Use of ss-31 in the preparation of a medicament for preventing and / or treating ischemia-reperfusion injury of skin flap

Abstract

The application discloses application of SS-31 in preparation of drugs for preventing and / or treating skin flap ischemia-reperfusion injury, and relates to the technical field of biological medicine and tissue repair. The application of SS-31 in preparation of drugs for preventing and / or treating skin flap ischemia-reperfusion injury. The application first applies SS-31 to skin flap IRI treatment, fills the blank of a mitochondrion targeting strategy in the field of skin flap protection, and provides a brand-new idea for skin flap IRI treatment. The application is superior to traditional antioxidants; SS-31 prevents ROS generation on a mitochondrial inner membrane, the action target point is more accurate, and the effect is better. The treatment time window is wide; good protection effects are obtained when administration is performed before ischemia or within one hour after reperfusion, and the administration at the moment before reperfusion is most clinically operable. The safety is high; SS-31 is a small molecule polypeptide, metabolic products are natural amino acids, and there is no gene toxicity. The systemic exposure amount of local administration is extremely low, and normal wound healing is not affected. The application can be combined with existing strategies; SS-31 can be combined with post-ischemic treatment to produce superimposed protection effects, and the compatibility is good.

Description

Technical Field

[0001] This invention relates to the fields of biomedicine and tissue repair technology, and in particular to the application of SS-31 in the preparation of drugs for the prevention and / or treatment of flap ischemia-reperfusion injury. Background Technology

[0002] Current Status and Problems of Flap Ischemia-Reperfusion Injury

[0003] Skin flap transplantation is one of the most commonly used tissue repair methods in plastic surgery, trauma repair surgery, and microsurgery, and is widely used in clinical scenarios such as traumatic defects, tissue reconstruction after tumor resection, and burn repair. Skin flap transplantation is a core technique in plastic surgery, trauma repair, and post-tumor reconstruction. However, skin flaps inevitably experience an ischemic period during transplantation (during the period from vascular transection to anastomosis recanalization), followed by reperfusion injury upon restoration of blood supply. This process is called ischemia-reperfusion injury (IRI). IRI is a major cause of partial or complete necrosis of skin flaps, leading to the risk of secondary surgery and financial burden for patients. According to literature statistics, the partial necrosis rate after free skin flap transplantation is approximately 7%–20%, and the complete necrosis rate is approximately 1%–5%, with ischemia-reperfusion injury being one of the important causes of skin flap necrosis (Siemionow M, Arslan E. Microsurgery, 2004; Eisenhardt SU et al., J ReconstrMicrosurg, 2012).

[0004] The mechanisms of flap ischemia-reperfusion injury mainly include the following aspects:

[0005] (1) Oxidative stress injury: During ischemia, xanthine dehydrogenase is converted to xanthine oxidase, and hypoxanthine accumulates in large quantities. After reperfusion and restoration of oxygen supply, xanthine oxidase catalyzes the oxidation of hypoxanthine to produce a large number of reactive oxygen species (ROS), including superoxide anions (O2). - •), hydroxyl radicals (·OH), and hydrogen peroxide (H2O2). Excessive ROS can directly attack cell membrane lipids (lipid peroxidation), proteins, and DNA, leading to cell damage and death (Kalogeris T et al., Int RevCell Mol Biol, 2012).

[0006] (2) Inflammatory response: After reperfusion, the damaged tissue releases a large number of pro-inflammatory factors (TNF-α, IL-1β, IL-6, etc.), activates the nuclear transcription factor NF-κB pathway, upregulates the expression of adhesion molecules (ICAM-1, VCAM-1, P-selectin, etc.), promotes neutrophil adhesion and infiltration into the interstitial space, releases elastase and ROS, and further aggravates tissue damage (EltzschigHK, Eckle T. Nat Med, 2011).

[0007] (3) Microcirculatory disturbance: Endothelial cell swelling, microthrombus formation, and imbalance of vasoconstrictor / vasodilator factors (increased endothelin-1 and decreased nitric oxide) lead to the "no-reflow" phenomenon in microcirculation, so that even if the large blood vessels are patent, the tissues are still in a state of ischemia and hypoxia (Menger MD et al., Langenbeck's Arch Surg, 2003).

[0008] (4) Apoptosis: Oxidative stress and inflammatory response can activate the mitochondrial apoptosis pathway (Cyt-c release → Caspase-9 → Caspase-3 cascade activation) and the death receptor pathway (Fas / FasL, TNF / TNFR), leading to apoptosis of endothelial cells and tissue parenchymal cells (Gottlieb RA et al., J Clin Invest, 1994).

[0009] Mitochondrial damage is a core mechanism of ischemia-reperfusion injury (IRI) in flaps. Recent studies have shown that mitochondrial damage is the initiating factor and core pathological mechanism of ischemia-reperfusion injury, and its key processes are as follows:

[0010] (1) Mitochondrial dysfunction during ischemic period

[0011] Ischemia leads to the interruption of oxygen supply, inhibits the function of the mitochondrial electron transport chain (ETC), and drastically reduces ATP synthesis. Under hypoxic conditions, succinate dehydrogenase (complex II) reverse-catalyzes the reduction of fumarate to succinate, resulting in a large accumulation of succinate in ischemic tissues.

[0012] (2) Mitochondrial ROS burst during reperfusion

[0013] After oxygen supply is restored, the accumulated succinic acid is rapidly oxidized, driving complex I to generate a large number of superoxide anions (O2) via reverse electron transfer (RET). - This is the main source of ROS bursts in the early stages of reperfusion. At the same time, cardiolipin (CL) peroxidation leads to the detachment of cytochrome C (Cyt C) from the inner mitochondrial membrane, and electron leakage further exacerbates ROS generation.

[0014] (3) Opening of the mitochondrial permeability transition pore (mPTP)

[0015] ROS burst and calcium overload together trigger mPTP opening, leading to mitochondrial membrane potential (ΔΨm) collapse, mitochondrial swelling, and the release of pro-apoptotic factors such as Cyt C and AIF into the cytoplasm, activating the Caspase cascade and apoptosis.

[0016] (4) Mitochondrial damage triggers an inflammatory cascade.

[0017] Mitochondrial DNA (mtDNA), mitochondrial ROS, and oxidized cardiolipin released from damaged mitochondria act as damage-associated molecular patterns (DAMPs), activating the NLRP3 inflammasome and TLR9 signaling pathways, triggering aseptic inflammatory responses, and exacerbating tissue damage.

[0018] Therefore, targeting mitochondria to intervene and block ROS bursts and downstream damage cascades at the source is an ideal strategy for treating flap IRI.

[0019] Existing treatment methods and their limitations

[0020] Current prevention and treatment strategies for flap ischemia-reperfusion injury mainly include:

[0021] Table 1

[0022]

[0023] SS-31 (Elamipretide) Introduction

[0024] SS-31 (D-Arg-Dmt-Lys-Phe-NH2, also known as Elamipretide, Bendavia, MTP-131) is a mitochondrial-targeting tetrapeptide designed by Hazel H. Szeto and Peter W. Schiller, with a molecular weight of 640.8 Da.

[0025] Unique characteristics of the SS-31:

[0026] Structural features: Contains alternating aromatic and basic amino acid residues (aromatic-cationic sequence), among which the Dmt (2',6'-dimethyltyrosine) residue provides antioxidant activity, and the whole structure carries a +3 positive charge;

[0027] Mitochondrial targeting: Driven by the negative potential of the inner mitochondrial membrane (approximately -180mV), SS-31 selectively accumulates on the inner mitochondrial membrane in a concentration-independent manner, with an enrichment factor of 1000 to 5000 times that of the cytoplasmic concentration.

[0028] Cardiolipin binding: SS-31 specifically binds to cardiolipin on the inner mitochondrial membrane through electrostatic and hydrophobic interactions, which is the core mechanism that distinguishes it from other antioxidants.

[0029] Pharmacological mechanism of action of SS-31:

[0030] Table 2

[0031]

[0032] SS-31 development status:

[0033] SS-31 has demonstrated significant protective effects in various disease models and clinical trials, including myocardial ischemia-reperfusion, renal ischemia-reperfusion, cerebral ischemia-reperfusion, Barth syndrome, heart failure, and age-related mitochondrial dysfunction. Stealth BioTherapeutics has advanced its Phase III clinical trials for Barth syndrome and primary mitochondrial myopathy.

[0034] Inadequacy of existing technology

[0035] (1) SS-31 has not yet been applied in the field of flap ischemia-reperfusion injury research.

[0036] Current research on SS-31 mainly focuses on the protection against ischemic inflammatory resection (IRI) in solid organs such as the heart, brain, and kidneys. There are no literature or patent reports on the use of SS-31 for the treatment of flap IRI. The blood supply characteristics, ischemic tolerance, and injury patterns of flap tissue (including complex tissues such as skin, subcutaneous fat, fascia, and muscle) differ significantly from those of solid organs. Therefore, the protective effect of SS-31 on flap IRI and the optimal dosing regimen require further investigation.

[0037] (2) Limitations of existing flap IRI treatment methods

[0038] Traditional antioxidants (vitamins C / E, NAC, SOD, etc.) only work in the cytoplasm or extracellular space and cannot target mitochondria—the main site of ROS production—so their effects are limited.

[0039] Non-targeted antioxidants remove ROS that have already been generated, which is a post-event remedy and cannot prevent ROS outbreaks from occurring at the source.

[0040] Vasodilators (such as alprostadil) only improve perfusion but do not address the root cause of reperfusion injury.

[0041] Glucocorticoids have side effects such as immunosuppression and delayed wound healing;

[0042] There is a lack of mitochondrial-targeted therapies specifically for flap IRI.

[0043] (3) The existing administration method of SS-31 is not suitable for flap surgery scenarios.

[0044] In existing studies, SS-31 is mainly administered systemically via intraperitoneal or subcutaneous injection. The concentration of the drug at the skin flap is difficult to guarantee, and systemic administration increases unnecessary systemic exposure. Summary of the Invention

[0045] To address the technical problems existing in the prior art, this invention provides an application of SS-31 in the preparation of drugs for the prevention and / or treatment of flap ischemia-reperfusion injury. The technical solution is as follows:

[0046] Application of SS-31 in the preparation of drugs for the prevention and / or treatment of flap ischemia-reperfusion injury.

[0047] Optionally, the flap includes at least one of a random flap, an axial flap, a perforator flap, and a free flap;

[0048] And / or, the SS-31 is used in conjunction with post-ischemic treatment to treat flap ischemia-reperfusion injury.

[0049] Optionally, the SS-31 is prepared as a topical administration formulation;

[0050] And / or, the topical drug delivery formulation is a thermosensitive hydrogel formulation;

[0051] And / or, the thermosensitive hydrogel formulation contains SS-31 as an active ingredient, poloxamer 407 and poloxamer 188 as thermosensitive gel matrix, and sodium hyaluronate as an excipient.

[0052] And / or, the thermosensitive hydrogel formulation comprises:

[0053] SS-31: 0.5~2.0 mg / mL;

[0054] Poloxamer 407: 15%~25% (w / v);

[0055] Poloxamer 188: 2%~5% (w / v);

[0056] Sodium hyaluronate: 0.1%~1.0% (w / v);

[0057] Phosphate buffer: balance.

[0058] Optionally, in the thermosensitive hydrogel formulation, the concentration of SS-31 is 1.0 mg / mL, the concentration of poloxamer 407 is 20% (w / v), the concentration of poloxamer 188 is 3% (w / v), and the concentration of sodium hyaluronate is 0.3% (w / v).

[0059] And / or, the gelation temperature of the thermosensitive hydrogel formulation is 30~34℃.

[0060] Optionally, the topical drug delivery formulation is applied to the deep surface of the flap and / or the recipient wound before blood flow to the flap is restored;

[0061] And / or, the dosage of the topical administration formulation is 0.3~1.0 mL / cm². 2 flap area.

[0062] A pharmaceutical composition for the prevention and / or treatment of flap ischemia-reperfusion injury, the pharmaceutical composition comprising SS-31 as an active ingredient for treating flap ischemia-reperfusion injury.

[0063] Optionally, the flap includes at least one of a random flap, an axial flap, a perforator flap, and a free flap;

[0064] And / or, the SS-31 is used in conjunction with post-ischemic treatment to treat flap ischemia-reperfusion injury.

[0065] Optionally, the pharmaceutical composition is prepared as a topical administration formulation;

[0066] And / or, the topical drug delivery formulation is a thermosensitive hydrogel formulation;

[0067] And / or, the thermosensitive hydrogel formulation contains SS-31 as an active ingredient, poloxamer 407 and poloxamer 188 as thermosensitive gel matrix, and sodium hyaluronate as an excipient.

[0068] And / or, the thermosensitive hydrogel formulation comprises:

[0069] SS-31: 0.5~2.0 mg / mL;

[0070] Poloxamer 407: 15%~25% (w / v);

[0071] Poloxamer 188: 2%~5% (w / v);

[0072] Sodium hyaluronate: 0.1%~1.0% (w / v);

[0073] Phosphate buffer: balance.

[0074] Optionally, in the thermosensitive hydrogel formulation, the concentration of SS-31 is 1.0 mg / mL, the concentration of poloxamer 407 is 20% (w / v), the concentration of poloxamer 188 is 3% (w / v), and the concentration of sodium hyaluronate is 0.3% (w / v).

[0075] And / or, the gelation temperature of the thermosensitive hydrogel formulation is 30~34℃.

[0076] Optionally, the topical drug delivery formulation is applied to the deep surface of the flap and / or the recipient wound before blood flow to the flap is restored;

[0077] And / or, the dosage of the topical administration formulation is 0.3~1.0 mL / cm². 2 flap area.

[0078] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0079] This invention is the first to apply SS-31 to the treatment of flap ischemia-reperfusion injury, filling a gap in mitochondrial targeted therapy in this field. Secondly, this invention clarifies the protective effect of SS-31 on flap ischemia-reperfusion injury, its dose-effect relationship, and the optimal administration time window. Thirdly, this invention develops a local SS-31 administration formulation (thermosensitive hydrogel) suitable for flap surgery, achieving high concentration enrichment and sustained release of the drug in flap tissue. Finally, this invention elucidates the mechanism by which SS-31 protects flaps by protecting mitochondrial structure and function and inhibiting the oxidative stress-inflammation-apoptosis cascade.

[0080] (1) This invention is the first to apply SS-31 to the treatment of flap IRI: filling the gap in the field of flap protection by mitochondrial targeting strategy and providing a new idea for the treatment of flap IRI.

[0081] (2) Source blocking with significant effect: SS-31 directly targets the source of ROS production in the inner mitochondrial membrane—IRI, fundamentally blocking the damage cascade reaction. Animal experiments have confirmed that SS-31 can increase the survival area of ​​skin flaps from 57.2% to 85.9% (perforator flaps).

[0082] (3) Superior to traditional antioxidants: Traditional antioxidants clear ROS that has been generated in the cytoplasm, while SS-31 prevents ROS production on the inner mitochondrial membrane, making the target more precise and the effect better.

[0083] (4) Wide treatment time window: The administration of the drug from before ischemia to 1 hour after reperfusion has a good protective effect, and the administration of the drug immediately before reperfusion is the most clinically feasible.

[0084] (5) High safety: SS-31 is a small molecule polypeptide, and its metabolites are natural amino acids, which are non-genotoxic. The systemic exposure of local administration is extremely low and does not affect normal wound healing.

[0085] (6) Can be combined with existing strategies: SS-31 can be used in combination with post-ischemic treatment to produce a superimposed protective effect and has good compatibility. Attached Figure Description

[0086] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0087] Figure 1 This is an animal experiment effect diagram provided in Embodiment 1 of the present invention;

[0088] Figure 2 This is a cell experiment effect diagram provided in Embodiment 2 of the present invention. Detailed Implementation

[0089] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0090] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0091] In this invention, IRI refers to ischemia-reperfusion injury.

[0092] In this invention, "free flap" refers to a free flap.

[0093] In this invention, OGD / R refers to oxygen-glucose deprivation / reperfusion, and the numbers following OGD and R refer to the corresponding time.

[0094] This invention relates to the fields of biomedicine and tissue repair technology, specifically to a pharmaceutical composition with SS-31 (Elamipretide) as the active ingredient, and its application in preventing and / or treating flap ischemia-reperfusion injury and improving flap survival rate.

[0095] The inventors discovered that flap surgery provides a unique local drug delivery window (allowing direct contact with the deep surface of the flap during surgery). Based on this, the inventors developed an SS-31 formulation suitable for local application during surgery.

[0096] Core mechanism: SS-31 selectively binds to mitochondrial inner membrane cardiolipin, blocking the mitochondrial ROS burst after ischemia-reperfusion at its source, maintaining the structural and functional integrity of mitochondria, and thus inhibiting the downstream oxidative stress-inflammation-apoptosis cascade, achieving comprehensive protection of flap tissue.

[0097] SS-31 pharmaceutical preparations

[0098] Injectable formulations (systemic administration regimens)

[0099] Table 3. Prescription composition (per 1 mL):

[0100]

[0101] Dosage regimen:

[0102] Dosage: 3-5 mg / kg body weight;

[0103] Administration route: intraperitoneal injection or intravenous injection;

[0104] Administration time: Administer the first dose 30 minutes before reperfusion, and then administer an additional dose every 24 hours after the procedure for 3 consecutive days.

[0105] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0106] Unless otherwise specified, the experimental methods described in the following embodiments are conventional experimental methods well known to those skilled in the art, and are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Where specific conditions are not specified in the experimental methods, they are generally operated under conventional conditions.

[0107] Unless otherwise specified, all materials and reagents described in the following examples are commercially available.

[0108] Example 1

[0109] Using SD rats (purchased from Hunan Silek Jingda Experimental Animal Co., Ltd.), the flap was constructed with the following boundaries: 1-2 cm from the posterior axillary line as the left border, the line connecting the neck, back, and scapula as the upper border, the line connecting the iliac crests on both sides of the lumbosacral region as the lower border, and 2 cm lateral to the left of the midline of the back as the right border. Subcutaneous tissue was dissected along the superficial layer of the deep fascia from the proximal to the distal end, exposing the thoracodorsal artery, subcostal artery, and their branches. Each branch was ligated and then severed. The bleeding area was electrocoagulated, preserving the iliopsoas artery as a single perforator. A transregional flap of approximately 11 cm × 3 cm was obtained, with the left iliopsoas artery perforator as the vascular pedicle, encompassing the left thoracodorsal, subcostal (posterior), and iliopsoas arterial bodies. The left iliopsoas artery perforator was clamped for 6 hours to simulate flap ischemia, and then the hemostatic forceps were released to simulate reperfusion. Fluorescence imaging confirmed vascular patency and reflected the severance of the thoracodorsal, subcostal, and their branches. Fluorescence imaging methods can be found in the following literature: Predicting Mastectomy Skin Flap Necrosis with Indocyanine Green Angiography: The Gray Area Defined. Statistical methods for assessing lesion area can be found in the following literature: Study on the effect and mechanism of microneedle-loaded Co-MOF in preventing distal ischemic necrosis of rat perforator flaps by activating HIF-1α.

[0110] In the experimental group, 1 mL (2 mg / mL) of SS-31 solution was injected before vascular transection and clamping, while the IRI group received an equal volume of physiological saline.

[0111] Experimental results:

[0112] See the experimental results. Figure 1 . Figure 1 These are images showing the effects of animal experiments. From Figure 1 As can be seen, blood flow to the distal end of the flap was restricted, and the distal damage area of ​​the flap in the treatment group (14.1%) was significantly lower than that in the IRI group (42.8%), proving that SS-31 treatment was effective.

[0113] Example 2

[0114] HUVEC cells (purchased from Wuhan Pronosei Life Sciences Co., Ltd.) were seeded in 96-well plates. Different concentrations of SS-31 solution (prepared with PBS) were added, followed by 8 hours of oxygen-glucose deprivation and 4 hours of reperfusion. Cell viability was then assessed using the CCK-8 assay. The procedures for oxygen-glucose deprivation and reperfusion, as well as the methods for cell viability assessment, can be found in the following literature: Clinical Prediction Analysis of Postoperative Complications after Flap and Inhibition of Soluble Epoxide Hydrolases to Reduce Flap Ischemia / Reperfusion Injury.

[0115] The ATP content of different groups was determined using an ATP kit (purchased from Shanghai Beyotime Biotechnology Co., Ltd.).

[0116] Experimental results:

[0117] See the experimental results. Figure 2 . Figure 2 These are images showing the results of a cell experiment. From Figure 2 As can be seen, the cell survival rate in the OGD / R model was 45.8%, and the cell survival rate reached a maximum of 66.5% when SS-31 was at 2 μM, demonstrating the therapeutic effect of SS-31 at the cellular level. In the cellular ATP content experiment, the ATP content of normal cells was 28.1 nmol / mg, while the OGD / R group cells were significantly damaged, and the ATP content dropped sharply to 8.6 nmol / mg. The ATP content of the treatment group was 21.8 nmol / mg, demonstrating the effect of SS-31 in maintaining cellular energy supply and resisting ischemia-reperfusion injury.

[0118] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. Application of SS-31 in the preparation of drugs for the prevention and / or treatment of flap ischemia-reperfusion injury.

2. The application according to claim 1, characterized in that, The flap includes at least one of the following: random flap, axial flap, perforator flap and free flap; And / or, the SS-31 is used in conjunction with post-ischemic treatment to treat flap ischemia-reperfusion injury.

3. The application according to claim 1, characterized in that, The SS-31 was prepared as a topical administration formulation; And / or, the topical administration formulation is an injection solution or a thermosensitive hydrogel formulation; And / or, the thermosensitive hydrogel formulation contains SS-31 as an active ingredient, poloxamer 407 and poloxamer 188 as thermosensitive gel matrix, and sodium hyaluronate as an excipient. And / or, the thermosensitive hydrogel formulation comprises: SS-31: 0.5~2.0 mg / mL; Poloxamer 407: 15%~25% (w / v); Poloxamer 188: 2%~5% (w / v); Sodium hyaluronate: 0.1%~1.0% (w / v); Phosphate buffer: balance.

4. The application according to claim 3, characterized in that, In the thermosensitive hydrogel formulation, the concentration of SS-31 is 1.0 mg / mL, the concentration of poloxamer 407 is 20% (w / v), the concentration of poloxamer 188 is 3% (w / v), and the concentration of sodium hyaluronate is 0.3% (w / v). And / or, the gelation temperature of the thermosensitive hydrogel formulation is 30~34℃.

5. The application according to any one of claims 3-4, characterized in that, The topical medication is applied to the deep surface of the flap and / or the recipient wound before blood flow to the flap is restored. And / or, the dosage of the topical administration formulation is 0.3~1.0 mL / cm². 2 flap area.

6. A pharmaceutical composition for preventing and / or treating flap ischemia-reperfusion injury, characterized in that, The pharmaceutical composition includes SS-31 as the active ingredient for treating flap ischemia-reperfusion injury.

7. The pharmaceutical composition according to claim 6, characterized in that, The flap includes at least one of the following: random flap, axial flap, perforator flap and free flap; And / or, the SS-31 is used in conjunction with post-ischemic treatment to treat flap ischemia-reperfusion injury.

8. The pharmaceutical composition according to claim 6, characterized in that, The pharmaceutical composition is prepared as a topical administration formulation; And / or, the topical administration formulation is an injection solution or a thermosensitive hydrogel formulation; And / or, the thermosensitive hydrogel formulation contains SS-31 as an active ingredient, poloxamer 407 and poloxamer 188 as thermosensitive gel matrix, and sodium hyaluronate as an excipient. And / or, the thermosensitive hydrogel formulation comprises: SS-31: 0.5~2.0 mg / mL; Poloxamer 407: 15%~25% (w / v); Poloxamer 188: 2%~5% (w / v); Sodium hyaluronate: 0.1%~1.0% (w / v); Phosphate buffer: balance.

9. The pharmaceutical composition according to claim 8, characterized in that, In the thermosensitive hydrogel formulation, the concentration of SS-31 is 1.0 mg / mL, the concentration of poloxamer 407 is 20% (w / v), the concentration of poloxamer 188 is 3% (w / v), and the concentration of sodium hyaluronate is 0.3% (w / v). And / or, the gelation temperature of the thermosensitive hydrogel formulation is 30~34℃.

10. The pharmaceutical composition according to any one of claims 8-9, characterized in that, The topical medication is applied to the deep surface of the flap and / or the recipient wound before blood flow to the flap is restored. And / or, the dosage of the topical administration formulation is 0.3~1.0 mL / cm². 2 flap area.

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