Mesoporous polydopamine-mediated hydrogel with programmed drug release effect

Abstract

The invention relates to a synthesis method of mesoporous polydopamine-mediated hydrogel with a programmed drug release effect, and belongs to the technical field of biological medicines. Specifically, mesoporous polydopamine nanoparticles encapsulating a host drug are taken as nodes and mixed with sol formed by acrylamide, 3-acrylamidophenylboronic acid and (3-acrylamidopropyl) trimethyl ammonium chloride, a guest drug is added before gelation, and the hydrogel is prepared. The hydrogel has multifunctionality and programmed drug release effect, solves the problem that single hydrogel cannot play a positive role in multiple wound healing stages, and can be applied to treatment of complex burn wounds.

Description

Technical Field

[0001] The invention belongs to the technical field of biomedicine and relates to a method for synthesizing a mesoporous polydopamine-mediated hydrogel with programmed drug release. Background Art

[0002] When treating burn wounds, the main means of treatment include skin transplantation, antibiotic treatment and wound dressing, but these strategies have certain limitations. Specifically, autologous skin donor resources are limited, and allogeneic skin transplantation may induce immune rejection; long-term or improper use of antibiotics will disrupt the balance of microbial communities and induce the emergence of drug-resistant bacteria. Traditional dressings, such as gauze and bandages, can effectively cover wounds and absorb some blood and exudate, but they have poor adaptability to complex wounds, making it difficult to effectively isolate bacteria and have limited protective effects. In addition, traditional dressings have strong adhesion to wounds and are prone to secondary damage when replaced. Therefore, most biological dressings currently used in burn treatment have turned to hydrogel materials. With their unique three-dimensional network structure and high water absorption, hydrogels can effectively absorb tissue exudates while providing a breathable and moist healing environment, which is conducive to wound recovery.

[0003] Compared with normal wounds, burn wounds have more complex characteristics. Severe burns destroy the skin barrier, leading to deep tissue damage and necrosis, triggering the activation of inflammatory mediators and the release of reactive oxygen species (ROS), causing excessive inflammatory responses. In severe cases, tissue damage can even damage capillaries, hair follicles, etc. Burn wounds release a large amount of exudate, causing edema. Untimely or improper treatment will aggravate the injury and expand the scope of the wound. However, traditional hydrogel dressings have a single function and cannot meet the needs of complex wounds. In view of the complexity of burn wounds and the limitations of traditional hydrogel dressings, it is crucial to develop a new multifunctional hydrogel dressing. This new dressing needs to have good moisture absorption and breathability to promote the effective management of wound exudate and reduce tissue edema. Considering that burn patients may need long-term bandaging, the comfort and ease of replacement of the dressing are also key factors. In summary, targeting the complex characteristics of burn wounds, developing a hydrogel dressing with multiple functions is of great significance for improving the treatment effect of burns and promoting patient recovery. Summary of the invention

[0004] The present invention designs a method for synthesizing a mesoporous polydopamine-mediated hydrogel with programmed drug release, which solves the problem that traditional hydrogels have only a single function in treating burn wounds and poor mechanical properties. The obtained hydrogel not only has a photothermal effect, can effectively control the release of drugs and the development of wound infection, but also can use phase change materials to encapsulate the main drug (taking minoxidil as an example) in the mesoporous structure of nanomaterials. More importantly, before gelation, guest drugs (taking indomethacin as an example) are added to the system to achieve multi-drug loading of hydrogels, which can meet the different needs of different wound healing stages. One of the purposes of the present invention is to provide a new technical strategy for the further application of hydrogel drug delivery systems in the biomedical field; the second purpose of the present invention is to provide a controlled release nano drug delivery system prepared by the above method; the third purpose of the present invention is to provide a programmed drug release hydrogel system prepared by the above method.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: 1. A method for synthesizing nanoparticles with a mesoporous structure, comprising the following steps: dissolving dopamine hydrochloride and poloxamer F-127 in an alcohol solution at a certain mass ratio and fully shaking to dissolve; then adding 1,3,5-trimethylbenzene and ammonia water to the above system and mixing, reacting under magnetic stirring conditions, and purifying and removing unreacted raw materials to obtain nanoparticles with a mesoporous structure.

[0006] Preferably, the mass ratio of dopamine hydrochloride to poloxamer F-127 is 3:2.

[0007] Preferably, the alcohol solution is a mixed solution of anhydrous ethanol and ultrapure water in a ratio of 1:1.

[0008] Preferably, the magnetic stirring condition is stirring at 1100 rpm / min.

[0009] Preferably, the reaction condition is 25° C. for 4 hours.

[0010] 2. A method for synthesizing a nano drug delivery system, comprising the following steps: adding MPDA-NPs to an organic solvent and shaking them thoroughly to dissolve (Solution A); then taking minoxidil dissolved in an organic solvent (Solution B) and adding it to the above system and mixing it evenly; dissolving lauric acid and stearic acid in an organic solvent at a certain mass ratio and shaking them thoroughly to dissolve them (Solution C); mixing the three at a certain volume ratio, and removing unencapsulated raw materials after rotary evaporation to obtain a nano drug delivery system.

[0011] Preferably, the organic solvent is methanol.

[0012] Preferably, the mass ratio of lauric acid to stearic acid is 4:1.

[0013] Preferably, the concentration of solution C is 4 mg / mL.

[0014] Preferably, the volume ratio of the A, B and C solutions is 10:3:2.

[0015] 3. A method for synthesizing a programmed drug release hydrogel, comprising the following steps: adding acrylamide (AM) to ultrapure water and shaking it thoroughly to dissolve; taking 3-acrylamidophenylboronic acid (APBA) dissolved in an organic solvent and adding it to the above system to mix well to obtain a solution A; then taking (3-acrylamidopropyl)trimethylammonium chloride (TAM) and adding it to the A solution, and quickly vortexing and mixing it well; reacting to form a sol under the action of a catalyst, and transferring it to a dialysis bag to remove unreacted monomers; after freeze-drying, dissolving it in PBS at a certain concentration to obtain an AAT-sol sol solution; adding the guest drug indomethacin (IND) to the above system at a certain ratio; then taking a certain concentration of MPM-TA and adding it to the above system at a certain ratio, and shaking and mixing it well to obtain a programmed drug release hydrogel system.

[0016] Preferably, the organic solvent is dimethyl sulfoxide.

[0017] Preferably, the catalyst is ammonium persulfate or N,N,N',N'-tetramethylethylenediamine.

[0018] Preferably, the molecular weight cut-off of the dialysis bag is 10 kD, and the dialysis time is 72 hours.

[0019] Preferably, the concentration of the AAT-sol solution is 150 mg / mL.

[0020] Preferably, the volume ratio of indomethacin to AAT-sol solution is 1:400.

[0021] Preferably, the concentration of MPM-TA is 20 mg / mL, and the volume ratio of the system is 1:4.

[0022] The beneficial effects of the present invention are as follows: the present invention discloses a method for synthesizing a mesoporous polydopamine-mediated hydrogel with programmed drug release. On the one hand, the hydrogel has excellent physical and chemical properties, providing more possibilities for its application; on the other hand, the hydrogel can utilize near-infrared laser to control drug release, and can meet the needs of different wound healing stages by loading different drugs.

[0023] The mesoporous polydopamine-mediated hydrogel obtained by the present invention has great application prospects in the fields of drug loading, programmed drug release and wound healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration: Figure 1 Characterization of the morphology, particle size and Zeta potential of MPDA-PEG (a: transmission electron microscopy, b: hydrated particle size, c: Zeta potential).

[0025] Figure 2 Characterization of the particle size and Zeta potential of MPM (a: hydrated particle size, b: Zeta potential).

[0026] Figure 3 is the UV-visible absorption spectrum of MPM.

[0027] Figure 4 Characterization of the morphology, particle size and Zeta potential of MPM-TA (a: transmission electron microscopy, b: hydrated particle size, c: Zeta potential).

[0028] Figure 5 is the UV-visible absorption spectrum of MPM-TA.

[0029] Figure 6 This is the temperature change diagram of MPM-TA.

[0030] Figure 7 This is the antioxidant activity diagram of MPM-TA.

[0031] Figure 8 This is the scanning electron microscopy image of MPM-TA / IND@Gel hydrogel.

[0032] Fig. 9 Characterization of the mechanical properties of MPM-TA / IND@Gel hydrogel (a: adhesion, b: stretchability, c: shape adaptability).

[0033] Fig.10 This is the temperature change diagram of MPM-TA / IND@Gel hydrogel.

[0034] Fig.11 Rheological diagram of MPM-TA / IND@Gel hydrogel (a: viscosity scan, b: strain scan, c: time scan at different strains).

[0035] Fig.12 Cumulative release of MXD in MPM-TA / IND@Gel hydrogel. Specific implementation methods

[0036] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] At room temperature, 75 mg of dopamine hydrochloride and 50 mg of poloxamer F-127 were weighed and dissolved in a 1:1 mixture of 5 mL of anhydrous ethanol and ultrapure water and fully shaken to dissolve. 70 μL of 1,3,5-trimethylbenzene was added dropwise to the above system and ultrasonically treated for 2 min to form an emulsion. At room temperature, 187 μL of ammonia water was added dropwise to the above reaction system by a pipette while magnetic stirring was performed at a speed of 1100 rpm / min to induce an anisotropic assembly reaction at the emulsion interface. After the reaction was carried out for 4 hours, the reaction mixture was placed in a centrifuge and centrifuged at a speed of 9500 rpm / min for 15 minutes to remove dopamine hydrochloride and other impurities that did not participate in the reaction, and the volume was fixed to 5 mL to obtain MPDA-NPs. Then 375 μL of 100 mg / mL mPEG-NH2 (MW 5000) solution was added to the above system and thoroughly shaken and mixed. The pH value was adjusted to 9. After reacting for 4 hours at room temperature under magnetic stirring at 1100 rpm / min, the mixture was collected by centrifugation (8000 rpm / min, 5 min) and the volume was fixed to 5 mL to obtain MPDA-PEG. Its average particle size is about 291 nm; its transmission electron microscopy (TEM), hydrated particle size in aqueous solution and Zeta potential are shown in Figure 2. Figure 1 shown.

[0038] At room temperature, weigh 5 mg of MPDA-PEG and add it to 2.5 mL of methanol and shake thoroughly to dissolve; add 750 μL of 20 mmol / L minoxidil (MXD) solution to the above solution and shake thoroughly to mix; then take 500 μL of a methanol solution (PCM) with a mass ratio of lauric acid to stearic acid of 4:1 and add it to the above system and shake thoroughly to mix. At 40 °C, use a rotary evaporator for evaporation, supplemented by one methanol and two ultrapure water washing steps, and adjust the volume to 5 mL to obtain MPM. The hydrated particle size and Zeta potential in its aqueous solution are shown in Figure 2. Figure 2 As shown; UV-visible absorption spectroscopy was used to verify the successful loading of MPM and the successful encapsulation of PCM (the results are shown in Figure 3 shown).

[0039] At room temperature, weigh 5 mg of MPM and add it to ultrapure water to fully shake and dissolve; then take 1.25 mL of 40 mg / mL tannic acid (TA) solution and add it to the above system to shake and mix thoroughly, adjust the pH value to 8, react at room temperature under 1100 rpm / min magnetic stirring for 2 hours, centrifuge (8000 rpm / min, 5 min) to collect and wash with ultrapure water twice, and adjust the volume to 5 mL to obtain MPM-TA. Its average particle size is about 325 nm; its transmission electron microscopy (TEM), hydrated particle size in aqueous solution and Zeta potential results are shown in Figure 4As shown; UV-visible absorption spectroscopy was used to verify the successful loading of TA (the results are shown in Figure 5 808 nm near-infrared laser and thermal imager were used to investigate the photothermal effect of MPM-TA. Within 300 s, the photothermal response was significantly enhanced as time went on. The results are shown in Figure 6 shown.

[0040] At room temperature, 35.5 mg of ethylenediaminetetraacetic acid disodium (EDTA-2Na) was weighed and dissolved in 1 mL of phosphate buffer (pH = 7.8) in a light-proof environment; 1.6 mg of nitro blue tetrazolium chloride (NBT) was weighed and dissolved in 1 mL of phosphate buffer; 1.1 mg of riboflavin was weighed and dissolved in 10 mL of phosphate buffer, and then 800 μL of EDTA-2Na, 300 μL of NBT, 200 μL of riboflavin and 11.4 mL of phosphate buffer were taken and mixed thoroughly to make a working solution. Subsequently, 50 μL of phosphate buffer or MPM-TA solutions of different concentrations (c = 0.2, 0.5, 1.0, 1.5, 2 mg / mL) were added to the 96-well plate, and 100 μL of working solution was added; then the 96-well plate was placed in a light box equipped with a 20 W incandescent lamp and irradiated for 4 minutes. The absorbance at 560 nm was measured and calculated using an enzyme reader to verify the antioxidant properties of MPM-TA. The results are as follows: Figure 7 shown.

[0041] At room temperature, weigh 452.6 mg of acrylamide and add it to 0.87 mL of ultrapure water and shake it thoroughly to dissolve; weigh 22.6 mg of 3-acrylamidophenylboronic acid and add it to 0.5 mL of DMSO and shake it thoroughly to dissolve; after the above two are fully mixed, quickly add 60 μL of (3-acrylamidopropyl) trimethylammonium chloride, 10 μL of ammonium persulfate (3.76 mol / mL), and 100 μL of N,N,N',N'-tetramethylethylenediamine to the system and shake it thoroughly to mix. After the system stops exothermic and cools to room temperature, it is moved to a dialysis bag for 72 hours of dialysis (changing water 6 times). The dialyzed sol is freeze-dried, weighed, and dissolved in PBS at 150 mg / mL to obtain an AAT-sol sol solution. Indomethacin (IND) was added to AAT-sol at a ratio of 0.25% (w / v); then a 20 mg / mL MPM-TA solution was added to the above system at a volume ratio of 1:4; after sufficient stirring, the MPM-TA / IND@Gel hydrogel was obtained. The morphology of MPM-TA / IND@Gel was observed by scanning electron microscopy (SEM), which showed a porous network structure. Figure 8 As shown; The mechanical properties of MPM-TA / IND@Gel hydrogel, such as adhesion, stretchability and shape adaptability, were investigated through macroscopic experiments (the results are shown in Fig. 9 The photothermal effect of MPM-TA / IND@Gel hydrogel was investigated by 808 nm near-infrared laser and thermal imager. As the power density increased, the temperature of the hydrogel increased. The results are shown in Fig.10 shown.

[0042] The present invention uses a rheometer to test the relationship between the viscosity and shear rate of MPM-TA / IND@Gel, the strain scanning situation and the self-healing ability. The results are as follows: Fig.11 shown.

[0043] Shear strain: temperature 25 °C, frequency 1 Hz, shear rate 1−500 s −1 , time 300 s. Strain sweep: temperature 25℃, frequency 1 Hz, strain 0.1%−2500%, time 150 s. Time sweep: ① temperature 25℃, frequency 1 Hz, strain 5%, time 100 s; ② temperature 25℃, frequency 1 Hz, strain 1500%, time 100 s. Repeat 3 times.

[0044] Depend on Fig.11 It can be seen from a that the MPM-TA / IND@Gel hydrogel prepared under this condition has a shear rate of 1 s −1 The viscosity is 122616.3, and the viscosity decreases with the increase of shear rate, which confirms the shear thinning ability of the hydrogel and its strong peelability.

[0045] Depend on Fig.11 b It can be seen that the internal network structure of the MPM-TA / IND@Gel hydrogel formed under this condition collapses only when the strain reaches 1300%, and has a higher critical strain, indicating that the hydrogel can withstand larger deformation.

[0046] Depend on Fig.11 As shown in Figure 3, when the strain recovered from 1500% to 5%, the G' and G" values ​​recovered and the structure of MPM-TA / IND@Gel hydrogel was reconstructed, confirming that the hydrogel has good self-healing ability.

[0047] The present invention verifies the release of MXD in the mesoporous structure after near-infrared laser irradiation.

[0048] The drug release from the hydrogel was detected by ultraviolet absorption of MXD. The untreated and near-infrared laser-treated MPM-TA / IND@Gel hydrogels were placed in PBS release medium and shaken at 37 °C (100 rpm / min). 1 mL of the release solution was taken at the predetermined time point and an equal amount of release medium was added to maintain a constant volume. The concentration of the main drug minoxidil was analyzed by UV-visible spectrophotometer. The maximum absorption wavelength of minoxidil is 231 nm. Fig.12 It can be seen that the release of MXD increases after near-infrared laser irradiation.

[0049] The above description is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements based on different inventive methods. These improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A method for synthesizing nanoparticles with a mesoporous structure, comprising the following steps: dissolving dopamine hydrochloride and poloxamer F-127 in an alcohol solution at a certain mass ratio and fully shaking to dissolve; then adding 1,3,5-trimethylbenzene and ammonia water to the above system and mixing, reacting under magnetic stirring conditions, and purifying and removing unreacted raw materials to obtain nanoparticles with a mesoporous structure.

2. The method for preparing nanoparticles according to claim 1, characterized in that: The mass ratio of dopamine to poloxamer F-127 is 3:

2.

3. The method for preparing nanoparticles according to claim 1, characterized in that: The alcohol solution is a mixed solution of anhydrous ethanol and ultrapure water in a ratio of 1:

1.

4. The method for preparing nanoparticles according to claim 1, characterized in that: The magnetic stirring condition is stirring at 1100 rpm / min.

5. A method for synthesizing a nano drug delivery system, comprising the following steps: adding MPDA-NPs to an organic solvent and shaking thoroughly to dissolve (Solution A); then taking minoxidil dissolved in an organic solvent (Solution B) and adding it to the above system and mixing evenly; dissolving lauric acid and stearic acid in an organic solvent at a certain mass ratio and shaking thoroughly to dissolve (Solution C); mixing the three in a certain volume ratio, and removing the unencapsulated raw materials after rotary evaporation to obtain a nano drug delivery system.

6. The method for preparing the nano drug delivery system according to claim 5, characterized in that: The organic solvent is methanol.

7. The method for preparing the nano drug delivery system according to claim 5, characterized in that: The mass ratio of the lauric acid to the stearic acid is 4:

1.

8. The method for preparing the nano drug delivery system according to claim 5, characterized in that: The concentration of the C solution is 4 mg / mL.

9. The method for preparing the nano drug delivery system according to claim 5, characterized in that: The volume ratio of the A, B and C solutions is 10:3:

2.

10. A method for synthesizing a programmed drug-releasing hydrogel, comprising the following steps: adding acrylamide (AM) to ultrapure water and shaking it thoroughly to dissolve; taking 3-acrylamidophenylboronic acid (APBA) dissolved in an organic solvent and adding it to the above system and mixing it to obtain a solution A; then taking (3-acrylamidopropyl)trimethylammonium chloride (TAM) and adding it to the A solution, and quickly vortexing and mixing it; reacting under the action of a catalyst to form a sol, and transferring it to a dialysis bag to remove unreacted monomers; after freeze-drying, dissolving it in PBS at a certain concentration to obtain an AAT-sol sol solution; adding the guest drug indomethacin (IND) to the above system at a certain ratio; then taking a certain concentration of MPM-TA and adding it to the above system at a certain ratio, shaking and mixing it thoroughly to obtain a programmed drug-releasing hydrogel system.

11. The method for preparing the programmed drug release hydrogel according to claim 10, characterized in that: The organic solvent is dimethyl sulfoxide.

12. The method for preparing the programmed drug release hydrogel according to claim 10, characterized in that: The catalyst is ammonium persulfate and N,N,N',N'-tetramethylethylenediamine.

13. The method for preparing the programmed drug release hydrogel according to claim 10, characterized in that: The molecular weight cut-off of the dialysis bag is 10 kD, and the dialysis time is 72 hours.

14. The method for preparing the programmed drug release hydrogel according to claim 10, characterized in that: The concentration of the AAT-sol sol solution is 150 mg / mL.

15. The method for preparing the programmed drug release hydrogel according to claim 10, characterized in that: The volume ratio of indomethacin to AAT-sol solution is 1:

400.

16. The method for preparing the programmed drug release hydrogel according to claim 10, characterized in that: The concentration of MPM-TA is 20 mg / mL, and the volume ratio of the system is 1:

4.

17. The method for preparing the programmed drug release hydrogel according to claim 10, characterized in that: The hydrogel has multifunctionality and programmed drug release function.

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