Red blood cell artificial oxygen carrier therapeutic agent as well as preparation method and application thereof

Abstract

The invention discloses a red blood cell artificial oxygen carrier therapeutic agent as well as a preparation method and application thereof. The therapeutic agent comprises a polyglutamic acid polymer initiated by methoxy polyethylene glycol, a stable composite structure is formed between polyglutamic acid and Prussian blue through coordination, electrostatic interaction and / or physical coating, and hemoglobin is grafted through amidation reaction. The preparation method comprises the following steps: synthesizing N-carbobenzoxy-L-glutamic acid N-carboxyl anhydride; initiating ring opening polymerization through mPEG-NH2, and performing deprotection to obtain mPEG-polyglutamic acid; a stable Prussian blue composite structure is formed through coordination, electrostatic interaction and / or physical coating; and finally, grafting hemoglobin. The compound has the functions of carrying oxygen and removing active oxygen, can perform long circulation in vivo and simulate red blood cells, is used for treating chronic inflammatory diseases combined with anemia, and can improve tissue hypoxia and relieve inflammatory response.

Description

Technical Field

[0001] This invention relates to artificial oxygen carrier therapeutic agents, specifically to an erythrocyte-like artificial oxygen carrier therapeutic agent, its preparation method, and its application. Background Technology

[0002] Artificial oxygen carriers, as red blood cell substitutes or adjuvant therapeutic agents, have significant application prospects in fields such as emergency medicine, surgery, and anemia treatment.

[0003] Existing hemoglobin-based artificial oxygen carriers can be used for emergency blood transfusions, but they lack the protective and regulatory effects of natural enzymes contained in red blood cells and have a short circulation time in vivo, resulting in high side effects and poor efficacy in vivo. Summary of the Invention

[0004] Objectives of the invention: The objective of this invention is to provide an artificial oxygen carrier therapeutic agent that possesses erythrocyte-like function, has no toxic side effects, and exhibits good long-term in vivo circulation time; the second objective of this invention is to provide a method for preparing this erythrocyte-like artificial oxygen carrier therapeutic agent; the third objective of this invention is to provide applications of this erythrocyte-like artificial oxygen carrier therapeutic agent.

[0005] Technical solution: The erythrocyte-like artificial oxygen carrier therapeutic agent of the present invention comprises a polyglutamic acid polymer initiated by methoxy polyethylene glycol. The polymer constructs a polyglutamic acid-modified Prussian blue nanoparticle composite structure by coordinating with iron ions, and grafts hemoglobin through an amidation reaction.

[0006] Preferably, the degree of polymerization n of the polyglutamic acid is 5-200, such as 20, 40 or 80.

[0007] Preferably, in the erythroblast-like artificial oxygen carrier therapeutic agent, the methoxy polyethylene glycol-initiated polyglutamic acid polymer mPEG-Glu: Fe for forming Prussian blue 3+ Fe used to form Prussian blue 2+ The mass ratio of hemoglobin (Hb) is 1:0.1-20:0.1-20:0.1-10.

[0008] The preparation method of the erythroblast-like artificial oxygen carrier therapeutic agent of the present invention includes the following steps: synthesizing N-benzyloxycarbonyl-L-glutamic acid N-carboxylic acid anhydride; preparing mPEG-PZGlu by initiating ring-opening polymerization with mPEG-NH2, and then deprotecting to obtain mPEG-PGlu; constructing a polyglutamic acid-modified Prussian blue nanoparticle composite structure, namely mPEG-PGlu-PB, on mPEG-PGlu by coordinating with iron ions; and grafting hemoglobin onto mPEG-PGlu-PB by amidation reaction to obtain mPEG-PGlu-PB-Hb. The ring-opening polymerization of N-benzyloxycarbonyl-L-glutamic acid N-carboxylic anhydride (L-Glu NCA) initiated by methoxy polyethylene glycol (mPEG) was designed. By controlling the ratio of initiator to NCA, mPEG-polyglutamic acid with different degrees of polymerization was synthesized. After deprotection, the glutamic acid side chain contained a large number of carboxyl groups. By controlling the feed ratio and reaction time, a polyglutamic acid-modified Prussian blue nanoparticle composite structure was constructed on the polymer backbone by coordination with iron ions. At the same time, hemoglobin of different proportions was grafted through amidation reaction.

[0009] Preferably, the ring-opening polymerization is carried out in a mixed solvent of anhydrous DMF and DCM, and the reaction is carried out under nitrogen protection for 24-96 hours. More preferably, the volume ratio of anhydrous DMF to DCM is 1:1-10.

[0010] Preferably, the specific steps for constructing a polyglutamic acid-modified Prussian blue nanoparticle composite structure on mPEG-PGlu by coordination with iron ions are as follows: ... 3+ A polymer solution containing [Fe(CN)6] was added dropwise. 4- In a solution, the reaction was carried out with stirring at room temperature for 1-12 hours; the Fe 3+ and [Fe(CN)6] 4- Fe 2+ The mass ratio is 0.1-20:0.1-20.

[0011] Preferably, the hemoglobin grafting reaction is carried out at 4°C for 2-72 hours in the presence of N-hydroxysuccinimide and carbodiimide; the molar ratio of hemoglobin:N-hydroxysuccinimide:carbodiimide is 1:1-20:1-20.

[0012] As one feasible approach, the preparation method specifically includes: Synthesis of N-benzyloxycarbonyl-L-glutamic acid N-carboxylic anhydride (L-Glu NCA): L-Glu (15 g) and triphosgene (10.8 g) were dispersed in 150 mL of anhydrous tetrahydrofuran. The mixture was bubbled under a stable nitrogen stream in a dry three-necked flask and stirred at 55 °C. After the turbid solution became clear, the reaction was continued for 20 min. The solution was then poured into 1000 mL of pre-cooled n-hexane and placed at -20 °C for 4 h. After filtering off the solvent, the white product was dissolved in 200 mL of cold ethyl acetate and washed four times with 50 mL of ice water. The organic phase was dried overnight with anhydrous magnesium sulfate, filtered, and the ethyl acetate was removed under vacuum to obtain L-Glu NCA.

[0013] Synthesis of mPEG-PZGlu and mPEG-PGlu: Methoxylated polyethylene glycol-poly(N-benzyloxycarbonyl-L-glutamic acid), i.e., mPEG-PZGlu (n=20), was synthesized by ring-opening polymerization (ROP) of L-Glu NCA using mPEG-NH2 as an initiator. Specifically, L-Glu NCA (6.7 g) dissolved in 90 mL of anhydrous DMF and mPEG-NH2 (6.44 g) dissolved in 15 mL of anhydrous DCM were added to a dry reaction flask. After stirring under nitrogen at 25 °C for 3 days, the solution was precipitated with diethyl ether, and the resulting product was washed twice with diethyl ether and dried under vacuum at room temperature for 24 h.

[0014] 2.8 g of mPEG-PZGlu (n=20) was dissolved in 28 mL of trifluoroacetic acid (TFA). After the solid dissolved, 10 mL of hydrogen bromide (33 wt.% acetic acid) was added, and the mixture was stirred at room temperature for 2 h. The solution was then precipitated into pre-cooled diethyl ether and dialyzed against deionized water in a dialysis bag (MWCO=7000 Da) for 3 days. After lyophilization, a white solid methoxy polyethylene glycol-poly(L-glutamic acid), i.e., mPEG-PGlu (n=20), was obtained. mPEG-PGlu with different degrees of polymerization, i.e., n=20, 40, 80, etc., was prepared using the same method.

[0015] Synthesis of mPEG-PGlu-PB: 1g mPEG-PGlu and 500mg FeCl3·6H2O were dissolved in 150mL of deionized water to prepare solution A, and 500mg K4Fe(CN)6·3H2O were dissolved in 150mL of deionized water to prepare solution B. Solution A was slowly added dropwise to solution B, and the mixture was stirred at room temperature for 2h. After purification and lyophilization using a 10kd ultrafiltration tube, methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue, i.e., mPEG-PGlu-PB, was obtained.

[0016] Synthesis of mPEG-PGlu-PB-Hb: 1g of mPEG-PGlu-PB was dissolved in 100mL of deionized water, and 17.8mg of N-hydroxysuccinimide and 29.5mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride were added and stirred at room temperature for half an hour to activate the reaction. 500mg of hemoglobin was added and the reaction was stirred at 4℃ for 24h. The reaction was purified and lyophilized using a 10kd ultrafiltration tube to obtain methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue-hemoglobin, i.e., mPEG-PGlu-PB-Hb.

[0017] The application of the erythroblast-like artificial oxygen carrier therapeutic agent described in this invention in the preparation of a drug for treating chronic anemia.

[0018] Preferably, the chronic disease-related anemia includes inflammatory anemia associated with chronic heart failure, chronic infection, chronic liver disease, chronic kidney disease, endocrine disorders, or malignant tumors.

[0019] Preferably, the erythroblast-like artificial oxygen carrier therapeutic agent improves tissue hypoxia by carrying oxygen and removes reactive oxygen species in the inflammatory microenvironment, thereby reducing the inflammatory response.

[0020] Chronic disease anemia, also known as inflammatory anemia, chronic inflammatory hypoferemia, or inflammatory hypoferemia, usually refers to chronic anemia secondary to non-hematopoietic system diseases. Currently, the most important cause of chronic disease anemia is considered to be increased hepcidin synthesis and secretion due to inflammatory factors, leading to abnormal iron homeostasis and iron-limiting erythropoiesis. Actively treating the primary chronic inflammation or chronic disease is crucial. The inflammatory microenvironment is often accompanied by excessive ROS levels, leading to over-activation of inflammation, which in turn causes anemia, resulting in decreased blood oxygen-carrying capacity, chronic tissue hypoxia, especially in the myocardium, kidneys, and skeletal muscle, and unstable cardiac preload / afterload. This chemical product aims to improve tissue hypoxia caused by anemia by carrying oxygen, improving microcirculation oxygen supply to the myocardium and kidneys, clearing ROS from the inflammatory microenvironment, reducing inflammatory responses, and decreasing the secretion of inflammatory factors, thereby treating the primary chronic inflammatory disease. Common chronic disease anemias include, but are not limited to, chronic heart failure, chronic infections, chronic liver disease, chronic kidney disease, endocrine disorders, and malignant tumors.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The erythroblast-like artificial oxygen carrier therapeutic agent provided by the present invention can realize the long-term circulation of hemoglobin in the body and simulate the function of red blood cells, protect hemoglobin from being oxidized and deteriorated during circulation, carry oxygen, improve the chronic tissue hypoxia caused by anemia, improve the microcirculation oxygen supply of myocardium and kidney, and clear ROS in the inflammatory microenvironment, reduce the inflammatory response, reduce the secretion of inflammatory factors, and achieve the purpose of treating primary chronic inflammatory diseases. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the preparation process of the present invention.

[0023] Figure 2 For mPEG-PZGlu 1 H-NMR spectrum.

[0024] Figure 3 For mPEG-PGlu 1 H-NMR spectrum.

[0025] Figure 4 This is a transmission electron microscope (TEM) image of mPEG-PGlu-PB-Hb.

[0026] Figure 5 The elemental mapping energy diagram for mPEG-PGlu-PB-Hb. Detailed Implementation

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Example 1

[0029] 1. Synthesis of N-benzyloxycarbonyl-L-glutamic acid N-carboxylic acid anhydride (L-Glu NCA) L-Glu (15 g) and triphosgene (10.8 g) were dispersed in 150 mL of anhydrous tetrahydrofuran. The mixture was bubbled under a stable nitrogen stream in a dry three-necked flask and stirred at 55 °C. After the turbid solution became clear, the reaction was continued for 20 min. The solution was then poured into 1000 mL of pre-cooled n-hexane and placed at -20 °C for 4 h. After filtering off the solvent, the white product was dissolved in 200 mL of cold ethyl acetate and washed four times with 50 mL of ice water. The organic phase was dried overnight with anhydrous magnesium sulfate, filtered, and the ethyl acetate was removed under vacuum to obtain L-Glu NCA.

[0030] 2. Synthesis of mPEG-PZGlu and mPEG-PGlu Using mPEG-NH2 as an initiator, methoxy polyethylene glycol-poly(N-benzyloxycarbonyl-L-glutamic acid), i.e., mPEG-PZGlu (n=20), was synthesized by ring-opening polymerization (ROP) of L-Glu NCA. Specifically, 6.7 g of L-Glu NCA dissolved in 90 mL of anhydrous DMF and 6.44 g of mPEG-NH2 dissolved in 15 mL of anhydrous DCM were added to a dry reaction flask. After stirring under nitrogen at 25 °C for 3 days, the solution was precipitated with diethyl ether, and the resulting product was washed twice with diethyl ether and dried under vacuum at room temperature for 24 h to obtain mPEG-PZGlu. The structure was confirmed by 1H NMR spectroscopy (see [link to spectroscopy]). Figure 2 ).

[0031] 2.8 g of mPEG-PZGlu (n=20) was dissolved in 28 mL of trifluoroacetic acid (TFA). After the solid dissolved, 10 mL of hydrogen bromide (33 wt.% acetic acid) was added, and the mixture was stirred at room temperature for 2 h. The solution was then precipitated into pre-cooled diethyl ether and dialyzed against deionized water in a dialysis bag (MWCO=7000 Da) for 3 days. After lyophilization, a white solid methoxy polyethylene glycol-poly(L-glutamic acid), i.e., mPEG-PGlu (n=20), was obtained. 1 See the H-NMR spectrum. Figure 3 .

[0032] 3. Synthesis of mPEG-PGlu-PB Solution A was prepared by dissolving 1g mPEG-PGlu and 100mg FeCl3·6H2O in 150mL deionized water, and solution B was prepared by dissolving 100mg K4Fe(CN)6·3H2O in 150mL deionized water. Solution A was slowly added dropwise to solution B, and the mixture was stirred at room temperature for 2 hours. The mixture was then purified and lyophilized using a 10kd ultrafiltration tube to obtain methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue, i.e., mPEG-PGlu-PB.

[0033] 4. Synthesis of mPEG-PGlu-PB-Hb 1 g of mPEG-PGlu-PB was dissolved in 100 mL of deionized water. 3.56 mg of N-hydroxysuccinimide and 5.94 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride were added, and the mixture was stirred at room temperature for half an hour to activate the reaction. Then, 100 mg of hemoglobin was added, and the reaction was carried out at 4 °C for 24 h. The mixture was purified using a 10 kDa ultrafiltration tube and lyophilized to obtain methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue-hemoglobin, i.e., mPEG-PGlu-PB-Hb. Its transmission electron microscopy (TEM) image showed it as uniform nanoparticles (see...). Figure 4 Elemental mapping analysis confirmed that elements such as Fe, C, N, and O are uniformly distributed (see...). Figure 5 ).

[0034] Example 2

[0035] 1. Synthesis of N-benzyloxycarbonyl-L-glutamic acid N-carboxylic acid anhydride (L-Glu NCA) L-Glu (15 g) and triphosgene (10.8 g) were dispersed in 150 mL of anhydrous tetrahydrofuran. The mixture was bubbled under a stable nitrogen stream in a dry three-necked flask and stirred at 55 °C. After the turbid solution became clear, the reaction was continued for 20 min. The solution was then poured into 1000 mL of pre-cooled n-hexane and placed at -20 °C for 4 h. After filtering off the solvent, the white product was dissolved in 200 mL of cold ethyl acetate and washed four times with 50 mL of ice water. The organic phase was dried overnight with anhydrous magnesium sulfate, filtered, and the ethyl acetate was removed under vacuum to obtain L-Glu NCA.

[0036] 2. Synthesis of mPEG-PZGlu and mPEG-PGlu Methoxylated polyethylene glycol-poly(N-benzyloxycarbonyl-L-glutamic acid), i.e., mPEG-PZGlu (n=50), was synthesized by ring-opening polymerization (ROP) of L-Glu NCA initiated by mPEG-NH2. Specifically, 16.75 g of L-Glu NCA dissolved in 150 mL of anhydrous DMF and 6.44 g of mPEG-NH2 dissolved in 15 mL of anhydrous DCM were added to a dry reaction flask. After stirring under nitrogen at 25 °C for 3 days, the solution was precipitated with diethyl ether, and the resulting product was washed twice with diethyl ether and dried under vacuum at room temperature for 24 h to obtain mPEG-PZGlu. The structure was confirmed by 1H NMR spectroscopy.

[0037] 2.8 g of mPEG-PZGlu (n=50) was dissolved in 28 mL of trifluoroacetic acid (TFA). After the solid dissolved, 10 mL of hydrogen bromide (33 wt.% acetic acid) was added, and the mixture was stirred at room temperature for 2 h. The solution was then precipitated into pre-cooled diethyl ether and dialyzed with deionized water in a dialysis bag (MWCO=7000 Da) for 3 days. After lyophilization, a white solid methoxy polyethylene glycol-poly(L-glutamic acid), i.e., mPEG-PGlu (n=50), was obtained.

[0038] 3. Synthesis of mPEG-PGlu-PB Solution A was prepared by dissolving 1g mPEG-PGlu and 500mg FeCl3·6H2O in 150mL deionized water, and solution B was prepared by dissolving 500mg K4Fe(CN)6·3H2O in 150mL deionized water. Solution A was slowly added dropwise to solution B, and the mixture was stirred at room temperature for 2 hours. The mixture was then purified and lyophilized using a 10kd ultrafiltration tube to obtain methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue, i.e., mPEG-PGlu-PB.

[0039] 4. Synthesis of mPEG-PGlu-PB-Hb 1 g of mPEG-PGlu-PB was dissolved in 100 mL of deionized water. 17.8 mg of N-hydroxysuccinimide and 29.5 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride were added and the mixture was stirred at room temperature for half an hour to activate the reaction. 500 mg of hemoglobin was then added, and the mixture was stirred at 4 °C for 24 h. The resulting product was purified using a 10 kDa ultrafiltration tube and lyophilized to obtain methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue-hemoglobin, i.e., mPEG-PGlu-PB-Hb. Transmission electron microscopy (TEM) images showed uniform nanoparticles, and elemental mapping analysis confirmed the uniform distribution of elements such as Fe, C, N, and O.

[0040] Example 3

[0041] 1. Synthesis of N-benzyloxycarbonyl-L-glutamic acid N-carboxylic acid anhydride (L-Glu NCA) L-Glu (15 g) and triphosgene (10.8 g) were dispersed in 150 mL of anhydrous tetrahydrofuran. The mixture was bubbled under a stable nitrogen stream in a dry three-necked flask and stirred at 55 °C. After the turbid solution became clear, the reaction was continued for 20 min. The solution was then poured into 1000 mL of pre-cooled n-hexane and placed at -20 °C for 4 h. After filtering off the solvent, the white product was dissolved in 200 mL of cold ethyl acetate and washed four times with 50 mL of ice water. The organic phase was dried overnight with anhydrous magnesium sulfate, filtered, and the ethyl acetate was removed under vacuum to obtain L-Glu NCA.

[0042] 2. Synthesis of mPEG-PZGlu and mPEG-PGlu Methoxylated polyethylene glycol-poly(N-benzyloxycarbonyl-L-glutamic acid), i.e., mPEG-PZGlu (n=80), was synthesized by ring-opening polymerization (ROP) of L-Glu NCA initiated by mPEG-NH2. Specifically, 26.8 g of L-Glu NCA dissolved in 200 mL of anhydrous DMF and 6.44 g of mPEG-NH2 dissolved in 60 mL of anhydrous DCM were added to a dry reaction flask. After stirring under nitrogen at 25 °C for 3 days, the solution was precipitated with diethyl ether, and the resulting product was washed twice with diethyl ether and dried under vacuum at room temperature for 24 h to obtain mPEG-PZGlu. The structure was confirmed by 1H NMR spectroscopy.

[0043] 2.8 g of mPEG-PZGlu (n=80) was dissolved in 28 mL of trifluoroacetic acid (TFA). After the solid dissolved, 10 mL of hydrogen bromide (33 wt.% acetic acid) was added, and the mixture was stirred at room temperature for 2 h. The solution was then precipitated into pre-cooled diethyl ether and dialyzed with deionized water in a dialysis bag (MWCO=7000 Da) for 3 days. After lyophilization, a white solid methoxy polyethylene glycol-poly(L-glutamic acid), i.e., mPEG-PGlu (n=80), was obtained.

[0044] 3. Synthesis of mPEG-PGlu-PB Solution A was prepared by dissolving 1g mPEG-PGlu and 20g FeCl3·6H2O in 150mL of deionized water, and solution B was prepared by dissolving 20g K4Fe(CN)6·3H2O in 150mL of deionized water. Solution A was slowly added dropwise to solution B, and the mixture was stirred at room temperature for 2 hours. After purification and freeze-drying using a 10kd ultrafiltration tube, methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue, i.e., mPEG-PGlu-PB, was obtained.

[0045] 4. Synthesis of mPEG-PGlu-PB-Hb 1 g of mPEG-PGlu-PB was dissolved in 100 mL of deionized water. 356 mg of N-hydroxysuccinimide and 594 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride were added and the mixture was stirred at room temperature for half an hour to activate the reaction. Then, 10 g of hemoglobin was added, and the mixture was stirred at 4 °C for 24 h. The resulting product was purified using a 10 kDa ultrafiltration tube and lyophilized to obtain methoxy polyethylene glycol-poly(L-glutamic acid)-Prussian blue-hemoglobin, i.e., mPEG-PGlu-PB-Hb. Transmission electron microscopy (TEM) images showed uniform nanoparticles, and elemental mapping analysis confirmed the uniform distribution of elements such as Fe, C, N, and O.

[0046] Example 4: The effect of the therapeutic agent in a model of chronic heart failure complicated with anemia A rat model of chronic heart failure complicated with anemia was established. Experimental rats were randomly divided into three groups: a model control group, a free hemoglobin treatment group, and the therapeutic agent group of this invention (mPEG-PGlu-PB-Hb). The drug was administered via tail vein injection twice a week for four weeks. Results showed that compared with the model control group and the free hemoglobin group, the therapeutic agent group of this invention significantly increased hemoglobin concentration and hematocrit, significantly decreased serum and cardiac tissue inflammatory factor levels, reduced expression of cardiac tissue hypoxia markers, and no significant hepatotoxicity or nephrotoxicity was observed. This demonstrates that the product of this invention can effectively improve anemia indicators, alleviate tissue hypoxia, and reduce systemic inflammatory responses.

Claims

1. A erythrocyte-like artificial oxygen carrier therapeutic agent, characterized in that, This includes a polyglutamic acid polymer initiated by methoxy polyethylene glycol, which constructs a polyglutamic acid-modified Prussian blue nanoparticle composite structure by coordination with iron ions and grafts hemoglobin via an amidation reaction.

2. The erythroblast-like artificial oxygen carrier therapeutic agent according to claim 1, characterized in that, The degree of polymerization (n) of the polyglutamic acid is 5-200.

3. The erythroblast-like artificial oxygen carrier therapeutic agent according to claim 1, characterized in that, The methoxy polyethylene glycol-initiated polyglutamic acid polymer mPEG-Glu in the erythroblast artificial oxygen carrier therapeutic agent: Fe for the formation of Prussian blue. 3+ Fe used to form Prussian blue 2+ The mass ratio of hemoglobin (Hb) is 1:0.1-20:0.1-20:0.1-10.

4. A method for preparing the erythroblast-like artificial oxygen carrier therapeutic agent according to claim 1, characterized in that, Includes the following steps: N-benzyloxycarbonyl-L-glutamic acid N-carboxylic acid anhydride was synthesized; mPEG-PZGlu was prepared by ring-opening polymerization initiated by mPEG-NH2, and then deprotected to obtain mPEG-PGlu; a polyglutamic acid-modified Prussian blue nanoparticle composite structure, mPEG-PGlu-PB, was constructed on mPEG-PGlu by coordination with iron ions; hemoglobin was grafted onto mPEG-PGlu-PB by amidation reaction to obtain mPEG-PGlu-PB-Hb.

5. The preparation method according to claim 4, characterized in that, The ring-opening polymerization was carried out in a mixed solvent of anhydrous DMF and DCM for 24-96 h under nitrogen protection.

6. The preparation method according to claim 4, characterized in that, The specific steps for constructing a polyglutamic acid-modified Prussian blue nanoparticle composite structure on mPEG-PGlu by coordination with iron ions are as follows: Fe-containing... 3+ A polymer solution containing [Fe(CN)6] was added dropwise. 4- In a solution, the reaction was carried out with stirring at room temperature for 1-12 hours; the Fe 3+ and [Fe(CN)6] 4- Fe 2+ The mass ratio is 0.1-20:0.1-20.

7. The preparation method according to claim 4, characterized in that, The hemoglobin grafting reaction was carried out at 4°C for 2-72 h in the presence of N-hydroxysuccinimide and carbodiimide; the molar ratio of hemoglobin:N-hydroxysuccinimide:carbodiimide was 1:1-20:1-20.

8. The use of the erythroblast-like artificial oxygen carrier therapeutic agent according to claim 1 in the preparation of a medicament for treating chronic anemia.

9. The application according to claim 8, characterized in that, The chronic disease-related anemia includes inflammatory anemia associated with chronic heart failure, chronic infection, chronic liver disease, chronic kidney disease, endocrine disorders, or malignant tumors.

10. The application according to claim 8, characterized in that, The erythroblast-like artificial oxygen carrier therapeutic agent improves tissue hypoxia by carrying oxygen and removes reactive oxygen species in the inflammatory microenvironment, thereby reducing the inflammatory response.

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