A phenylboronic acid compound, a polymer, an insulin sustained-release preparation and use thereof

Abstract

The present application discloses a phenyl boronic acid compound, which contains a phenyl boronic acid group and a carbon-carbon double bond group, and the phenyl boronic acid group can be combined with glucose. The present application also discloses a polymer, which is obtained by free radical copolymerization of the above-mentioned phenyl boronic acid compound, a monomer containing A and an initiator in a solvent. The present application further discloses an insulin sustained-release preparation containing the above-mentioned polymer, which has different insulin release rates under different glucose concentrations, and can accelerate the release of insulin under a hyperglycemic environment to reduce blood glucose. The present application further discloses a preparation method of the above-mentioned insulin sustained-release preparation, which self-assembles the negatively charged insulin and the positively charged double-phenyl boronic acid modified polymer into the insulin sustained-release preparation through electrostatic interaction, and has the characteristics of high loading rate. The prepared insulin sustained-release preparation can release insulin, and the released insulin can bind to insulin receptors in the body to reduce blood glucose level.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, specifically to a phenylboronic acid compound, a polymer, an insulin sustained-release formulation, and its applications. Background Technology

[0002] Diabetes mellitus is a metabolic disease characterized by prolonged hyperglycemia, affecting more than one-tenth of adults worldwide. Driven by rapid urbanization, unhealthy dietary habits, and increasingly sedentary lifestyles, obesity has become a prominent global problem in recent years, leading to a rapid rise in diabetes incidence. Sustained hyperglycemia can cause diabetes-related complications, threatening patients' lives and health. Currently, the most mainstream treatment for diabetes is the use of exogenous insulin to maintain normal blood glucose levels. However, the temperature and enzymatic instability of insulin molecules, the risk of hypoglycemia from insulin injections, and poor adherence due to frequent insulin injections limit its widespread application. Therefore, we need to design novel insulin delivery systems that can improve insulin's ability to regulate blood glucose while reducing injection frequency.

[0003] Currently, there are three main glucose response mechanisms: phenylboronic acid derivatives, glucose-binding molecules, and glucose oxidase. Pphenylboronic acid (PBA)-based glucose-responsive insulin has been validated for its rapid and potent in vitro and in vivo glucose-responsive insulin release performance, making it relatively close to clinical applications. However, current glucose-responsive insulin still struggles to maintain blood glucose levels within a normal range over a prolonged period after a single injection. PBA and its derivatives are hydrophobic monomers that exhibit hydrophilicity after forming a complex with glucose; this transformation can alter the swelling degree of the polymer system. These substances exist in aqueous solutions in two forms: a hydrophilic, negatively charged dissociated state and a hydrophobic, uncharged, undissociated state. A dissociation equilibrium exists between these two states, and in both forms, the dissociated PBA is more likely to covalently bind glucose, forming a more hydrophilic structure. Therefore, this glucose-responsiveness of PBA can be used to design self-regulating insulin release systems for blood glucose detection and control.

[0004] Publication number CN118255997A discloses a polymer, an insulin composition containing the polymer, and its applications. The polymer is composed of three different structural units, wherein structural unit III contains a phenylboronic acid structure. Insulin compositions prepared using this polymer as a drug carrier have advantages such as good stability, easy control of injection dosage, high drug loading, long insulin retention time in vivo, and easy metabolism and clearance of the carrier from the body.

[0005] CN117771387A discloses a sugar-responsive complex, its preparation method, and its application. The sugar-responsive complex comprises mutually complexed phenylboronic acid-based polylysine and insulin having a diol structure. The complexing forces include: (1) dynamic electrostatic attraction, and (2) covalent interaction between the phenylboronic acid structure of the phenylboronic acid-based polylysine and the diol structure of the insulin having a diol structure. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention provides a phenylboronic acid compound containing a phenylboronic acid group and a carbon-carbon double bond group. The phenylboronic acid group can bind to glucose and can be used for glucose response.

[0007] A phenylboronic acid compound, the structure of which is shown in formula (1),

[0008]

[0009] R1 is selected from one of hydrogen atoms, C1 to C6 alkyl groups, or halogens; R2 and R3 are each independently selected from C1 to C6 alkyl groups.

[0010] Phenylboronic acid exhibits Lewis acid properties, enabling it to reversibly form esters with compounds such as glucose that have cis-1,2 or cis-1,3 diol structures. In aqueous media, phenylboronic acid exists in equilibrium as an uncharged trihedral structure and a negatively charged tetrahedral borate structure; both structures can reversibly bind to glucose to form cyclic phenylboronic acid complexes. In this invention, a compound containing a phenylboronic acid group was designed and synthesized. This compound can bind to glucose and can be used to design glucose-responsive sustained-release insulin formulations.

[0011] The present invention also provides a method for preparing the above-mentioned phenylboronic acid compound, which is simple and requires only one reaction step to obtain the phenylboronic acid compound.

[0012] A method for preparing a phenylboronic acid compound includes the following steps: reacting N-(3-aminopropyl)acryloylamide with a dialkyl-substituted terminal amino group and 4-bromomethylphenylboronic acid with a substituted benzene ring in N,N-dimethylformamide in one step.

[0013] The specific synthetic route is as follows:

[0014]

[0015] The nitrogen atom of a tertiary amine has a lone pair of electrons, which can attack the carbon atom bonded to bromine, causing the bromide ion to leave and pair with the quaternary ammonium salt cation formed. In this invention, the N-(3-aminopropyl)acryloylamide with dialkyl substitution on the terminal amino group and the 4-bromomethylphenylboronic acid with substitution on the benzene ring are both commercially available. Different substituted phenylboronic acid compounds can be obtained simply by replacing the reactants with different substitutions, R1, R2, and R3.

[0016] The present invention also provides a polymer containing phenylboronic acid groups that can bind to glucose.

[0017] A polymer is obtained by free radical copolymerization of the above-mentioned phenylboronic acid compound, an A-containing monomer, and an initiator in a solvent, and the structure of the polymer is shown in formula (2).

[0018]

[0019] In equation (2), A is One of them,

[0020] n = 5 ~ 1000, m = 1 ~ 200 For the connection position, R1 is selected from one of hydrogen atoms, C1 to C6 alkyl groups, and halogens; R2 and R3 are each independently selected from C1 to C6 alkyl groups.

[0021] Preferably, the structure of the polymer is as follows:

[0022]

[0023] Where n = 5 ~ 1000, m = 1 ~ 200, For connection positions.

[0024] Preferably, the molar ratio of the phenylboronic acid compound to the A-containing monomer is 1-2:3-19.

[0025] In this invention, a polymer with a phenylboronic acid content of 5% to 40% can be obtained by adjusting the molar ratio of the monomer containing A and the phenylboronic acid compound.

[0026] Preferably, the initiator is an azo initiator or an inorganic peroxide initiator.

[0027] In this invention, the azo initiator can be azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), etc., and the inorganic peroxide initiator can be hydrogen peroxide, ammonium persulfate, potassium persulfate, etc.

[0028] Preferably, the solvent is one or more of alcohol or water.

[0029] Preferably, the total mass ratio of the monomer containing A and the phenylboronic acid compound to the volume ratio of the solvent is 100–400 mg / mL.

[0030] Preferably, the free radical copolymerization reaction is carried out at a temperature of 35–75°C and for a reaction time of 3–10 h.

[0031] Preferably, the dialysis step involves performing at least 5 dialysis cycles on the solution after the reaction is completed using a dialysis membrane with a capacity of 3500–15000 kDa, with each dialysis cycle lasting 6–8 hours.

[0032] The present invention also provides an insulin sustained-release formulation comprising the above-mentioned polymer, which has different insulin release rates at different glucose concentrations and accelerates insulin release to lower blood sugar in a hyperglycemic environment.

[0033] An insulin sustained-release formulation comprising the aforementioned polymer and insulin.

[0034] Compared to polymers with a secondary amine structure at the benzylic position, polymers with a positively charged quaternary ammonium salt structure can better adsorb negatively charged insulin, increasing the insulin loading rate in sustained-release insulin formulations. In normal blood glucose conditions, the binding of glucose to phenylboronic acid groups reduces the positive charge density on the polymer chain, allowing for the release of a small amount of insulin, thus providing a slow and continuous insulin delivery and enabling high-dose injections. In hyperglycemic conditions, the binding of a large number of phenylboronic acid groups to glucose accelerates insulin release, thereby lowering blood glucose levels.

[0035] Preferably, the insulin is porcine insulin, human insulin, recombinant human insulin, or FITC-porcine insulin.

[0036] In this invention, the FITC-insulin is obtained by labeling porcine insulin with fluorescein isothiocyanate.

[0037] Preferably, the mass ratio of the polymer to insulin is 1-4:1-4.

[0038] The present invention also provides a method for preparing the above-mentioned insulin sustained-release formulation, wherein negatively charged insulin and positively charged phenylboronic acid-modified polymer are self-assembled into an insulin sustained-release formulation through electrostatic interaction, which has the characteristics of high loading rate.

[0039] A method for preparing an insulin sustained-release formulation includes the following steps: dissolving the above-mentioned polymer and insulin in acidified water, adjusting the pH to neutral with alkaline solution to form an insulin complex, adding PBS solution to adjust the insulin concentration, centrifuging and resuspending to obtain the insulin sustained-release formulation.

[0040] Preferably, the acidified water is an aqueous solution of hydrochloric acid, and the concentration of the acidified water is 0.01 to 1 M.

[0041] Preferably, the total mass ratio of the polymer and insulin to the acidified water is 5–20 mg / mL.

[0042] Preferably, the alkaline solution is an aqueous solution of sodium hydroxide, and the concentration of the alkaline solution is 0.01 to 1 M.

[0043] Preferably, the centrifugation speed is 10,000 to 20,000 rpm and the centrifugation time is 5 to 10 minutes.

[0044] The present invention also provides the application of the above-mentioned insulin sustained-release formulation in the preparation of a drug for treating diabetes. The insulin sustained-release formulation can release insulin, and the released insulin can lower blood glucose levels after binding to insulin receptors in the body.

[0045] In this invention, diabetes can refer to a disease with blood glucose levels higher than normal, specifically referring to a fasting blood glucose level ≥7.0 mmol / L, a 2-hour glucose load test blood glucose level ≥11.1 mmol / L, or a glycated hemoglobin level ≥6.5%.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] (1) The phenylboronic acid compound and the polymer obtained from the phenylboronic acid compound in this invention both contain phenylboronic acid groups that can bind to glucose, and can recognize glucose and bind to glucose.

[0048] (2) The insulin sustained-release formulation of the present invention has different insulin release rates at different glucose concentrations, and accelerates insulin release to lower blood sugar in a hyperglycemic environment.

[0049] (3) The method for preparing the insulin sustained-release formulation in this invention involves the self-assembly of negatively charged insulin and positively charged phenylboronic acid-modified polymers through electrostatic interaction to form an insulin sustained-release formulation, which has the characteristic of high loading rate. Attached Figure Description

[0050] Figure 1 The specific synthetic route for obtaining the phenylboronic acid compound (AAPBA) in Example 1 is shown below.

[0051] Figure 2 The image shows the 1H NMR spectrum of the phenylboronic acid compound (AAPBA) prepared in Example 1.

[0052] Figure 3 The image shows the carbon NMR spectrum of the phenylboronic acid compound (AAPBA) prepared in Example 1.

[0053] Figure 4 The image shows the proton NMR spectrum of the polymer obtained in Example 2.

[0054] Figure 5 This is the gel permeation chromatography (GPC) spectrum of the polymer prepared in Example 2.

[0055] Figure 6 The image shows the proton NMR spectrum of the polymer obtained in Example 2.

[0056] Figure 7 The image shows the proton NMR spectrum of the polymer obtained in Example 2.

[0057] Figure 8 The image shows the proton NMR spectrum of the polymer obtained in Example 2.

[0058] Figure 9 The specific synthetic route for obtaining polymers for comparison is shown below.

[0059] Figure 10 The image shows the hydrogen nuclear magnetic resonance spectrum of the polymer prepared in comparison.

[0060] Figure 11 The graph shows the response of the 1 mg / mL insulin sustained-release formulation obtained in Example 6 to glucose.

[0061] Figure 12 The figures are single-release curves of the insulin sustained-release formulations obtained in Examples 6 to 11 in glucose solution, where A to G are single-release curves of Examples 6 to 11 respectively.

[0062] Figure 13 The cumulative release curve of the insulin sustained-release formulation obtained in Example 6 in vitro after multiple cycles in glucose solution. Detailed Implementation

[0063] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited to the following embodiments.

[0064] All raw materials used in this invention are commercially available.

[0065] Example 1: Preparation of phenylboronic acid compounds

[0066] Specific routes are as follows Figure 1As shown. 4-Bromomethylphenylboronic acid (160 mg, 0.745 mmol) was dissolved in DMF (5 mL) and then added dropwise to dimethylaminopropylacrylamide (232.8 mg, 1.49 mmol) dissolved in DMF (5 mL). The mixture was stirred at room temperature for 5 h. After the reaction was complete, the reaction solution was added dropwise to more than 20 times its volume of ethyl acetate to precipitate the product. Stirring was maintained during the addition. After precipitation was complete, the mixture was filtered and dried in a vacuum drying oven to obtain the crude product. The crude product was dissolved in a small amount of water and purified by C18 reversed-phase silica gel column chromatography. The sample was eluted with 10% methanol and lyophilized to obtain a white transparent solid, which was a phenylboronic acid compound (hereinafter referred to as AAPBA) (159.8 mg, 58.0%). Its 1H and 1C spectra are shown below. Figure 2 and Figure 3 As shown.

[0067] Example 2: Preparation of Polymers

[0068] AAPBA (50 mg, 0.227 mmol) obtained in Example 1 was added to a reaction flask, along with 400 μL of ethanol and 20 μL of water as solvents. Oxygen was removed by bubbling with N2. Then, 101 mg (97.1 μL, 0.909 mmol) of N-vinylpyrrolidone was added, dissolving 1.51 mg of AIBN (1% of the total mass of AAPBA and N-vinylpyrrolidone). The mixture was heated to 65 °C and reacted for 5 h. The mixture was then separated by dialysis using a 7000 kDa membrane, with 5 water changes. After dialysis, the polymer was lyophilized to obtain a white solid (132 mg, 87.4%). The proton NMR spectrum of the polymer is shown below. Figure 4 As shown, the gel permeation chromatography (GPC) spectrum of the polymer is as follows: Figure 5 As shown, the polymer has a weight-average molecular weight (Mw) of 15403 and a polydispersity index (PD) of 2.03.

[0069] Examples 3-5: Preparation of Polymers

[0070] The preparation methods of Examples 3 to 5 are the same as those of Example 2, with the differences shown in the table below.

[0071] Table 1: Differences in preparation methods of Examples 2-5

[0072]

[0073] Example 6: Preparation of Insulin Sustained-Release Formulation

[0074] FITC-porcine insulin (1 mg) and the polymer obtained in Example 2 (1 mg) were dissolved in 0.2 mL of HCl aqueous solution (0.1 M), mixed, and NaOH aqueous solution (1 M) was added to adjust the pH to 7.4 to obtain the insulin sustained-release formulation.

[0075] The solution was brought to a final volume of 1 mL with PBS (10 mM, pH 7.4), centrifuged, and the supernatant was removed. The solution was then resuspended in 1 mL of PBS for washing. This washing process was repeated three times, and the insulin concentration in the supernatant was measured each time. Finally, an insulin sustained-release formulation with an insulin concentration of 1 mg / mL was prepared for subsequent experiments.

[0076] Examples 7-11: Preparation of Insulin Sustained-Release Formulations

[0077] The preparation methods of Examples 7 to 11 are the same as those of Example 6, with the differences shown in the table below.

[0078] Table 2: Differences in preparation methods of Examples 6-11

[0079]

[0080] Method for testing insulin loading rate: The concentration of insulin in the supernatant from three washes during the preparation of the insulin sustained-release formulation in Examples 6-11 was measured to determine the total amount of insulin washed away; Loading rate = (Total amount of insulin added - Total amount of insulin washed away) / Total amount of insulin added * 100%

[0081] Comparative Example: Preparation of Amine Polymers and Sustained-Release Insulin Formulations

[0082] (1) Polymer preparation

[0083] Specific routes are as follows Figure 9 As shown. In a reaction flask, 100 mg (0.524 mmol) of 3-acrylamidophenylboronic acid and 86.71 mg (0.524 mmol) of 2-aminoethyl methacrylate hydrochloride were added, along with 4 mL of ethanol as a solvent. Oxygen was removed by bubbling with N2. Then, 349 mg (335.6 μL, 3.14 mmol) of N-vinylpyrrolidone was added, dissolving 5.36 mg of AIBN (1% of the total monomer mass). The mixture was heated to 65 °C and reacted for 5 h. The polymer was separated by dialysis using a 7000 kDa membrane, with 5 water changes. After dialysis, the polymer was lyophilized to obtain a white solid (476 mg, 88.1%). The proton NMR spectrum of the polymer is shown below. Figure 10 As shown.

[0084] (2) Preparation of insulin sustained-release formulations

[0085] FITC-porcine insulin (1 mg) and the polymer obtained in step (1) (1 mg) were dissolved in 0.2 mL of HCl aqueous solution (0.1 M), mixed, and NaOH aqueous solution (1 M) was added to adjust the pH to 7.4 to obtain an insulin sustained-release formulation with an amino group at the benzyl position.

[0086] The solution was brought to a final volume of 1 mL with PBS (10 mM, pH 7.4), centrifuged, and the supernatant was removed. The solution was then resuspended in 1 mL of PBS for washing. This washing process was repeated three times, and the insulin concentration in the supernatant was measured each time. Finally, an insulin sustained-release formulation with an insulin concentration of 1 mg / mL was prepared for subsequent experiments.

[0087] The loading rate of the comparative insulin sustained-release formulation was 26.11% obtained by the above loading rate test method, indicating that the electrostatic adsorption of insulin by the benzylic position of the quaternary ammonium salt in Examples 6-11 is better than that of the primary amine.

[0088] Sample Analysis

[0089] I. Response test of insulin sustained-release formulations to glucose

[0090] Construction of the standard curve: Weigh 1 mg of FITC-porcine insulin into an EP tube, add 0.1 mL of HCl solution (0.1 M), add 0.15 mL of NaOH solution (0.1 M) to completely dissolve the insulin, and add PBS (10 mM, pH 7.4) to bring the volume to 1 mL to obtain a concentration of 1 mg / mL FITC-porcine insulin. Prepare insulin solutions of 1, 5, 10, 20, 40, 80, and 160 μg / mL using the 1 mg / mL FITC-porcine insulin stock solution. Take 100 x 3 μL of each solution and measure the fluorescence intensity at 525 nm after excitation at 495 nm using a microplate reader. Finally, plot a linear standard curve of fluorescence intensity versus insulin concentration.

[0091] The 1 mg / mL insulin sustained-release formulation obtained in Example 6 was cyclically exposed to glucose solutions at concentrations of 100 and 400 mg / dL (n=3). At the start of the experiment, the insulin sustained-release formulation (equivalent to 1 mg of insulin) was centrifuged and then mixed with 1 mL of glucose solution (400 mg / dL). After incubation at 37°C and 400 rpm for 10 minutes, the suspension was centrifuged again, and the supernatant was collected to determine the insulin concentration. Then, 1 mL of glucose solution (100 mg / dL) was added, and after 10 minutes, the suspension was centrifuged again, and the supernatant was collected to determine the insulin concentration. Then, 1 mL of glucose solution (400 mg / dL) was added. This process was repeated three times. The insulin concentration in the supernatant of the EP tube was quantitatively determined using a fluorescence spectrophotometer, and the insulin concentration was calculated using a standard curve.

[0092] Figure 11This is a graph showing the glucose response of the 1 mg / mL insulin sustained-release formulation obtained in Example 6. As shown in the figure, during three high-glucose-normal-glucose cycles, the amount of insulin released by the sustained-release formulation in the high-glucose solution was greater than that in the normal-glucose solution. This fully verifies that this insulin sustained-release formulation has the ability to release insulin in response to high concentrations of glucose, thereby providing a long-acting, ultra-low dose of insulin to maintain blood glucose stability under normal blood glucose conditions, while providing a high dose of insulin to lower blood glucose to the normal range when blood glucose rises. The slightly lower release amount each time is partly due to the decrease in stored insulin as insulin is released, and partly due to the aggregation of the insulin sustained-release formulation caused by centrifugation.

[0093] II. Single-shot kinetic release test of insulin sustained-release formulations

[0094] First, the insulin sustained-release formulations from Examples 6-11 were prepared into 160 μg / ml PBS solutions as stock solutions. Samples were then added to the microplates according to the following groups:

[0095] PBS group: 50 μL stock solution + 125 μL PBS;

[0096] 100G group: 50μL stock solution + 17.5μL 10mg / mL glucose + 107.5μL PBS;

[0097] 400G group: 50μL stock solution + 70μL 100mg / mL glucose + 55μL PBS; after preparing the solution, the 96-well plate was placed into the microplate reader, the total testing time was set to 12h, and tests were performed every 5min, with shaking for 10s between each test. The fluorescence intensity at 525nm under 495nm excitation was measured each time, and the change in fluorescence intensity over time was plotted. The results are as follows. Figure 12 As shown in A to F.

[0098] The 1 mg / mL insulin sustained-release formulation obtained in Example 6 was prepared in 96-well plates with glucose solutions of different concentrations to create a release solution of 500 μg / mL insulin, with a total volume of 100 μL per well. Three release groups were set up: PBS, 100 mg / dL glucose (100g), and 400 mg / dL glucose (400g). After preparation, the 96-well plates were inserted into a microplate reader, with a total testing time of 4 hours. Tests were performed every 2.5 minutes, with shaking for 10 seconds between each test. The fluorescence intensity at 525 nm under 495 nm excitation was measured each time, and the change in fluorescence intensity over time was plotted. The results are shown below. Figure 12 As shown in G.

[0099] Figure 12 The graphs show the single-release curves of the insulin sustained-release formulations obtained in Examples 6-11 in glucose solution. Figure 11 As shown in A to G, in the normal blood glucose environment (100G group), the insulin sustained-release preparation will release a small amount of insulin to provide slow and continuous insulin and allow for high-dose injection. In the hyperglycemic environment (400G group), the binding of a large number of phenylboronic acid groups with glucose will accelerate the release of insulin and thus lower blood glucose.

[0100] III. In vitro cumulative release test of insulin sustained-release formulations across multiple cycles

[0101] The insulin sustained-release formulation obtained in Example 6 was resuspended in PBS at pH 7.4 to achieve a final insulin concentration of 1 mg / dL. This was added to EP tubes to prepare final glucose concentrations of 100 mg / dL and 400 mg / dL, resulting in a final insulin concentration of 500 μg / mL (n=3). Each release experiment lasted 1 hour, with 10 cycles. After each cycle, 90% of the supernatant was collected by centrifugation, and the same volume and concentration of insulin-free glucose solution were added. 100 μL of the release supernatant was added to a 96-well plate, and the fluorescence intensity of FITC-insulin was detected using a microplate reader. The insulin concentration was calculated using a standard curve, plotted as described above. The cumulative release was calculated using the following formula:

[0102] Q n =C1×V1+C2×V2×0.9+C3×V3×0.9+……+C n ×V n ×0.9

[0103] Q n C represents the cumulative release amount in the nth cycle. n V represents the insulin concentration in the supernatant measured during the nth cycle. n This represents the total volume of the liquid released during the nth cycle.

[0104] Figure 13 This is the in vitro cumulative release curve of the insulin sustained-release formulation obtained in Example 6 in glucose solution after multiple cycles. During long-term cumulative release, the insulin sustained-release formulation still maintained its responsiveness to glucose solution, and its responsiveness to 400 mg / dL glucose solution was better than that to 100 mg / dL glucose solution.

[0105] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A phenylboronic acid compound, characterized in that, The structure of the phenylboronic acid compound is shown in formula (1). ， R1 is selected from hydrogen atoms; R2 and R3 are each independently selected from C1 to C6 alkyl groups.

2. The method for preparing the phenylboronic acid compound according to claim 1, characterized in that, Includes the following steps: The product is prepared by reacting N-(3-aminopropyl)acryloylamide with a dialkyl-substituted terminal amino group and 4-bromomethylphenylboronic acid with a substituted benzene ring in N,N-dimethylformamide in one step.

3. A polymer, characterized in that, The polymer is obtained by free radical copolymerization of the phenylboronic acid compound of claim 1, a monomer containing A, and an initiator in a solvent, and the structure of the polymer is shown in formula (2). ， In equation (2), A is , n=5~1000, m=1~200, " is the connection position, R1 is selected from hydrogen atoms; R2 and R3 are each independently selected from C1~C6 alkyl groups.

4. The polymer according to claim 3, characterized in that, The molar ratio of the phenylboronic acid compound to the A-containing monomer is 1~2:3~19.

5. The polymer according to claim 3, characterized in that, The initiator is an azo initiator or an inorganic peroxide initiator.

6. The polymer according to claim 3, characterized in that, The total mass ratio of the monomer containing A and the phenylboronic acid compound to the volume of the solvent is 100~400 mg / mL.

7. A sustained-release insulin formulation, characterized in that, Includes the polymer and insulin as described in any one of claims 3 to 6.

8. The insulin sustained-release formulation according to claim 7, characterized in that, The insulin is porcine insulin, human insulin, recombinant human insulin, or FITC-porcine insulin; the mass ratio of the polymer to insulin is 1~4:1~4.

9. The method for preparing the insulin sustained-release formulation according to claim 7 or 8, characterized in that, The process includes the following steps: dissolving the polymer described in any one of claims 3 to 6 with insulin in acidified water, adjusting the pH to neutral with an alkaline solution to form an insulin complex, adding PBS solution to adjust the insulin concentration, centrifuging and resuspending to obtain an insulin sustained-release formulation.

10. The use of the insulin sustained-release formulation according to claim 7 or 8 in the preparation of a medicament for treating diabetes.

Images