Photocrosslinked hydrogels, methods of making and using the same, radionuclide formulations and applicators

Abstract

The application belongs to the technical field of hydrogels, and provides a photo-crosslinking hydrogel, a preparation method and application thereof, a radionuclide preparation and a patch. The photo-crosslinking hydrogel with adhesion provided by the application comprises a crosslinking network structure composed of dopamine-modified methyl methacrylated gelatin and o-nitrobenzyl sulfide photo-triggered modified hyaluronic acid, which not only has injectability, can be gelled after being triggered by light, but also has strong adhesion, improves the mechanical properties, enables the hydrogel to bear greater deformation and maintain better elasticity, thus realizing physical-chemical synergistic enhancement of adhesion, and can realize instantaneous and firm adhesion with biological tissues. Further, the photo-crosslinking hydrogel can be used as a carrier, for example, loading a radionuclide preparation, or preparing a patch containing a radionuclide, or can also be used as a hemostatic material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomedical materials, and more particularly to a photo-crosslinking hydrogel, a preparation method and application thereof, a radionuclide preparation and a patch. BACKGROUND

[0002] The photo-crosslinking hydrogel is a gelation system triggered by light and is widely used in the field of biomedical materials. Firstly, the photo-crosslinking hydrogel can be used as a carrier of a radionuclide drug and is applied to embolization therapy. By injecting an embolic agent into a blood vessel, the blood supply of a lesion site is blocked, so as to reduce or eliminate the lesion. The radionuclide can be embedded in the hydrogel as a radioactive particle or be locally injected into a tumor site through a rare earth ion coordinated with the hydrogel. This combination strategy not only "starves" tumor cells by inhibiting blood supply, but also directly kills these cells by releasing radiation energy. However, although the hydrogel as a carrier of the radionuclide has obvious advantages, it still faces challenges, for example, the stability of the radionuclide is insufficient, which leads to rapid failure in the body.

[0003] Secondly, the hydrogel is used as a patch for keloid. The existing photo-crosslinking hydrogel has poor adhesion and is difficult to closely adhere to the irregular surface of the keloid, which is easy to displace or fall off, thereby affecting the treatment effect of the drug. Thirdly, the photo-crosslinking hydrogel can also be used as a hemostatic material. The photo-crosslinking hydrogel can be used to block conventional biological tissue wounds, and the hydrogel precursor solution can be delivered to deep, narrow and irregular wounds after a puncture operation, and the hydrogel is formed in situ by light triggering. However, due to insufficient adhesion, the hemostatic effect of these hydrogels is still not satisfactory.

[0004] Therefore, it is urgent to develop a photo-crosslinking hydrogel with strong adhesion, which can achieve instantaneous and firm adhesion to biological tissues to meet the needs of the field of biomedical materials, for example, such hydrogel not only has excellent radionuclide carrier characteristics, but also can be widely used in wound sealing and hemostasis and other medical treatments. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a photo-crosslinking hydrogel, a preparation method and application thereof, a radionuclide preparation and a patch. The photo-crosslinking hydrogel provided by the present application has excellent adhesion and can achieve instantaneous and firm adhesion to biological tissues, and has anti-fatigue performance. The photo-crosslinking hydrogel can meet the needs of medical field applications, for example, it can not only be used as a good carrier of radionuclide, but also be used for wound sealing and hemostasis.

[0006] The first aspect of the present application provides a photo-crosslinking hydrogel with adhesion.

[0007] Specifically, the light crosslinking hydrogel (GDHL) with adhesion includes a crosslinking network structure composed of dopamine-modified methyl methacrylate gelatin (GelMADA) and ortho-nitrobenzyl sulfide photo trigger modified hyaluronic acid (HANT).

[0008] The light crosslinking hydrogel provided by the application can be crosslinked in multiple modes under the triggering of light to form a complex crosslinking network structure, wherein the first crosslinking mode is a polymer network formed by the free radical crosslinking of GelMADA under the triggering of light; the second crosslinking mode is a polymer network formed by the Michael addition reaction between the free thiol generated by the carbon-sulfur bond breakage of the benzyl position of HANT under the triggering of light and the double bond on the skeleton of GelMADA, with the dynamic carbon-sulfur bond as the crosslinking point; and the third crosslinking mode is a polymer network (HH) composed of the disulfide dynamic covalent bond generated by the oxidation crosslinking of HANT itself. Thus, the GDHL hydrogel not only has a main skeleton composed of permanent covalent bonds formed by the free radical crosslinking of double bonds, but also has an energy dissipation region formed by dynamic covalent bonds embedded in the main skeleton. When a certain pressure is applied to the hydrogel, the dynamic crosslinking points in the interior of the hydrogel are effectively dissipated through the process of covalent bond breakage and reformation, and the long-chain network formed by the free radical crosslinking mode of double bonds can fix the dynamic crosslinking points in the interior of the hydrogel, avoiding the displacement of the crosslinking points in the energy dissipation process, further improving the fatigue resistance of the hydrogel, and maintaining the integrity of the three-dimensional network skeleton of the hydrogel. Further applying the light crosslinking hydrogel to a biological tissue, the polar groups on the hyaluronic acid skeleton can be firmly adhered to the polar environment on the surface of the biological tissue through the formation of hydrogen bonds and coordination bonds, and the mutual penetration between the hyaluronic acid skeleton and the biological tissue can also improve the adhesion to a certain extent. Meanwhile, the hydrogen bonds, coordination bonds, π-π stacking interactions (chemical interactions) and imine covalent bonds (physical interactions) brought by dopamine can be used for synergistic adhesion. Under the above comprehensive effects, the adhesion of the hydrogel is greatly improved. Further, the light crosslinking hydrogel can be used as a carrier, for example, to load a radionuclide. The prepared radionuclide preparation can be firmly positioned at the lesion site, and the dopamine structure in the hydrogel contains two phenol groups, which can form a complex with rare earth ions (radionuclides) through coordination to form a more stable radionuclide preparation, preventing the leakage of the radionuclide. Alternatively, a radionuclide-containing patch can be prepared, which can be closely attached to the irregular surface of a keloid, so that the therapeutic effect of the radionuclide can be fully exerted, and the biocompatibility is good. Alternatively, the light crosslinking hydrogel can be used as a hemostatic material to achieve excellent hemostatic effect.

[0009] Preferably, in step (1), the dopamine substitution degree of the dopamine-modified methyl methacrylate gelatin is 14-18%.

[0010] Further preferably, in step (1), the dopamine substitution degree of the dopamine-modified methylacrylated gelatin is 16-17%.

[0011] Preferably, in step (2), the mass ratio of the dopamine-modified methylacrylated gelatin to the o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid is (3-6):1.

[0012] Further preferably, in step (2), the mass ratio of the dopamine-modified methylacrylated gelatin to the o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid is (4-5):1.

[0013] If the content of GelMADA is too high, the crosslinking degree is too high, the high crosslinking degree leads to a too fast solidification process, causing the non-uniformity of the hydrogel, which is difficult to apply; and a lower content of GelMADA leads to a less dense crosslinking network, and the structural strength and mechanical properties of the hydrogel are adversely affected.

[0014] The second aspect of the present application provides a preparation method of a photo-crosslinked hydrogel with adhesion.

[0015] The preparation method of the photo-crosslinked hydrogel (GDHL) with adhesion comprises the following steps:

[0016] (1) A sodium hyaluronate solution is taken, 2-((2-nitrobenzyl)thio)ethan-1-amine and a first condensing agent are added and mixed, the pH value is adjusted to 4-5, then a second condensing agent is added, a first amide reaction is performed, and o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid is obtained.

[0017] (2) The dopamine-modified methylacrylated gelatin and the o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid are respectively dissolved in a solvent to obtain a solution containing dopamine-modified methylacrylated gelatin and a solution containing o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid, then the two solutions are mixed, a photoinitiator is added, a hydrogel precursor solution is obtained, and the photo-crosslinked hydrogel is obtained through light curing.

[0018] Preferably, in step (1), the temperature of the first amide reaction is 20-30℃, and / or the time of the first amide reaction is 24-60h.

[0019] Preferably, in step (1), in step (1), the first condensing agent is 1-hydroxybenzotriazole, and / or the second condensing agent is N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride.

[0020] Preferably, in step (1), the molar ratio of sodium hyaluronate, 2-((2-nitrobenzyl)thio)ethane-1-amine, the first condensing agent, and the second condensing agent is 1:1:1:0.5 to 1:1:1:1.

[0021] Preferably, in step (2), the light curing time is 1s-3min.

[0022] Further preferably, in step (2), the light curing time is 1.5s-1min.

[0023] Preferably, in step (2), the photoinitiator is lithium phenyl (2,4,6-trimethylbenzoyl) phosphate (LAP).

[0024] Preferably, in step (2), the solvent is phosphate buffered saline (PBS).

[0025] Preferably, in step (2), the solid content of the hydrogel precursor solution is 4-8%.

[0026] Preferably, in step (2), the method for preparing the dopamine-modified methacrylated gelatin comprises the following steps: mixing dopamine hydrochloride and methacrylated gelatin, and preparing the dopamine-modified methacrylated gelatin through a second amide reaction.

[0027] Preferably, the temperature of the second amide reaction is 20-30° C., and / or the time of the second amide reaction is 10-24 h.

[0028] Preferably, the methacrylated gelatin is activated before mixing, and the activation step comprises: first dissolving the methacrylated gelatin in a buffer solution, then adding 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, and mixing at 20-30° C. for 2-8 minutes.

[0029] Preferably, the buffer solution is a phosphate-buffered saline (PBS) solution, and / or the pH value of the buffer solution is 4-6.

[0030] Preferably, after the amide reaction, post-treatment is performed, and the post-treatment sequentially includes dialysis and drying.

[0031] More preferably, the post-treatment sequentially comprises dialysis with water for 2-5 days and then freeze-drying.

[0032] Preferably, the dialysis uses a dialysis bag with a molecular weight cut-off of 10,000-16,000 Da.

[0033] The third aspect of the present invention provides a use of a photo-crosslinked hydrogel having adhesive properties.

[0034] Use of an adhesive photocrosslinked hydrogel in the preparation of a medical carrier, a hemostatic material, a patch, a wearable device or a sensor.

[0035] A radionuclide-containing preparation comprising a radionuclide and a carrier, the radionuclide being loaded on the carrier, the carrier being the adhesive photocrosslinked hydrogel.

[0036] A radionuclide-containing patch comprising a radionuclide and the adhesive photocrosslinked hydrogel.

[0037] A hemostatic material comprising the adhesive photocrosslinked hydrogel.

[0038] The beneficial effects of the present application relative to the prior art are as follows:

[0039] The photo-crosslinking hydrogel with adhesion provided by the application comprises a crosslinking network structure of dopamine-modified methyl methacrylate gelatin (GelMADA) and ortho-nitrobenzyl sulfide photo trigger modified hyaluronic acid (HANT), which not only has injectability and can be gelled after being triggered by light, but also has improved adhesion of the hydrogel by introducing dopamine, and further improved adhesion of the hydrogel by introducing carbon-sulfur bonds and disulfide bonds, which are dynamic covalent bonds, and better energy dissipation capacity, which improves the mechanical properties of the hydrogel and enables the hydrogel to withstand greater deformation and maintain better elasticity and strong fatigue resistance. In addition, physical adhesion is realized through imine covalent bonds, and chemical adhesion is realized through various chemical reactions of the photo-crosslinking hydrogel, hydrogen bonds, coordination bonds and pi-pi stacking interactions. On the one hand, the physical viscosity ensures that the photo-crosslinking hydrogel produces instant adhesion when it comes into contact with biological tissues, thereby ensuring that the photo-crosslinking hydrogel is not easily detached by external force. On the other hand, chemical adhesion requires a corresponding reaction time to produce adhesion, so after the photo-crosslinking hydrogel comes into contact with biological tissues, the two gradually bond in the form of chemical bonds, thereby firmly anchoring the photo-crosslinking hydrogel on the tissue surface and providing long-term adhesion. The application combines the characteristics of fast and weak physical adhesion with the characteristics of slow and strong chemical adhesion, realizes physical-chemical synergistic adhesion, and constructs a photo-crosslinking adhesive with instantaneous and firm adhesion, which realizes firm adhesion with biological tissues. Further, the photo-crosslinking hydrogel can be used as a carrier, for example, after loading a radionuclide, it can be stably positioned at a lesion site, or a dressing containing a radionuclide can be prepared and closely attached to the irregular surface of a keloid, which has good biocompatibility, so that the therapeutic effect of the radionuclide is fully exerted, or the photo-crosslinking hydrogel can also be used as a hemostatic material to achieve excellent in-situ plugging hemostasis effect. In addition, when the hydrogel is used as a carrier to incorporate radionuclide particles or form a coordination compound with radionuclide ions, the dopamine structure contains two phenol groups, which can form a complex with rare earth ions through coordination to form a more stable radionuclide preparation and prevent radionuclide leakage. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 SEM of the GDHL, GDL and HH hydrogels prepared in Example 1 of the application;

[0041] Figure 2 Rheological property test result graph of the GDHL hydrogel prepared in Example 1 of the application;

[0042] Figure 3 Comparison graph of the lap shear test results of the GDHL hydrogel and fibrin glue prepared in Example 1 of the application;

[0043] Figure 4 Figure of the results of the biological tissue adhesion test of the GDHL hydrogel prepared in Example 1 of the present application;

[0044] Figure 5 Figure of the labeling efficiency results of the GDHL hydrogel prepared in Example 1 of the present application loaded with radionuclides;

[0045] Figure 6 Figure of the stability tracking of the GDHL hydrogel incorporated with RENP prepared in Example 1 of the present application in mice;

[0046] Figure 7 Figure of the test results of the plugging effect of the GDHL hydrogel prepared in Example 1 of the present application on the kidney puncture wound. DETAILED DESCRIPTION

[0047] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0048] The raw materials, reagents or devices used in the following examples, if not specifically stated, can be obtained from conventional commercial channels, or can be obtained by existing known methods.

[0049] The parameters and reagents used in the examples, comparative examples of the present application are as follows:

[0050] Da: unit of weight average molecular weight of biological macromolecules (such as proteins, nucleic acids, etc.), which is equivalent to the mass of 24783 hydrogen atoms.

[0051] Preparation method of PBS solution (pH = 5): adjust 0.2 mol / L sodium dihydrogen phosphate solution to pH = 5 with NaOH solution.

[0052] Example 1

[0053] A light cross-linked hydrogel (GDHL) with adhesion, comprising a cross-linked network structure of dopamine-modified methylacrylated gelatin and o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid.

[0054] The preparation method of the light cross-linked hydrogel (GDHL) with adhesion described above, comprising the following steps:

[0055] (1) Preparation of dopamine-modified methacrylated gelatin (GelMADA): Methacrylated gelatin GelMA was dissolved in PBS solution (pH = 5) to form a uniform and transparent solution. Then EDC (3.8 mmol) and NHS (3.9 mmol) were added and stirred at room temperature for 5 min. Dopamine hydrochloride (3.9 mmol) was added to the reaction bottle in batches, and the reaction mixture was stirred at room temperature. After the reaction was completed, the reaction mixture was placed in a dialysis bag (14000 Da), and after dialysis with deionized water for three days, it was freeze-dried to obtain GelMADA as a brown foam solid. 1 HNMR nuclear magnetic resonance hydrogen spectrum showed that the multiplet at δ = 2.8 ppm was the peak Hc of dopamine benzyl methylene, the singlet at δ = 3.12 ppm was the peak Hd on the gel molecule, and the doublet at δ = 5.34 ppm was the peak Hb on GelMADA, indicating that dopamine was used to modify methacrylated gelatin. The calculated DA substitution degree of GelMADA was about 16.4%. The MALDI-TOF mass spectrum test result showed that the weight average molecular weight of GelMADA was about 24783 Da.

[0056] The above GDHL synthesis route is as follows:

[0057]

[0058] (2) Preparation of hyaluronic acid modified with o-nitrobenzyl sulfide phototrigger (HANT):

[0059] Sodium hyaluronate (HA) was dissolved in deionized water to form a uniform and transparent solution. 2-((2-nitrobenzyl)thio)ethan-1-amine (NT) (1 mmol) and 1-hydroxybenzotriazole (HOBT) (1.5 mmol) were dissolved in dimethyl sulfoxide respectively, and added dropwise into the reaction bottle. After stirring the reaction mixture at room temperature, the pH of the reaction solution was adjusted to about 4.5. At this time, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) (1.56 mmol) was dissolved in dimethyl sulfoxide, and added dropwise into the reaction system. After stirring the reaction mixture, the reaction solution was placed in a dialysis bag (molecular weight cut-off 14000 Da) and placed in a deionized water solution containing 0.1 mol / L NaCl at pH 3.5 for dialysis. Subsequently, it was placed in deionized water for further dialysis, and the dialysis solution was replaced every 3 hours during the dialysis process. After dialysis, the mixture in the dialysis bag was placed in a centrifuge tube and freeze-dried in the dark. The white flocculent product was collected, and the nuclear magnetic resonance hydrogen spectrum characterization result showed that the NT substitution degree was about 19.5%.

[0060] The above HANT synthesis route is as follows:

[0061]

[0062] (3) GelMADA (50 mg) and HANT (10 mg) were dissolved in 500 μL PBS solution, respectively. Then the GelMADA solution and the HANT solution were mixed well, and then LAP (10 mg / mL) was added into the mixture, which was stirred at room temperature to mix well, obtaining a GDHL hydrogel precursor solution (solid content 6%, the weight ratio of GelMADA:HANT = 5:1). The above mixture was rapidly cured into gel under an ultraviolet lamp (365 nm, 40 mW / cm 2 ) to form a GDHL hydrogel.

[0063] The preparation process of the GDHL hydrogel involves multiple crosslinking modes. The first crosslinking mode is the polymer network formed by the free radical crosslinking of GelMADA under light triggering. The second crosslinking mode is the polymer network with dynamic carbon-sulfur bonds as crosslinking points formed by the Michael addition reaction between the free thiol generated by the intramolecular carbon-sulfur bond of HANT under light triggering and the double bond on the GelMADA backbone. The third crosslinking mode is the polymer network (HH) composed of disulfide dynamic covalent bonds generated by the oxidation crosslinking of HANT itself. Thus, a complex crosslinking network structure of the GDHL hydrogel is formed.

[0064] Example 2

[0065] A photo-crosslinking hydrogel, which is different from Example 1 in that the DA substitution degree of GelMADA is replaced by 18%. The GDHL hydrogel is successfully prepared by rapidly curing the mixture under an ultraviolet lamp (365 nm, 40 mW / cm 2 ). The increase of the DA substitution degree to 18% helps to reduce the crosslinking time of the material, improve the formation efficiency of the hydrogel, and improve the curing uniformity.

[0066] Example 3

[0067] A photo-crosslinking hydrogel, which is different from Example 1 in that the DA substitution degree of GelMADA is replaced by 14%. The GDHL hydrogel is successfully prepared by rapidly curing the mixture under an ultraviolet lamp (365 nm, 40 mW / cm 2 ). The lower DA substitution degree (14%) of the hydrogel helps to improve the stability and overall structural integrity of the hydrogel.

[0068] Example 4

[0069] A photo-crosslinking hydrogel, which is different from Example 1 in that the weight ratio of GelMADA:HANT = 6:1. The results show that the hydrogel with good crosslinking degree is successfully obtained under this weight ratio.

[0070] Example 5

[0071] A photocrosslinking hydrogel, which is different from Example 1 in that the weight ratio of GelMADA:HANT = 3:1. The result shows that a hydrogel with excellent crosslinking degree is successfully prepared at this ratio.

[0072] Comparative Example 1 (increasing DA substitution degree)

[0073] A photocrosslinking hydrogel, which is different from Example 1 in that the DA substitution degree of GelMADA is replaced with 20%. Compared with Example 1, too high DA substitution degree leads to aggregation or interaction of the material to form a non-uniform hydrogel, which shows a non-uniform gelation morphology during the curing process, making it difficult to apply.

[0074] Comparative Example 2 (decreasing DA substitution degree)

[0075] A photocrosslinking hydrogel, which is different from Example 1 in that the DA substitution degree of GelMADA is replaced with 13%. The result proves that the content of dopamine is insufficient, which greatly reduces the porosity or crosslinking degree of the hydrogel.

[0076] Comparative Example 3

[0077] A hydrogel (HH), which is prepared by:

[0078] The HANT prepared in Example 1 is added to 1 mL of PBS solution, and the HANT and PBS solution are stirred at a moderate speed to ensure that the HANT is completely dissolved and a uniform solution is formed. After the above steps are completed, the prepared HANT solution is transferred to a suitable curing mold. Then, the HANT solution under the mold is irradiated with a UV lamp (wavelength 365 nm, power 40 mW / cm 2 ) to cure the gel.

[0079] Comparative Example 4

[0080] A hydrogel (GDL), which is prepared by:

[0081] Gelatin is dissolved in deionized water at about 40°C to prepare a 10% (w / v) gelatin solution, and stirred until completely dissolved. Glutaraldehyde is added to the solution and mixed thoroughly. The solution is poured into a mold and the crosslinking process is carried out. The crosslinking is maintained under suitable conditions for 24 hours. After gelation, the hydrogel is removed from the mold. It is washed thoroughly with deionized water to remove residual crosslinking agents and unreacted components.

[0082] Comparative Example 5

[0083] Gelatin-dextrin hydrogel (GDH), which is prepared by:

[0084] Gelatin was dissolved in deionized water to prepare a 10% (w / v) gelatin solution, which was stirred at 40°C until completely dissolved. Dextrin was dissolved in deionized water to prepare a dextrin solution with a suitable concentration. The gelatin solution and the dextrin solution were mixed and stirred thoroughly. An appropriate amount of glutaraldehyde was added and stirred until uniform. The mixed solution was poured into a mold. The solution was left to stand at a suitable temperature for 12-24 hours to complete the gelation process. The hydrogel was removed from the mold. The hydrogel was washed with deionized water to remove unreacted substances.

[0085] Comparative Example 6

[0086] Methacrylated gelatin (GL) was prepared by the following method:

[0087] GelMA (60 mg) and LAP (1 mg) were dissolved in 900 μL and 100 μL PBS solution, respectively, and dissolved by ultrasonic heating at 50°C to form a uniform transparent solution. The GelMA solution and the LAP solution were mixed and stirred until uniform. The mixture was cured into a gel under a UV lamp to obtain a GL hydrogel with a solid content of 6%. The GelMA was prepared by ammonolysis of gelatin and methacrylic anhydride.

[0088] Comparative Example 7

[0089] Gelatin-hyaluronic acid hydrogel (GHL) was prepared by the following method:

[0090] GelMA (50 mg), HANT (10 mg), and LAP (1 mg) were dissolved in 400 μL, 500 μL, and 100 μL PBS solution, respectively, and dissolved by ultrasonic heating at 50°C to form a uniform transparent solution. The GelMA solution, the HANT solution, and the LAP solution were mixed and stirred until uniform. The mixture was cured into a gel under a UV lamp to obtain a GHL hydrogel with a solid content of 6%, wherein mGelMA:mHANT = 5:1.

[0091] Application effect test

[0092] The GDHL hydrogel prepared in Example 1 was subjected to the following performance tests.

[0093] 1. Appearance and morphology

[0094] The GDHL, GDL, and HH hydrogels were subjected to SEM characterization, and the results are shown in Figure 1 A, B, and C, respectively. It was found that the GDHL hydrogel had a dense crosslinking inside, the pore sizes were different and showed a cross-distribution characteristic, and compared with the traditional single crosslinking network hydrogels (GDL and HH), the GDHL hydrogel had a more dense pore distribution and a relatively larger crosslinking density.

[0095] After determining that the GDHL hydrogel system has good gelation performance, the single-point gelation ability of the GDHL hydrogel system is further tested. Specifically, the GDHL hydrogel is cured by light irradiation in heavy water, and the heavy water around the GDHL hydrogel is characterized by nuclear magnetic resonance. The results show that there is no uncured monomer fragment in the aqueous solution, and no free GDHL hydrogel fragment is found, which proves that the GDHL hydrogel has good single-point gelation performance.

[0096] 2. Rheological properties

[0097] The GDHL hydrogel precursor solution of Example 1 is uniformly coated on the lower plate of a rotational rheometer. The in-situ UV curing gelation process is tested in the time scanning oscillation mode. The test conditions are as follows: the wavelength of the UV light source is 365 nm, the light power density is 40 mW / cm 2 The gelation point is the intersection of the G' (storage modulus) and G'' (loss modulus) curves, and the final gelation modulus is the average modulus of the G' curve when the G' curve tends to be balanced.

[0098] The results are shown in Figure 2 As the irradiation time increases, the G' and G'' of the GDHL hydrogel gradually increase, and the G' and G'' intersect at 1.5 s after the start of irradiation, which proves that the GDHL hydrogel has shown solid viscoelasticity at this time. Continue to irradiate, and the G' and G'' continue to increase, and the final gelation modulus of G' can reach 4845.7 Pa. Among them, Figure 2 G' and G'' in the above formula respectively represent the storage modulus and the loss modulus of the material, the storage modulus represents the elastic energy stored by the material when a strain is applied, and the loss modulus represents the energy dissipated by the material when a strain is applied. Time represents time. When the compression strain is 50%, the compression strength of the GDHL hydrogel is 51.5 kPa, and the Young's modulus is 17.7 kPa. These results show that the GDHL hydrogel has excellent mechanical properties, which ensures that the GDHL hydrogel can withstand higher mechanical load and deformation. In addition, the energy dissipation of the GDHL hydrogel sharply rises to 102.34 kJ / m 3 , which is mainly due to the dynamic covalent bonds existing in the hydrogel. Through the breaking of the dynamic C-S bond and the S-S bond, the mechanical force acting on the hydrogel is dissipated, so that it can withstand greater pressure and still maintain good elasticity after the pressure is removed, and has excellent fatigue resistance. In addition, the shear thinning property characterization of the GDHL hydrogel precursor solution shows that the viscosity of the GDHL hydrogel precursor solution gradually decreases with the increase of the shear rate, which indicates that the intermolecular force in the GDHL hydrogel precursor solution gradually weakens under the action of shear force. It shows that the GDHL hydrogel has good injectability, which is conducive to its injection administration in subsequent biological applications.

[0099] Under the same light power density of 365 nm UV irradiation, the gelation point of single cross-linking mode hydrogel HH, GDH, GDL is 2.8 s, 2.5 s and 15.63 s respectively, indicating that GDHL shows faster gelation speed compared with each single cross-linking mode hydrogel HH, GDH, GDL, GL. Compared with commercial UV-cured hydrogel GelMA (GL), GDHL hydrogel also exhibits faster gelation rate and higher mechanical strength. GL hydrogel can reach the gelation point at 2.82 s, nearly twice slower than GDHL hydrogel, and its ultimate modulus is only 1 / 6 of GDHL hydrogel. This result shows that the introduction of HANT greatly improves the gelation performance of GDHL hydrogel.

[0100] The gelation speed of GDHL hydrogel is much faster than that of GDL hydrogel, which may be due to the introduction of dopamine. The benzene ring in dopamine acts as a rigid skeleton, which will cause the formation of a stacking structure after introducing a flexible molecular chain. The resulting decrease in compatibility may cause a small phase separation structure in the hydrogel precursor solution. This effect will reduce the gelation efficiency of the GDL hydrogel precursor solution, thereby extending its gelation time. After adding the HANT macromolecule, the large number of polar groups on the surface of the macromolecule not only can interact closely with the aqueous solution, but also can reduce the distance between molecules, weaken the phase separation result caused by dopamine, and thus improve the gelation efficiency of GDHL. In addition, HH, GDH hydrogel is mainly formed by oxidation reaction and Michael addition reaction, and its reaction rate is significantly slower than that of photo-induced radical addition. Therefore, its gelation rate is also relatively slow. In addition, compared with each single cross-linking mode hydrogel, GDHL hydrogel also shows higher mechanical strength, and its ultimate modulus is 7.5, 4.0 and 88 times that of HH, GDH, GDL hydrogel, respectively, further proving the advantage of hybrid cross-linked hydrogel in gelation performance.

[0101] 3. Tissue adhesion

[0102] The tissue adhesion of GDHL hydrogel was evaluated by pig skin lap shear experiment. Specifically, two pieces of pig intestine were adhered to two pieces of glass with cyanoacrylate glue. After fixing, GDHL hydrogel precursor solution was taken and evenly coated on the surface of pig intestine. The other glass piece covered with pig intestine was placed on the glass piece, so that the pig intestine parts on the two glass pieces adhered together. After pressing, it was placed under a UV lamp (365 nm, 40 mW / cm 2) for 5 min to solidify the hydrogel between the pig casings into a glue and adhere together. The prepared samples were tested by a tensile testing machine and the breaking force was recorded. The fibrin glue and GHL hydrogel were tested by the same method and testing parameters to calculate the adhesive strength. To make a comparison, the hydrogel GHL without modified dopamine and the commercial medical glue fibrin glue were also selected for comparison. See Figure 3 , the experimental results show that the adhesive strength of the GDHL hydrogel can reach 49 kPa, which is much higher than that of the GHL hydrogel (24.3 kPa) and the fibrin glue (12.7 kPa). Among them, Figure 3 , the tissue adhesive strength represents the tissue adhesion strength.

[0103] 4. Used as a medical dressing

[0104] To explore the application effect of the GDHL hydrogel as a medical dressing, GelMADA was dissolved in 400 μL of PBS solution to ensure its complete dissolution, and a magnetic stirrer can be used for stirring until the solution is uniform. At the same time, HANT was dissolved in 500 μL of PBS solution, and a magnetic stirrer was also used for stirring until the solution was uniform. The GelMADA solution was mixed with the HANT solution, placed in a sterile container, and stirred at room temperature using a magnetic stirrer, and then LAP photoinitiator was added to the mixed solution, followed by slow addition of 32 P solution (Na2HPO4) and mixed with Eosin Y (Eosin Y) for staining. This process should be carried out on a radioactivity bench and avoid generating bubbles. The mixed solution was transferred to a mold. The mold was placed under a UV lamp (365 nm, 40 mW / cm 2 ) for light curing to obtain 32 P-GDHL hydrogel. The GDHL hydrogel precursor solution was coated on the pig skin tissue and formed a hydrogel in situ under UV light, and the adhesion of the 32 P-GDHL hydrogel on the pig skin tissue was tested. See Figure 4 , the results show that before soaking, 32 P-GDHL hydrogel can firmly adhere to the pig skin tissue without falling off during the process of stretching, bending, twisting and different pressure water flushing; then, the pig skin tissue with the adhered hydrogel was soaked in PBS solution, and it was found that the GDHL hydrogel could still adhere to the surface of the pig skin after about 48 hours of soaking, indicating that the GDHL hydrogel has strong tissue adhesion. This proves 32The P-GDHL hydrogel has excellent mechanical properties and elasticity, and can closely adhere to the biological tissue to be treated (such as a keloid), providing effective local fixation, reducing the displacement or shedding of the patch, and improving the stability and effectiveness of the treatment. In addition, hyaluronic acid has moisturizing and antibacterial properties, 32 The P-GDHL hydrogel patch can also provide certain antibacterial effect during the treatment process, reduce the risk of infection, and promote the regeneration of damaged skin, and can be used as a medical patch for the treatment of keloids and the like. Among them Figure 4 In the above table, before soaking is before soaking, after soaking is after soaking, original state is original state, stretching is stretching, twisting is twisting, folding is bending, and water flow is water flow.

[0105] The above experimental results all show that the adhesion between the hydrogel and the tissue is significantly improved after the introduction of dopamine; the introduction of HANT greatly improves the adhesion of the hydrogel, which is due to the presence of a large number of polar groups such as hydroxyl groups on the hyaluronic acid molecules, which can interact with the tissue through hydrogen bonds and other adhesion effects.

[0106] 5. Used as a radionuclide carrier

[0107] The 177 The LuCl3 solution was added to the physiological saline containing the GDHL hydrogel of Example 1, and was treated with ultrasound at 50°C for 30 min, then the pH value was adjusted to 12-13 with a sodium hydroxide solution, followed by centrifugation at a speed of 5000 rpm per minute for 5 min, after removing the supernatant, washing and using deionized water and physiological saline to centrifuge alternately 3 times to remove free 177 LuCl3, and finally obtained 177 Lu-GDHL radiolabeled hydrogel. Further 177 The Lu-GDHL radiolabeled hydrogel was applied as a radioactive embolization agent in the treatment of liver cancer, the process was as follows: first, anesthetic was injected into the abdominal cavity, and the rabbit was fixed on the rabbit board; then the right thigh was shaved, the skin and muscle were cut open, and the femoral artery was found and exposed; then a small opening was cut on the femoral artery with scissors, the sheath was introduced into the femoral artery, then the catheter and guide wire were introduced into the sheath, and the catheter was inserted into the hepatic artery, and 177 The Lu-GDHL radiolabeled hydrogel was injected into the artery through the catheter, and the diffusion of the material in the body was monitored by digital subtraction angiography (DSA) and fluorescence imaging.

[0108] Under the monitoring of digital subtraction angiography (DSA) and fluorescence imaging, the results showed that,177 After Lu-GDHL radiolabeled hydrogel embolization, the hydrogel can be accurately injected into the hepatic artery and clearly visible in imaging, 77 Lu-GDHL radiolabeled hydrogel forms local concentration in the liver tumor area, and the distribution in the tumor is stable, with low radioactive leakage rate, 177 The stability of Lu radiolabeling is more than 95% (see Figure 5 Due to 177 The slow-release characteristics of Lu can maintain a high radioactive dose in the tumor area for a long time, and this continuous radioactive irradiation can enhance the killing effect on tumor cells, while relatively reducing the radiation damage to normal tissues. The above results show that the dynamic covalent bond of the hydrogel can form strong chemical interactions in the tumor tissue environment, promote the adhesion between the hydrogel and the tumor tissue, so that 177 Lu can be stably combined in the hydrogel network, reducing the leakage of radionuclides, which further means 177 Lu-GDHL hydrogel can form local concentration in the tumor area, improving the targeted therapy effect. In addition, since the prepared hydrogel in the embodiment of the present application is used as a carrier to form a coordination compound with the ions of the radionuclide, the dopamine structure contains two phenol groups, which can form a complex with rare earth ions through coordination, forming a more stable radionuclide preparation to prevent radionuclide leakage.

[0109] In order to track the state of the hydrogel implanted in the body, a double-layer structure of rare earth nanoparticles NaYbF4:2%Er,2%Ce@NaYF4 (RENP) is used, the particle size of the rare earth nanoparticles is about 35 nm, the excitation light wavelength is 980 nm, and the emission peak is located at 1550 nm. Because the emission wavelength of RENP is in the near-infrared region, compared with RENP emitting in the visible light region, it can reduce the influence of biological tissue on light absorption and scattering, and is suitable for high-resolution in vivo imaging. Therefore, RENP is doped into the GDHL hydrogel precursor solution and solidified in situ to form a hydrogel. The hydrogel is implanted into the back of the mouse by subcutaneous injection, and in situ gelation is carried out by ultraviolet light. The results show that Figure 6 After being implanted in the body for 7 hours, the GDHL hydrogel still firmly adheres to the in situ without moving and spreading, proving that the GDHL hydrogel has good in vivo adhesion and stability.

[0110] 6、Hemostatic performance

[0111] The hydrogel prepared in Example 1 was applied to the plugging of a kidney puncture wound, specifically to evaluate the hemostatic performance of the GDHL hydrogel for plugging a rabbit kidney puncture wound. First, a puncture needle was used to puncture the lower end of the rabbit kidney and create a bleeding wound; then a photocuring needle was inserted into the bottom of the needle channel, the ultraviolet light source was turned on, and the GDHL hydrogel precursor solution was injected; as the photocuring needle slowly retracted, a dense GDHL hydrogel plugging matrix was formed inside the puncture needle channel, the needle channel was plugged, and bleeding stopped. The amount of blood loss of the GDHL hydrogel, fibrin glue, and control groups is shown in Table 1. Figure 7 As shown in Table 1, by counting the hemostatic time and amount of bleeding during the plugging process, it was found that the GDHL hydrogel could completely plug and stop bleeding in 34 s, and its hemostatic time was basically the same as that of the commonly used fibrin glue (37 s), while the blank control group without any hemostatic measures completely stopped bleeding in about 135 s. In addition, the amount of bleeding in the GDHL hydrogel plugging experimental group was significantly reduced compared with the fibrin glue, which may be caused by the hemostatic characteristics of the photocuring needle. Since the photocuring needle is inserted into the bottom of the needle channel to stop bleeding, this method can timely plug the bleeding wound, thereby avoiding a large amount of blood gushing out along the needle channel. The fibrin glue mainly plugs the needle hole at the top of the needle channel, i.e., the surface of the kidney wound. In the plugging process, fibrinogen and thrombin need to be mixed, and this cumbersome operation process inevitably increases the amount of bleeding during hemostasis, so compared with the GDHL hydrogel, the fibrin glue control group has a larger amount of bleeding. These results show that the GDHL hydrogel has excellent hemostatic performance and can plug the wound in a short time while greatly reducing the amount of bleeding. Among them, Figure 7 Bleeding weight is the amount of bleeding, and Control is the control group.

Claims

1. A photocrosslinked hydrogel, characterized in that The invention relates to a cross-linked network structure comprising dopamine-modified methacrylated gelatin and o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid; the degree of dopamine substitution in the dopamine-modified methacrylated gelatin is 14-18%; and the mass ratio of the dopamine-modified methacrylated gelatin to the o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid is (3-6):1; The photocrosslinked hydrogel is prepared by a preparation method comprising the following steps: (1) taking a sodium hyaluronate solution, adding 2-((2-nitrobenzyl)thio)ethane-1-amine and a first condensing agent, mixing, adjusting the pH value to 4-5, then adding a second condensing agent, performing a first amide reaction, and obtaining o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid; (2) Dopamine-modified methacrylated gelatin and o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid are dissolved in a solvent respectively to obtain a solution containing dopamine-modified methacrylated gelatin and a solution containing o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid, and then the two solutions are mixed, a photoinitiator is added to obtain a hydrogel precursor solution, and the photocuring is performed to obtain the photocrosslinked hydrogel.

2. The method for preparing the photocrosslinked hydrogel according to claim 1, characterized in that: The steps include: (1) taking a sodium hyaluronate solution, adding 2-((2-nitrobenzyl)thio)ethane-1-amine and a first condensing agent, mixing, adjusting the pH value to 4-5, then adding a second condensing agent, performing a first amide reaction, and obtaining o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid; (2) Dopamine-modified methacrylated gelatin and o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid are dissolved in a solvent respectively to obtain a solution containing dopamine-modified methacrylated gelatin and a solution containing o-nitrobenzyl sulfide phototrigger-modified hyaluronic acid, and then the two solutions are mixed, a photoinitiator is added to obtain a hydrogel precursor solution, and the photocuring is performed to obtain the photocrosslinked hydrogel.

3. The method for preparing the photocrosslinked hydrogel according to claim 2, wherein: In step (1), the temperature of the first amide reaction is 20-30° C., and / or the time of the first amide reaction is 24-60 h.

4. The method for preparing a photocrosslinked hydrogel according to claim 2, wherein: In step (1), the first condensing agent is 1-hydroxybenzotriazole, and / or the second condensing agent is N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride.

5. The method for preparing the photocrosslinked hydrogel according to claim 2, wherein: In step (2), the photoinitiator is phenyl (2,4,6-trimethylbenzoyl) lithium phosphate.

6. The method for preparing the photocrosslinked hydrogel according to claim 2, wherein: In step (2), the solid content of the hydrogel precursor solution is 4-8%.

7. The method for preparing a photocrosslinked hydrogel according to claim 2, wherein: In step (2), the method for preparing the dopamine-modified methacrylated gelatin comprises the following steps: mixing dopamine hydrochloride and methacrylated gelatin, and preparing the dopamine-modified methacrylated gelatin through a second amide reaction.

8. The method for preparing a photocrosslinked hydrogel according to claim 7, wherein: The temperature of the second amide reaction is 20-30° C., and / or the time of the second amide reaction is 10-24 hours.

9. The method for preparing a photocrosslinked hydrogel according to claim 7, wherein: The methacrylated gelatin is activated before mixing. The activation step comprises: first dissolving the methacrylated gelatin in a buffer solution, then adding 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, and mixing at 20-30° C. for 2-8 minutes.

10. Use of the photocrosslinked hydrogel according to claim 1 or the photocrosslinked hydrogel prepared by the preparation method according to any one of claims 2 to 9 in the preparation of medical carriers, hemostatic materials, dressings, wearable devices or sensors.

11. A preparation containing radionuclides, characterized in that: The invention comprises a radioactive nuclide and a carrier, wherein the radioactive nuclide is loaded on the carrier, and the carrier is the photo-crosslinked hydrogel according to claim 1 or the photo-crosslinked hydrogel prepared by the preparation method according to any one of claims 2 to 9.

12. A radionuclide-containing patch, characterized in that: The invention comprises a radionuclide and the photo-crosslinked hydrogel according to claim 1 or the photo-crosslinked hydrogel prepared by the preparation method according to any one of claims 2 to 9.

13. A hemostatic material, characterized in that: The invention comprises the photo-crosslinked hydrogel according to claim 1 or the photo-crosslinked hydrogel prepared by the preparation method according to any one of claims 2 to 9.

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