CN116510066A - Temperature-sensitive transition point adjustable drug sustained-release carrier hydrogel and preparation method thereof - Google Patents

Abstract

The invention discloses a temperature-sensitive transformation point adjustable drug slow-release carrier hydrogel and a preparation method thereof. Adding calcium carbonate into carboxymethyl chitosan homogeneous solution, adding oxidized sodium alginate-g-poly N-isopropyl acrylamide homogeneous solution, uniformly stirring, adding D-gluconolactone, stirring for reaction, standing to form hydrogel, sealing, and preserving at room temperature to obtain the hydrogel; according to the invention, PNIPAM is grafted onto sodium alginate, and the temperature-sensitive transition point is regulated and controlled by regulating and controlling the molecular chain length of PNIPAM, so that the medicine in the hydrogel can be slowly released, the medicine slow-release period is prolonged, the gel is formed into a double-network structure adopting Schiff base reaction and ion crosslinking, the hydrogel has good physical and mechanical capabilities, the injectability of the hydrogel also has good wound adaptability, and the wound healing is promoted.

Description

Temperature-sensitive transition point adjustable drug sustained-release carrier hydrogel and preparation method thereof

technical field

The invention relates to biomedical materials and the technical field thereof, in particular to an injectable temperature-sensitive drug slow-release carrier hydrogel and a preparation method thereof; it belongs to the field of medical dressing manufacturing for skin wound regeneration and repair.

Background technique

The skin is composed of the epidermis, dermis and subcutaneous tissue. It is the largest organ of the human body and has very important physical, chemical and biological barrier functions. It can not only maintain the balance of the internal environment and prevent microbial invasion, but also protect the body from damage. But wounds such as burns, cuts, and cuts can impair the function of the skin, which can lead to problems such as bacterial infection. Therefore, wound dressings are critical to wound care, providing a physical barrier between the wound and the external environment to prevent further injury or infection. While protecting and isolating, wound dressings also accelerate wound healing and reduce infection by promoting collagen synthesis, re-epithelialization, hypoxia, and reducing wound pH.

Traditional dressings mainly include gauze, bandages and cotton wool, etc. These dressings can absorb the liquid exuded from the wound in the early stage, but they cannot provide a moist environment for the wound, and they are easy to adhere to the wound, and it is easy to damage the new granulation tissue when replaced . An ideal wound dressing should have the following characteristics: (1) stop bleeding, relieve pain, provide mechanical protection; absorb excessive exudate, keep the wound moist, dissolve necrotic tissue and fibrin; (3) easily adhere to healthy skin, but not sticky Attach new granulation tissue to avoid secondary damage during dressing change; (4) good air permeability; (5) reduce infection risk; (6) enhance healing, accelerate granulation tissue formation and re-epithelialization rate; (7) biocompatibility , non-toxic, etc.

Hydrogels have a three-dimensional cross-linked structure and are composed of hydrophilic polymers that have the ability to absorb water without dissolving. The existence of hydrophilic groups in the polymer, such as amine (-NH2), carboxyl (-COOH), and sulfate (-SO3H) groups, makes the hydrogel have good water-holding ability, and the three-dimensional cross-linked polymers The water absorption rate can reach hundreds to thousands of times of its own weight. As a new type of wound dressing, hydrogel medical dressing has the following characteristics compared with traditional dressings (1) it can control wound exudate and maintain a proper moist environment; (2) it has good biocompatibility and low cytotoxicity , no local irritation and allergic reaction; (3) It can fit tightly but not stick to the wound, which can avoid secondary trauma; (4) It can prevent the invasion of exogenous microorganisms and other harmful substances, and effectively protect the wound.

Chinese invention patent CN114042034 discloses a preparation method of an injectable temperature-sensitive drug sustained-release carrier hydrogel. The preparation method of the hydrogel is simple, the reaction conditions are mild, and it has excellent injectability, temperature sensitivity and self-healing properties. However, the sustained release period of the drug is not long enough, about 70h; the invention realizes the sol-gel conversion through the Schiff base reaction, and its hydrogel cross-linking degree is lower than that of the double cross-linking, and the water molecules can be well absorbed from the outside world. Diffusion into the interior of the hydrogel, the drug can also quickly migrate and diffuse to the outside with the water molecules, and finally released, which is not conducive to the sustained release of the drug, and cannot provide good antibacterial and anti-inflammatory effects in the later stage.

Contents of the invention

The purpose of the present invention is to solve the problems existing in the prior art, and provide an injectable temperature-sensitive drug sustained-release carrier hydrogel with an adjustable temperature-sensitive transition point and a drug release period of more than 130 hours and a preparation method thereof.

The object of the present invention is achieved through the following technical solutions:

A temperature-sensitive transition point adjustable drug sustained-release carrier hydrogel gel, which is composed of calcium carbonate added to carboxymethyl chitosan homogeneous solution, and then added with oxidized sodium alginate-g-poly N-isopropylacrylamide Homogeneous solution, after stirring evenly, add D-gluconolactone, after stirring and reacting, let it stand to form a hydrogel, seal it, and store the result at room temperature; the oxidized sodium alginate-g-poly N-isopropylpropylene The amide homogeneous solution is composed of sodium methacrylate alginate or methacrylated sodium alginate, and poly-N-isopropylacrylamide dissolved in deionized water to form a homogeneous solution, adding a photoinitiator, and under dark conditions Bubble N ₂ under an ice bath, irradiate with ultraviolet rays for 30-45 minutes in an ice bath, centrifuge, dialyze, and freeze-dry; Sodium iodate, obtained by freeze-drying.

In order to further realize the purpose of the present invention, preferably, the mass ratio of the oxidized sodium alginate-g-poly N-isopropylacrylamide to carboxymethyl chitosan is 0.5～1.5; -The mass percent concentration of oxidized sodium alginate-g-poly N-isopropylacrylamide in the homogeneous solution of polyN-isopropylacrylamide is 10% to 20%; in the homogeneous solution of carboxymethyl chitosan The mass percent concentration of carboxymethyl chitosan is 5% to 10%; the mass ratio of calcium carbonate to oxidized sodium alginate-g-poly N isopropylacrylamide is 5 to 15:100; D-gluconolactone The mass ratio to calcium carbonate is 0.3-0.6:1.

Preferably, the homogeneous solution of oxidized sodium alginate-g-polyN-isopropylacrylamide is formed by dissolving oxidized sodium alginate-g-polyN-isopropylacrylamide in deionized water; carboxymethyl Chitosan homogeneous solution is formed by dissolving carboxymethyl chitosan in deionized water.

Preferably, the photoinitiator is 2-hydroxy-4'-(2-hydroxyethoxy)-2-methyl, 2-methyl-1-(4-methylthiophenyl)-2- Morpholinyl-1-propanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylbenzyl One or more of ketones.

Preferably, the amount of the photoinitiator is 2% to 5% of the mass of sodium methacrylate alginate or methacrylated sodium alginate; sodium periodate and methacrylate sodium alginate or methacrylate The molar ratio of oxidized sodium alginate is 1:10-25; the sodium methacrylate alginate or methacrylated alginate in the homogeneous solution of oxidized sodium alginate-g-poly N-isopropylacrylamide The mass percent concentration of sodium is 1-2%, and the concentration of poly-N-isopropylacrylamide is 0.1-0.6mol/ml; the time for bubbling _N2 is 30-45 minutes to remove oxygen in the system; The dialysis after centrifugation is carried out through a dialysis membrane with a molecular weight cut-off of 8000-14000; the dialysis to remove sodium periodate is carried out through a dialysis membrane with a molecular weight cut-off of 8000-14000.

Preferably, the poly-N-isopropylacrylamide is prepared by the following method: dissolving N-isopropylacrylamide, a chain transfer agent, and a second initiator in deionized water, and bubbling with N ₂ for 30-45 minutes , react at 65-75°C for 5-7 hours, wash the obtained solution with n-hexane to remove impurities, dry it in a vacuum oven at room temperature, dissolve it with tetrahydrofuran, add n-butylamine to reduce it, use n-hexane to centrifuge to remove impurities, and then add Deionized water is dissolved and transferred to a dialysis membrane to remove unreacted monomers and impurities, freeze-dried and stored at low temperature.

Preferably, the chain transfer agent is 2-(dodecyltrithiocarbonate)-2-methylpropionic acid, S-(2-cyano-2-propyl)-S-dodecyl One or more of alkyl trithiocarbonyl esters, 4-cyano-4-(thiobenzoyl)pentanoic acid and 2-phenyl-2-propyl benzodisulfide; The second initiator is one or more of azobisisobutyronitrile, azobisisoheptanonitrile, dibenzoyl peroxide and potassium persulfate; the chain transfer agent and N-isopropylacrylamide The molar ratio of the chain transfer agent to the initiator is 1:100~400; the molar ratio of the chain transfer agent to the initiator is 1:0.1~0.5; the molar concentration of N-isopropylacrylamide is 0.5~1mol/L, and the amount of n-butylamine is poly 0.2 to 0.4 times the mass of N-isopropylacrylamide; the dialysis membrane is a dialysis bag with a molecular weight cut-off of 3500.

Preferably, the sodium alginate methacrylic acid is synthesized by the following method: dissolving sodium alginate in an aqueous solution, adjusting the pH value to 7-9, adding methacrylic anhydride, and reacting at 40-50°C for 20-25 hours, The product adopts a dialysis bag with a molecular weight cut-off of 8000-14000, dialyzes with deionized water, and freeze-dries to obtain sodium alginate methacrylate; wherein, the concentration of sodium alginate aqueous solution is 1%-2% by mass; the pH value is adjusted by NaOH solution adjustment, the mass percent concentration of NaOH solution is 2% to 4%; the mass ratio of methacrylic anhydride and sodium alginate is 15 to 30:1; the deionized water dialysis time is 3 to 5 days;

The methacrylated sodium alginate is synthesized by the following method: dissolving sodium alginate in NaOH aqueous solution, adjusting the pH value to 10-12, adding glycidyl methacrylate, and bubbling with _N2 for 30-60 minutes , reacted at 60-75°C for 15-24 hours, and the product was dialyzed with deionized water and freeze-dried using a dialysis bag with a molecular weight cut-off of 8000-14000 to obtain methacrylated sodium alginate; among them, the mass of sodium alginate aqueous solution The percentage concentration is 1% to 2%; the pH value is adjusted by NaOH solution, and the mass percentage concentration of NaOH solution is 2% to 4%; the mass ratio of glycidyl methacrylate to sodium alginate is 1 to 2:1; Deionized water dialysis time is 3 ~ 5d.

The preparation method of the temperature-sensitive transition point adjustable drug sustained-release carrier hydrogel comprises the following steps:

1) Preparation of oxidized sodium alginate-g-poly-N-isopropylacrylamide: sodium alginate methacrylate or methacrylated sodium alginate and poly-N-isopropylacrylamide were completely dissolved in deionized water , to form a homogeneous solution, add a photoinitiator, bubble N2 under the condition of avoiding light, irradiate with ultraviolet light for 30-45min under the condition of ice bath, centrifuge, dialyze, purify again, freeze-dry it and dissolve it in deionized water, add sodium periodate, react for 3 to 5 hours in the dark, dialyze to remove sodium periodate, freeze-dry, and store at low temperature;

2) The temperature-sensitive transition point can be adjusted to prepare the drug sustained-release carrier hydrogel gel: oxidized sodium alginate-g-poly N-isopropylacrylamide and carboxymethyl chitosan were dissolved in deionized water respectively to form For two homogeneous solutions, calcium carbonate is added to the homogeneous solution of carboxymethyl chitosan, and then the homogeneous solution of oxidized macromolecular macromonomer-g-poly N-isopropylacrylamide is added, after stirring evenly, add D-gluconolactone, after stirring for 20-40s, standing still to form a temperature-sensitive transition point adjustable drug slow-release carrier hydrogel.

Preferably, the centrifugation for dialysis after centrifugation is centrifugation with absolute ethanol to remove unreacted poly-N-isopropylacrylamide; the standing time is 90-120s.

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

1) The present invention utilizes the chelation reaction of oxidized sodium alginate and calcium ions and the Schiff base reaction of carboxymethyl chitosan to prepare injectable temperature-sensitive drug slow-release carrier hydrogel; and wherein the oxidized sodium alginate SA is grafted with a temperature-sensitive polymer (PNIPAM), and PNIPAM molecular chains are grafted to SA, which does not participate in the internal network structure of the hydrogel, so it is affected by the binding of the cross-linking points of the hydrogel network compared to PNIPAM. The small size of the hydrogel network can achieve good stretching and curling. The PNIPAM molecular chain can be well curled inside the hydrogel to wrap the drug, which is more conducive to the coating of the drug, so that the release cycle of the drug can reach more than 130h. The slow-release cycle far exceeds the existing technology, and it is of great significance for some wounds that are not suitable for frequent dressing changes (such as trauma left by surgery, burns, etc.). Good antibacterial and anti-inflammatory effects can avoid slowing down the speed of wound healing due to insufficient drugs.

2) The present invention can realize the regulation of the temperature-sensitive transition point of the hydrogel by regulating the molecular weight of PNIPAM; the LCST of the temperature-sensitive hydrogel is 30-35°C, which is higher than room temperature. At room temperature, the drug-loaded injectable temperature-sensitive hydrogel Injected on the rough surface of the wound, the internal calcium ions will quickly complex with the carboxyl groups in sodium alginate to form a hydrogel, which can fit the skin well, and the poly N-isopropyl in the hydrogel Acrylamide has an LCST lower than body temperature, which can release the drug well, avoid the explosive release of the drug, and can better promote wound healing.

3) The hydrogel of the present invention has self-healing properties, the hydrogel can well adapt to the wound, fit the wound, and can release the drug well, can maintain a certain bactericidal and anti-inflammatory effect, and promote the regeneration and repair of the wound , can heal itself without serious damage, avoiding infection caused by damaged hydrogel.

4) The formation of the hydrogel of the present invention is through Schiff base reaction and ion cross-linking, and its biodegradability is excellent.

5) The present invention does not use a cross-linking agent, avoiding the residual cross-linking agent when the hydrogel is formed, which needs to be cleaned and removed many times in the later stage, and may not be cleaned, resulting in the hydrogel having cytotoxicity and not easy to adhere to On the wound surface, it is easy to remove when changing.

6) The hydrogel prepared by the present invention can be injected onto the wound surface, can fit the wound well, and promotes better wound healing through the slow release of drugs, and reduces the number of replacements to avoid secondary damage.

Description of drawings

Fig. 1 is the chemical reaction route diagram of embodiment 1 of the present invention.

Fig. 2 is four kinds of infrared spectra of SA-GMA, PNIPAM-CTA, PNIPAM-SH, SA-GMA-g-PNIPAM prepared in Example 1 of the present invention.

Fig. 3 is four nuclear magnetic spectra of SA-GMA, PNIPAM-CTA, PNIPAM-SH, SA-GMA-g-PNIPAM prepared in Example 1 of the present invention.

Fig. 4 is a graph of absorbance-temperature variation of poly-N-isopropylacrylamide (PNIPAM-SH) prepared in Example 1 of the present invention.

Fig. 5 is the absorbance-temperature change graph of SA-GMA-g-PNIPAM prepared in Example 2 of the present invention.

Fig. 6 is the drug release curves at 37°C of hydrogels of different drugs prepared in Example 3 of the present invention.

Fig. 7 is the drug release curve of the hydrogel prepared in Comparative Example 1 of the present invention.

Fig. 8 is the drug release curve of the hydrogel material prepared in Comparative Example 2 of the present invention at 37°C.

Fig. 9 is a cell live/dead staining test of the hydrogel prepared in Example 3 of the present invention.

Detailed ways

In order to better understand the present invention, the present invention will be further described below in conjunction with the embodiments. It should be noted that the examples are not intended to limit the protection scope of the present invention. The reagents used in the examples of the present invention are all purchased from the market.

Referring to Fig. 1, the present invention utilizes the hydroxyl group on the macromolecular chain of sodium alginate (SA) and the epoxy group on glycidyl methacrylate (GMA) to generate ring-opening reaction to synthesize sodium alginate methacrylate (SA-GMA) , and then carry out free radical polymerization with chain transfer agent and N-isopropylacrylamide, use amines to reduce trithiocarbonate group to mercapto group, and undergo click chemical reaction with vinyl sodium alginate derivatives to prepare sodium alginate -g-poly N-isopropylacrylamide (SA-g-PNIPAM), and finally use Schiff base reaction and ion cross-linking to form hydrogel.

Example 1

As shown in Figure 1, a method for preparing a drug sustained-release carrier hydrogel gel with a temperature-sensitive transition point that can be regulated, comprising the following steps:

(1) In a 500ml flask equipped with a magnetic stirrer, dissolve 3g of sodium alginate (SA) in 200m NaOH aqueous solution (PH=11), stir and dissolve fully at room temperature, shrink 3g of methacrylic acid Glyceride (GMA) was added to the sodium alginate solution, filled with N ₂ and bubbled for 45 minutes to remove the oxygen in the system, and reacted at 60°C for 18 hours. When the temperature of the solution was lowered to room temperature, a large amount of ethanol was added, and the unreacted monomer was removed by centrifugation. , the gel-like solid obtained by centrifugation was transferred to an 8-10kDa cut-off dialysis membrane, dialyzed with deionized water for three days (deionized water was replaced twice a day) to remove impurities and unreacted monomers, and then the solution was placed at -80 Freeze-dry at ℃ for one week to obtain sodium methacrylated alginate (SA-GMA).

(2) In a 100ml flask equipped with a magnetic stirring bar, mix N-isopropylacrylamide (NIPAM), 2-(dodecyltrithiocarbonate)-2-methylpropionic acid (CTA) The molar ratio to azobisisobutyronitrile (AIBN) is 75:1:0.5, 300:1:0.5 and 500:1:0.5, respectively dissolved in 40ml 1,4-dioxane, filled with N _{2 and} bubbled 30min, remove oxygen in the system, react at 73°C for 5h, when the solution cools down to room temperature, add a large amount of n-hexane, centrifuge to remove unreacted monomer, transfer the light yellow solid obtained by centrifugation to a 3500Da cut-off dialysis membrane, and use Dialyzed against deionized water for three days (deionized water was replaced twice a day) to remove impurities and unreacted monomers, and then the solution was lyophilized at -80 °C for one week to obtain poly-N-isopropylpropylene with chain transfer agent Amide (PNIPAM-CTA); Dissolve N-isopropylacrylamide (PNIPAM-CTA) with 1g of chain transfer agent in a 100ml flask equipped with 50ml of tetrahydrofuran and add 2ml of n-butylamine , stirred for 3h (the light yellow solution completely turned into a colorless transparent solution), added a large amount of n-hexane, centrifuged to remove unreacted monomers, transferred the white solid obtained by centrifugation to a 3500Da cut-off dialysis membrane, and dialyzed with deionized water for three days ( The deionized water was replaced twice a day) to remove impurities and unreacted monomers, and then the solution was freeze-dried at −80 °C for one week to obtain three polyN-isopropylacrylamides (PNIPAM-SH) with mercapto groups.

(3) In a 250ml flask equipped with a magnetic stirring bar, mix sodium methacrylated alginate (SA-GMA) with poly-N-isopropylacrylamide (PNIPAM-SH) (N-isopropylacrylamide) with mercapto The molar ratio of propylacrylamide (NIPAM), 2-(dodecyltrithiocarbonate)-2-methylpropionic acid (CTA) to azobisisobutyronitrile (AIBN) is 300:1: 0.5) was dissolved in deionized water at a mass ratio of 1:10 to make it fully dissolved, then added photoinitiator 2-hydroxyl-4'-(2-hydroxyethoxy)-2-methylbenzophenone ( 2959) (the quality is 5% of SA-GMA), under the condition of avoiding light, fill with _N Bubble 30min, remove the oxygen in the system, use ultraviolet radiation 60min under the condition of ice bath, add a large amount of dehydrated alcohol, centrifuge Unreacted PNIPAM-SH was removed, and the colloidal solid obtained by centrifugation was transferred to an 8-10kDa cut-off dialysis membrane and dialyzed with deionized water for three days (deionized water was changed twice a day) to remove impurities and unreacted monomers , and then the solution was freeze-dried at -80°C for one week to obtain sodium alginate grafted poly-N-isopropylacrylamide (SA-GMA-g-PNIPAM)

(4) In a 250ml flask equipped with a magnetic stirrer, graft poly-N-isopropylacrylamide (SA-GMA-g-PNIPAM) with 3g of sodium alginate and 1.3g of sodium periodate (NaIO4) Dissolve in 100ml deionized water, fully dissolve under light-shielded conditions, and react at room temperature for 4 hours, add 4ml ethylene glycol to terminate the reaction, transfer the solution to a 3500Da cut-off dialysis membrane, and dialyze with deionized water for three days (daily Deionized water was replaced twice) to remove impurities and unreacted monomers, and then the solution was freeze-dried at -80°C for one week to obtain oxidized sodium alginate grafted poly-N-isopropylacrylamide (OSA-GMA-g- PNIPAM).

(5) At room temperature, 0.3 g of oxidized sodium alginate grafted poly-N-isopropylacrylamide (OSA-GMA-g-PNIPAM) and 0.3 g of carboxymethyl chitosan (CMCS) were dissolved in 1.5 ml and 3ml of deionized water, after it is completely dissolved, add 22.5mg of calcium carbonate to the CMCS solution and stir evenly, then add the OSA-GMA-g-PNIPAM solution, stir evenly and add 80mg of D-gluconolactone (GDL), stirred for about 1min, poured the solution into the mold, and made a temperature-sensitive hydrogel for about 1min.

Fig. 2 is the infrared spectrum of the polymer obtained in the present embodiment 1, wherein the infrared spectrum of SA-GMA can see that 1739cm-1 place is the characteristic peak of-C=O, and 1697cm-1 is-C=C- The characteristic peaks indicate that vinyl sodium alginate derivatives have been successfully synthesized; while the characteristic peaks at 2680cm-1 on the infrared spectrum of PNIPAM-SH indicate that poly-N-isopropylacrylamide has a mercapto group successfully; while SA- The characteristic peak at 2978cm-1 on GMA-g-PNIPAM represents that it has -CONH-group, and poly-N-isopropylacrylamide has been successfully grafted onto vinyl sodium alginate derivatives.

Fig. 3 is the NMR spectrum of the polymer obtained in Example 1, wherein the chemical shift 3.96ppm belongs to the characteristic peak of -CH-NH-, the chemical shift 3.30ppm belongs to the characteristic peak of -CH2-S-, and the chemical shift 2.78ppm belongs to the characteristic peak of HS The characteristic peaks of -CH-CH2-, these characteristic peaks indicate that PNIPAM-CTA and PNIAPM-SH were successfully synthesized; the chemical shifts of 5.8ppm and 6.3ppm belong to the characteristic peaks of double bonds.

Example 2

(1) In a 500ml flask equipped with a magnetic stirrer, dissolve 3g of sodium alginate (SA) in 200m NaOH aqueous solution (PH=11), stir and dissolve fully at room temperature, shrink 3g of methacrylic acid Glyceride (GMA) was added to the sodium alginate solution, filled with N2 and bubbled for 45 minutes to remove the oxygen in the system, and reacted at 60°C for 18 hours. When the temperature of the solution was lowered to room temperature, a large amount of ethanol was added, and the unreacted monomer was removed by centrifugation. The gel-like solid obtained by centrifugation was transferred to an 8-10 kDa cut-off dialysis membrane, dialyzed against deionized water for three days (deionized water was replaced twice a day) to remove impurities and unreacted monomers, and then the solution was cooled at -80 °C Freeze-dried for one week to obtain sodium methacrylated alginate (SA-GMA).

(2) In a 100ml flask equipped with a magnetic stirring bar, mix 2.3g of N-isopropylacrylamide (NIPAM), 0.0243g of 2-(dodecyltrithiocarbonate)-2-methylpropane Acid (CTA) and 0.0033g of azobisisobutyronitrile were dissolved in 40ml of 1,4-dioxane, filled with N2 and bubbled for 30min to remove the oxygen in the system, reacted at 73°C for 5h, and when the solution cooled down to room temperature, Add a large amount of n-hexane, centrifuge to remove unreacted monomers, transfer the centrifuged light yellow solid to a 3500Da cut-off dialysis membrane, and dialyze with deionized water for three days (change the deionized water twice a day) to remove impurities and unreacted monomers. body, and then the solution was freeze-dried at -80°C for one week to obtain poly-N-isopropylacrylamide (PNIPAM-CTA) with a chain transfer agent; (PNIPAM-CTA) was dissolved in a 100ml flask with 50ml tetrahydrofuran equipped with a magnetic stirrer, added 2ml of n-butylamine, stirred for 3h (the light yellow solution completely turned into a colorless and transparent solution), added a large amount of n-hexane, and centrifuged To remove unreacted monomers, the white solid obtained by centrifugation was transferred to a 3500Da cut-off dialysis membrane, and dialyzed with deionized water for three days (deionized water was changed twice a day) to remove impurities and unreacted monomers, and then the solution was in- Freeze-dry at 80°C for one week to obtain poly-N-isopropylacrylamide (PNIPAM-SH) with mercapto groups.

(3) In a 250ml flask equipped with a magnetic stirring bar, mix sodium methacrylated alginate (SA-GMA) and poly-N-isopropylacrylamide (PNIPAM-SH) with mercapto groups at a ratio of 1:5 , 1:10, 1:12.5, 1:15, and 1:20 were dissolved in 100ml of deionized water to fully dissolve, and then 0.05g of 2-hydroxy-4'-(2-hydroxyethoxy Base)-2-methylbenzophenone (2959) was filled with N2 and bubbled for 30 minutes to remove the oxygen in the system under the condition of avoiding light, and was irradiated with ultraviolet light for 60 minutes under the condition of ice bath, added a large amount of absolute ethanol, and centrifuged to remove Unreacted PNIPAM-SH, then transfer the colloidal solid obtained by centrifugation to 8-10kDa cut-off dialysis membrane, and dialyze with deionized water for three days (change deionized water twice a day) to remove impurities and unreacted monomers, Then the solution was lyophilized at -80°C for one week to obtain five kinds of sodium alginate grafted poly-N-isopropylacrylamide (SA-GMA-g-PNIPAM).

(4) In a 250ml flask equipped with a magnetic stirring bar, graft 3 g of sodium alginate poly-N-isopropylacrylamide (SA-GMA-g-PNIPAM) (sodium methacrylated alginate with The mass ratio of poly(N-isopropylacrylamide) with mercapto groups is 1:10) and 1.3g of sodium periodate (NaIO4) are dissolved in 100ml of deionized water, fully dissolved under light-shielding conditions, and reacted at room temperature 4h, add 4ml of ethylene glycol to terminate the reaction, transfer the solution to a 3500Da cut-off dialysis membrane, dialyze with deionized water for three days (change the deionized water twice a day) to remove impurities and unreacted monomers, and then place the solution in - Freeze-dry at 80° C. for one week to obtain oxidized sodium alginate grafted poly-N-isopropylacrylamide (OSA-GMA-g-PNIPAM).

(5) At room temperature, 0.3 g of oxidized sodium alginate grafted poly-N-isopropylacrylamide (OSA-GMA-g-PNIPAM) and 0.3 g of carboxymethyl chitosan (CMCS) were dissolved in 1.5 ml and 3ml of deionized water, after it is completely dissolved, add 22.5mg of calcium carbonate to the CMCS solution and stir evenly, then add the OSA-GMA-g-PNIPAM solution, stir evenly and add 80mg of D-gluconolactone (GDL), stirred for about 1min, poured the solution into the mold, and made a temperature-sensitive hydrogel for about 1min.

Example 3

(1) Dissolve 3.0 g of sodium alginate (SA) in 200 mL of 1% acetic acid aqueous solution, adjust the pH to 8 with 4% NaOH solution, and add 1.38 mL of methacrylic anhydride; The system was reacted at room temperature for 24 hours, and the product was dialyzed with deionized water for 3 days using a dialysis bag with a molecular weight cut-off of 8,000 to 14,000 to remove impurities and unreacted monomers; then freeze-dried to obtain a vinyl sodium alginate derivative ( SA-MA).

(2) In a 100ml flask equipped with a magnetic stirring bar, mix 2.3g of N-isopropylacrylamide (NIPAM), 0.0243g of 2-(dodecyltrithiocarbonate)-2-methylpropane Acid (CTA) and 0.0033g of azobisisobutyronitrile were dissolved in 40ml of 1,4-dioxane, filled with N2 and bubbled for 30min to remove the oxygen in the system, reacted at 73°C for 5h, and when the solution cooled down to room temperature, Add a large amount of n-hexane, centrifuge to remove unreacted monomers, transfer the light yellow solid obtained by centrifugation to a 3500Da cut-off dialysis membrane, and dialyze with deionized water for three days (change the deionized water twice a day) to remove impurities and unreacted monomers. body, and then the solution was freeze-dried at -80°C for one week to obtain poly-N-isopropylacrylamide (PNIPAM-CTA) with a chain transfer agent; (PNIPAM-CTA) was dissolved in a 100ml flask with 50ml tetrahydrofuran equipped with a magnetic stirrer, added 2ml n-butylamine, stirred for 3h (the light yellow solution completely turned into a colorless transparent solution), added a large amount of n-hexane, and centrifuged Unreacted monomers were removed, and the white solid obtained by centrifugation was transferred to a 3500Da cut-off dialysis membrane, and dialyzed with deionized water for three days (deionized water was changed twice a day) to remove impurities and unreacted monomers, and then the solution was in- Freeze-dry at 80°C for one week to obtain poly-N-isopropylacrylamide (PNIPAM-SH) with mercapto groups.

(3) In a 250ml flask equipped with a magnetic stirring bar, dissolve 1g of vinyl sodium alginate derivatives (SA-MA) and 7.5g of poly-N-isopropylacrylamide (PNIPAM-SH) with mercapto groups in Dissolve it fully in 100ml of deionized water, then add 0.05g of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylbenzophenone (2959) and bubble with N2 under dark conditions 30min, remove the oxygen in the system, use ultraviolet radiation for 60min under ice bath conditions, add a large amount of absolute ethanol, centrifuge to remove unreacted PNIPAM-SH, and then transfer the colloidal solid obtained by centrifugation to 8-10kDa cut-off dialysis membrane , dialyzed against deionized water for three days (replacing deionized water twice a day) to remove impurities and unreacted monomers, and then freeze-dried the solution at -80°C for one week to obtain sodium alginate grafted poly-N-isopropyl Acrylamide (SA-MA-g-PNIPAM)

(4) In a 250ml flask equipped with a magnetic stirrer, graft poly-N-isopropylacrylamide (SA-MA-g-PNIPAM) with 3g of sodium alginate and 1.3g of sodium periodate (NaIO4) Dissolve in 100ml deionized water, fully dissolve under light-shielded conditions, and react at room temperature for 4 hours, add 4ml ethylene glycol to terminate the reaction, transfer the solution to a 3500Da cut-off dialysis membrane, and dialyze with deionized water for three days (daily Deionized water was replaced twice) to remove impurities and unreacted monomers, and then the solution was freeze-dried at -80°C for one week to obtain oxidized sodium alginate grafted poly-N-isopropylacrylamide (OSA-MA-g- PNIPAM).

(5) At room temperature, 0.3 g of oxidized sodium alginate grafted poly-N-isopropylacrylamide (OSA-MA-g-PNIPAM) and 0.3 g of carboxymethyl chitosan (CMCS) were dissolved in 1.5 ml and 3ml of deionized water, after it is completely dissolved, add 22.5mg of calcium carbonate to the CMCS solution and stir evenly, then add the OSA-MA-g-PNIPAM solution, stir evenly and add 80mg of D-gluconolactone (GDL), stirred for about 1min, poured the solution into the mold, and made a temperature-sensitive hydrogel for about 1min.

Application Example 1

Dissolve 0.04g of curcumin and 0.1g of carboxymethyl chitosan in 1ml of deionized water at room temperature. After completely dissolving, add 7.5mg of calcium carbonate and stir evenly (A solution), 0.2g of oxidized sodium alginate Graft poly N-isopropylacrylamide (OSA-MA-g-PNIPAM prepared in Example 3) was dissolved in 1ml of deionized water, added to solution A, and then 27mg of D-gluconolactone (GDL) was added , and stir evenly to obtain a hydrogel (Cur-gel).

Weigh 0.04g of hydrogel (Cur-gel) sample into a dialysis bag (molecular weight cut-off 3.5KDa), then immerse in 50ml of PBS buffer, and incubate in a shaking water bath at 37°C, at the time point in Figure 8 , Take out 1ml of the leachate, measure the absorbance of the corresponding wavelength using a UV spectrophotometer, and calculate the drug concentration according to the standard curve of the drug, and supplement 1ml of PBS buffer to maintain the constant leachate.

Application Example 2

Dissolve 0.04g of ciprofloxacin hydrochloride and 0.1g of carboxymethyl chitosan in 1ml of deionized water at room temperature. After completely dissolving, add 7.5mg of calcium carbonate and stir evenly (A solution), 0.2g of oxidized Sodium alginate grafted poly-N-isopropylacrylamide (OSA-MA-g-PNIPAM prepared in Example 3) was dissolved in 1ml of deionized water, added to solution A, and then 27mg of D-gluconolactone was added (GDL), and stir evenly to obtain a hydrogel (Ch-gel).

Weigh 0.04g of the sample into a dialysis bag (molecular weight cut-off 3.5KDa), then immerse in 50ml of PBS buffer, and incubate in a shaking water bath at 37°C. The absorbance of the corresponding wavelength was measured by a photometer, and the drug concentration was calculated according to the standard curve of the drug, and 1ml of PBS buffer was added to maintain a constant leaching liquid.

Comparative example 1 (referring to CN106619491B)

Mix 0.5g sodium tetradecylpropanesulfonate maleic anhydride, 3g ethanol, 15g glycerol, 0.35g indomethacin and 2g penetration enhancer laurocapram to form a monomer-coated drug solution; then mix 0.1 G catalyzer tartaric acid is dissolved in 64.03g water and is prepared into tartaric acid aqueous solution; Add successively 10g sodium acrylate resin, 0.02g cross-linking agent glycolic aluminum, 5g tackifier polyvinylpyrrolidone and The aqueous solution of tartaric acid obtained in step (2) is uniformly mixed to obtain a thick hydrogel precursor; the hydrogel precursor is molded into a sheet, and taken out after being irradiated under 60Co gamma rays, and the irradiation amount of 60Co gamma rays is 4kGy , to obtain the drug sustained-release hydrogel product. In order to better demonstrate the slow-release effect of the drug sustained-release hydrogel, the drug sustained-release hydrogel (A) was compared with the commercially available hydrogel patch (B).

Comparative example 2 (referring to CN114042034)

Weigh 100mg of dexamethasone sodium phosphate powder into a 10mL small beaker, add 5mL of ultrapure water, dissolve it by ultrasonication for 1min, transfer to a 10mL volumetric flask, and constant volume to obtain 10mg/mL dexamethasone sodium phosphate solution. Weigh 30 mg of Pluronic (F127-CHO) with terminal aldehydes in a 4 mL vial, add 0.5 mL of ultrapure water, stir at a stirring rate of 300 rpm/min in an ice-water bath, and prepare a mass concentration of 6% ( w/v) F127-CHO solution. Weigh 40mg of carboxymethyl chitosan in a 4mL small glass bottle, add 0.5mL of 10mg/mL dexamethasone sodium phosphate solution, fully stir and dissolve at room temperature, and prepare carboxymethyl chitosan with a mass concentration of 8% (w/v). Methyl chitosan solution. The solution of F127-CHO and the solution of carboxymethyl chitosan were stirred and mixed in an ice-water bath, the stirring speed was 300rmp/min, and the stirring time was 30min. A clear, transparent mucus was obtained in an ice-water bath. The obtained mucus was reacted at 37° C. for 12 hours to fully cross-link to obtain an injectable temperature-sensitive hydrogel loaded with dexamethasone sodium phosphate.

Take the above hydrogel into a 4mL centrifuge tube, add 1mL of PBS buffer solution (PH=7.4), place in a constant temperature water bath shaker for slow release, the temperature is 37°C, and the shaking speed is 100rmp/min; take out at different time points 0.2mL of the upper layer sustained-release solution, and at the same time, add 0.2mL of isothermal fresh PBS buffer solution (PH=7.4) to the centrifuge tube; utilize a UV spectrophotometer to test the absorbance of the sustained-release solution, calculate the cumulative sustained-release amount of the drug, and draw Cumulative drug release curve.

Fig. 4 is the relation figure of the absorbance and temperature of the PNIPAM-SH polymer solution in embodiment 1 measured by ultraviolet spectrophotometer, can obtain the thermosensitive transition point of polymer by the temperature that absorbance changes abruptly in the figure, PNIPAM- When the SH molecular chain temperature is lower than the lower critical solution temperature (LCST), the amide group combines with water molecules to form a hydrogen bond, and the polymer is dissolved in the aqueous solution. When the temperature is higher than the LCST, the hydrogen bond is broken, and the isopropyl group Hydrophobicity will dominate, the polymer is insoluble in water, and different molecular weights will have different temperature-sensitive transition points, so the temperature-sensitive transition point of the polymer can be adjusted by adjusting the molecular weight of PNIPAM, as shown in the ratio of NIPAM:CTA When the temperature is 75:1 and 300:1, the temperature-sensitive transition point will change from 36°C to 32°C, and the temperature-sensitive transition point will first decrease and then basically remain unchanged with the change of molecular weight.

Fig. 5 is the relation figure of the absorbance and temperature of the SA-g-PNIPAM polymer solution in the embodiment 2 measured by the ultraviolet spectrophotometer, can obtain the thermosensitive transition point by the temperature that the absorbance changes abruptly in the figure, from the figure It can be seen that the temperature-sensitive transition point is between 30 and 35°C. Different graft ratios have little effect on the temperature-sensitive transition point, but have a greater impact on the sensitivity of the temperature-sensitive transition. When the graft ratio SA-GMA:PNIPAM- When SH is 1:15 and 1:20, the maximum absorbance can be reached fastest.

Fig. 6 is the drug sustained-release hydrogel prepared in Comparative Example 1. It can be seen from the figure that the drug sustained-release hydrogel and the products on the market all have a certain sustained-release effect, but the sustained-release effect is not obvious enough. The cumulative release rate can reach about 60% in about 20 hours, and the drug cannot be released continuously for a long time, which will increase the frequency of dressing changes.

Figure 7 is the drug release curve of the temperature-sensitive hydrogel material prepared in Comparative Example 2 at 37°C. It can be seen from the figure that the sustained release effect of the drug is obvious, but the release period is not long enough, and the cumulative release is about 70 hours The rate is around 70%.

Fig. 8 is the drug release curve of the hydrogel prepared in Example 3 loaded with two different drugs of ciprofloxacin hydrochloride (Ch) and curcumin (Cur) at 37°C. It can be seen that the water-soluble drug (Ch ) at this temperature has a longer release period, can reach more than 130h, and the release amount can reach about 80%, and can release the water-soluble drug loaded in the hydrogel well; the non-water-soluble drug (Cur) is here The release period is also longer at high temperature, and the release amount is about 30% at 130 hours. This is because water-insoluble drugs are not easily released through the diffusion of water molecules, which can well maintain long-term drug release and maintain long-term wound healing. Antibacterial and anti-inflammatory properties; compared with Comparative Example 1 and Comparative Example 2, the hydrogel sustained-release period of the present invention can be increased from 70h to 130h, which is greatly improved, and it is not suitable to change frequently for trauma and burns left by surgery. The wound surface of medicine is of great significance.

Figure 9 is a cell live/dead staining test, using the CCK-8 method to determine the co-cultivation of the sample extract and L929 cells, it can be seen that the number of viable cells in the L929 cells cultured on the hydrogel increased significantly after 96 hours, and the number of live cells in the hydrogel Under the influence, L929 cells can maintain normal physiological activities, indicating low cytotoxicity.

From the comparison of the above examples and comparative examples, it can be seen that the hydrogel of the present invention has good wound self-adaptability, can better avoid wound infection, promote faster and better wound healing, and ensure that the drug will not be used in the early stage of wound healing. Burst release, with good sustained-release drug effect, especially the temperature-sensitive polymer (PNIPAM) in the hydrogel is grafted to sodium alginate, on the one hand, the temperature-sensitive transition point can be adjusted by molecular weight regulation On the other hand, PNIPAM molecular chain grafting to SA, which does not participate in the internal network structure of the hydrogel, is less affected by the binding of the cross-linking points of the hydrogel network than PNIPAM participating in the hydrogel network, To achieve good stretching and curling, the PNIPAM molecular chain can be well curled inside the hydrogel to wrap the drug, which is more conducive to the coating of the drug, so that the release cycle of the drug can reach more than 130h, far exceeding the sustained release of the existing technology cycle, which is of great significance for some wounds that are not suitable for frequent dressing changes (such as wounds left by surgery, burns, etc.), it can well ensure that the wounds are not infected by bacteria, and can provide good antibacterial and anti-inflammatory effects for later wounds. The speed of wound healing is slowed down due to insufficient medicine. In addition, the hydrogel of the present invention has self-healing properties, and can heal itself without serious damage, avoiding infection caused by damage to the hydrogel.

The formation of the hydrogel of the present invention is through Schiff base reaction and ionic cross-linking, which has excellent biodegradability, and does not use a cross-linking agent, avoiding the residual cross-linking agent during the formation of the hydrogel, which requires multiple cleanings in the later stage It may not be removed, which may cause the hydrogel to be cytotoxic, and it is not easy to adhere to the wound surface. It is easy to remove when changing, and the drug release cycle exceeds 130h. For some wounds that are not suitable for frequent dressing changes (such as surgery left It is of great significance to ensure that the wound surface is not infected by bacteria, provide good antibacterial and anti-inflammatory effects for the later wound surface, and avoid slowing down the speed of wound healing due to insufficient drugs.

Claims (10)

1. A temperature-sensitive transition point can be regulated and controlled medicine slow-release carrier hydrogel, is characterized in that, joins in carboxymethyl chitosan homogeneous solution by calcium carbonate, then adds oxidized sodium alginate-g-polyN - Isopropylacrylamide homogeneous solution, after stirring evenly, add D-gluconolactone, after stirring and reacting, let it stand to form a hydrogel, seal it, and store the result at room temperature; the oxidized sodium alginate-g-poly N-isopropylacrylamide homogeneous solution consists of sodium alginate methacrylate or methacrylated sodium alginate, poly-N-isopropylacrylamide dissolved in deionized water to form a homogeneous solution, adding photoinitiator , bubbling with N ₂ under the condition of avoiding light, irradiating with ultraviolet light for 30-45min under ice bath, centrifuging, dialyzing, and freeze-drying; the obtained product was dissolved in deionized water, added sodium periodate, and reacted for 3 ~5h, dialyzed to remove sodium periodate, freeze-dried the obtained. 2. The temperature-sensitive transition point according to claim 1 can regulate the drug slow-release carrier hydrogel, wherein the oxidized sodium alginate-g-poly N-isopropylacrylamide and carboxymethyl The mass ratio of chitosan is 0.5 to 1.5; the mass percentage concentration of oxidized sodium alginate-g-poly N-isopropylacrylamide in the oxidized sodium alginate-g-poly N-isopropylacrylamide homogeneous solution 10% to 20%; the mass percent concentration of carboxymethyl chitosan in carboxymethyl chitosan homogeneous solution is 5% to 10%; calcium carbonate and oxidized sodium alginate-g-poly N isopropyl The mass ratio of acrylamide is 5-15:100; the mass ratio of D-gluconolactone to calcium carbonate is 0.3-0.6:1. 3. temperature-sensitive transition point according to claim 2 can regulate and control drug slow-release carrier hydrogel gel, it is characterized in that, described oxidized sodium alginate-g-poly N-isopropylacrylamide homogeneous solution is made of Oxidized sodium alginate-g-poly N-isopropylacrylamide is dissolved in deionized water to form; carboxymethyl chitosan homogeneous solution is formed by dissolving carboxymethyl chitosan in deionized water. 4. The temperature-sensitive transition point according to claim 1, wherein the drug sustained-release carrier hydrogel can be regulated, wherein the photoinitiator is 2-hydroxyl-4'-(2-hydroxyethoxy) -2-methyl, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, phenylbis(2,4,6-trimethylbenzoyl) One or more of phosphine oxide and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylbenzophenone. 5. The temperature-sensitive transition point according to claim 1 can regulate the drug slow-release carrier hydrogel, wherein the amount of the photoinitiator is sodium methacrylate alginate or methacrylated seaweed 2-5% of the mass of sodium alginate; the molar ratio of sodium periodate to sodium alginate methacrylate or sodium methacrylated alginate is 1:10-25; the oxidized sodium alginate-g-poly The mass percent concentration of sodium alginate methacrylate or methacrylated sodium alginate in N-isopropylacrylamide homogeneous solution is 1-2%, and the concentration of poly-N-isopropylacrylamide is 0.1-0.6 mol/ml; the time for bubbling with N ₂ is 30-45min to remove the oxygen in the system; the dialysis after the centrifugation is carried out through a dialysis membrane with a molecular weight cut-off of 8000-14000; the dialysis removes Sodium periodate is carried out through a dialysis membrane with a molecular weight cut-off of 8000-14000. 6. The temperature-sensitive transition point adjustable drug sustained-release carrier hydrogel gel according to claim 1, characterized in that, the poly-N-isopropylacrylamide is prepared by the following method: N-isopropyl Dissolve acrylamide, chain transfer agent, and second initiator in deionized water, fill with N ₂ and bubble for 30-45 minutes, react at 65-75°C for 5-7 hours, wash the obtained solution with n-hexane to remove impurities, and store in a vacuum oven at room temperature Dry it, dissolve it with tetrahydrofuran, then add n-butylamine to reduce it, use n-hexane to centrifuge to remove impurities, add deionized water to dissolve it, and transfer it to a dialysis membrane to remove unreacted monomers and impurities, freeze-dry , low temperature preservation. 7. The temperature-sensitive transition point according to claim 6, wherein the drug sustained-release carrier hydrogel can be regulated, wherein the chain transfer agent is 2-(dodecyl trithiocarbonate group)- 2-methylpropanoic acid, S-(2-cyano-2-propyl)-S-dodecyltrithiocarbonyl ester, 4-cyano-4-(thiobenzoyl)pentanoic acid and One or more of 2-phenyl-2-propyl benzodisulfide; the second initiator is azobisisobutyronitrile, azobisisoheptanonitrile, dibenzoyl peroxide and One or more of potassium persulfate; the molar ratio of the chain transfer agent to N-isopropylacrylamide is 1:100-400; the molar ratio of the chain transfer agent to the initiator is 1:0.1-0.5 The molar concentration of N-isopropylacrylamide is 0.5-1mol/L, and the amount of n-butylamine is 0.2-0.4 times the mass of poly-N-isopropylacrylamide; the dialysis membrane is a molecular weight cut-off of 3500 Dialysis bag. 8. The temperature-sensitive transition point according to claim 1, wherein the drug slow-release carrier hydrogel can be regulated, wherein the sodium alginate methacrylate is synthesized by the following method: dissolving sodium alginate in an aqueous solution , adjust the pH value to 7-9, add methacrylic anhydride, react at 40-50°C for 20-25 hours, use a dialysis bag with a molecular weight cut-off of 8000-14000, dialyze with deionized water, and freeze-dry to obtain methacrylic acid Sodium alginate; wherein, the mass percent concentration of sodium alginate aqueous solution is 1% to 2%; the pH value is adjusted by NaOH solution, and the mass percent concentration of NaOH solution is 2% to 4%; methacrylic anhydride and sodium alginate The mass ratio is 15-30:1; the deionized water dialysis time is 3-5 days; The methacrylated sodium alginate is synthesized by the following method: dissolving sodium alginate in NaOH aqueous solution, adjusting the pH value to 10-12, adding glycidyl methacrylate, and bubbling with _N2 for 30-60 minutes , reacted at 60-75°C for 15-24 hours, and the product was dialyzed with deionized water and freeze-dried using a dialysis bag with a molecular weight cut-off of 8000-14000 to obtain methacrylated sodium alginate; among them, the mass of sodium alginate aqueous solution The percentage concentration is 1% to 2%; the pH value is adjusted by NaOH solution, and the mass percentage concentration of NaOH solution is 2% to 4%; the mass ratio of glycidyl methacrylate to sodium alginate is 1 to 2:1; Deionized water dialysis time is 3 ~ 5d. 9. The preparation method of the temperature-sensitive transition point of any one of claims 1-8, which can regulate the drug slow-release carrier hydrogel, is characterized in that it comprises the following steps: 1) Preparation of oxidized sodium alginate-g-poly-N-isopropylacrylamide: sodium alginate methacrylate or methacrylated sodium alginate and poly-N-isopropylacrylamide were completely dissolved in deionized water , to form a homogeneous solution, add a photoinitiator, bubble N2 under the condition of avoiding light, irradiate with ultraviolet light for 30-45min under the condition of ice bath, centrifuge, dialyze, purify again, freeze-dry it and dissolve it in deionized water, add sodium periodate, react for 3 to 5 hours in the dark, dialyze to remove sodium periodate, freeze-dry, and store at low temperature; 2) The temperature-sensitive transition point can be adjusted to prepare the drug sustained-release carrier hydrogel gel: oxidized sodium alginate-g-poly N-isopropylacrylamide and carboxymethyl chitosan were dissolved in deionized water respectively to form For two homogeneous solutions, calcium carbonate is added to the homogeneous solution of carboxymethyl chitosan, and then the homogeneous solution of oxidized macromolecular macromonomer-g-poly N-isopropylacrylamide is added, after stirring evenly, add D-gluconolactone, after stirring for 20-40s, standing still to form a temperature-sensitive transition point adjustable drug slow-release carrier hydrogel. 10. The preparation method of the temperature-sensitive transition point adjustable drug sustained-release carrier hydrogel according to claim 9, characterized in that, the centrifugation of the dialysis after the centrifugation is to remove unreacted polymer by centrifugation with absolute ethanol. N-isopropylacrylamide; the standing time is 90-120s.