A supramolecular polypeptide hydrogel with ferroptosis reversal function and its application

Abstract

This invention provides a supramolecular polypeptide hydrogel with ferroptosis reversal function and its application. The supramolecular polypeptide hydrogel is formed by the self-assembly of polypeptide FRC through intermolecular non-covalent interactions. The amino acid sequence of polypeptide FRC is shown in SEQ ID NO.1. This invention uses a solid-phase peptide synthesis method to obtain a novel polypeptide FRC with highly efficient ferroptosis reversal activity. It can significantly reduce ROS levels, upregulate GPX4 expression, and enhance the antioxidant capacity of cardiomyocytes, thereby effectively inhibiting cardiomyocyte ferroptosis under oxidative stress. Simultaneously, polypeptide FRC can self-assemble into a supramolecular polypeptide hydrogel through intermolecular non-covalent interactions, allowing direct injection into the myocardial injury site. Utilizing the sustained-release properties of the hydrogel, the drug can be released for a long time, requiring only a single injection to continuously reverse the ferroptosis process, significantly reducing tissue damage and improving cardiac function, providing a new strategy for the development of related drugs and formulations.

Description

Technical Field

[0001] This invention belongs to the field of biomedicine, specifically relating to a supramolecular polypeptide hydrogel with ferroptosis reversal function and its application. Background Technology

[0002] Cardiovascular disease (CVD) is one of the leading causes of death and morbidity worldwide. In the clinical treatment of severe cardiovascular diseases such as myocardial infarction and heart failure, myocardial ischemia-reperfusion injury (MIRI) is a critical challenge that urgently needs to be addressed. After blood supply is restored to ischemic myocardial tissue, pathological processes such as reactive oxygen species (ROS) bursts, calcium overload, and inflammatory cascades are triggered, which in turn exacerbate myocardial cell death, promote myocardial fibrosis, and worsen cardiac function, severely impacting patient prognosis and long-term quality of life.

[0003] Ferroprelation is a novel, iron-dependent, lipid peroxide-driven regulatory cell death pathway characterized by imbalances in the cellular antioxidant system, glutathione (GSH) depletion, downregulation of glutathione peroxidase 4 (GPX4) levels, and excessive accumulation of lipid reactive oxygen species. It differs from traditional cell death pathways such as apoptosis and necrosis. Existing research has confirmed that ferroptosis is a key pathway mediating the pathological process of MIRI. During ischemia-reperfusion, disordered iron metabolism and excessive ROS production in cardiomyocytes directly induce ferroptosis, thereby amplifying tissue damage. Therefore, targeting and reversing ferroptosis has become an important research direction for the prevention and treatment of MIRI.

[0004] Currently reported ferroptosis inhibitors (such as Ferrostatin-1, deferoxamine, and Liproxstatin-1) have significant drawbacks: poor in vivo stability, short half-life, insufficient myocardial targeting, significant systemic toxicity, and difficulty in achieving prolonged retention at the site of injury, limiting their clinical translation. Peptide drugs, with their excellent biocompatibility, strong structural designability, low toxicity, and ease of modification, have shown great potential in targeted therapy for cardiovascular diseases. In particular, peptides with self-assembly properties can form three-dimensional network-like supramolecular hydrogels, enabling precise delivery to the injury site after local injection and long-term sustained drug release, effectively overcoming the delivery challenges of traditional ferroptosis inhibitors. However, there are currently no reported peptide molecules or related formulations that possess both highly efficient ability to reverse cardiomyocyte ferroptosis and the ability to form injectable self-assembling hydrogels, making it difficult to meet the clinical needs of MIRI (Minimally Invasive Myocardial Infection).

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a polypeptide with a novel structure, excellent ferroptosis reversal activity, and the ability to self-assemble into an injectable hydrogel, and to develop a corresponding supramolecular polypeptide hydrogel formulation to achieve long-term treatment of myocardial injury with a single injection, providing a novel and efficient drug candidate for myocardial ischemia-reperfusion injury. Summary of the Invention

[0006] To address the gaps in existing technologies and clinical needs, this invention provides a supramolecular polypeptide hydrogel with ferroptosis reversal function and its application. A specific polypeptide FRC is prepared by solid-phase synthesis. This polypeptide can self-assemble into a three-dimensional network hydrogel through intermolecular non-covalent interactions. It has the functions of efficiently scavenging ROS, upregulating the expression of ferroptosis-related antioxidant proteins, and reversing ferroptosis in cardiomyocytes. Moreover, it can achieve long-term sustained release after intramyocardial injection, significantly improving cardiac function damage caused by MIRI.

[0007] The technical solution of the present invention is as follows: Firstly, this invention provides a polypeptide FRC with ferroptosis reversal function. The amino acid sequence of the polypeptide FRC is: Fmoc-Phe-Phe-Arg-Arg-Cys(StBu) (SEQ ID NO.1), wherein Fmoc is 9-fluorenylmethoxycarbonyl, Phe is phenylalanine, Arg is arginine, and Cys(StBu) is cysteine ​​with a thiol group protected by StBu. This polypeptide has a novel structure, not reported in existing literature, and possesses specific ferroptosis reversal activity and self-assembly potential.

[0008] Secondly, the present invention provides a method for preparing the above-mentioned polypeptide FRC. In this embodiment, the polypeptide FRC with the sequence shown in SEQ ID NO.1 is prepared using the Fmoc solid-phase synthesis method. The specific steps are as follows: S1. Resin swelling: The solid support is fully swollen with dichloromethane, and the protecting groups are removed using a deprotection solution; S2, Amino Acid Coupling: A coupling agent is used to couple the first protected amino acid to the deprotected solid support. S3. Add deprotection solution to remove the terminal protecting groups of amino acids; S4. Repeat steps S2-S3 according to the amino acid sequence described in SEQ ID NO.1 to complete the full sequence amino acid coupling; S5. The polypeptide is cleaved from the solid support using a cleavage reagent, and then separated and purified to obtain the polypeptide.

[0009] Furthermore, the solid support is Rink resin; the deprotection solution is a 20% (v / v) piperidine solution, and the deprotection time is 15-30 min.

[0010] Further, in step S2, the coupling agent is a mixed solution of HBTU and DIPEA, and the coupling reaction time is 5-8 hours.

[0011] Furthermore, after each deprotection using the deprotection solution, the ninhydrin assay was used to check whether the Fmoc protecting group was successfully removed. If successful, the coupling of the next amino acid was then performed.

[0012] Furthermore, in step S5, the cleavage reagent is 95% TFA (TFA: triisopropylsilane: H2O = 95%: 2.5%: 2.5%). This method is a dedicated synthetic process for this novel polypeptide, with mild reaction conditions, high product purity, and suitability for scale-up preparation.

[0013] Thirdly, this invention provides a supramolecular polypeptide hydrogel with ferroptosis reversal function. The supramolecular polypeptide hydrogel is formed by the self-assembly of the polypeptide described in the first aspect or prepared by the method described in the second aspect through intermolecular non-covalent interactions. The supramolecular polypeptide hydrogel uses polypeptide FRC as the sole active building block and is formed through self-assembly via intermolecular hydrogen bonding, π-π stacking, hydrophobic interactions, and other non-covalent interactions. It possesses a three-dimensional fibrous network structure and typical hydrogel rheological properties, exhibiting excellent biocompatibility, degradability, and no significant cytotoxicity.

[0014] Fourthly, this invention provides a method for preparing supramolecular polypeptide hydrogels as described in the third aspect. The preparation method is mild and easy to operate, requires no chemical cross-linking agents, and is green and safe. The specific steps are as follows: the polypeptide FRC is mixed uniformly with a buffer solution in a certain proportion, and after brief heating for denaturation, it is allowed to stand at low temperature to complete self-assembly, directly obtaining an injectable supramolecular polypeptide hydrogel.

[0015] Furthermore, the mass-to-volume ratio of peptide FRC to buffer is 1 mg:400 μL; the buffer is a phosphate (PB) buffer with pH=7.4, which conforms to the physiological pH environment and ensures peptide activity and assembly stability. Furthermore, the heating temperature is 100℃ and the heating time is 2~5 min to fully dissolve and depolymerize the peptides; the refrigeration temperature is 3~5℃ and the refrigeration time is 2~5 h to promote the orderly self-assembly of peptide molecules and form a stable hydrogel.

[0016] Fifthly, the present invention provides a pharmaceutical formulation comprising at least one of the following: a polypeptide as described in the first aspect, a polypeptide prepared by the preparation method described in the second aspect, a supramolecular polypeptide hydrogel as described in the third aspect, or a supramolecular polypeptide hydrogel prepared by the preparation method described in the fourth aspect.

[0017] In a sixth aspect, the present invention provides the use of the polypeptide as described in the first aspect, or the polypeptide prepared by the method described in the second aspect, or the supramolecular polypeptide hydrogel as described in the third aspect, or the supramolecular polypeptide hydrogel prepared by the method described in the fourth aspect, or the pharmaceutical formulation as described in the fifth aspect. Preferably, it is used in the preparation of a drug for treating myocardial ischemia-reperfusion injury.

[0018] Furthermore, the application specifically includes at least one of the following: (1) Application in the preparation of drugs that reduce or reverse Erastin-induced myocardial ferroptosis; (2) Application in the preparation of drugs that improve left ventricular ejection fraction (LVEF) and enhance cardiac function; (3) Application in the preparation of drugs that improve left ventricular fractional shortening (LVFS) and relieve myocardial contractile dysfunction; (4) Application in the preparation of drugs that reduce intracellular ROS concentration and inhibit oxidative stress damage; (5) Application in the preparation of drugs that upregulate GPX4 expression in cardiomyocytes and enhance cellular antioxidant capacity; (6) Application in the preparation of drugs that upregulate SLC7A11 expression in cardiomyocytes and maintain glutathione metabolic homeostasis; (7) Application in the preparation of drugs that increase GSH content in cardiomyocytes and reverse the core pathway of ferroptosis.

[0019] Compared with existing technologies, the supramolecular polypeptide hydrogel with ferroptosis reversal function and its applications described in this invention have the following advantages: (1) The polypeptide with ferroptosis reversal function of the present invention has excellent activity and strong targeting: the polypeptide FRC has a novel structure, can efficiently clear ROS in cardiomyocytes, significantly upregulate the expression of antioxidant proteins such as GPX4 and SLC7A11, increase GSH content, reverse the ferroptosis process from the source, and specifically block the core pathological pathway of MIRI.

[0020] (2) The peptide delivery of the present invention with ferroptosis reversal function has outstanding advantages: the peptide FRC can self-assemble into an injectable supramolecular hydrogel without chemical cross-linking, and has high biosafety; after local injection into the myocardium, it relies on the three-dimensional network of the hydrogel to achieve long-term retention and sustained release, and only a single injection is needed to exert a continuous therapeutic effect, avoiding the inconvenience of multiple administrations and systemic toxic side effects. (3) The peptide preparation process of the present invention with ferroptosis reversal function is mature: the peptide FRC is prepared by solid-phase synthesis, the process is controllable, the purity is easy to ensure, and it is suitable for large-scale production; the hydrogel preparation conditions are mild, the excipients are simple, and it is easy to translate into clinical applications, providing a new treatment plan for myocardial ischemia-reperfusion injury that is both safe and effective. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram illustrating the function of the polypeptide hydrogel FRC in this invention; Figure 2 This is a schematic diagram of the synthetic route of the polypeptide FRC of the present invention; Figure 3 This is a schematic diagram of the characterization results of the supramolecular polypeptide hydrogel of the present invention, wherein A is a TEM image, B is a rheological strain scanning curve, C is a circular dichroism chromatogram, and D is a transmission electron microscopy image. Figure 4 The image shows the changes in intracellular ROS (green) levels in H9C2 cardiomyocytes after co-treatment with the peptide FRC and / or Erastin of the present invention. A is a ROS fluorescence imaging image, and B is a quantitative statistical graph of ROS levels. Figure 5 This is a schematic diagram showing the detection results of intracellular GPX4 and SLC7A11 protein levels after H9C2 cardiomyocytes were co-treated with the polypeptide FRC and / or Erastin of the present invention. In the diagram, A is a representative image of protein immunoblotting, B is a statistical graph of GPX4 protein level, and C is a statistical graph of SLC7A11 protein level. Figure 6 The changes in the intracellular GSH / GSSS ratio of H9C2 cardiomyocytes after co-treatment with the peptide FRC and / or Erastin of this invention; Figure 7 The present invention describes the rescue effect of the polypeptide FRC on Erastin-induced ferroptosis in H9C2 cardiomyocytes. Figure 8 This is a schematic diagram illustrating the therapeutic effect of the peptide FRC of the present invention on myocardial ischemia-reperfusion injury in mice. In the diagram, A is a schematic diagram of H&E and MASSON staining results, B is a schematic diagram of left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) results, and C is an echocardiogram. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the following embodiments are only used to explain the present invention and are not intended to limit the scope of protection of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] Example 1 Preparation of peptide FRC Rink resin was selected as the solid-phase support, and Fmoc was used to protect the polypeptide FRC with an amino acid synthesis sequence such as SEQ ID NO.1. The steps are as follows: S1. Resin swelling: Add an appropriate amount of Rink resin to the reaction column, add dichloromethane (DCM) and swell at room temperature for 30 min, then filter to remove DCM. S2, Deprotection: Add DMF solution with a volume fraction of 20% piperidine, deprotect at room temperature for 20 min, filter, and wash the resin three times alternately with DMF and DCM. The complete deprotection of the resin is verified by the ninhydrin detection method. S3, Amino Acid Coupling: Weigh the first Fmoc protected amino acid according to the resin:amino acid molar ratio of 1:2.5, dissolve it in DMF, add HBTU and DIPEA in a molar ratio of 1:1 to activate for 5 min, transfer it to the reaction column and mix it with the resin, react it in a shaker at room temperature for 6 h, filter and wash the resin, and use ninhydrin to detect complete coupling. S4. Peptide chain extension: Repeat steps S2-S3, and couple the remaining amino acids sequentially according to the sequence of SEQ ID NO.1 until the entire sequence is synthesized; S5. Cutting and purification: Add cutting reagent (TFA: triisopropylsilane: H2O = 95:2.5:2.5), react at room temperature for 2 hours to cut the peptide from the resin; collect the filtrate, remove excess TFA by rotary evaporation, add ice-cold ether to precipitate the peptide, centrifuge and discard the supernatant, freeze-dry the precipitate to obtain white pure peptide FRC product, and store in a sealed container at -20℃ for later use.

[0024] Example 2 Preparation of supramolecular polypeptide hydrogels Accurately weigh 1 mg of the peptide FRC prepared in Example 1, place it in a centrifuge tube, add 400 μL of PB buffer (pH=7.4, 200 mM), and vortex to mix. Place the centrifuge tube in a 100°C metal bath and heat for 3 min to completely dissolve and depolymerize the peptide. Quickly transfer it to a 4°C refrigerator and refrigerate for 4 h. The peptide self-assembles through non-covalent interactions to form a milky white, non-flowing supramolecular peptide hydrogel (Gel FRC), which is injectable and ready for use.

[0025] Performance Example 1: Gel FRC Characterization The prepared gel FRC was subjected to rheological tests on a Discovery HR-20 TA instrument. In dynamic frequency scanning mode, 200 μL of gel FRC was placed on the test sample platform with a fixed strain of 0.1%. The changes in storage modulus (G') and loss modulus (G'') of the hydrogel were measured within the frequency range of 1–100 Hz according to a pre-determined procedure. Dynamic strain scanning characterization of the hydrogel was performed at a fixed frequency of 1 rad / s within the range of 0.01%–1%, and the changes in G' and G'' were measured to verify the formation of the hydrogel.

[0026] The hydrogel FRC that had been allowed to stand was diluted to 500 μM with PB solution. Transmission electron microscopy (TEM) images of the diluted FRC were obtained using a Tecnai G2 F20 microscope to verify the assembly morphology of the FRC. In addition, circular dichroism chromatograms in the range of 180-280 nm were recorded using a J-715 circular dichroism spectrophotometer to verify the secondary structure of the FRC assembly.

[0027] The results are as follows Figure 3 As shown, the inverted bottle method demonstrates the formation of Fmoc-FFRRC polypeptide hydrogel (Gel FRC). Furthermore, rheological measurements of the Gel FRC sample show that its storage modulus (G') is greater than its loss modulus (G''), further verifying the hydrogel formation. Transmission electron microscopy images show that the surface morphology of the Gel FRC is a fibrous network structure.

[0028] Performance Example 2: ROS Testing Intracellular ROS levels were detected using the fluorescent probe DCFH-DA from a ROS assay kit (S0033S, Beyotime Biotech, China): H9C2 cells were cultured overnight in six-well plates (1×10⁻⁶ cells / wells). 5 Cells were treated with Erasrin / peptide FRC for 12 h, followed by pretreatment with an indicator for 0.5 h. After treatment, 500 μM DCFH-DA diluent was added to the six-well plates, and the cells were washed three times with serum-free medium. The cells were detected using a fluorescence microscope (WYS-41XDY, VIYEE, China) with an optical signal [fluorescein isothiocyanate (FITC), Ex / Em = 494 / 517 nm], and analyzed using ImageJ software.

[0029] The results are as follows Figure 4 As shown, Erastin can induce H9C2 cardiomyocytes to produce a large amount of ROS, but after co-treatment with the peptide FRC, the ROS level in cardiomyocytes decreased significantly, indicating that the peptide FRC can react with the ROS induced by Erastin and reduce the concentration of ROS in cardiomyocytes.

[0030] Performance Example 3: Expression determination of GPX4 and SLC7A11 Western blotting (WB) was used to assess the cellular-level promotion of GPX4 and SLC7A11 expression by peptide FRC: H9C2 cells were seeded in 6-well plates at a density of 1 × 10⁻⁶ cells / well. 5Cells / well. After 12 h of culture, PBS, peptide FRC, Erastin, and FRC+Erastin were added sequentially to six-well plates, with FRC and Erastin at a concentration of 10 μM each. After co-incubating the cells with each drug group for 24 h, the cells were washed twice with pre-chilled PBS, and 60 μL of RIPA lysis buffer was added to each well of the six-well plate. The culture plate was then placed on ice for lysis for 30 min. After lysis, the cells were scraped off with a cell scraper, and the lysis buffer was transferred to chilled 1.5 mL centrifuge tubes. The levels of GPX4 and SLC7A11 in H9C2 cells were determined by Western blotting.

[0031] The results are as follows Figure 5 As shown, in H9C2 cardiomyocytes, compared with the PBS group, Erastin treatment alone significantly downregulated the expression of GPX4 and SLC7A11 proteins. After treatment with the peptide FRC, the expression levels of GPX4 and SLC7A11 proteins were significantly upregulated compared to the Erastin-only treatment group, indicating that the peptide FRC can significantly reverse the Erastin-induced downregulation of GPX4 and SLC7A11 protein expression.

[0032] Performance Example 4: Determination of GSH Content in H9C2 Cardiomyocytes The GSH / GSSG ratio in H9C2 cells was determined using a GSH and GSSG assay kit (S0053, Beyotime Biotech, China). A brief sample of H9C2 cells (2 × 10⁶ cells) was collected. 6 Following the kit instructions, protein removal agent M was added, and the supernatant was collected to determine the total GSH value. GSH removal aid and working solution of the removal reagent were added to a portion of the sample to remove GSH, and the GSSG content was detected using a microplate reader at a wavelength of 412 nm. The GSSG content was subtracted from the total GSH content to determine the net GSH content, and the GSH / GSSG ratio was obtained.

[0033] The results are as follows Figure 6 As shown, compared with the control group, the GSH / GSSG ratio in the Erastin group was significantly decreased, indicating that the antioxidant capacity of H9C2 cells was significantly reduced after Erastin treatment; the GSH / GSSG ratio in the FRC group was significantly increased, indicating that FRC treatment can enhance the antioxidant capacity of H9C2 cells; the GSH / GSSG ratio in H9C2 cells after co-treatment with Erastin and FRC was significantly increased compared with the Erastin group, indicating that FRC can reverse the decrease in antioxidant capacity caused by Erastin.

[0034] Performance Example 5: Salvage Test of H9C2 Cardiac Cell Ferric Death Injury Digest H9C2 cells in the logarithmic growth phase at a concentration of 8 × 10⁻⁶. 3 Cells were seeded at a density of 100 cells / well in 96-well plates and incubated overnight. The old culture medium was discarded, and fresh culture medium containing different concentrations of peptide FRC / peptide FRC+Erastin was added and incubated for 24 hours. The old culture medium was discarded, the cells were washed once with PBS, and then incubated with CCK-8 for 2 hours. The absorbance of the solution was measured at 450 nm using a microplate reader. Cell viability was expressed as a percentage of the control culture and calculated using the following formula: Cell viability (%) = (OD drug - OD blank) / (OD control - OD blank) × 100%.

[0035] Concentrations of peptide FRC: 1 μmol / L, 2 μmol / L, 5 μmol / L, 10 μmol / L, 20 μmol / L, 50 μmol / L; Erastin concentration: 10 μmol / L.

[0036] The results are as follows Figure 7 As shown, compared with the control group, the cell viability of the Erastin group was significantly decreased, indicating that Erastin effectively induced ferroptosis. The cell viability of the FRC 50μM group was almost the same as that of the control group, indicating that the peptide FRC had no obvious toxicity to cells and had good biocompatibility. However, the cell viability of the peptide FRC+Erastin group was significantly increased compared with the Erastin group, indicating that the peptide FRC can effectively reverse Erastin-induced ferroptosis, reduce cell death, and restore cell viability.

[0037] Performance Example 5: Therapeutic Test of Myocardial Ischemia-Reperfusion Injury in Mice Mice were anesthetized and fixed with isoflurane. Hair was removed from the left side of the chest and the area was disinfected. The chest skin was cut open, and the pectoralis major and pectoralis minor muscles were bluntly separated. An opening was made between the 3rd and 4th ribs, and the chest cavity was opened. The heart was squeezed out and the capsule was cut open to expose the left anterior descending coronary artery. The coronary artery was ligated with 6-0 sutures 1-2 mm below the lower edge of the left atrial appendage. The ligation area was pale, indicating success. Then, 10 μL of Gel FRC was injected at each of the three sites in the infarct border area with an insulin injection needle. The muscle and skin were quickly sutured. The mice were placed on a preheating pad to recover. After 30 minutes, the ligation sutures were loosened to complete the IR model construction and intramyocardial injection in mice.

[0038] One week after the surgery, echocardiography was used to measure left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS). The mice were then euthanized, their hearts were removed, fixed, embedded in paraffin, and cut into 5 mm sections for further histological analysis, including H&E staining and MASSON staining.

[0039] The results are as follows Figure 8As shown, in the sham-operated group of mice, Gel FRC treatment had minimal impact on heart rate, cardiac function, and myocardial fibrosis. In the myocardial infarction group, Gel FRC significantly reduced cardiac dysfunction. Seven days after myocardial infarction, the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were significantly improved in the Gel FRC treatment group. H&E and MASSON staining results of cardiac sections also indicated that Gel FRC could reduce myocardial tissue necrosis caused by myocardial infarction in mice. These results demonstrate that Gel FRC can effectively treat cardiac damage caused by myocardial infarction in mice.

[0040] In summary, the supramolecular polypeptide hydrogel FRC of the present invention can significantly reverse ferroptosis injury in cardiomyocytes induced by Erastin. In a mouse model of myocardial ischemia-reperfusion injury, it can also significantly improve cardiac function and reduce myocardial tissue damage. It provides a new drug candidate molecule and formulation for the treatment of myocardial ischemia-reperfusion injury and has important clinical application value and translational prospects.

[0041] The embodiments described above are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

Claims

1. A polypeptide with ferroptosis reversal function, characterized in that, The amino acid sequence of the polypeptide is shown in SEQ ID NO.

1.

2. A supramolecular polypeptide hydrogel with ferroptosis reversal function, characterized in that: The supramolecular polypeptide hydrogel is formed by the self-assembly of the polypeptide described in claim 1 through intermolecular non-covalent interactions.

3. A pharmaceutical preparation, characterized in that: The pharmaceutical preparation comprises at least one of the polypeptides as described in claim 1 or the supramolecular polypeptide hydrogels as described in claim 2.

4. The use of the polypeptide of claim 1, the supramolecular polypeptide hydrogel of claim 2, or the pharmaceutical formulation of claim 3 in the preparation of drugs for treating myocardial ischemia-reperfusion injury.

5. The application according to claim 4, characterized in that, The application includes at least one of the following: (1) Application in the preparation of drugs that reduce or reverse Erastin / oxidative stress-induced myocardial cell ferroptosis; (2) Application in the preparation of drugs that improve left ventricular ejection fraction (LVEF); (3) Application in the preparation of drugs that improve left ventricular fractional shortening (LVFS); (4) Application in the preparation of drugs that reduce ROS concentration in cardiomyocytes; (5) Application in the preparation of drugs that upregulate GPX4 expression in cardiomyocytes; (6) Application in the preparation of drugs that upregulate the expression of SLC7A11 in cardiomyocytes; (7) Application in the preparation of drugs that increase the GSH content of cardiomyocytes.

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