CN112661958B

CN112661958B - Inositol and arginine-based polyesteramide and preparation method and application thereof

Info

Publication number: CN112661958B
Application number: CN202011432184.0A
Authority: CN
Inventors: 吴钧; 袁奇娟
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2023-03-17
Anticipated expiration: 2040-12-09
Also published as: CN112661958A

Abstract

The invention discloses a polyesteramide based on inositol and arginine, a preparation method and application thereof, and belongs to the technical field of biomedical materials. The polyesteramide of the invention is synthesized by using arginine, phenylalanine and inositol as synthesis raw materials and adopting a solution polymerization method. The introduction of inositol can not only reduce the cytotoxicity of the carrier, but also 6 hydroxyl groups can be used for constructing polyesteramide with more molecular structures. The synergistic effect of arginine, phenylalanine and inositol can control the hydrophilicity and hydrophobicity and solubility of the branched polyesteramide. The polyesteramide of the invention is used as a drug delivery carrier, and can be self-assembled into a stable nano system with uniform particle size by a nano precipitation method. The nano system is safe and nontoxic, has good biocompatibility, and the degradation product is amino acid, has excellent biocompatibility, can be used for loading antitumor drugs, hydrophobic antioxidants and water-soluble protein drugs, and has great application potential in the field of biomedicine.

Description

Inositol and arginine-based polyesteramide and preparation method and application thereof

Technical Field

The invention relates to the technical field of biomedical materials, in particular to a polyesteramide based on inositol and arginine, and a preparation method and application thereof.

Background

Biodegradable synthetic polymers have become a very important class of materials in the biomedical field since 1960. These materials include poly-alpha-hydroxy acids, poly-alpha-amino acids. Polyhydroxy acids are a class of polymeric materials with excellent biodegradability and biocompatibility, and have been used in various aspects of the biomedical field. Aliphatic polyesters are by far the most important commercial poly-alpha-hydroxy acid materials. Among them, polyglycolic acid (PGA), polylactic acid (PLA) and copolymers thereof (PLGA) are the most used in biomedical applications. Absorbable surgical sutures are a prominent representative of those that are degraded by endogenous esterases after implantation in the body. However, the commonly used aliphatic polyesters may induce a more severe inflammatory reaction in vivo, and the lack of reactive sites in their backbone also makes their modification a great difficulty. In addition, the mechanical properties of the material are difficult to meet different biomedical application directions. Thus, scientists have invested considerable effort in recent years to develop new materials with potential biomedical applications.

Polyesteramide is a polymer that integrates a polyester structure and a polyamide structure in the same molecular chain. The special molecular structure provides possibility for researchers to freely regulate and control the physical and chemical properties of the material. The degradation product of polyesteramide is alpha-amino acid, and is non-toxic to organisms. In the molecular chain of the polyester amide, the existence of ester bonds enables the molecular chain to have good biodegradability. The introduction of amido bond makes the molecular chains easily form hydrogen bond, and greatly improves the physical and chemical properties of the material. The regulation and control of the biodegradation performance, the physical and chemical performance, the mechanical performance, the thermal performance and the biological performance of the polymer can be realized by adjusting the proportion of various structures in the molecular chain of the polyester amide. The sources of monomers used for the synthesis of polyesteramides are also very rich, mainly amino acids, amino alcohols, carbohydrates, etc. By adjusting the variety and the proportion of the monomers, the polyesteramide with different molecular structure, ester bond/amido bond proportion and aliphatic structure family/aromatic ring structure proportion can be obtained. The hydrophilicity of the polyesteramide can be increased by introducing a polyethylene oxide structure. Varying the length of the methylene sequence can adjust the hydrophobicity of the material. In addition, the functionality, crystallinity, rigidity and elasticity of the molecular chain of the polyesteramide can be obtained by adjusting the molecular structure as required.

However, the existing polyester amides based on alpha-amino acid are all linear structures, and although the material performance can be optimized by adjusting the monomer formula, certain defects still exist in the aspect of mechanical property. The molecular structure is relatively fixed, and the introduction of a later functional group is also very challenging.

Disclosure of Invention

To compensate for the limitations of chemical structure on the biological applications of polyesteramide materials, branched polyesteramides can be constructed by incorporating polyfunctional monomers such as polyamines, polyols and polyacids. The branched polyesteramide can reduce the formation of intermolecular hydrogen bonds, reduce the entanglement of molecular chains, improve the solubility of materials in a solvent, and is beneficial to the construction of nano-scale, micron-scale to macro-scale hydrogel and other materials. In addition, the introduction of the multifunctional monomer enables the structure to contain a large number of active groups such as amino, carboxyl or sulfydryl and the like, thereby providing more possibilities for designing the chemical structure of the material. By introducing more functional structures into the polyesteramide molecules, the material can realize the multifunctionality in practical application or the responsiveness to the microenvironment of the body. Therefore, the branched polyesteramide is expected to be synthesized by introducing multifunctional bioactive natural small molecules into the polyesteramide structure, and the application potential of the branched polyesteramide in the biomedical field such as drug carriers is explored. The branched polyesteramide is used for constructing an anticancer drug nano-carrier for chemotherapy, and a hydrophobic small molecular antioxidant nano-carrier for regulating a tissue engineering microenvironment and delivering in-vivo and in-vitro protein drugs to research the application potential of the branched polyesteramide in the field of biomedicine.

The primary object of the present invention is to provide a process for the preparation of inositol and arginine Based Polyesteramides (BPEA).

Another object of the present invention is to provide a polyesteramide prepared by the above preparation method.

It is a further object of the present invention to provide the use of the above polyesteramides.

The purpose of the invention is realized by the following technical scheme:

a preparation method of a branched polyesteramide based on inositol and arginine adopts arginine, phenylalanine and inositol as synthesis raw materials and adopts a solution polymerization method to synthesize the branched polyesteramide. The hydrophilic and hydrophobic properties of the material can be adjusted by changing the formula of the monomer containing the arginine component and the monomer containing the phenylalanine component in the synthesis process; the preferred operation is as follows:

s1, dispersing arginine, dihydric alcohol and p-toluenesulfonic acid monohydrate into a solvent, performing esterification reaction, and purifying a primary product to obtain a monomer A;

s2, dispersing phenylalanine, inositol and p-toluenesulfonic acid monohydrate into a solvent, reacting, and purifying a primary product to obtain a monomer B;

s3, dissolving binary acyl chloride and triethylamine in a solvent under an ice bath state, and then dropwise adding the p-nitrophenol dissolved in the precooled solvent into the system for reaction; changing to the normal temperature state, and continuing the reaction; purifying the primary product to obtain a monomer C;

s4, heating and dissolving the monomer A, the monomer B and the monomer C in a solvent, adding triethylamine, uniformly stirring, and carrying out polycondensation reaction; purifying the primary product to obtain the polyesteramide based on inositol and arginine.

The dihydric alcohol in the step S1 can be one or more of 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol or 1,10-decanediol and other aliphatic dihydric alcohols.

The proportion of the arginine, the dihydric alcohol and the p-toluenesulfonic acid monohydrate in the step S1 is preferably 1-4:1-2:4-10 in a molar ratio; more preferably, the molar ratio is 2.

The solvent described in step S1 is preferably toluene.

The esterification reaction in the step S1 is preferably carried out at the temperature of 120-140 ℃ for 20-30 h, and water generated in the reaction process is removed through a water separator; more preferably at a temperature of 130 ℃ for 24 hours.

The specific operation of the purification of the primary product in the step S1 is as follows: after the esterification reaction is finished, cooling the reaction system to room temperature, removing the solvent in the system, adding isopropanol into the product, heating and stirring until the isopropanol is dissolved, cooling and settling, repeatedly purifying for 3-5 times, and drying to obtain the product. If the tea is not used temporarily, the tea is sealed and stored for standby after being dried for 48 hours.

The preferred ratio of the phenylalanine, the inositol and the p-toluenesulfonic acid monohydrate in the step S2 is 5-14 mol ratio of 1-2:7-30; more preferably, the molar ratio is 6.

The solvent described in step S2 is preferably toluene.

The esterification reaction in the step S2 is preferably carried out at the temperature of 120-140 ℃ for 20-30 h, and the water generated in the reaction process is removed by a water separator; more preferably at a temperature of 130 ℃ for 24 hours.

The specific operation of the purification of the primary product in the step S2 is as follows: after the reaction is finished, cooling the reaction system to room temperature, removing the solvent in the system, extracting, washing and drying the product. If the tea leaves are not used temporarily, the tea leaves are sealed and stored for standby after being dried for 48 hours.

The diacid chloride in the step S3 can be one or more of fatty diacid chlorides such as oxalyl chloride, succinyl chloride or suberoyl chloride.

The preferable molar ratio of the binary acyl chloride, the triethylamine and the nitrophenol in the step S3 is 15-25; more preferably, the molar ratio is 20.

The solvents described in step S3 are preferably acetone.

The time for the reaction after the p-nitrophenol is dropwise added in the step S3 is preferably 1 to 2 hours, and the time for the reaction to continue after the normal temperature state is changed is preferably 20 to 30 hours.

The specific operation of the purification of the primary product in the step S3 is as follows: after the reaction is finished, repeatedly settling the primary product in water for 3-5 times, drying, recrystallizing in a mixed solvent of acetone and N, N-Dimethylformamide (DMF) for 3-5 times, and drying to obtain the product.

The preferable ratio of the monomer A, the monomer B, the monomer C and the triethylamine in the step S4 is 0.5-1g; more preferably 0.774g.

The heating temperature in the step S4 is preferably 70-80 ℃; more preferably 75 deg.c.

The solvent described in step S4 is preferably dimethyl sulfoxide (DMSO).

The conditions of the polycondensation reaction in the step S4 are preferably 70-80 ℃ and 45-55 h; more preferably, the temperature is 75 ℃ and the time is 48h.

The specific operation of the purification of the primary product in the step S4 is as follows: dissolving the initial product in methanol, precipitating the product with precooled ethyl acetate, repeatedly dissolving the precipitate for 3-5 times, and drying. If the tea is not used temporarily, the tea is sealed and stored for standby after being dried for 24 hours.

A polyesteramide based on inositol and arginine, prepared by the above preparation method.

The molecular weight range of the polyesteramide is 1000-50000 Da; preferably 2000 to 10000; more preferably 4000 to 5000.

Preferably, the chemical structure of the polyesteramide is shown as formula (I):

in the formula, n, x and y all represent polymerization degrees, wherein the value range of n is 1-20, and the value ranges of x and y are 1-12.

The application of the polyester amide based on the inositol and the arginine in preparing a drug nano delivery carrier or a nano drug-carrying system.

The medicine includes but is not limited to antineoplastic medicine, such as paclitaxel, docetaxel, methotrexate, camptothecin, adriamycin, curcumin and other medicines; hydrophobic antioxidants such as vitamin antioxidants, carotenoid antioxidants, flavonoid compounds, enzyme antioxidants, protein antioxidants, and the like; water-soluble protein drugs, such as insulin, serum albumin, interferon, tissue plasminogen activator, erythropoietin, granulocyte macrophage colony stimulating factor, interleukin, immunosuppressant, antibody or antigen polypeptide.

The drug nano delivery carrier or the nano drug-carrying system can be prepared by a nano precipitation method.

When the application is the application in preparing a drug nano delivery carrier, the specific operation of the application is as follows: dissolving the polyesteramide and the stabilizer in an organic solvent, dropwise adding the obtained mixed solution into water under a stirring state, and self-assembling into nanoparticles;

the preferable proportion of the polyesteramide, the stabilizer and the organic solvent is 5 g.

The stabilizer is preferably DSPE-PEG 2000.

The organic solvent is preferably dimethyl sulfoxide.

When the medicine is an anti-tumor medicine or a hydrophobic antioxidant, the specific operation is as follows: dissolving the polyesteramide, the stabilizer and the medicine in an organic solvent, dropwise adding the obtained mixed solution into water under a stirring state, and self-assembling into nanoparticles; wherein the mass ratio of the polyesteramide to the medicine is 5:0.1 to 10.

When the medicine is a water-soluble protein medicine, the specific operation is as follows: dissolving the polyesteramide in an organic solvent to prepare a solution M with the concentration of 0.05-40 mg/mL, dissolving a stabilizer in the organic solvent to prepare a solution N with the concentration of 0.05-40 mg/mL, and uniformly mixing the solution M and the solution N according to the volume ratio of 1:1-2 to obtain a solution L; dissolving the medicine in a proper solvent system to prepare a medicine solution with the concentration of 150-250 mug/mL; and dropwise adding the solution L into the medicinal solution at the rotating speed of 1500-2500 rpm to self-assemble the nanoparticles.

A nano drug-carrying system, which is prepared by the specific operation method.

1) The invention provides a polyesteramide material based on inositol and arginine, which has excellent biosafety and biodegradability, and is safe and nontoxic. The molecular structure is introduced with the growth factor inositol with biological activity to construct the branched polyester amide, thus providing more possibilities for designing the structure of the polyester amide. The natural cyclic polyol is introduced into the polyester amide skeleton to constitute branched polyester amide. The inositol is introduced into the polyester amide structure, so that the cytotoxicity of the carrier to internal organs can be greatly reduced, and 6 hydroxyl groups in the inositol structure can be used for constructing polyester amides with more molecular structures. In addition, such active inositol can either bring about an additional therapeutic effect. Cationic arginine and hydrophobic amino acids (phenylalanine, etc.) are used to construct positively charged hydrophilic and hydrophobic segments, respectively, in the molecular structure of polyesteramides to adjust the structure and properties of the molecule. The synergistic effect of arginine, phenylalanine and inositol can control the hydrophilicity and hydrophobicity and solubility of the branched polyesteramide.

2) The invention provides a inositol and arginine-based polyesteramide nano drug delivery system and a preparation method thereof.

3) The invention provides application of a polyesteramide nano-carrier based on inositol and arginine in serving as or preparing an anti-tumor medicament nano-carrier. The synthesized polyesteramide is used for constructing a natural anticancer drug such as taxol nano-carrier. And the anticancer performance of the nano-carrier loaded with the paclitaxel and the biocompatibility of the material per se are researched through a cell experiment and a tumor-bearing mouse animal model. Systematic analysis of the effect of nanomaterials on the anticancer effect of paclitaxel.

4) The present invention provides inositol and arginine based polyesteramide nanocarriers as a delivery system for hydrophobic antioxidants. The synthesized polyesteramide is utilized to construct a nano carrier of a hydrophobic small molecule antioxidant such as vitamin E. The application of vitamin E is challenged by solving the problems of hydrophobicity and environmental sensitivity of the vitamin E. Meanwhile, the vitamin E loaded nano-carrier is introduced into the tissue regeneration support material to regulate the microenvironment by utilizing the dispersing capacity of the nano-carrier in a water-containing system and the protective effect of the polyesteramide on the vitamin E. The research on the oxidation resistance and the immunoregulation capability of the nano-carrier inside and outside the cell deeply discusses the regulation effect of the vitamin E loaded nano-carrier on the tissue engineering microenvironment and the promotion effect of the tissue regeneration.

5) The invention provides a polyesteramide nanocarrier based on inositol and arginine as a delivery system for protein drugs. The synthesized polyesteramide and the protein drug with negative charge form a nano-composite through electrostatic interaction. The capability of the polyester amide nano-composite containing arginine to deliver protein drugs into cells is researched through cell experiments. Meanwhile, the influence of the compound of the polyesteramide and the insulin on the slow release effect of the insulin in vivo and the effective acting time of the insulin is researched through a diabetes mouse model. The branched polyesteramide carrier with biosafety is optimized and utilized to prolong the effective acting time of the insulin and reduce the pain of patients caused by insulin injection.

Compared with the prior art, the invention has the following advantages and effects:

1) The invention takes inositol, arginine and other amino acids and the like as main raw materials, synthesizes the polyester amide high molecular material based on the inositol and the arginine through solution polymerization, and has the advantages of good repeatability, simple and convenient operation, and nontoxic, economic and easily obtained raw materials.

2) The invention takes the polyesteramide based on inositol and arginine as a drug delivery carrier, and can self-assemble with DSPE-PEG2000 into a stable nano system with uniform particle size in water by a nano precipitation method. The nanometer system has a particle size of about 100nm and a moderate size, and can reach tumor sites through a high permeability and long retention (EPR) effect. The nano system is safe and non-toxic, has good biocompatibility, and the degradation product is amino acid, so that the nano system has excellent biocompatibility. The nano drug-loading system can wrap the hydrophobic chemotherapeutic drug PTX through hydrophobic interaction, and the nano carrier can remarkably prolong the circulation time of the PTX in blood, so that the PTX is gathered at a tumor position, and the bioavailability of the drug is improved.

3) The invention takes the polyesteramide based on inositol and arginine as the carrier of the hydrophobic micromolecular antioxidant vitamin E, and can be self-assembled into a stable nano system BPEA @ VE NPs with uniform particle size with DSPE-PEG2000 in water by a nano precipitation method. Experimental results show that BPEA @ VE NPs show excellent antioxidant performance in both extracellular and intracellular environments. The BPEA nano-carrier can improve the dissolution of vitamin E in a water system and enhance the oxidation resistance of the vitamin E. The BPEA @ VE NPs can be applied to wound dressings and tissue engineering, and play the roles of resisting oxidation and stabilizing the cell growth microenvironment. With the help of BPEA nano-carrier, cells and tissues can be protected from being damaged by excessive antioxidant. In addition, the BPEA based on natural amino acids contains arginine in the molecular structure, so the BPEA also has certain antioxidant and anti-inflammatory capacities. In conclusion, BPEA @ VE NPs have great application potential in the biomedical field.

4) The invention constructs micro-nano-scale compound of BPEA and protein by electrostatic interaction and hydrophobic interaction based on polyester amide protein of inositol and arginine. The regulation and control of the particle size from nanometer to micron can be realized by adjusting the formula. It is stable without aggregation in phosphate buffer. On one hand, the nano-composite constructed by BPEA and protein realizes the effective delivery of intracellular protein. Overcomes the difficulty of delivering the macromolecular protein drugs into cells. Meanwhile, the BPEA molecular structure contains a large amount of active ingredients such as arginine, so that ROS generated inside and outside cells can be eliminated, and the cells are protected from oxidative damage of the ROS. BPEA can also promote the proliferation of cells, and has very good biocompatibility and safety. On the other hand, BPEA and protein are used for constructing micron-sized complexes, such as the micron-sized complexes of BPEA and insulin. The micron-sized compound of BPEA and insulin can realize long-acting slow release of insulin and reduce the hypoglycemia risk of patients. The long-acting slow release effect can reduce the injection frequency of insulin and reduce the pain of patients. In addition, the excellent antioxidant property and anti-inflammatory capability of BPEA can greatly reduce the damage to skin and subcutaneous tissues caused by long-term insulin injection.

Drawings

FIG. 1 is a nuclear magnetic map of inositol and arginine-based polyester amide BPEA polymers prepared in examples 1,6, and 7.

FIG. 2 is a nuclear magnetic map of the inositol and arginine-based polyester amide BPEA polymer prepared in example 2.

FIG. 3 is a TEM image and a graph showing the results of particle size distribution before and after paclitaxel loading on polyesteramide BPEA based on inositol and arginine prepared in example 1; wherein, the graph a is a TEM image before paclitaxel loading, the graph b is a TEM image after paclitaxel loading, the graph c is a particle size distribution graph before paclitaxel loading, and the graph d is a particle size distribution graph after paclitaxel loading.

FIG. 4 is a graph showing the experimental results of paclitaxel-loaded inhibition of tumor cell proliferation by the polyesteramide BPEA based on inositol and arginine, prepared in example 1; the graph a is a graph of the effect result of the nanoparticles formed by loading paclitaxel on the 4T1 cell at different concentrations on the cell proliferation, the graph b is a graph of the change trend of the cell proliferation with the increase of the action time after the nanoparticles formed by loading paclitaxel on the material act on the 4T1 cell, the graph c is a graph of the effect result of the nanoparticles formed by loading paclitaxel on the MDA-MB-231 cell at different concentrations on the cell proliferation, the graph d is a graph of the change trend of the cell proliferation with the increase of the action time after the nanoparticles formed by loading paclitaxel on the material act on the MDA-MB-231 cell, the graph e is a graph of the effect result of the nanoparticles formed by loading paclitaxel on the MCF-7 cell at different concentrations on the cell proliferation, and the graph f is a graph of the change trend of the cell proliferation with the increase of the action time after the nanoparticles formed by loading paclitaxel on the MCF-7 cell.

FIG. 5 is a graph showing the experimental results of paclitaxel loaded paclitaxel on the polyesteramide BPEA based on inositol and arginine prepared in example 1 for the inhibition of solid tumor growth in mice.

FIG. 6 is a graph of the results of experiments on the scavenging of intracellular ROS by vitamin E loaded polyesteramide BPEA based on inositol and arginine, prepared in example 1; wherein, the graph a is a clearing action mechanism graph, and the graph b is a clearing action experiment result graph.

FIG. 7 is a graph showing the experimental results of vitamin E loading of the Sar-and Arg-based polyesteramide BPEA prepared in example 1 into a hydrogel to promote wound healing in the skin.

FIG. 8 is a graph of cellular uptake of inositol and arginine-based polyesteramide BPEA prepared in example 2 and rhodamine-labeled bovine serum albumin nanocomplex; the graph I is an uptake result graph of Hela cells on free rhodamine-labeled bovine serum albumin, the graph II is an uptake result graph of Hela cells on bovine serum albumin nanoparticles with rhodamine labels loaded on BPEA materials, and the graph III is an uptake result graph of Hela cells on bovine serum albumin nanoparticles with rhodamine labels loaded on BPEA materials (after the concentration of the nanoparticles is increased).

FIG. 9 is a graph of the results of experiments on the enhanced effect of inositol and arginine-based polyesteramide BPEA complex prepared in example 2 on glycemic control in diabetic mice.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

Example 1: synthesis of inositol-based amino acid-based branched polyesteramide (BPEA-3):

the invention provides a method for synthesizing a polyesteramide macromolecule based on inositol and arginine, which comprises the following steps:

(1) Synthesis of Arg-6 monomer

The synthetic route for the Arg-6 monomer is as follows: arginine (0.04 mol), 1,6-hexanediol (0.02 mol) and p-toluenesulfonic acid monohydrate (0.082 mol) were dispersed in 300mL of toluene with magnetic stirring. Stirring is carried out continuously, and the monomer Arg-6 is generated after the esterification reaction is carried out for 24 hours at 130 ℃. And simultaneously removing the generated moisture through the water separator. After the esterification reaction is completely finished, the reaction system is naturally cooled to room temperature. The solvent toluene in the system was removed. Adding isopropanol into the product, heating and stirring until the isopropanol is dissolved, and cooling and settling in a refrigerator. Repeatedly purifying for 3 times to obtain monomer Arg-6, vacuum drying for 48h, sealing and storing for later use. The chemical structure of the purified monomer Arg-6 was identified by 1H NMR by dissolving it in deuterated water.

(2) Synthesis of Phe-ino monomer

The synthesis of Phe-ino monomers is achieved by an esterification reaction between phenylalanine and inositol. The synthesis method comprises the following steps: phenylalanine (0.12 mol), inositol (0.02 mol), and p-toluenesulfonic acid monohydrate (0.24 mol) were dispersed in 300mL of toluene under magnetic stirring. The reaction was carried out at 130 ℃ with mechanical stirring for 24h. And simultaneously removing the generated moisture through the water separator. After the reaction was completed completely, the solution was naturally cooled to room temperature. The solvent toluene was removed from the system. And repeatedly extracting and washing the primary product by deionized water to obtain a pure Phe-ino monomer, drying for 48h in vacuum, and sealing and storing for later use. Finally, the chemical structure of the monomer Phe-ino was identified by 1H NMR by dissolving it in deuterated dimethyl sulfoxide.

(3) Synthesis of N4 monomer

The synthesis of the N4 monomer is realized by condensation reaction of adipoyl chloride and p-nitrophenol. The synthesis method comprises the following steps: succinyl chloride (0.2 mol), triethylamine (0.45 mol) were dissolved in 200mL of acetone and the ice bath was maintained at 0 ℃. P-nitrophenol (0.42 mol) was dissolved in pre-cooled acetone under ice bath and added dropwise to the system. The reaction is continued for 24 hours at normal temperature after 2 hours of reaction in an ice bath. The initial product is settled in water repeatedly at least 3 times to obtain monomer N4. After vacuum drying for 24h, it was recrystallized three times from a mixed solvent of acetone and DMF and then vacuum dried. The purified monomer N4 was dissolved in deuterated dimethyl sulfoxide and its chemical structure was identified by 1H NMR.

(4) Synthesis of inositol-based amino acid-based branched polyesteramides

Branched Polyesteramide (BPEA) based on inositol is synthesized by carrying out polycondensation reaction on monomers Arg-6, phe-ino and N4 under the catalysis of triethylamine. The specific synthesis method comprises the following steps: arg-6 (0.774 g), phe-ino (1.776 g) and N4 (0.338 g) were dissolved in 10mL DMSO by heating to 75 deg.C with stirring. Then 0.3mL of triethylamine as a catalyst was added to the reaction system and stirred uniformly. After the polycondensation reaction was carried out at 75 ℃ for 48h, the product was dissolved in methanol and then precipitated with precooled ethyl acetate. Dissolving and precipitating repeatedly for three times to obtain purified BPEA, vacuum drying for 24h, and sealing for storage. The purified polymer BPEA was chemically identified by 1H NMR.

As a result: the polyester amide BPEA is successfully prepared by carrying out amidation condensation polymerization on an arginine monomer Arg-6 containing diamine, a phenylalanine monomer Phe-ino containing polyamine and a diacid monomer N4 with a leaving group under the catalysis of triethylamine, and the obtained product is named as BPEA-3. The results of nuclear magnetic resonance are shown in FIG. 1, and GPC measurements showed that the molecular weight was 4386. The chemical structural formula is as follows:

example 2: synthesis of inositol-based amino acid-based branched polyesteramide (BPEA-4):

the invention provides a method for synthesizing a polyesteramide polymer based on inositol and arginine, which comprises the following steps:

(1) Synthesis of the Arg-8 monomer

The synthetic route for the Arg-8 monomer is as follows: arginine (0.04 mol), 1,6-octanediol (0.02 mol) and p-toluenesulfonic acid monohydrate (0.082 mol) were dispersed in 300mL of toluene with magnetic stirring. Stirring is carried out continuously, and the monomer Arg-8 is generated after the esterification reaction is carried out for 24 hours at 130 ℃. And simultaneously removing the generated moisture through the water separator. After the esterification reaction is completely finished, the reaction system is naturally cooled to room temperature. The solvent toluene in the system was removed. Adding isopropanol into the product, heating and stirring until the isopropanol is dissolved, and cooling and settling in a refrigerator. Repeatedly purifying for 3 times to obtain monomer Arg-8, vacuum drying for 48h, sealing and storing for later use. The chemical structure of the purified monomer Arg-8 was identified by 1H NMR after dissolution in deuterated water.

(2) Synthesis of Phe-ino monomer

The synthesis of Phe-ino monomers is achieved by an esterification reaction between phenylalanine and inositol. The synthesis method comprises the following steps: phenylalanine (0.12 mol), inositol (0.02 mol), and p-toluenesulfonic acid monohydrate (0.24 mol) were dispersed in 300mL of toluene under magnetic stirring. The reaction was carried out at 130 ℃ with mechanical stirring for 24h. And simultaneously removing the generated moisture through the water separator. After the reaction was complete, the solution was allowed to cool to room temperature. The solvent toluene was removed from the system. And repeatedly extracting and washing the primary product by deionized water to obtain a pure Phe-ino monomer, drying for 48 hours in vacuum, and sealing and storing for later use. Finally, the chemical structure of the monomer Phe-ino was identified by 1H NMR by dissolving it in deuterated dimethyl sulfoxide.

(3) Synthesis of N8 monomer

The synthesis of the N4 monomer is realized by the condensation reaction of suberoyl chloride and p-nitrophenol. The synthesis method comprises the following steps: suberoyl chloride (0.2 mol), triethylamine (0.45 mol) were dissolved in 200mL of acetone, and maintained at 0 ℃ in an ice bath. P-nitrophenol (0.42 mol) was dissolved in pre-cooled acetone under ice bath and added dropwise to the system. The reaction is continued for 24 hours at normal temperature after 2 hours of reaction in an ice bath. The initial product is settled in water repeatedly at least 3 times to obtain monomer N8. After vacuum drying for 24h, it was recrystallized three times from a mixed solvent of acetone and DMF and then vacuum dried. The purified monomer N8 was dissolved in deuterated dimethyl sulfoxide and its chemical structure was identified by 1H NMR.

(4) Synthesis of inositol-based amino acid-based branched polyesteramides

Branched Polyesteramide (BPEA) based on inositol is synthesized by carrying out polycondensation reaction on monomers Arg-8, phe-ino and N8 under the catalysis of triethylamine. The specific synthesis method comprises the following steps: arg-6 (0.917 g), phe-ino (0.455 g) and N4 (0.444 g) were dissolved in 10mL of DMSO by heating to 75 ℃ with stirring. Then 0.3mL of triethylamine as a catalyst was added to the reaction system and stirred uniformly. After the polycondensation reaction was carried out at 75 ℃ for 48h, the product was dissolved in methanol and then precipitated with precooled ethyl acetate. Dissolving and precipitating repeatedly for three times to obtain purified BPEA, vacuum drying for 24h, and sealing for storage. The purified polymer BPEA was chemically identified by 1H NMR.

As a result: the polyester amide BPEA is successfully prepared by carrying out amidation condensation polymerization on an arginine monomer Arg-8 containing diamine, a phenylalanine monomer Phe-ino containing polyamine and a diacid monomer N8 with a leaving group under the catalysis of triethylamine, and the obtained product is named as BPEA-4. The nuclear magnetic results are shown in FIG. 2, and the chemical structural formula is shown as follows:

example 3: the preparation method of the paclitaxel-loaded polyesteramide nano-particles and the anti-tumor capability test thereof are as follows:

first, 5mg of the branched polyesteramide BPEA prepared in example 1, 1mg of DSPE-PEG2000 and 1mg of paclitaxel were dissolved in 0.5mL of dimethyl sulfoxide. The above mixed solution was added dropwise to 9mL of deionized water with magnetic stirring (1000 rpm) to form BPEA @ PTX NPs. DSPE-PEG2000 as a stabilizer stabilizes the morphology of the nanoparticles. The organic solvent DMSO in the medium was then removed by multiple ultrafiltration. The method for preparing empty vector BPEA NPs is consistent with BPEA @ PTX NPs, and paclitaxel is not added in the system. The prepared nanoparticles are stored in a refrigerator at 4 ℃ for later use. The morphological structure of the particle size of the nanoparticles was characterized by DLS and TEM, respectively. The stability of paclitaxel loaded nanoparticles was evaluated by DLS particle size determination. Finally, the anti-tumor capability of BPEA @ PTX NPs is tested through a cell experiment and an in vivo tumor inhibition experiment.

The cell experiment method comprises the following steps: toxicity of paclitaxel-loaded vectors BPEA @ PTX NPs, empty vectors PEA NPs and free paclitaxel on tumor cells was evaluated by MTT method. The tumor cells used in the experiment were breast cancer cells MDA-MB-231, MCF7 and 4T1 (ATCC). Cells were first seeded at a concentration of 1000 per well in 96-well plates. After the cells were completely adhered to the bottom of the well plate, BPEA @ PTX NPs, BPEA NPs and free paclitaxel were added to the medium at a certain concentration to continue culturing the cells. After 24h, the medium was replaced with fresh MTT-containing medium and incubation was continued for 4h. The medium containing MTT was removed. 150mL of DMSO was added to each well. And reading the absorbance value at 560nm by using a microplate reader, and drawing a cell viability curve. Meanwhile, the cell activities of cells at different action times under the same drug concentration were also evaluated by the MTT method.

The tumor inhibition experiment method comprises the following steps: the anti-cancer effect of BPEA @ PTX NPs in vivo was evaluated in 4T1 tumor-bearing mice. The experimental method is as follows: 100 μ l of serum-free medium containing about 3000000 4T1 cells was inoculated by subcutaneous injection into the backs of 4-week-old female BALB/c mice. When the tumor grows to about 100mm ³ At this time, tumor-bearing mice were randomly divided into four groups of 5 mice each. Mice in each group were injected every three days with BPEA @ PTX NPs, PTX, BPEA NPs and saline, respectively, via tail vein injection. The injection dosage of paclitaxel is 5mg/Kg. In the free paclitaxel group, polyoxyethylene castor oil is used as a cosolvent to dissolve paclitaxel in physiological saline, and then tail vein injection is carried out. Body weights of mouse tumor sizes were measured every three days. The tumor size is calculated as follows.

As a result: the results showed that the average particle size of BPEA @ PTX NPs was about 100nm (FIG. 3). It is known that the particle size of nanocarriers has a large influence on the uptake capacity of cells. The particle size of the BPEA @ PTX NPs prepared by the method is small, and the BPEA @ PTX NPs are beneficial to the uptake of a carrier by tumor cells and play the role of resisting cancers. As shown in FIG. 4, the toxicity of BPEA @ PTX NPs was comparable to that of free paclitaxel at the same time point and at different time points at the same concentration for the three tumor cells. When the concentration of paclitaxel in the sample of BPEA @ PTX NPs is 100ng/mL, the cell viability of three breast cancer cells is reduced to below 50%, and the tendency of BPEA @ PTX NPs to combine free paclitaxel is consistent. This indicates that the BPEA vector has no effect on the tumor cell potency of paclitaxel. In addition, the tumor cytotoxicity test results of BPEA empty vector BPEA NPs are consistent with the results of a blank control group, and the empty vector has no influence on the proliferation of tumor cells. The BPEA carrier has good biocompatibility and no toxic or side effect on cells. And the use safety of the BPEA is ensured.

The results of the tumor inhibition experiment are shown in FIG. 5. The growth trends of the tumor volume in the backs of the mice in the blank control group and the empty vector BPEA NPs group are consistent, which indicates that the empty vector has no influence on the growth of the tumor of the mice and the health of the mice. In free paclitaxel, the growth rate of tumor volume was significantly lower than that of the blank control group, and the growth of tumor was inhibited to some extent. In the bpea @ ptx NPs group, the growth of the tumor in the back of the mice was further inhibited compared to free paclitaxel. From the results it can be seen that the size of the tumors in the bpea @ ptx NPs group was one-half of that of the free paclitaxel group.

Example 4: the preparation method of the vitamin E-loaded polyesteramide nano-particles and the oxidation resistance test thereof are as follows:

we used the amino acid-based branched polyesteramide BPEA synthesized in example 1 to construct vitamin E (VE, a widely used commercial antioxidant) nanocarriers such as BPEA @ VE NPs. The process for preparing BPEA @ VE NPs by the nanoprecipitation method is as follows: first, BPEA (5 mg) and DSPE-PEG2000 (1 mg) and an amount of vitamin E (1mg, 2mg,4 mg) were dissolved in 0.5mL of dimethyl sulfoxide. Then, the above mixed solution was added dropwise to 9.5mL of stirred deionized water. In the process, hydrophobic vitamin E is loaded in BPEA nano-carrier by a nano-precipitation method to obtain BPEA @ VE NPs. The medium in BPEA @ VE NPs solution was freed from the organic solvent dimethyl sulfoxide using an ultrafiltration tube with PBS (pH 7.4). The above samples containing different vitamin E ratios are labeled BPEA @ VE1 NPs, BPEA @ VE2NPs, BPEA @ VE4 NPs, respectively. BPEA NPs represent BPEA empty vector without vitamin E loading. The particle size of BPEA @ VE NPs loaded with different proportions of vitamin E was characterized by DLS. And the morphological structure of BPEA @ VE NPs is observed by a transmission electron microscope. Before use in cellular experiments, samples were sterilized with 0.22 μm filters. And finally, testing the antioxidant capacity and the promotion effect on tissue regeneration of the BPEA @ VE NPs through a cell experiment and a skin wound healing experiment.

Intracellular ROS clearance assay: mouse embryonic fibroblast NIH 3T3 cells (ATCC) were cultured at 10 ⁵ The density of individual/well was seeded in 12-well plates. After overnight incubation in a cell incubator. The medium was removed. Fresh medium containing BPEA @ VE NPs at a certain concentration was added to the well plates and the culture was continued. The medium was removed after 6 h. Addition of roop to fresh medium following instructions stimulates cells for 30min to produce ROS. The cells were then washed 3 times with PBS (pH 7.4). And adding a fluorescent probe DCFH-DA into the pore plate according to the instruction, and incubating for 30min in a cell culture box. Finally, cells were observed by fluorescence microscopy to assess the ability of BPEA @ VE NPs to scavenge intracellular ROS.

Skin wound healing test method: a temperature-sensitive material Pluronic F-127 is used as a BPEA @ VE NPs carrier to carry out SD rat full-thickness skin wound repair experiments. Pluronic F-127 as a temperature sensitive material is a novel high molecular nonionic surfactant. Can be dissolved in water at 4 ℃ to form Pluronic F-127 solution. And the sol-gel transformation occurs at 37 ℃, and the hydrogel without fluidity is formed and stored in a refrigerator at 4 ℃ for later use. In full-thickness skin wound healing experiments, we used Pluronic F-127 as the BPEA @ VE NPs vector. The experimental procedure was as follows: BPEA @ VE NPs were first prepared according to the method previously mentioned. 20mg of Pluronic F-127 was dissolved in 100ml PBS (pH 7.4) buffer and stored in a refrigerator at 4 ℃.

Male SD rats weighing approximately 250g were selected to evaluate the effect of BPEA @ C6 NPs on wound healing. First, SD rats were randomly divided into three groups. A circular full-thickness skin defect of 1.5cm in diameter was created on the back of the rat with surgical scissors. In the blank control group, the wound was washed with sterile PBS (pH 7.4) and covered with a 3M protective wound film. In the experimental group, after the wounds were cleaned with sterile PBS (pH 7.4), the wounds were coated with Pluronic F-127 sol containing BPEA @ VE NPs and formed gels in situ at body temperature. And then covering a layer of 3M wound protection film on the surface. In the control group, the skin wound was coated with a layer of Pluronic F-127 sol without treatment after washing the wound with sterile PBS (pH 7.4). And then covering a layer of 3M wound protection film on the surface. After wound treatment, each rat was individually housed to avoid cross-challenge effects on wound healing and evaluation of experimental results. The wound repair on the back of the rats was observed and recorded at regular time points.

As a result: we used the fluorescent probe DCFH-DA (2 ',7' -dichlorodihydrofluorescein diacetate) to study the ROS-scavenging ability of BPEA @ VE NPs in cells (FIG. 6). DCFH-DA itself has no fluorescence, can freely pass through the cell membrane and enter the cell, and then is hydrolyzed by esterase to generate DCFH. Whereas DCFH cannot cross the cell membrane and become loaded inside the cell. DCFH is capable of generating a DC F that is oohm fluorescent upon oxidation by intracellular ROS. We can know the intracellular ROS level by detecting the fluorescence intensity of cells, thereby evaluating the scavenging capacity of BPEA @ VE NPs on the intracellular ROS. Rosp was used to stimulate the production of intracellular ROS in 3T3 cells (fig. 6). Significant green fluorescence was observed in cells of the control species that were stimulated by Rosu and treated with fluorescent probe DCFH-DA. In the experimental group, cells were incubated with BPEA @ VE NPs and then stimulated with Rosup, and then were loaded with the fluorescent probe DCFH-DA. A decrease in the intensity of green fluorescence can be observed. And the fluorescence intensity further decays as the vitamin E loading in the BPEA vector increases. In addition, it can be seen from the results that the empty polyester amide carrier also has a certain antioxidant capacity.

In fig. 7, the wounds in all three groups had transitioned from the inflammatory phase to the proliferative phase on day 5 after wound formation. Pink granulation tissue was formed at the skin defect. In addition, the wound area is also gradually reduced by the tension of the large number of fibroblasts in the granulation tissue. It can be seen from the figure that the BPEA @ VE NCs loaded F-127hydrogel treated wounds contracted more rapidly than the area in the control and F-127hydrogel groups. As wound healing progressed, the differences between groups were less pronounced. This result suggests that BPEA @ VE NCs can accelerate the early healing of wounds by shortening the formation of granulation-promoting tissue during inflammation, reducing the likelihood of chronic wound formation.

Example 5: preparation method of protein drug-loaded polyesteramide particle and capability test of protein drug-loaded polyesteramide particle in intracellular delivery:

cell uptake experiments: the uptake behavior of BPEA/BSA-Rhodamine nanocomplexes by HeLa cells was observed by fluorescence microscopy. The experimental procedure was as follows: first, a BPEA/BSA-Rhodamine nanocomposite was prepared by nanoprecipitation using bovine serum albumin BSA-Rhodamine labeled with Rhodamine and BPEA prepared in example 2. Wherein the concentration of BSA-Rhodamine is 200. Mu.g/mL. BPEA at 40mg/mL was dissolved in DMSO, stabilizer DSPE-PEG2000 at 20mg/mL was dissolved in DMSO, and BSA-Rhodamine at 200. Mu.g/mL was dissolved in DI water. 100 μ L of BPEA dilution was mixed with 160 μ L of DSPE-PEG2000 solution. Then 0.2mL of the mixed solution of BPEA and DSPE-PEG2000 was added dropwise to 5mL of the aqueous solution of BSA-Rhodamine at 2000rpm to form BPEA/BSA-Rhodamine nanocomposite. Dimethyl sulfoxide was removed from the solution using an ultrafiltration tube. HeLa cells were seeded in 6-well plates at a density of 20 ten thousand per well. After overnight incubation in the cell incubator, the medium was removed. BPEA/BSA-Rhodamine nanocomposite with medium diluted to a BSA-Rhodamine concentration of 50 μ g/mL was added to 6-well plates and cells were incubated. After incubating the cells for 6h, the cells were washed 3 times with sterile PBS (pH 7.4). And finally, observing and collecting a fluorescence image by using a fluorescence microscope.

As a result: FIG. 8 shows that no significant red fluorescence was observed with a fluorescence microscope after incubating cells with free BSA-Rhodamine for 5 h. And after the BPEA @ BSA-Rhodamine NCs are incubated for 5h, obvious red fluorescence can be observed. It was demonstrated that BPEA @ BSA-Rhodamine NCs can successfully deliver BSA-Rhodamine into cells. After increasing the concentration of BPEA @ BSA-Rhdamineo NCs in the medium by two-fold, the red fluorescence intensity in the cells was significantly increased compared to the lower concentration group. Increasing the concentration of the nanocomplexes also has the benefit of increasing protein uptake by the cells.

Example 6: preparation method of insulin-loaded polyesteramide particles and test of control capability of insulin-loaded polyesteramide particles on blood sugar of type 1 diabetic mice

The experimental method comprises the following steps: in the first step, a BPEA/insulin nanocomposite is prepared. The method comprises the following steps: hydrochloric acid with the concentration of 0.01mol/L is prepared. Insulin was dissolved in a 0.01mol/L hydrochloric acid solution at an insulin concentration of 200. Mu.g/mL. BPEA, prepared in example 2, was dissolved in dimethyl sulfoxide at a concentration of 20mg/mL. The stabilizer DSPE-PEG2000 was dissolved in dimethyl sulfoxide at a concentration of 20mg/mL. 100 μ L of BPEA solution was mixed well with 160 μ L of DSPE-PEG2000 solution. Then, 0.2mL of a mixed solution of BPEA and DSPE-PEG2000 was added dropwise to 5mL of a stirred hydrochloric acid solution of insulin at 2000 rpm. Dimethyl sulfoxide was removed from the solution using an ultrafiltration tube. And secondly, carrying out a blood sugar reducing capability test on the type 1 diabetic mice. BPEA/insulin nanocomplex was injected into mice by cervical subcutaneous injection at doses of 3 units/Kg and 6 units/Kg, respectively. At each time point set, the blood glucose concentration of the mice was monitored with a glucometer. The free insulin group injected with a dose of 3 units/Kg served as a control group.

As a result, as shown in FIG. 9, the blood glucose concentration of the diabetic mice rapidly decreased after the injection of free insulin subcutaneously through the neck. After 1h after insulin injection, the blood glucose concentration reached a minimum of about 5.0mmol/L. After 1h, the blood glucose concentration of the mice rapidly increased. The blood glucose concentration exceeded the normal blood glucose concentration value 2h after injection. The blood glucose concentration of the mice returned to the initial value 4h after injection. Thus, free insulin acts rapidly on glycemic control but has a short duration. The blood sugar can rebound uncontrollably in a short time. Frequent injections are required if the blood glucose concentration of the mice is to be controlled within the normal range. Frequent administration of the drug causes severe pain and inconvenience to the patient. However, the blood glucose concentration of diabetic mice also decreased rapidly after the injection of the nanocomposite of BPEA and insulin. 1.5h after injection of the nanocomposite, the blood glucose concentration of the mice was minimized to a concentration of about 11.6mmol/L. Subsequently, the blood glucose concentration of the mice slowly rose. After 8h post injection, the blood glucose concentration rose to 15.6mmol/L. The blood glucose concentration at this time was still within the normal range. At 24h after injection, the blood glucose of the mice returned to essentially the initial value. The nanocomplex of BPEA with insulin is effective in prolonging the effective duration of action of insulin compared to free insulin. The duration of normal blood glucose concentration of the mice is obviously improved. The slow release of the insulin in vivo can be effectively realized after the compound is formed with the BPEA.

Example 7: synthesis of inositol-based amino acid-based branched polyesteramides:

other conditions were the same as in example 1 except that the monomer formulation for synthesizing the polyesteramide polymer was different. The specific method comprises the following steps: branched Polyesteramide (BPEA) based on inositol is synthesized by carrying out polycondensation reaction on monomers Arg-6, phe-ino and N4 under the catalysis of triethylamine. The specific synthesis method comprises the following steps: arg-6 (0.774 g), phe-ino (0.888 g) and N4 (0.338 g) were dissolved in 10mL of DMSO by heating to 75 ℃ with stirring. Then 0.3mL of triethylamine as a catalyst was added to the reaction system and stirred uniformly. After the polycondensation reaction was carried out at 75 ℃ for 48h, the product was dissolved in methanol and then precipitated with precooled ethyl acetate. Dissolving and precipitating repeatedly for three times to obtain purified BPEA, vacuum drying for 24h, and sealing for storage. The chemical structure of the purified polymer BPEA was identified by 1H NMR, and the result is shown in FIG. 1 and is named BPEA-2.GPC measurement showed that the molecular weight was 4627.

Example 8: synthesis of inositol-based amino acid-based branched polyesteramides:

other conditions were the same as in example 1 except that the monomer formulation for synthesizing the polyesteramide polymer was different. The specific method comprises the following steps: branched Polyesteramide (BPEA) based on inositol is synthesized by carrying out polycondensation reaction on monomers Arg-6, phe-ino and N4 under the catalysis of triethylamine. The specific synthesis method comprises the following steps: arg-6 (0.774 g), phe-ino (0.444 g) and N4 (0.338 g) were dissolved in 10mL of DMSO by heating to 75 ℃ with stirring. Then 0.3mL of triethylamine as a catalyst was added to the reaction system and stirred uniformly. After the polycondensation reaction was carried out at 75 ℃ for 48h, the product was dissolved in methanol and then precipitated with precooled ethyl acetate. Dissolving and precipitating repeatedly for three times to obtain purified BPEA, vacuum drying for 24h, and sealing for storage. The chemical structure of the purified polymer BPEA was identified by 1H NMR and the result is shown in FIG. 1, which was designated BPEA-1.GPC measurement showed that the molecular weight was 4551.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A method for preparing a polyesteramide based on inositol and arginine, which is characterized in that: the method comprises the following steps:

s4, heating and dissolving the monomer A, the monomer B and the monomer C in a solvent, adding triethylamine, uniformly stirring, and carrying out polycondensation reaction; purifying the primary product to obtain the inositol-and arginine-based polyesteramide;

the proportion of the arginine, the dihydric alcohol and the paratoluenesulfonic acid monohydrate in the step S1 is 1-4:1-2:4-10 by mol ratio;

the mixture ratio of phenylalanine, inositol and p-toluenesulfonic acid monohydrate in the step S2 is 5-14, and the molar ratio is 1-2:7-30;

the molar ratio of the binary acyl chloride, the triethylamine and the p-nitrophenol in the step S3 is (15-25);

the proportion of the monomer A, the monomer B, the monomer C and the triethylamine in the step S4 is 0.5-1g.

2. Process for the preparation of polyesteramides based on inositol and arginine according to claim 1, characterized in that:

the dihydric alcohol in the step S1 is one or more selected from 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol or 1,10-decanediol;

the solvents in the step S1 and the step S2 are toluene;

the binary acyl chloride in the step S3 is selected from one or more of oxalyl chloride, succinyl chloride or suberoyl chloride;

all solvents in the step S3 are acetone;

the solvent in step S4 is dimethyl sulfoxide.

3. The process for the preparation of the polyester amides based on inositol and arginine according to claim 1, characterized in that:

the esterification reaction in the step S1 is carried out at the temperature of 120-140 ℃ for 20-30 h, and water generated in the reaction process is removed by a water separator; the specific operation of the purification of the primary product is as follows: after the esterification reaction is finished, cooling the reaction system to room temperature, removing the solvent in the system, adding isopropanol into the product, heating and stirring until the isopropanol is dissolved, cooling and settling, repeatedly purifying for 3-5 times, and drying;

the reaction conditions in the step S2 are that the temperature is 120-140 ℃ and the time is 20-30 h, and the water generated in the reaction process is removed through a water separator; the specific operation of the purification of the primary product is as follows: after the reaction is finished, cooling the reaction system to room temperature, removing the solvent in the system, extracting, washing and drying the product;

in the step S3, the reaction time is 1-2 h after the p-nitrophenol is dripped, and the reaction time is 20-30 h after the normal temperature state is changed; the specific operation of the purification of the primary product is as follows: after the reaction is finished, repeatedly settling the primary product in water for 3-5 times, drying, recrystallizing in a mixed solvent of acetone and N, N-dimethylformamide for 3-5 times, and drying again to obtain the product;

the heating temperature in the step S4 is 70-80 ℃; the polycondensation reaction is carried out at the temperature of 70-80 ℃ for 45-55 h; the specific operation of the purification of the primary product is as follows: dissolving the initial product in methanol, precipitating the product with precooled ethyl acetate, repeatedly dissolving the precipitate for 3-5 times, and drying.

4. A polyesteramide based on inositol and arginine, characterized in that: prepared by the preparation method of any one of claims 1 to 3.

5. Inositol-and arginine-based polyester amides as claimed in claim 4, characterized in that: the chemical structure of the polyesteramide is shown as the formula (I):

6. Use of the inositol and arginine-based polyesteramide of claim 5 for the preparation of a drug nano-delivery vehicle or for the preparation of a drug nano-delivery system.

7. Use according to claim 6, characterized in that:

the medicine comprises antitumor drugs, hydrophobic antioxidants, vitamin antioxidants, carotenoid antioxidants, flavonoid compounds, enzyme antioxidants, protein antioxidants and water-soluble protein drugs.

8. Use according to claim 7, characterized in that:

the antitumor drug comprises paclitaxel, docetaxel, methotrexate, camptothecin, adriamycin and curcumin; the water-soluble protein medicine comprises insulin, serum albumin, interferon, tissue plasminogen activator, erythropoietin, granulocyte macrophage colony stimulating factor, interleukin, immunosuppressant, antibody and antigen polypeptide.

9. Use according to any one of claims 6 to 8, characterized in that:

the proportion of the polyesteramide, the stabilizer and the organic solvent is 5g: 0.1-10g;

the stabilizer is DSPE-PEG 2000;

the organic solvent is dimethyl sulfoxide;

when the medicine is an anti-tumor medicine or a hydrophobic antioxidant, the specific operation is as follows: dissolving the polyesteramide, the stabilizer and the medicine in an organic solvent, dropwise adding the obtained mixed solution into water under a stirring state, and self-assembling into nanoparticles; wherein the mass ratio of the polyesteramide to the medicine is 5:0.1 to 10;

when the medicine is a water-soluble protein medicine, the specific operation is as follows: dissolving the polyesteramide in an organic solvent to prepare a solution M with the concentration of 0.05-40 mg/mL, dissolving a stabilizer in the organic solvent to prepare a solution N with the concentration of 0.05-40 mg/mL, and uniformly mixing the solution M and the solution N according to the volume ratio of 1:1-2 to obtain a solution L; dissolving the medicine in a proper solvent system to prepare a medicine solution with the concentration of 150-250 mug/mL; and dropwise adding the solution L into the medicinal solution at the rotating speed of 1500-2500 rpm to self-assemble into nanoparticles.

10. A nano drug-carrying system, which is characterized in that: prepared by the specific procedure for the use as described in claim 9.