contains both catechol structure (participating in transition metal ion coordination crosslinking) and aldehyde group (participating in Schiff base crosslinking), thus achieving the functional integration of "one agent, two crosslinks".

[0031] In one specific embodiment of the present invention, the transition metal ion is preferably Fe. 3+ Au 3+ With Mn 2 + One or more of them.

[0032] In one specific embodiment of the present invention, the mass of the coordination complex is preferably 0.5% to 3% of the mass of the photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel; optionally, the mass of the coordination complex is 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3% of the mass of the photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel, or a range between any two of the above values.

[0033] In this invention, the thermosensitive liposomes utilize the property of specific phospholipids undergoing membrane phase transitions at a phase transition temperature (Tm) to achieve precise controlled drug release. At normal body temperature, the phospholipid bilayer is in a dense colloidal crystalline state, stably encapsulating the drug. When the local temperature rises to the phase transition temperature, the phospholipid molecules move more rapidly, the membrane structure transforms into a loose liquid crystal state, and permeability increases significantly, thereby triggering rapid drug release.

[0034] In one specific embodiment of the present invention, the particle size of the thermosensitive liposomes is preferably 100~300 nm; optionally, the particle size of the thermosensitive liposomes is 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 280 nm, 300 nm or any two of the above values.

[0035] In this invention, the membrane material of the thermosensitive liposome is a phospholipid bilayer membrane; in a specific embodiment provided by this invention, the phospholipid bilayer membrane preferably includes bilayer phospholipids and cholesterol; the phospholipids include dipalmitoylphosphatidylcholine (DPPC); this invention uses dipalmitoylphosphatidylcholine as the main phospholipid component of the thermosensitive liposome, and its phase transition temperature is about 41°C.

[0036] In one specific embodiment of the present invention, the preferred mass ratio of phospholipids to cholesterol is (3~8):1; optionally, the mass ratio of phospholipids to cholesterol is 3:1, 4:1, 5:1, 6:1, 7:2, 8:1 or any two of the above values.

[0037] In a specific embodiment of the present invention, the phospholipid further includes one or more of hydrogenated soybean phospholipid (HSPC), distearylphosphatidylcholine (DSPC), monopalmitoylphosphatidylcholine (MSPC), and PEGylated phospholipid derivatives; the PEGylated phospholipid derivative is preferably a PEGylated derivative of one or more of hydrogenated soybean phospholipid (HSPC), distearylphosphatidylcholine (DSPC), and monopalmitoylphosphatidylcholine (MSPC), more preferably DSPE-mPEG and / or DSPE-PEG; the PEGylated phospholipid derivative is preferably a PEG1000 phospholipid derivative, mPEG1000 phospholipid derivative, PEG2000 phospholipid derivative, mPEG2000 phospholipid derivative, P One or more of EG3000 phospholipid derivatives and mPEG3000 phospholipid derivatives are used. By heating these phospholipids, the temperature sensitivity and in vivo circulation time of the liposomes can be adjusted, thereby obtaining thermosensitive liposomes with adjustable phase transition temperature and better stability. The mass ratio of one or more of hydrogenated soybean phospholipids, distearyl phosphatidylcholine, monopalmitoyl phosphatidylcholine and PEGylated phospholipid derivatives to distearyl phosphatidylcholine is preferably 1:(2~6). Optionally, the mass ratio of one or more of hydrogenated soybean phospholipids, distearyl phosphatidylcholine, monopalmitoyl phosphatidylcholine and PEGylated phospholipid derivatives to distearyl phosphatidylcholine is 1:2, 1:3, 1:4, 1:5, 1:6 or any two of the above ratios.

[0038] In this invention, the phospholipid bilayer membrane encapsulates an antitumor drug; the antitumor drug is preferably paclitaxel (PTX).

[0039] In one specific embodiment of the present invention, the mass of the thermosensitive liposome is preferably 0.0005% to 0.5% of the mass of the photothermal-chemotherapy synergistic dual cross-linked drug-loaded hydrogel; optionally, the mass of the thermosensitive liposome is 0.0005%, 0.0008%, 0.001%, 0.0012%, 0.0015%, 0.0016%, 0.0018%, 0.002%, 0.0008%, 0.001%, 0.0012%, 0.0015%, 0.0016%, 0.0018%, 0.002%, 0.0001% of the mass of the photothermal-chemotherapy synergistic dual cross-linked drug-loaded hydrogel. The concentrations can be 0.0025%, 0.003%, 0.0035%, 0.004%, 0.0045%, 0.005%, 0.01%, 0.015%, 0.02%, 0.025%, 0.028%, 0.03%, 0.033%, 0.035%, 0.04%, 0.05%, 0.08%, 0.1%, 0.15%, 0.2%, 0.3%, 0.4%, 0.5%, or any two of the above values. The content of antitumor drugs in the photothermal-chemotherapy synergistic double-crosslinked drug-loaded hydrogel can be controlled by adjusting the content of thermosensitive liposomes within it; the specific selection can be made according to the application requirements and specific needs.

[0040] In a specific embodiment of the present invention, the amino-containing macromolecule is preferably gelatin; the aldehyde-containing macromolecule is preferably oxidized dextran; the polyphenol compound is preferably protocatechuic aldehyde (PA); and the transition metal ion is preferably iron ion (Fe). 3+ The preferred antitumor drug is paclitaxel (PTX). The photothermal-chemotherapy synergistic dual-crosslinked drug-loaded hydrogel gelatin (Gel) and oxidized dextran (ODex) provided by this invention form a first crosslinking network through a Schiff base reaction. The catechol structure of protocatechuic aldehyde and its aldehyde group participate in iron ion coordination crosslinking and Schiff base crosslinking, respectively, forming a second crosslinking network. Paclitaxel (DPPC-PTX) is encapsulated in thermosensitive liposomes and co-loaded into this dual-crosslinking network. Utilizing the photothermal conversion effect of iron-catechol coordination compounds (TPF) under near-infrared light irradiation, on the one hand, local high temperature directly kills residual tumor cells and exerts broad-spectrum antibacterial effects; on the other hand, this heat precisely triggers the gel-liquid phase transition of DPPC liposomes at the phase transition temperature (approximately 41°C), rapidly releasing the encapsulated paclitaxel. This achieves in-situ synergistic photothermal therapy and chemotherapy, effectively clearing postoperative residual tumor cells, inhibiting local recurrence, preventing wound infection, and promoting tissue repair. See also... Figure 1 , Figure 1 This is a schematic diagram illustrating the preparation and application of the photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel provided by the present invention.

[0041] In a specific embodiment of the present invention, the crosslinking method is preferably one or more of Schiff base reaction crosslinking, coordination crosslinking, photocuring reaction crosslinking, click reaction crosslinking, catalytic reaction crosslinking, and Michael addition reaction crosslinking; for example, if the mixture includes methacrylamide gelatin (GelMA) and oxidized dextran (ODex), a double-network double-crosslinked hydrogel can be formed by visible light curing; if the mixture includes gelatin (Gel) and quaternary ammonium salt chitosan, a biocompatible hydrogel with excellent mechanical properties can also be prepared through click reaction and hydrophobic interaction.

[0042] The present invention also provides a method for preparing the above-mentioned photothermal-chemotherapy synergistic dual cross-linked drug-loaded hydrogel, comprising the following steps: mixing a first solution and a second solution to obtain a photothermal-chemotherapy synergistic dual cross-linked drug-loaded hydrogel; the first solution comprises a macromolecule with an aldehyde group and a coordination complex; the second solution comprises a macromolecule with an amino group and a thermosensitive liposome.

[0043] In this invention, there are no special restrictions on the source of any raw materials; commercially available materials are acceptable. The types and proportions of the macromolecules with aldehyde groups, coordination complexes, thermosensitive liposomes, and macromolecules with amino groups are the same as described above and will not be repeated here.

[0044] In a specific embodiment of the present invention, the coordination complex is prepared by the following method: a polyphenol compound and a metal salt are mixed in water, and then the pH value is adjusted to alkaline to obtain a coordination complex; the metal salt includes transition metal ions; the molar ratio of the polyphenol compound to the metal salt is preferably (2~4):1, more preferably (2~3):1; the metal salt is preferably one or more of a transition metal halide, a transition metal nitrate, and a transition metal sulfate; the transition metal halide is preferably a transition metal chloride; the alkaline pH value is preferably 9~11, more preferably 9.5~10.5, and even more preferably 10; after adjusting the pH value to alkaline, it is preferably stirred for 2~4 h, more preferably 2.5~3.5 h, and even more preferably 3 h.

[0045] In a specific embodiment of the present invention, the thermosensitive liposomes are prepared by the following method: A1) Phospholipids, cholesterol, and antitumor drugs are mixed in a solvent, the solvent is removed, and a lipid film is obtained; A2) The lipid film is hydrated with a buffer solution, and then sonicated under ice bath conditions to obtain thermosensitive liposomes; the types of phospholipids, cholesterol, and antitumor drugs are the same as those described above, and will not be repeated here; the solvent is preferably chloroform or a mixture of chloroform and an alcohol solvent; the alcohol solvent can be any alcohol solvent known to those skilled in the art, and there are no special restrictions, but methanol and / or ethanol are preferred in the present invention; the volume ratio of chloroform to alcohol solvent is preferably (1~3):1, more preferably (1.5~2.5):1, and even more preferably 2:1; the ratio of the total mass of phospholipids and cholesterol to solvent is preferably (10~30) mg:6 mL, more preferably (12~28) mg:6 mL, even more preferably (15~28) mg:6 mL, and even more preferably (18~28) mg:6 mL. The solvent ratio is 6 mL, preferably (20~24) mg: 6 mL; the method for removing the solvent can be any method well known to those skilled in the art and is not particularly limited, but rotary evaporation is preferred in this invention; the rotary evaporation is preferably carried out under vacuum conditions; the rotary evaporation temperature is preferably 40℃~50℃; the rotary evaporation time is preferably 0.5~2 h, more preferably 1~1.5 h; the buffer solution can be any buffer solution well known to those skilled in the art and is not particularly limited, but PBS buffer is preferred in this invention; the hydration temperature is preferably 40℃~60℃, more preferably 45℃~55℃, and even more preferably 50℃; the ultrasonic power is preferably 50~200 W, more preferably 100~150 W; the ultrasonic time is preferably 5~20 min, more preferably 8~15 min, and even more preferably 10~12 min; the ultrasonic is preferably intermittent ultrasonic; the intermittent ultrasonic consists of multiple cycles; each cycle includes working time and interval time; the working time of each cycle of the intermittent ultrasonic is preferably 1~5 s, more preferably 2~4 s, and even more preferably 3 The interval time for each cycle of the intermittent ultrasound is preferably 1 to 5 seconds, more preferably 2 to 4 seconds, and even more preferably 3 seconds.

[0046] In this invention, the first solution is preferably obtained by mixing a solution of a macromolecule containing an aldehyde group with a coordination complex; the mass concentration of the macromolecule containing the aldehyde group in the solution is preferably 5% to 20%, more preferably 8% to 15%, even more preferably 8% to 12%, and most preferably 10%; the solvent of the solution of the macromolecule containing the aldehyde group is preferably water.

[0047] In this invention, the second solution is preferably obtained by mixing a solution of amino-containing macromolecules with thermosensitive liposomes; the mass concentration of amino-containing macromolecules in the solution is preferably 10% to 30%, more preferably 15% to 25%, even more preferably 18% to 22%, and most preferably 20%; the solvent of the solution of amino-containing macromolecules is preferably water.

[0048] By mixing the first solution and the second solution, a photothermal-chemotherapy synergistic dual cross-linked drug-loaded hydrogel can be obtained.

[0049] The present invention also provides the application of the above-mentioned photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel in the preparation of drugs for treating skin tumors.

[0050] In one specific embodiment of the present invention, the skin tumor is preferably a melanoma.

[0051] In one specific embodiment of the present invention, the photothermal-chemotherapy synergistic double cross-linked drug-loaded hydrogel can be used to prepare postoperative recurrence prevention drugs for melanoma, postoperative wound anti-infection drugs, and postoperative treatment drugs for melanoma patients with diabetes.

[0052] This invention relates to a photothermal-chemotherapy synergistic dual-crosslinked drug-loaded hydrogel. Utilizing the localized heat generated by iron-catechol coordination compounds under near-infrared light irradiation, this hydrogel not only directly kills residual tumor cells but also serves as an "endogenous trigger signal" for drug release. At approximately 41°C, it precisely triggers the gel-liquid crystal phase transition of DPPC liposomes, enabling the rapid, pulsed release of encapsulated paclitaxel from the tumor site. This closed-loop design of "photothermal heat generation—thermosensitive drug release" ensures precise temporal and spatial matching between photothermal therapy and chemotherapy, avoiding the poor synergistic effect caused by the independent operation of the photothermal agent and drug-loaded nanoparticles and the lack of thermal regulation in existing methods.

[0053] Furthermore, the photothermal-chemotherapy synergistic dual-crosslinked drug-loaded hydrogel provided by this invention integrates anti-tumor, anti-infection, and wound healing promotion functions, making it particularly suitable for high-risk patients with diabetes. Existing solutions mostly focus on single or dual functions. This invention achieves broad-spectrum antibacterial activity through the photothermal effect of the iron-catechol coordination system, achieves anti-tumor activity through the on-demand release of paclitaxel mediated by thermosensitive liposomes, and achieves tissue adhesion through the Schiff base reaction of the aldehyde group of oxidized dextran with histamine. These three functions synergistically promote tissue regeneration. Especially considering the unique microenvironment of diabetic patients (high glucose, susceptibility to infection, and delayed healing), this invention can simultaneously address the challenges of infection control and wound repair, filling the gap in existing technologies for the lack of effective postoperative treatment options for patients with underlying diseases such as diabetes. Simultaneously, the preparation process is mild and simple, facilitating clinical translation. All crosslinking reactions in this invention are completed under aqueous conditions at 25-37°C, without involving organic solvents or high-temperature treatment, which helps maintain the activity of liposomes and paclitaxel. The raw materials, gelatin and dextran, are widely available, biocompatible, and low-cost, possessing good potential for large-scale production and clinical translation.

[0054] This invention addresses the specific needs of melanoma patients with diabetes by utilizing the photothermal antibacterial and healing-promoting properties of hydrogels to synergistically address the challenges of infection and healing in a high-glucose microenvironment, providing a safe and effective postoperative treatment option for these high-risk patients. Furthermore, the preparation method of this invention is mild, simple to operate, and uses widely available raw materials, demonstrating promising prospects for clinical translation.

[0055] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel provided by the present invention, its preparation method and application.

[0056] All reagents used in the following examples are commercially available.

[0057] Example 1

[0058] 1.1 Preparation of Oxidized Dextran

[0059] At room temperature, dextran (Mw = 11 × 10⁻⁶) was added. 6 The dextran and sodium periodate were dissolved in water at a molar ratio of 1:1.5, with a dextran to water ratio of 2 g:30 mL. The reaction was carried out in the dark for 24 hours. Finally, 300 μL of ethylene glycol was added to cool and terminate the reaction. The reaction solution was transferred to a dialysis bag (MWCO=3.5 kDa) and dialyzed with deionized water for 2-3 days, changing the solution every 6 hours. Finally, the oxidized dextran was obtained by freeze-drying.

[0060] The obtained oxidized dextran was analyzed using Fourier transform infrared spectroscopy (FT-IR), and its infrared spectrum is shown below. Figure 2As shown in the infrared spectrum, at 1729 cm⁻¹... -1 Characteristic peaks of aldehyde groups appear at this location.

[0061] use 1 The obtained oxidized dextran was analyzed by 1H NMR (D2O as solvent), and its 1H NMR spectrum was obtained as follows: Figure 3 As shown.

[0062] Infrared spectroscopy was used to measure the infrared spectrum at 1729 cm⁻¹. -1 The presence of characteristic peaks of aldehyde groups at 4.7-5.5 ppm in the NMR spectrum confirms the successful synthesis of oxidized dextran.

[0063] The aldehyde content was determined by hydroxylamine hydrochloride-potential titration, and the aldehyde content was 57.51%. Three parallel samples were used in each group.

[0064] 1.2 Preparation of PA@Fe nanoparticles

[0065] 1.62% (w / v) anhydrous ferric chloride was added to a 4.14% (w / v) (0.3M) PA solution, with a molar ratio of protocatechuic aldehyde to ferric chloride of 3:1. The pH of the mixture was adjusted to 10, and the mixture was stirred at 80°C for 3 hours. PA and Fe then formed a stable ternary complex molecule in the aqueous solution, named the TPF coordination complex solution.

[0066] The formation of coordination bonds in PA@Fe was determined using ultraviolet-visible spectroscopy, and its ultraviolet-visible spectrum is shown below. Figure 4 As shown, by Figure 4 It can be seen that an ultraviolet absorption peak appears at 450 nm in the ultraviolet-visible spectrum, indicating the formation of PA@Fe(TPF) coordination complex.

[0067] 1.3 Preparation of DPPC-PTX micelles

[0068] 16 mg of dipalmitoylphosphatidylcholine (DPPC), 4 mg of cholesterol, 4 mg of DSPE-PEG2000, and 2.4 mg of paclitaxel (40:10:10:6) were dissolved in a mixture of 4 mL of chloroform and 2 mL of methanol and stirred thoroughly. The solution was then rotary evaporated under vacuum at 40 °C and 100 rpm for 1 hour to form a membrane. Afterward, 3 mL of PBS was added at 55 °C for hydration, followed by sonication at 100 W for 10 minutes in an ice bath, with a 3-second on-time and 3-second off-time interval during sonication, to obtain the DPPC-PTX liposome solution.

[0069] The particle size of DPPC-PTX liposomes was determined by dynamic light scattering, and their particle size distribution was obtained as follows: Figure 5 As shown. By Figure 5The average particle size of DPPC-PTX liposomes was approximately 164.2 ± 1.6 nm, with a uniform particle size distribution. The calculated drug loading and encapsulation efficiency were 5.02 ± 0.33% and 45.01 ± 4.64%, respectively.

[0070] 1.4 Preparation of hydrogels

[0071] By maintaining consistent concentrations of gelatin and oxidized dextran, and adjusting the concentration of the TPF coordination complex, hydrogels with different components were obtained. Specifically, 0, 5, 10, 15, and 20 μL of TPF coordination complex solution and 200 μL of 10% oxidized dextran solution were mixed thoroughly to obtain ODex / TPF solutions. The specific ratios were as follows: Figure 6 As shown, hydrogels with different components were obtained by mixing with 200 μL of 20% gelatin solution, and named Gel-ODex, Gel-ODex-TPF5, and Gel-ODex-TPF, respectively. 10 Gel-ODex-TPF 15 Gel-ODex-TPF 20 .

[0072] Adhesion performance test: Fresh pigskin was cut into 1 cm × 4 cm slices and soaked in PBS at 4°C overnight. Two tissue sections were taken, and 150 μL of hydrogel mixture was spread on each section with an overlap of 1 cm × 1 cm. A weight of 100 g was applied to the exposed adhesion area of ​​each sample, and incubation was carried out at 37°C for 30 minutes. A universal testing machine (TFW-50S) equipped with a 50 Newton gravimeter was used at a speed of 2 mm·s⁻¹. -1 A tensile load was applied to the specimen at a certain speed, and stress changes were monitored. Each group contained five parallel samples. The maximum combined stress was defined as the stress value corresponding to the complete separation of the two samples and the failure of the bond. The maximum bond strength was calculated by dividing the maximum bond stress by the area. The test results obtained through the pigskin shear test are shown in the figure below. Figure 7 As shown, the left figure is the adhesion strength-displacement curve, and the right figure is the adhesion strength bar graph. With the increase of the amount of TPF nanoparticles added, the double cross-linked network becomes tighter and the adhesion strength increases, reaching a maximum of 31 kPa.

[0073] Photothermal heating and photothermal cycling tests: The photothermal properties of the obtained hydrogel were tested. A 200 μL hydrogel sample loaded with TPF coordination complex was placed on a glass slide and irradiated with an 808 nm near-infrared laser. The vertical distance between the laser source and the sample surface was fixed at 10 cm. Photothermal heating tests were conducted at different power densities (0.8 W / cm²). 2 1.0 W / cm 2 1.2 W / cm 2The sample was continuously irradiated for 10 minutes, and the surface temperature change was recorded every 60 seconds using an infrared thermal imager. Time-temperature curves were plotted at different powers. Photothermal cycling tests were conducted at 1.0 W / cm². 2 The laser irradiation was performed at a specific power density. The sample was irradiated for 10 minutes to reach its maximum temperature, then the laser was turned off, and the sample was allowed to cool naturally back to its initial temperature (approximately 10 minutes). This process was defined as one cycle. This laser irradiation-natural cooling operation was repeated four times. The heating and cooling curves for each cycle were recorded, and the highest temperature (T0) in each cycle was compared. max The photothermal stability and repeatability of the material were assessed by measuring changes in the heating rate. A blank hydrogel without TPF coordination complexes was used as a control group. The test results are shown in the figure below. Figure 8 As shown, the upper figure is an infrared thermal image at different times, the lower left figure is a time-temperature rise curve at different powers, and the lower left figure is a cyclic temperature rise and fall curve. It can be seen that the temperature of the Gel-ODex group remains almost unchanged with time, while the temperature of the TPF-added group increases with time.

[0074] Preliminary validation of in vivo photothermal properties: Balb / c mice were used to establish subcutaneous embedding and surface wound models, respectively. In the subcutaneous embedding model, a 1.5 cm incision was made in the back, and the subcutaneous tissue was bluntly dissected to form a cyst. 200 μL of a hydrogel containing a TPF coordination complex, Gel-ODex-TPF, was injected. 20 The incision was then sutured; a full-thickness skin defect with a diameter of 1.0 cm was prepared on the back of the body surface wound model, and 200 μL of hydrogel containing TPF coordination complex (Gel-ODex-TPF) was applied and covered. 20 An 808 nm laser (1.0 W / cm²) was used. 2 Irradiate the area (10 cm) for 3 minutes, and use an infrared thermal imager to record the temperature change of the irradiated area in real time during the period to qualitatively evaluate the heating ability of the hydrogel in two application scenarios: subcutaneous and surface.

[0075] Photothermal imaging detection results ( Figure 9 (Left image shows surface coverage, right image shows subcutaneous embedding) This demonstrates that under 808 nm laser light (1.0 W / cm²), 2 Under irradiation, both the surface coating and subcutaneous embedding groups of the hydrogel containing TPF coordination complex showed significant temperature increases. The initial temperature before irradiation was approximately 20℃. After 3 minutes of irradiation, the local tissue temperature in both groups rose to above 37℃ (ΔT > 17℃), and the high-temperature areas in the thermal images highly overlapped with the gel administration sites. These results indicate that the hydrogel containing TPF coordination complex exhibits good photothermal temperature-increasing properties in both surface and subcutaneous application modes.

[0076] Near-infrared photothermal response antibacterial performance test: using Escherichia coli E. coli and Staphylococcus aureus S. aureus As a model strain, the hydrogel containing TPF coordination complexes, Gel-ODex-TPF, was used. 20 200 μL each of the experimental group and the blank hydrogel Gel-ODex (control group) without TPF coordination complex were placed in a 24-well plate, and 1 mL of 1×10⁻⁶ hydrogel was added. 6 CFU / mL bacterial suspension. An 808 nm laser (1.0 W / cm²) was used. 2 Irradiation was performed at 5 cm depth for 0, 1, 3, 5, and 10 min, respectively, with a total contact time of 10 min for all groups. After illumination, 200 μL of bacterial culture was taken from each well to measure the OD. 600 Another 10 μL was inoculated onto LB agar plates and incubated at 37℃ for 18-24 h before observing colony growth.

[0077] Antibacterial test results ( Figure 10 The two images on the left are photographs of the antibacterial experiment on plate coating, and the two images on the right are bar graphs of the antibacterial experiment with two different bacteria. This shows that the OD values ​​of the blank hydrogel + light-illuminated group at each time point are... 600 The values ​​and plate colonies showed no significant changes, proving that light itself has no bactericidal effect. The OD values ​​of the hydrogel containing TPF coordination complex + light-treated group were... 600 The value decreased in a time-dependent manner with prolonged light exposure, and the survival rate decreased significantly after 3 minutes, while the antibacterial rate was >99% after 5 minutes. The results of plate drop were consistent with this, with no colonies forming in the droplet after 5 minutes, confirming that the hydrogel containing the TPF coordination complex has excellent photothermal antibacterial properties.

[0078] Evaluation of in vivo wound repair and antibacterial properties: SD rats were used. After hair removal from the back, full-thickness skin defects with a diameter of 10 mm were prepared using sterile surgical scissors (4 wounds per rat). 30 μL of 1×10⁻⁶ oz. was inoculated into the wounds. 8 An infection model of Staphylococcus aureus was established using CFU / mL. Rats were randomly divided into 4 groups (n=4): ① blank control group, ② blank hydrogel group without TPF coordination complex (Gel-ODex), ③ TPF hydrogel group containing TPF coordination complex (Gel-ODex-TPF). 20 ), ④ TPF hydrogels containing TPF coordination complexes (Gel-ODex-TPF) 20 The NIR group and the corresponding TPF hydrogel (Gel-ODex-TPF) were used to cover the wound. 20 The NIR group was immediately treated with an 808 nm laser (1.0 W / cm²) after drug administration. 2Irradiate the wound (5 cm) for 5 min. On days 0, 3, 7, and 14, the wound surface was photographed and the healing rate was calculated. On day 3, wound tissue was homogenized, diluted, and plated to count CFU to evaluate the in vivo antibacterial effect.

[0079] Test results as follows Figure 11 ( Figure 11 The upper left image shows scatter plots of wound images and wound area taken at different times; the upper right image is a bar chart of wound contraction rate; and the lower image shows the in vivo antibacterial effect on day 3. As shown, quantified bacterial count analysis on day 3 post-surgery revealed a large number of viable bacteria in both the blank control group and the blank hydrogel group, while the TPF hydrogel + NIR group showed a significant reduction in bacterial count compared to the blank control group. Wound healing statistics showed that the wound area in the TPF hydrogel + NIR group was significantly smaller than that in the control group on day 7, and essentially closed by day 14 (healing rate >95%). These results indicate that hydrogels containing TPF coordination complexes can effectively eliminate infectious bacteria and significantly promote wound healing under near-infrared light irradiation.

[0080] 1.5 Preparation of drug-loaded hydrogels

[0081] Select the group with the highest adhesion strength: Gel-ODex-TPF 20 Subsequent experiments were conducted to verify its antibacterial and wound-healing properties. In the hydrogel preparation process described in 1.4 above, 20 μL of the DPPC-PTX liposome solution obtained in 1.3 was added to the gelatin solution, and then mixed with the ODex / TPF solution to form a gel, thus obtaining the Gel / ODex / TPF / DPPC-PTX hydrogel.

[0082] CCK-8 in vitro proliferation inhibition assay: B16F10 melanoma cells were used at a density of 5 × 10⁶ cells per well. 3 Cells were seeded at a density of 1000 μg / mL in 96-well plates and incubated at 37°C in a 5% CO2 incubator for 24 h. The old culture medium was discarded, and fresh culture medium containing different concentrations of PTX (30, 15, 7.5, 3.75, 1.88, 0.95, 0.47, 0.23 μg / mL) of free PTX and DPPC-PTX liposomes was added. A negative control group without any drugs was also included. After incubation for another 48 h, the medium was replaced with 10% CCK, and the cells were incubated at 37°C in the dark for 2 h. The absorbance (OD) at 450 nm was measured using a microplate reader. 450 Cell viability was calculated as follows: Cell viability (%) = (OD experimental group - OD blank group) / (OD negative group - OD blank group) × 100%.

[0083] Experimental results are as follows Figure 12As shown, the inhibitory effect of both free PTX and DPPC-PTX liposomes on B16F10 cells increased in a concentration-dependent manner, and cell viability gradually decreased with increasing drug concentration. At all concentration gradients, the cell viability of the free PTX group was lower than that of the DPPC-PTX liposome group, indicating that free PTX at the same drug concentration exhibited stronger short-term antitumor activity after 48 h of incubation. This is consistent with the sustained-release characteristic of liposomes, meaning that DPPC-PTX liposomes had not fully released the encapsulated paclitaxel in the short term. These results indicate that although the apparent activity of DPPC-PTX liposomes is lower than that of free drug during short-term incubation, its sustained-release behavior is beneficial for prolonging the duration of drug action.

[0084] In vitro drug release assay with dual pH and temperature regulation: The drug release behavior of drug-loaded hydrogels under different conditions was investigated using the dialysis bag method. Hydrogels (400 μL) loaded with free PTX or DPPC-PTX liposomes were sealed in dialysis bags (MWCO 3.5 kDa) and placed in four release media (4 mL each): ① PBS (pH 7.4, 0.5% Tween 80) + 37℃, ② PBS (pH 7.4, 0.5% Tween 80) + 45℃, ③ PBS (pH 6.5, 0.5% Tween 80) + 37℃, ④ PBS (pH 6.5, 0.5% Tween 80) + 45℃, incubated in a constant temperature shaking incubator (150 rpm). Samples were taken at preset time points, and an equal volume of fresh media was added simultaneously. The PTX content was detected by HPLC, and the cumulative release rate was calculated.

[0085] Experimental results are as follows Figure 13 As shown, the drug release from the drug-loaded hydrogel exhibits a clear dual-response characteristic of temperature and pH. Regarding temperature, the release rate of DPPC-PTX at 45℃ is significantly higher than that at 37℃, attributed to the increased fluidity of the lipid bilayer due to temperature (>41℃ phase transition temperature), accelerating PTX release; the cumulative release amount is essentially equal to that of free PTX. Regarding pH, acidic conditions (pH 6.5) significantly promote drug release, attributed to the disruption of the hydrogel network structure. These results indicate that this system can achieve synergistic regulation of drug release by both temperature and pH signals.

[0086] The in vitro antitumor activity of each group of materials against melanoma cells was evaluated using a 24-hour CCK-8 cell proliferation inhibition assay and a 24-hour live / dead cell fluorescence staining assay. B16F10 melanoma cells were used at a density of 5 × 10⁶ cells per well. 3 10 cells were seeded per well in a 96-well plate (CCK-8) or 2 × 10 cells per well. 4Cells were seeded in 24-well plates (live / dead staining) and cultured adherently for 24 h, after which the old culture medium was discarded. Experimental groups were: ① Blank control group (cells only), ② Gel / ODex / DPPC-PTX group (chemotherapy group, prepared using the same method as 1.5, except without the addition of TPF coordination complex), ③ Gel / ODex / TPF hydrogel group (Gel-ODex-TPF). 20 The photothermal group, and the synergistic group (Gel / ODex / TPF / DPPC-PTX hydrogel group) were used. After adding 200 μL of the corresponding material to each group, groups ③ and ④ were subjected to an 808 nm laser (1.0 W / cm²). 2 Irradiate for 5 min, and protect the remaining groups from light. After culturing for another 24 h, add 200 μL of fresh medium containing 10% CCK-8 to each well of the CCK-8 group, incubate at 37℃ in the dark for 2 h, measure the 450 nm OD value with a microplate reader and calculate the cell viability; stain the live and dead cell staining groups with Calcein-AM / PI staining solution in the dark for 15 min, observe and collect fluorescence images of live cells (green) and dead cells (red) under a fluorescence microscope.

[0087] Experimental results: CCK-8 results ( Figure 14 ) and live / dead staining results ( Figure 15 The trends were consistent. The Gel / ODex / DPPC-PTX group showed a certain inhibitory effect on cell proliferation, which was attributed to the chemotherapeutic effect of DPPC-PTX liposome-released paclitaxel. The cell survival rate of the Gel / ODex / TPF hydrogel group decreased significantly after light irradiation, confirming the antitumor effect of TPF photothermal ablation. The Gel / ODex / TPF / DPPC-PTX hydrogel group had the most significant killing effect on B16F10 cells, and the proportion of dead cells (red) in the live-dead staining was significantly higher than that of other groups, indicating that the TPF-mediated photothermal ablation and the chemotherapeutic effect of DPPC-PTX continuous release of paclitaxel produced a synergistic antitumor effect, and the killing and inhibitory effect on melanoma cells was significantly better than that of the single chemotherapy group or the simple photothermal group.

[0088] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel, characterized in that, It is formed by cross-linking of a mixture; the mixture includes macromolecules with amino groups, macromolecules with aldehyde groups, coordination complexes and thermosensitive liposomes; The coordination complex is formed by polyphenolic compounds and transition metal ions; The thermosensitive liposome comprises a phospholipid bilayer and an antitumor drug; the antitumor drug is encapsulated inside the phospholipid bilayer.

2. The photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel according to claim 1, characterized in that, The amino-containing macromolecules are selected from one or more of gelatin, methacrylamide gelatin, silk fibroin, polyethyleneimine, polylysine, amino-modified hyaluronic acid, and quaternary ammonium chitosan. And / or, the macromolecule with an aldehyde group is selected from one or more of oxidized dextran, aldehyde-modified hyaluronic acid, and aldehyde-modified PF127; And / or, the polyphenolic compound is selected from one or more of protocatechuic aldehyde, tannic acid, protocatechuic acid and epigallocatechin gallate; And / or, the transition metal ion is selected from Fe 3+ Au 3+ With Mn 2+ One or more of the following; And / or, the phospholipid bilayer membrane comprises phospholipids and cholesterol; the phospholipids comprise dipalmitoylphosphatidylcholine; And / or, the antitumor drug is selected from paclitaxel.

3. The photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel according to claim 2, characterized in that, The phospholipids also include one or more of hydrogenated soybean phospholipids, distearyl phosphatidylcholine, monopalmitoyl phosphatidylcholine, and PEGylated phospholipid derivatives.

4. The photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel according to claim 3, characterized in that, The mass ratio of phospholipids to cholesterol is (3~8):1; And / or, the mass ratio of one or more of the hydrogenated soybean phospholipids, distearyl phosphatidylcholine, monopalmitoyl phosphatidylcholine and PEGylated phospholipid derivatives to distearyl phosphatidylcholine is 1:(2~6).

5. The photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel according to claim 1, characterized in that, The mass ratio of the macromolecule with amino groups to the macromolecule with aldehyde groups is (1~3):

1.

6. The photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel according to claim 1, characterized in that, The mass of the coordination complex is 0.5% to 3% of the mass of the photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel; And / or, the mass of the thermosensitive liposome is 0.0005% to 0.5% of the mass of the photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel.

7. The photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel according to claim 6, characterized in that, The particle size of the thermosensitive liposomes is 100~300 nm.

8. The method for preparing the photothermal-chemotherapy synergistic double crosslinked drug-loaded hydrogel according to any one of claims 1 to 7, characterized in that, Includes the following steps: The first solution and the second solution are mixed to obtain a photothermal-chemotherapy synergistic dual cross-linked drug-loaded hydrogel; the first solution includes macromolecules with aldehyde groups and coordination complexes; the second solution includes macromolecules with amino groups and thermosensitive liposomes.

9. The preparation method according to claim 8, characterized in that, The coordination complex was prepared according to the following method: A polyphenol compound is mixed with a metal salt in water, and then the pH is adjusted to alkaline to obtain a coordination complex; the metal salt includes transition metal ions. And / or, the thermosensitive liposomes are prepared according to the following method: A1) Phospholipids, cholesterol, and antitumor drugs are mixed in a solvent, the solvent is removed, and a lipid film is obtained; A2) The lipid film was hydrated with a buffer solution and then sonicated under ice bath conditions to obtain thermosensitive liposomes.

10. The use of the photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel according to any one of claims 1 to 7, or the photothermal-chemotherapy synergistic dual crosslinked drug-loaded hydrogel prepared by the preparation method according to claim 8 or 9, in the preparation of a drug for treating skin tumors.

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