Preparation method of OHA-DA / PAM / BC multifunctional hydrogel

Abstract

The invention relates to the technical field of biomedical materials, and in particular to a method for preparing an OHA‑DA / PAM / BC multifunctional hydrogel, comprising preparing OHA; chemically grafting dopamine to OHA to obtain OHA‑DA; preparing a BC suspension; diluting an OHA‑DA aqueous solution to different concentrations and then adding AM; introducing BC suspensions of different mass concentrations into the OHA‑DA / PAM self-healing hydrogel for nano-enhancement to obtain the OHA‑DA / PAM / BC multifunctional hydrogel, and realizing an OHA‑DA / PAM / BC multifunctional hydrogel with multiple properties such as self-healing, good mechanical properties, self-adhesion and good antibacterial properties integrated in a single hydrogel.

Description

Technical Field

[0001] The invention relates to the technical field of biomedical materials, and in particular to a method for preparing an OHA-DA / PAM / BC multifunctional hydrogel. Background Art

[0002] Hydrogel is known as the most promising wound dressing. It can absorb tissue exudate and keep the wound surface moist and breathable, thereby accelerating wound healing.

[0003] However, traditional hydrogels often have poor mechanical properties, poor antibacterial ability, and are not injectable and self-healing. In addition, since wound shapes are often irregular, traditional hydrogels cannot perfectly cover the wound, further limiting their use as wound dressings.

[0004] Therefore, it is necessary to propose a method for preparing OHA-DA / PAM / BC multifunctional hydrogel that integrates multiple properties such as self-healing, good mechanical properties, self-adhesion and good antibacterial properties in a single hydrogel. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing an OHA-DA / PAM / BC multifunctional hydrogel, so as to realize an OHA-DA / PAM / BC multifunctional hydrogel integrating multiple properties such as self-healing, good mechanical properties, self-adhesion and good antibacterial properties in a single hydrogel.

[0006] To achieve the above object, the present invention adopts a method for preparing an OHA-DA / PAM / BC multifunctional hydrogel, comprising the following steps:

[0007] HA is modified with aldehyde groups to prepare OHA;

[0008] Chemical grafting of dopamine onto OHA to obtain OHA-DA;

[0009] Purify BC;

[0010] The purified BC was taken out, added with water and put into a soybean milk machine at a speed of 30000 r / min. The soybean milk machine stirred for 30 min and crushed to form a uniform BC suspension with different mass concentrations;

[0011] Prepare a 10wt% OHA-DA aqueous solution, dilute the OHA-DA aqueous solution with secondary water to different concentrations, add 315mgAM, stir and react for 30min, then add 150μL of 50mg / mL APS and 150μL of 2mg / mL MBA respectively, stir and mix evenly, blow nitrogen, add 3μL of TEMED at the same time, then transfer to a 60℃ oven to react for 4h to obtain OHA-DA / PAM self-healing hydrogel;

[0012] BC suspensions of different mass concentrations were introduced into the OHA-DA / PAM self-healing hydrogel for nano-reinforcement. Based on the Schiff base reaction of OHA-DA and PAM and the hydrogen bonding between BC, OHA-DA and PAM, the hydrogel was endowed with certain mechanical strength and tensile properties, and the OHA-DA / PAM / BC multifunctional hydrogel was prepared.

[0013] Among them, in the step of preparing OHA, the preparation process is:

[0014] Prepare 200 mL of deionized water and 2 g of HA, stir and dissolve the deionized water and HA at room temperature 25°C to obtain a 1 wt% HA aqueous solution;

[0015] Weigh 2-3 g NaIO4 and dissolve it in 20 mL of deionized water in a dark environment. When NaIO4 is completely dissolved, a NaIO4 solution is obtained.

[0016] Add NaIO4 solution dropwise to the HA aqueous solution and stir to react for 8 h in the dark;

[0017] 1 mL of ethylene glycol was added to terminate the reaction, and the reaction was continued with stirring for 1 h. The product was dialyzed for 3 days using a dialysis bag with a molecular weight of 3500, and freeze-dried to obtain OHA.

[0018] Wherein, in the step of chemically grafting dopamine onto OHA to obtain OHA-DA, the preparation process is as follows:

[0019] Weigh 1 g OHA and dissolve it in 100 mL PBS;

[0020] Add 388 mg EDC and 117 mg NHS, and activate with stirring under nitrogen atmosphere for 1 h;

[0021] The pH value of the solution was adjusted to 5.5;

[0022] Add 474 mg DA and stir the reaction for 24 h;

[0023] The unreacted chemicals and by-products were removed by dialysis, and the doubly modified pure product OHA-DA was obtained after freeze-drying.

[0024] Among them, after the step of weighing 1g OHA and dissolving it in 100mL PBS:

[0025] Nitrogen was blown for 30 min to prevent dopamine from oxidative self-polymerization.

[0026] Among them, in the step of purifying BC, the purification process is:

[0027] BC was cleaned with deionized water;

[0028] Soak BC in deionized water for 3 days, changing the water every 4 hours. After taking out, soak BC in 0.1 mol / L NaOH for stirring at 80°C for 4 hours, changing the NaOH once in the middle.

[0029] After taking out the BC, it was washed with deionized water until it became neutral, and white translucent BC was obtained, which was stored at a temperature of 4°C for future use.

[0030] Among them, after taking out the purified BC, adding water and putting it into a soymilk machine with a rotation speed of 30000r / min, the soymilk machine is stirred for 30min, and the BC suspension with different mass concentrations is crushed into a uniform suspension.

[0031] The mass concentrations include 0.3%, 0.5%, 0.8%, 1%, and 2%.

[0032] Among them, in the step of preparing a 10 wt % OHA-DA aqueous solution, diluting the OHA-DA aqueous solution with secondary water to different concentrations, adding 315 mg AM, and stirring the reaction for 30 minutes:

[0033] Concentrations include 0.3%, 0.5%, 0.7%, 1.0%, and 1.3%.

[0034] The invention discloses a method for preparing an OHA-DA / PAM / BC multifunctional hydrogel, comprising the steps of: preparing OHA by performing aldehyde group modification on HA; performing dopamine chemical grafting on OHA to obtain OHA-DA; purifying BC; taking out the purified BC, adding water and putting it into a soybean milk machine with a rotation speed of 30000 r / min, stirring the soybean milk machine for 30 minutes, and breaking it to form a uniform BC suspension with different mass concentrations; preparing a 10wt% OHA-DA aqueous solution, diluting the OHA-DA aqueous solution with secondary water to different concentrations, adding 315mgAM, stirring for reaction for 30 minutes, and then adding 50mg / mL APS 150μL and 2mg / mL MBA 150μL, stirring for 30 minutes. The mixture was mixed evenly, nitrogen was blown, and 3 μL of TEMED was added at the same time. The mixture was then transferred to an oven at 60°C for reaction for 4 hours to obtain OHA-DA / PAM self-healing hydrogel. BC suspensions of different mass concentrations were introduced into the OHA-DA / PAM self-healing hydrogel for nano-reinforcement. Based on the Schiff base reaction of OHA-DA and PAM and the hydrogen bonding between BC, OHA-DA and PAM, the hydrogel was given certain mechanical strength and tensile properties to prepare OHA-DA / PAM / BC multifunctional hydrogel, which integrated multiple properties such as self-healing, good mechanical properties, self-adhesion and good antibacterial properties into a single hydrogel. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a flow chart of the steps of the preparation method of the OHA-DA / PAM / BC multifunctional hydrogel of the present invention.

[0037] Figure 2 It is a flow chart of the steps of preparing OHA of the present invention.

[0038] Figure 3 It is a flow chart of the steps of preparing OHA-DA of the present invention.

[0039] Figure 4 is a flow chart of the steps of purifying BC of the present invention.

[0040] Figure 5 It is the OHA modification chemical reaction formula of the present invention.

[0041] Figure 6It is a schematic diagram of the reaction mechanism of the aldehyde-modified hyaluronic acid of the present invention.

[0042] Figure 7 It is a schematic diagram of the preparation of the OHA-DA / PAM self-healing hydrogel of the present invention. DETAILED DESCRIPTION

[0043] See also Figure 1 to Figure 7 The present invention provides a method for preparing an OHA-DA / PAM / BC multifunctional hydrogel, comprising the following steps:

[0044] S1: aldehyde-modify HA to prepare OHA;

[0045] S2: chemically grafting dopamine onto OHA to obtain OHA-DA;

[0046] S3: purified BC;

[0047] S4: taking out the purified BC, adding water and putting it into a soymilk machine with a rotation speed of 30000r / min, and stirring the soymilk machine for 30min to break it into a uniform BC suspension with different mass concentrations, including 0.3%, 0.5%, 0.8%, 1%, and 2%;

[0048] S5: Prepare a 10wt% OHA-DA aqueous solution, dilute the OHA-DA aqueous solution with secondary water to different concentrations, then add 315mgAM, including concentrations of 0.3%, 0.5%, 0.7%, 1.0%, and 1.3%, stir and react for 30min, then add 150μL of 50mg / mL APS and 150μL of 2mg / mL MBA, stir and mix evenly, blow nitrogen, add 3μL of TEMED, and then transfer to a 60℃ oven to react for 4h to obtain OHA-DA / PAM self-healing hydrogel;

[0049] S6: BC suspensions with different mass concentrations were introduced into the OHA-DA / PAM self-healing hydrogel for nano-reinforcement. Based on the Schiff base reaction of OHA-DA and PAM and the hydrogen bonding between BC, OHA-DA and PAM, the hydrogel was endowed with certain mechanical strength and tensile properties, and the OHA-DA / PAM / BC multifunctional hydrogel was prepared.

[0050] In this embodiment, HA is hyaluronic acid, OHA is oxidized hyaluronic acid, PBS is phosphate buffered saline, EDC is carbodiimide hydrochloride, NHS is succinic hydroxyimide, BC is bacterial cellulose, AM is acrylamide, PAM is polyacrylamide, and the remaining materials are shown in Table 1:

[0051]

[0052]

[0053] Table 1 List of materials

[0054] First, HA was modified with aldehyde groups to prepare OHA; then, OHA was chemically grafted with dopamine to obtain OHA-DA; BC was purified; the purified BC was taken out, added with water and put into a soymilk machine with a rotation speed of 30000r / min, and the soymilk machine was stirred for 30min, and the BC was broken into uniform BC suspensions of different mass concentrations, including 0.3%, 0.5%, 0.8%, 1%, and 2%; then, a 10wt% OHA-DA aqueous solution was prepared, and the OHA-DA aqueous solution was diluted with secondary water to different concentrations, and then 315mgAM was added, including concentrations of 0.3%, 0.5%, 0.7%, 1.0%, and 1.3%, and the reaction was stirred for 30min, and then 50mg / mL APS150μL and 2mg / mL MBA150μL were added respectively, and the mixture was stirred and mixed evenly, nitrogen was blown, and 3μL TEMED was added at the same time, and then the mixture was transferred to a 60°C oven for reaction for 4h. The specific ratio is shown in Table 2.

[0055]

[0056] Table 2 Ratio of raw materials of hydrogels with different OHA-DA concentrations

[0057] PAM is obtained by cross-linking the polymer of AM. The aldehyde group of OHA-DA forms an imine bond with the amino group of the PAM chain. OHA-DA / PAM self-healing hydrogel is prepared based on the Schiff base reaction. The preparation diagram is shown in the figure. Figure 7As shown; finally, BC suspensions of different mass concentrations were introduced into the OHA-DA / PAM self-healing hydrogel for nano-enhancement, and BC suspensions of different concentrations were used to replace secondary water as solvent, as shown in Table 2. The other raw material ratios remained unchanged. Based on the Schiff base reaction of OHA-DA and PAM and the hydrogen bonding between BC, OHA-DA and PAM, the hydrogel was given certain mechanical strength and tensile properties to prepare the OHA-DA / PAM / BC multifunctional hydrogel; hyaluronic acid was chemically grafted with dopamine and double-modified with aldehyde groups (OHA-DA), so that its side chain had aldehyde groups, which could react with the amino groups of acrylamide to undergo Schiff base reaction. , enhancing the mechanical properties of the hydrogel while giving it self-healing function; the maximum tensile strain of the pure PAM hydrogel is 4022%, and the tensile strength is 26.42kPa; the OHA-DA / PAM hydrogel has a maximum elongation at break of 9949% and a tensile strength of 34.73kPa (reflecting the mechanical enhancement of the Schiff base reaction); the pure PAM hydrogel has no self-healing function, but has a self-healing function after adding OHA-DA, with a self-healing rate of 80.44%, realizing the OHA-DA / PAM / BC multifunctional hydrogel with multiple properties such as self-healing, good mechanical properties, self-adhesion and good antibacterial properties integrated in a single hydrogel.

[0058] Further, in the step of preparing OHA, the preparation process is:

[0059] S11: prepare 200 mL of deionized water and 2 g of HA, stir and dissolve the deionized water and HA at room temperature 25° C. to obtain a 1 wt % HA aqueous solution;

[0060] S12: weigh 2-3 g of NaIO4, dissolve the NaIO4 in 20 mL of deionized water in a light-proof environment, and obtain a NaIO4 solution when the NaIO4 is completely dissolved;

[0061] S13: NaIO4 solution was added dropwise to the HA aqueous solution, and the mixture was stirred in the dark for 8 h;

[0062] S14: Add 1 mL of ethylene glycol to terminate the reaction, continue stirring the reaction for 1 h, dialyze with a dialysis bag with a molecular weight of 3500 for 3 days, and freeze-dry to obtain OHA.

[0063] In this embodiment, first prepare 200 mL of deionized water and 2 g of HA, stir and dissolve the deionized water and HA at room temperature 25°C to obtain a 1 wt% HA aqueous solution; then weigh 2 to 3 g of NaIO4, preferably 3.17 g of NaIO4, and dissolve NaIO4 in 20 mL of deionized water in a light-proof environment. When NaIO4 is completely dissolved, a NaIO4 solution is obtained; then dropwise add the NaIO4 solution to the HA aqueous solution, stir and react for 8 h in a light-proof environment; finally, add 1 mL of ethylene glycol to terminate the reaction, continue stirring and reacting for 1 h, dialyze with a dialysis bag with a molecular weight of 3500 for 3 days, and freeze-dry to obtain OHA. The modified chemical reaction formula is as follows: Figure 5 shown.

[0064] Furthermore, in the step of chemically grafting dopamine onto OHA to obtain OHA-DA, the preparation process is as follows:

[0065] S21: Weigh 1 g OHA and dissolve it in 100 mL PBS, and blow nitrogen for 30 min to prevent dopamine from oxidative self-polymerization;

[0066] S22: Add 388 mg EDC and 117 mg NHS, and activate under nitrogen atmosphere with stirring for 1 h;

[0067] S23: adjusting the pH value of the solution to maintain at 5.5;

[0068] S24: Add 474 mg DA and stir to react for 24 h;

[0069] S25: The unreacted chemicals and by-products are removed by dialysis, and the doubly modified pure product OHA-DA is obtained after freeze drying.

[0070] In this embodiment, first, 1g OHA is weighed and dissolved in 100mL PBS, and nitrogen is blown for 30 minutes to prevent dopamine from oxidative self-polymerization; then 388mg EDC and 117mg NHS are added, and the solution is stirred and activated for 1 hour under a nitrogen atmosphere; the pH value of the solution is adjusted to 5.5, and 0.1M HCl can be used for pH adjustment; then 474mg DA is added, and a nitrogen balloon is connected, and the reaction is stirred for 24 hours; finally, dialysis is used to remove unreacted chemicals and by-products, and the double-modified pure product OHA-DA is obtained after freeze-drying. The reaction mechanism is as follows: Figure 6 shown.

[0071] Further, in the step of purifying BC, the purification process is:

[0072] S31: washing BC with deionized water;

[0073] S32: Soak BC in deionized water for 3 days, changing the water every 4 hours. After taking out, soak BC in 0.1 mol / L NaOH for stirring. The soaking and stirring temperature is 80°C and the soaking and stirring time is 4 hours. Replace NaOH once in the middle.

[0074] S33: After taking out the BC, wash it with deionized water until it becomes neutral, and obtain white translucent BC, which is stored at a temperature of 4° C. for future use.

[0075] In this embodiment, BC is firstly cleaned with deionized water; then BC is stirred and soaked in deionized water for 3 days, during which the water is changed every 4 hours, and after being taken out, BC is placed in 0.1 mol / L NaOH for soaking and stirring, the soaking and stirring temperature is 80°C, the soaking and stirring time is 4 hours, and NaOH is replaced once in the middle; finally, BC is taken out and washed with deionized water until neutral, to obtain white and translucent BC, which is stored at a temperature of 4°C for standby use; after adding BC, the hydrogen bonding effect is enhanced, the mechanical properties of the hydrogel are enhanced, and the self-healing function is imparted, and the OHA-DA / PAM / BC multifunctional hydrogel is The gel has both a tightly cross-linked polyacrylamide network and a loosely cross-linked OHA-DA network system. The synergistic effect between the double-layer network structures gives the hydrogel certain mechanical properties. The self-healing rate of OHA-DA / PAM / BC multifunctional hydrogel increases to 84.74%. The introduction of BC further enhances the adhesion strength of OHA-DA / PAM / BC multifunctional hydrogel. The adhesion strengths on metal, glass, paper, rubber, and plastic are 36.69 KPa, 23.86 KPa, 19.58 KPa, 26.21 KPa, 12.32 KPa, and 5.88 KPa, respectively.

[0076] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for preparing an OHA-DA / PAM / BC multifunctional hydrogel, characterized in that: The steps include: HA is modified with aldehyde groups to prepare OHA; Chemical grafting of dopamine onto OHA to obtain OHA-DA; Purify BC; The purified BC was taken out, added with water and put into a soymilk machine at a speed of 30,000 r / min. The soymilk machine stirred for 30 min and crushed to form a uniform BC suspension with different mass concentrations; Prepare a 10wt% OHA-DA aqueous solution, dilute the OHA-DA aqueous solution with secondary water to different concentrations, add 315mgAM, stir and react for 30min, then add 150μL of 50mg / mL APS and 150μL of 2mg / mL MBA respectively, stir and mix evenly, blow nitrogen, add 3μL of TEMED at the same time, then transfer to a 60℃ oven to react for 4h to obtain OHA-DA / PAM self-healing hydrogel; BC suspensions of different mass concentrations were introduced into the OHA-DA / PAM self-healing hydrogel for nano-reinforcement. Based on the Schiff base reaction of OHA-DA and PAM and the hydrogen bonding between BC, OHA-DA and PAM, the hydrogel was endowed with certain mechanical strength and tensile properties, and the OHA-DA / PAM / BC multifunctional hydrogel was prepared. In the step of purifying BC, the purification process is: BC was cleaned with deionized water; Soak BC in deionized water for 3 days, changing the water every 4 hours. After taking out, soak BC in 0.1 mol / L NaOH for stirring at 80°C for 4 hours, changing the NaOH once in the middle. After taking out the BC, wash it with deionized water until it becomes neutral, and obtain white translucent BC, which is stored at a temperature of 4°C for future use; In the step of chemically grafting dopamine onto OHA to obtain OHA-DA, the preparation process is as follows: Weigh 1 g OHA and dissolve it in 100 mL PBS; Add 388 mg EDC and 117 mg NHS, and activate with stirring under nitrogen atmosphere for 1 h; The pH value of the solution was adjusted to 5.5; Add 474 mg DA and stir the reaction for 24 h; The unreacted chemicals and by-products were removed by dialysis, and the doubly modified pure product OHA-DA was obtained after freeze-drying.

2. The method for preparing the OHA-DA / PAM / BC multifunctional hydrogel according to claim 1, characterized in that: In the step of preparing OHA, the preparation process is: Prepare 200 mL of deionized water and 2 g of HA, stir and dissolve the deionized water and HA at room temperature 25°C to obtain a 1 wt% HA aqueous solution; Weigh 2-3 g NaIO4 and dissolve it in 20 mL of deionized water in a dark environment. When NaIO4 is completely dissolved, a NaIO4 solution is obtained. Add NaIO4 solution dropwise to the HA aqueous solution and stir to react for 8 h in the dark; 1 mL of ethylene glycol was added to terminate the reaction, and the reaction was continued with stirring for 1 h. The product was dialyzed for 3 days using a dialysis bag with a molecular weight of 3500, and freeze-dried to obtain OHA.

3. The method for preparing the OHA-DA / PAM / BC multifunctional hydrogel according to claim 1, characterized in that: After the step of weighing 1 g OHA dissolved in 100 mL PBS: Nitrogen was blown for 30 min to prevent dopamine from oxidative self-polymerization.

4. The method for preparing the OHA-DA / PAM / BC multifunctional hydrogel according to claim 1, characterized in that: After taking out the purified BC, adding water and putting it into a soymilk machine with a rotation speed of 30000r / min, the soymilk machine is stirred for 30min, and the BC suspension with different mass concentrations is broken into uniform ones: The mass concentrations include 0.3%, 0.5%, 0.8%, 1%, and 2%.

5. The method for preparing the OHA-DA / PAM / BC multifunctional hydrogel according to claim 1, characterized in that: In the step of preparing a 10 wt % OHA-DA aqueous solution, diluting the OHA-DA aqueous solution with secondary water to different concentrations, adding 315 mg AM, and stirring the reaction for 30 min: Concentrations include 0.3%, 0.5%, 0.7%, 1.0%, and 1.3%.

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