Drug loading system for treating corneal scars based on Tbeta4 and EISA hydrogel

Abstract

The invention provides a medicine carrying system for treating corneal scars based on Tbeta4 and EISA hydrogel, the medicine carrying system is formed by covalently connecting the Tbeta4 and an EISA hydrogel skeleton, the Tbeta4 is a peptide fragment TB500 with an active function, the EISA hydrogel skeleton selects a YYY hydrogel skeleton Nap-YYY-G, and the formed medicine carrying system is YYY-TB500. By combining the anti-fibrosis effect of the Tbeta4 and the drug delivery advantage of the EISA polypeptide hydrogel, the delivery efficiency and drug effect of the Tbeta4 can be effectively improved, so that the repair process after corneal injury is improved, scar formation is reduced, and a new thought and treatment means are provided for treatment of corneal injury and scar.

Description

Technical Field

[0001] The invention belongs to the field of medical and pharmaceutical technology, and in particular relates to a drug-carrying system based on Tβ4 and EISA hydrogel for treating corneal scars. Background Art

[0002] The cornea is a transparent tissue in the front part of the eyeball that focuses light, maintains the shape of the eyeball, and protects the eyes. Under normal circumstances, the cornea is composed of five layers of tissue, of which the stroma occupies most of the thickness of the cornea and is mainly composed of collagen fibers and corneal stroma cells, which maintain the transparency and morphology of the cornea. However, when the cornea is affected by trauma, infection or other pathological conditions, fibrosis or scarring may occur, resulting in loss of corneal transparency, seriously affecting vision, and may even cause blindness.

[0003] Common causes of corneal injury include trauma, infection, refractive surgery, etc. The healing process of the cornea after injury usually involves inflammatory response, cell migration, proliferation and matrix reconstruction. During the healing process, if the fiber cells proliferate excessively and transform into myofibroblasts, it will cause the formation of corneal scars, which will lead to the loss of corneal transparency and affect vision. The occurrence of corneal scars is closely related to factors such as the severity of the injury, the type of injury and individual differences. Although existing treatments can alleviate scar formation after corneal injury to a certain extent, there are still problems with limited efficacy and large side effects.

[0004] At present, conventional methods for treating corneal scars mainly include topical use of corticosteroids, mitomycin C and other drugs. These drugs can slow down scar formation by inhibiting the proliferation and migration of fibroblasts, but their efficacy is limited and may cause side effects such as glaucoma, cataracts, and corneal scleral fusion. When these drugs are not effective enough or the patient's condition is serious, corneal transplantation becomes the last resort. However, corneal transplantation faces problems such as insufficient supply of donated corneas and rejection reactions, and patients also need long-term medical follow-up and immunosuppressive treatment after surgery.

[0005] With the popularity of refractive surgery (such as LASIK and PRK), the treatment of corneal scarring has become more important. In order to promote the healing of corneal wounds and reduce scar formation, new treatment strategies including cell therapy, tissue engineering and bioactive molecules have been introduced into the research of corneal injury repair in recent years. For example, the in vitro culture and transplantation of corneal stromal cells have improved the healing process of the cornea to a certain extent, but it still faces challenges such as cell differentiation into fibroblasts and inducing fibrosis.

[0006] In terms of molecular therapy, Tβ4, as a peptide molecule with anti-inflammatory, anti-fibrotic and tissue repair properties, has shown significant therapeutic potential in corneal injury repair. Tβ4 can promote the migration and regeneration of corneal epithelial cells, reduce the inflammatory response after corneal injury, and effectively inhibit the process of fibrosis. In addition, Tβ4 can also significantly accelerate the regeneration of corneal epithelium and improve the structure and function of the damaged site in local application after corneal abrasions or alkali burns. Therefore, Tβ4 has become a research focus as a potential drug for corneal injury repair.

[0007] However, existing drug delivery systems still face problems such as low bioavailability, poor stability and poor persistence of efficacy. Although traditional topical eye drops and eye ointments can provide drug treatment for patients, the bioavailability of the drug is low, and it may cause an uncomfortable foreign body sensation, affecting the patient's medication compliance. In order to overcome these problems, EISA hydrogel has received extensive attention in ophthalmic drug delivery in recent years. EISA hydrogel has good biocompatibility and biodegradability. Through enzyme-catalyzed self-assembly, it can form a hydrogel in situ at the drug delivery site, prolong the retention time of the drug on the ocular surface, thereby improving the local concentration and efficacy of the drug. This hydrogel system is particularly suitable for the treatment of corneal damage because it can be formed in situ at the site of corneal damage to ensure efficient delivery and sustained release of the drug.

[0008] At present, there has been no fundamental breakthrough in the treatment of corneal scars, especially in drug delivery. There is still a lack of treatment options that can stably and effectively deliver drugs with long-term effects.

[0009] In summary, the development of a new Tβ4 drug delivery system can not only overcome the limitations of existing treatment options, but also provide a more effective and safe treatment option for corneal injury repair and scar treatment, which has important clinical application value. Summary of the invention

[0010] In view of this, the present invention aims to propose a drug delivery system based on Tβ4 and EISA hydrogel for the treatment of corneal scars. By combining the anti-fibrotic effect of Tβ4 with the drug delivery advantages of EISA polypeptide hydrogel, the delivery efficiency and efficacy of Tβ4 can be effectively improved, thereby improving the repair process after corneal injury and reducing scar formation, providing a new idea and treatment method for the treatment of corneal injury and scars.

[0011] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0012] A drug delivery system based on Tβ4 and EISA hydrogel for treating corneal scars. The drug delivery system is formed by covalently linking Tβ4 and an EISA hydrogel skeleton. Tβ4 is a peptide segment TB500 with active functions. The EISA hydrogel skeleton selects a YYY hydrogel skeleton Nap-YYY. The formed drug delivery system is YYY-TB500.

[0013] Furthermore, YYY-TB500 is a phosphorylation system, and after phosphorylation it becomes YpYY-TB500 or YYpY-TB500 or YYYp-TB500.

[0014] Furthermore, the drug delivery system is prepared by a method comprising the following steps:

[0015] 1) Solid phase synthesis of the functional peptide fragment TB500 of thymosin Tβ4;

[0016] 2) Then, amino acid G, amino acid YYY and amino acid Nap are sequentially connected to peptide segment TB500 to form a drug delivery system.

[0017] Further, the specific content of step 1) is: using dichloromethane to swell the dichloro resin, using DIPEA base to assist affinity substitution reaction, the first amino acid Q Fmoc-Gln(Trt)-OH of the polypeptide is bound to the solid phase dichloro resin; DCM-methanol solution is used to seal the resin; then, piperidine de-Fmoc and amino acid connection are carried out in sequence to connect the polypeptide NH 2 -L'K'K'T'E'T'Q-COOH carboxyl end is connected to the amino group of the amino acid to complete the synthesis of the thymosin Tβ4 functional peptide segment.

[0018] Further, the specific content of step 2) is:

[0019] 2.1) Connecting of amino acid G:

[0020] The Fmoc protecting group on the peptide TB500 was removed by piperidine, and then the treated peptide TB500 was added to DMF dissolved with amino acid G, HBTU, and DIPEA to react and realize the connection of amino acid G;

[0021] 2.2) Connecting of amino acids YYY:

[0022] The Fmoc protecting group is removed by piperidine, and then DMF containing amino acid Y or phosphorylated amino acid Yp, HBTU, and DIPEA is added for reaction; after the reaction, amino acid Y or Yp is repeatedly added for reaction to realize the connection of amino acid YYY;

[0023] 2.3) Connecting the amino acid Nap:

[0024] The Fmoc protecting group was removed with piperidine, and then Nap, HATU, and DIPEA were added to DMF for reaction to achieve the connection of amino acid Nap; finally, a drug delivery system based on Tβ4 and EISA hydrogel for the treatment of corneal scars was formed.

[0025] Furthermore, in step 2.1), the amount of amino acid G added is 1-2 molar equivalents, the amount of HBTU added is 1-2 molar equivalents, the amount of DIPEA added is 2-4 molar equivalents, and 15 ml of DMF is added; the reaction is carried out for 2 hours, and after the reaction, it is necessary to wash with DMF 3 times.

[0026] Further, in step 2.2), the amount of amino acid Y or phosphorylated amino acid Yp added is 0.5-1 molar equivalent, the amount of HBTU added is 0.5-1 molar equivalent, the amount of DIPEA added is 1-2 molar equivalent, and 15 ml of DMF is added; each reaction is carried out for 2 hours, and at the end of the reaction, it is necessary to wash with DMF 3 times.

[0027] Further, in step 2.3), the amount of amino acid Nap added is 0.5-1 molar equivalent, the amount of HATU added is 0.5-1 molar equivalent, the amount of DIPEA added is 1-2 molar equivalent, and 15 ml of DMF is added; the reaction is carried out for 2 hours.

[0028] Furthermore, after completing step 2.3), the polypeptide needs to be removed: wash with DMF 3 times, and then wash with DCM 3 times; then use a vacuum pump to drain the solution, and add trifluoroacetic acid, TTS, and pure water solution to carry out acid hydrolysis reaction for 1 hour; after the reaction, transfer the solution to a spherical glass bottle and purge it with DCM 3 times; then perform rotary evaporation to concentrate the polypeptide sample, and precipitate the polypeptide with ether, and finally perform liquid chromatography separation and purification and mass spectrometry detection to obtain a single component and a drug delivery system with a determined molecular weight.

[0029] The present invention also provides an application of the drug-carrying system for treating corneal scars based on Tβ4 and EISA hydrogel as described above in preventing and treating corneal scars.

[0030] Compared with the prior art, the drug delivery system based on Tβ4 and EISA hydrogel for treating corneal scars described in the present invention has the following advantages:

[0031] (1) The drug delivery system based on Tβ4 and EISA hydrogel for treating corneal scars described in the present invention is achieved by covalently linking Tβ4 (a 4.9 kDa protein composed of 43 amino acid residues) to the EISA hydrogel backbone. Since the length of Tβ4 may cause the instability of the hydrogel, its active functional peptide segment TB500 is selected for modification and combined with the YYY hydrogel backbone, thereby improving the stability and therapeutic effect of the hydrogel.

[0032] (2) The present invention designs and synthesizes three drug delivery systems with different phosphorylation sites, the structures of which are YpYY-TB500 (Nap-YpYY-G-LKKTETQ-COOH), YYpY-TB500 (Nap-YYpY-G-LKKTETQ-COOH) and YYYp-TB500 (Nap-YYYp-G-LKKTETQ-COOH), respectively, and utilizes the changes in phosphorylation sites to regulate the biological activity of the peptide. Based on the combined results of cell experiments and animal experiments, the drug delivery system YYpY-TB500 is preferred; and by comparing the gel properties, secondary structures and morphologies of different drug delivery systems, YYpY shows the best stability and therapeutic effect. The YYpY-TB500 drug delivery system can inhibit the formation and development of corneal scars by promoting the proliferation and migration of corneal epithelial cells. The provided drug delivery system has excellent biocompatibility and stability, can prolong drug release time, improve therapeutic effects, has broad clinical application prospects, and can provide a new option for the prevention and treatment of corneal scars. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0034] Figure 1 The gelation conditions of different drug delivery systems; (A) is YpYY-TB500, (B) is YYpY-TB500, and (C) is YYYp-TB500;

[0035] Figure 2 Nanostructure characterization of different drug delivery systems; (A) is YpYY-TB500 before ALP catalysis, (B) is YpYY-TB500 after ALP catalysis, (C) is YYpY-TB500 before ALP catalysis, (D) is YYpY-TB500 after ALP catalysis, (E) is YYYp-TB500 before ALP catalysis, (F) is YYYp-TB500 after ALP catalysis;

[0036] Figure 3 In vitro cytotoxicity evaluation of different drug delivery systems on human corneal epithelial cells (HCECs), (A) 24h, (B) 48h, (C) 72h;

[0037] Figure 4 To evaluate the in vivo therapeutic efficacy of YYpY-TB500 drug delivery system as eye drops in corneal epithelial wound healing;

[0038] Figure 5 To quantitatively analyze corneal healing in different treatment groups;

[0039] Figure 6 Comparison of the retention of sodium fluorescein-loaded drug delivery systems in the anterior cornea. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example 1 Preparation of drug delivery system

[0043] The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel of the present invention is formed by covalently linking Tβ4 and an EISA hydrogel skeleton, wherein Tβ4 is a peptide segment TB500 with active functions, and the EISA hydrogel skeleton is a YYY hydrogel skeleton, and the formed drug delivery system is YYY-TB500.

[0044] The drug delivery system is prepared by the following method:

[0045] 1) Solid phase synthesis of thymosin Tβ4 functional peptide TB500:

[0046] Dichloromethane (DCM) was used to swell the dichloro resin, and the first amino acid Q (Fmoc-Gln (Trt) -OH) of the peptide was bound to the solid phase dichloro resin by DIPEA (N-N' diisopropylethylamine) base-assisted affinity substitution reaction, and the resin was blocked by DCM-methanol solution. Then, 20% piperidine was used to remove Fmoc and connect the amino acids, and the NH2-L'K'K'T'E'T'Q-COOH carboxyl end of the peptide was gradually connected to the amino group of the amino acid, completing the synthesis of the thymosin Tβ4 functional peptide TB500.

[0047] 2) Construction of drug delivery system

[0048] 2.1) Connecting of amino acid G:

[0049] Remove the Fmoc protecting group of peptide TB500 with 20% piperidine and react for 20 minutes. Then weigh 2 molar equivalents of amino acid G and 2 molar equivalents of HBTU (benzotriazole-N,N,N,N-tetramethyluronium hexafluorophosphate), dissolve them in 15 ml DMF (N,N-dimethylformamide), and add 4 molar equivalents of DIPEA (N,N-diisopropylethylamine). Place the reaction system on a shaker and react for 2 hours until it is basically dissolved. After the reaction, wash with DMF 3 times.

[0050] 2.2) Connecting of amino acids YYY:

[0051] Considering that TB500 peptides with different phosphorylation sites may have different biological activities and functions, three peptides phosphorylated at different sites were designed and synthesized, namely YpYY-TB500', YYpY-TB500' and YYYp-TB500'. YYY-TB500' without phosphorylation was also constructed.

[0052] YpYY-TB500': Remove the Fmoc protecting group with 20% piperidine and react for 20 minutes. Weigh 1 / 2 molar equivalent of amino acid Y (Fmoc-Yyr(tBu)-OH) and 1 / 2 molar equivalent of HBTU, dissolve them in 15ml DMF, and add 1 molar equivalent of DIPEA. After reacting for 2 hours, add amino acid Y and phosphorylated amino acid Yp (Fmoc-Tyr(H2PO3-)OH) in sequence, and react for 2 hours each time. Finally, wash the reaction system 3 times with DMF.

[0053] YYpY-TB500': Remove the Fmoc protecting group with 20% piperidine and react for 20 minutes. Weigh 1 / 2 molar equivalent of amino acid Y (Fmoc-Yyr(tBu)-OH) and 1 / 2 molar equivalent of HBTU, dissolve them in 15 ml of DMF, and add 1 molar equivalent of DIPEA. After reacting for 2 hours, add phosphorylated amino acid Yp and amino acid Y in sequence, and react for 2 hours each time. Finally, wash the reaction system with DMF 3 times.

[0054] YYYp-TB500': Remove the Fmoc protecting group with 20% piperidine and react for 20 minutes. Weigh 1 / 2 molar equivalent of phosphorylated amino acid Yp and 1 / 2 molar equivalent of HBTU, dissolve them in 15 ml of DMF, and add 1 molar equivalent of DIPEA. After reacting for 2 hours, add amino acid Y twice in sequence, and react for 2 hours each time. Finally, wash the reaction system with DMF 3 times.

[0055] YYY-TB500': Remove the Fmoc protecting group with 20% piperidine and react for 20 minutes. Weigh 1 / 2 molar equivalent of amino acid Y and 1 / 2 molar equivalent of HBTU, dissolve them in 15 ml of DMF, and add 1 molar equivalent of DIPEA. After reacting for 2 hours, add amino acid Y twice in sequence, and react for 2 hours each time. Finally, wash the reaction system with DMF 3 times.

[0056] 2.3) Connecting the amino acid Nap:

[0057] Remove the Fmoc protecting group with 20% piperidine solution and react for 20 minutes. Weigh 1 / 2 molar equivalent of Nap and 1 / 2 molar equivalent of HATU (2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate), dissolve them in 15 ml of DMF, and add 1 molar equivalent of DIPEA. React for 2 hours.

[0058] 2.4) Peptide removal

[0059] Wash with DMF 3 times, and then wash with DCM 3 times. Use a vacuum pump to drain the solution, and add 20 ml of trifluoroacetic acid (TFA) + 2.5% TTS + 2.5% pure water solution for acid hydrolysis reaction for 1 hour. After the reaction, the solution was transferred to a spherical glass bottle and purged with DCM 3 times. The peptide sample was concentrated by rotary evaporation, and the peptide was precipitated by ether. Finally, liquid chromatography separation and purification and mass spectrometry were performed to obtain a single component and molecular weight determined drug delivery system: YpYY-TB500 (Nap-YpYY-G-LKKTETQ-COOH), YYpY-TB500 (Nap-YYpY-G-LKKTETQ-COOH), YYYp-TB500 (Nap-YYYp-G-LKKTETQ-COOH) and YYY-TB500 (Nap-YYY-G-LKKTETQ-COOH).

[0060] Example 2 Self-assembly ability and hydrogel formation ability detection

[0061] The drug delivery systems prepared in Example 1: YpYY-TB500, YYpY-TB500, YYYp-TB500 and YYY-TB500 were taken and catalyzed by 1 U / mL alkaline phosphatase (ALP) at 37°C for 12 hours to observe the status of each drug delivery system.

[0062] The results are as follows Figure 1 As shown, YpYY-TB500 and YYYp-TB500 failed to form clear hydrogels, while YYpY-TB500 formed clear hydrogels at the same concentration.

[0063] The critical aggregation concentration (CAC) of different drug delivery systems was also obtained by dynamic light scattering (DLS) measurement. The CAC value of YYpY-TB500 was 72.1μM, the CAC of YpYY-TB500 was 318.7μM, and the CAC of YYYp-TB500 was 116μM. YYpY-TB500 was significantly lower than the other two, indicating that YYpY-TB500 was easier to aggregate to form stable self-assemblies.

[0064] In addition, if Figure 2 Transmission electron microscopy (TEM) characterization results showed that YpYY-TB500 before and after ALP catalysis failed to form regular nanostructures; short and thick nanofibers with a length of about 200 to 500 nm and a width of 25 to 35 nm were observed in YYpY-TB500 before ALP catalysis, and longer and entangled nanofibers were observed in YYpY-TB500 after ALP catalysis, forming nanotubes with a diameter of 50-150 nm; YYYp-TB500 before ALP catalysis failed to form regular nanostructures, and YYYp-TB500 after ALP catalysis formed short and thin nanofibers with a length of 300 to 700 nm and a diameter of 10 to 25 nm, but these nanofibers could not form a sufficiently stable network structure.

[0065] In summary, enzyme sites and catalytic kinetics have an important influence on the morphology of self-assemblies. Next, the optimal drug delivery system will be determined through joint verification of cell experiments and animal experiments.

[0066] Experiment 1 Cytotoxicity Assessment

[0067] Tβ4, TB500, YYY-TB500 (0 μM, 25 μM, 50 μM, 100 μM, 200 μM, 400 μM) were used respectively. Figure 3 YYY in Chinese), YpYY-TB500( Figure 3 YpYY), YYpY-TB500( Figure 3 YYpY) and YYYp-TB500 ( Figure 3 The toxicity to the cells was evaluated within 24, 48 and 72 hours respectively.

[0068] The results are as follows Figure 3 As shown in the figure, it can be seen that YYY-TB500( Figure 3 YYY in Chinese), YpYY-TB500( Figure 3 YpYY), YYpY-TB500( Figure 3YYpY) and YYYp-TB500 ( Figure 3 The YYpY-TB500 group had the highest cell activity and the best effect.

[0069] Experiment 2 Treatment effect evaluation

[0070] To evaluate the in vivo therapeutic effects of different drug delivery systems as eye drops in corneal epithelial wound healing, alkali burns were performed on the corneas of normal mice, and different formulations such as Tβ4, B500, YYY-TB500 ( Figure 4 YYY in Chinese), YpYY-TB500( Figure 4 YpYY), YYpY-TB500( Figure 4 YYpY) and YYYp-TB500 ( Figure 4 PBS was used as a control.

[0071] The drug delivery system with a minimum gelation concentration of 10 mg / mL (about 9 mM) was used as eye drops. Figure 4 The results showed that after 72 hours of treatment, the corneal wounds in all groups except the PBS and TB500 groups were basically closed.

[0072] like Figure 5 The quantitative analysis results showed that Tβ4 was taken three times a day, TB500 was taken three times a day, and YYY-TB500 ( Figure 5 YYY in Chinese), YpYY-TB500( Figure 5 YpYY), YYpY-TB500( Figure 5 YYpY) and YYYp-TB500 ( Figure 5 The corneal healing effects of each treatment group were different, among which the healing rates of Tβ4, YYY-TB500, YpYY-TB500, YYpY-TB500 and YYYp-TB500 groups were 99.87±0.26%, 89.79±0.25%, 90.17±0.67%, 98.65±1.69% and 88.29±0.65%, respectively. The healing rates of PBS group and TB500 group were 70.85±1.74% and 70.55±1.54%, respectively, which were consistent with normal conditions, and there was no infection or other influencing factors. These results show that Tβ4, YYY-TB500, YpYY-TB500, YYpY-TB500 and YYYp-TB500 can effectively accelerate the healing of corneal epithelial wounds.

[0073] In addition, combined Figure 4 and Figure 5 It can be found that the healing effect of the YYpY-TB500 group is the best.

[0074] Experiment 3: Evaluation of Residency

[0075] In order to observe and evaluate the precorneal retention of YYY-TB500, YpYY-TB500, YYpY-TB500 and YYYp-TB500, sodium fluorescein was physically loaded into the corresponding drug delivery systems, and the precorneal retention of sodium fluorescein was compared.

[0076] like Figure 6 As shown in the figure, the sodium fluorescein solution in the PBS group and the TB500 group disappeared rapidly from the lower conjunctival sac within 15 minutes after topical eye drops, indicating that sodium fluorescein was rapidly cleared due to the circulation and flushing of tears. In contrast, the sodium fluorescein-loaded YYY-TB500, YpYY-TB500, YYpY-TB500, and YYYp-TB500 significantly prolonged the precorneal residence time of sodium fluorescein. After more than 30 minutes, the green fluorescence was still visible in the lower conjunctival sac. The longer the residence time, the better the therapeutic effect. This prolonged precorneal residence may be related to the viscoelasticity of the hydrogel of the drug-carrying system.

[0077] For the potential application of this eye drop, it is recommended to use it before bedtime to reduce the blurred vision that may be caused by prolonged residence time in front of the cornea.

[0078] These results further indicate that YYY-TB500, YpYY-TB500, YYpY-TB500, and YYYp-TB500 drug delivery systems can be used as sustained-release systems for the prevention and treatment of corneal damage and scarring, especially YYpY-TB500, which is more effective and may become a promising topical ocular drug delivery vehicle.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel, characterized by: The drug delivery system is formed by covalently linking Tβ4 to an EISA hydrogel skeleton, wherein Tβ4 is a peptide segment TB500 with active functions, and the EISA hydrogel skeleton is selected as a YYY hydrogel skeleton Nap-YYY, and the formed drug delivery system is YYY-TB500.

2. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 1, characterized in that: YYY-TB500 is a phosphorylation system, and after phosphorylation it becomes YpYY-TB500 or YYpY-TB500 or YYYp-TB500.

3. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 2, characterized in that: The drug delivery system is prepared by a method comprising the following steps: 1) Solid phase synthesis of thymosin Tβ4 functional peptide TB500; 2) Then, amino acid G, amino acid YYY and amino acid Nap are sequentially connected to peptide segment TB500 to form a drug delivery system.

4. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 3, characterized in that: The specific content of step 1) is: using dichloromethane to swell the dichloro resin, using DIPEA base to assist affinity substitution reaction, and binding the first amino acid Q Fmoc-Gln(Trt)-OH of the polypeptide to the solid phase dichloro resin; DCM-methanol solution to seal the resin; then, piperidine de-Fmoc and amino acid connection are carried out in sequence to connect the NH2-LKKTETQ-COOH carboxyl end of the polypeptide to the amino group of the amino acid, thereby completing the synthesis of the thymosin Tβ4 functional peptide segment.

5. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 3, characterized in that: The specific content of step 2) is: 2.1) Connecting of amino acid G: The Fmoc protecting group on the peptide TB500 was removed by piperidine, and then the treated peptide TB500 was added to DMF dissolved with amino acid G, HBTU, and DIPEA to react and realize the connection of amino acid G; 2.2) Connecting of amino acids YYY: The Fmoc protecting group is removed by piperidine, and then DMF containing amino acid Y or phosphorylated amino acid Yp, HBTU, and DIPEA is added for reaction; after the reaction, amino acid Y or Yp is repeatedly added for reaction to realize the connection of amino acid YYY; 2.3) Connecting the amino acid Nap: The Fmoc protecting group was removed with piperidine, and then Nap, HATU, and DIPEA were added to DMF for reaction to achieve the connection of amino acid Nap; finally, a drug delivery system based on Tβ4 and EISA hydrogel for the treatment of corneal scars was formed.

6. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 5, characterized in that: In step 2.1), the amount of amino acid G added is 1-2 molar equivalents, the amount of HBTU added is 1-2 molar equivalents, the amount of DIPEA added is 2-4 molar equivalents, and 15 ml of DMF is added; the reaction is carried out for 2 hours, and after the reaction, it is necessary to wash with DMF 3 times.

7. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 5, characterized in that: In step 2.2), the amount of amino acid Y or phosphorylated amino acid Yp added is 0.5-1 molar equivalent, the amount of HBTU added is 0.5-1 molar equivalent, the amount of DIPEA added is 1-2 molar equivalent, and 15 ml of DMF is added; each reaction is carried out for 2 hours, and at the end of the reaction, it is necessary to wash with DMF 3 times.

8. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 5, characterized in that: In step 2.3), the amount of amino acid Nap added is 0.5-1 molar equivalent, the amount of HATU added is 0.5-1 molar equivalent, the amount of DIPEA added is 1-2 molar equivalent, and 15 ml of DMF is added; the reaction is carried out for 2 hours.

9. The drug delivery system for treating corneal scars based on Tβ4 and EISA hydrogel according to claim 5, characterized in that: After completing step 2.3), the polypeptide needs to be removed: wash with DMF 3 times, and then wash with DCM 3 times; then use a vacuum pump to drain the solution, and add trifluoroacetic acid, TTS, and pure water solution for acid hydrolysis reaction for 1 hour; after the reaction, transfer the solution to a spherical glass bottle and purge it with DCM 3 times; then perform rotary evaporation to concentrate the polypeptide sample, and precipitate the polypeptide with ether, and finally perform liquid chromatography separation and purification and mass spectrometry detection to obtain a single component and a drug delivery system with a determined molecular weight.

10. Use of the drug delivery system based on Tβ4 and EISA hydrogel for treating corneal scars as claimed in any one of claims 1 to 9 in preventing and treating corneal scars.

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