Preparation method of red light triggered long-acting controlled release co hydrogel dressing

Abstract

The application relates to the technical field of biomedical materials, and discloses a preparation method of a red-light-triggered long-acting controlled-release CO hydrogel dressing, which comprises the following steps: S1. synthesizing AgPCN with photo-thermal and photo-catalytic properties; S2. grafting polyethyleneimine (PEI) with CO2 adsorption characteristics on the surface of the AgPCN to obtain AgPCN@PEI; S3. introducing CO2 gas into the AgPCN@PEI nanomaterial to obtain AgPCN@PEI@CO2; and S4. mixing the AgPCN@PEI@CO2 with silk fibroin (SF) to obtain an AgPCN@PEI@CO2 / SF hydrogel dressing. The application has the advantages of simple preparation, safety controllability and difficulty in causing bacterial drug resistance, and has potential application prospects in the field of biomedicine.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials technology, and in particular to a method for preparing a red light-triggered long-lasting controlled-release CO2 hydrogel dressing. Background Technology

[0002] Diabetes, one of the world's top ten chronic diseases, causes high blood sugar levels, easily leading to tissue ischemia and hypoxia, which can then trigger serious infections. Statistics show that approximately 25% of diabetic patients worldwide suffer from wound ulcer complications, often accompanied by chronic ulcers and gangrene in surrounding tissues; in severe cases, amputation or even death may be imminent. Currently, treatment for diabetic wounds primarily involves surgical debridement and antibiotic therapy. However, the widespread use of antibiotics has led to bacterial resistance, a major global challenge.

[0003] In recent years, researchers have developed a series of non-antibiotic antibacterial strategies to alleviate bacterial resistance, such as quaternary ammonium salts, metal / metal oxides, antimicrobial peptides, and gas therapy. Among these, gas therapy, as an emerging and promising treatment method, is receiving increasing attention in the treatment of inflammation-related diseases. Some gas molecules (such as NO, H2S, and CO) have excellent permeability and tunability, offering unique advantages for treating various deep tissue diseases and enhancing their curative efficacy. CO, as an endogenous signaling molecule, has multiple biological functions, but its effects are strictly dependent on its concentration. Within a suitable concentration range, CO exhibits anti-inflammatory, anti-apoptotic, hypotensive, vasodilatory, anti-atherosclerotic, and cytoprotective functions (Nano-designed carbon monoxide donor SMA / CORM2 exhibits protective effect against acetaminophen-induced liver injury through macrophage reprogramming and promoting liver regeneration. Journal of Controlled Release, 2021, 331: 350-363). Studies have shown that CO molecules are effective in killing drug-resistant bacteria and are less likely to induce bacterial resistance, thus attracting increasing attention in combating bacterial resistance. However, excessively high CO concentrations can reduce the oxygen-carrying capacity of hemoglobin, leading to respiratory disorders (Harnessing carbon monoxide-releasing platforms for cancer therapy. Biomaterials, 2020, 255: 120193). Therefore, the controllable regulation of CO gas concentration is of great significance in the biomedical field.

[0004] Studies have shown that, in the presence of a photocatalyst, endogenous CO2 can be converted into CO under external light conditions, achieving controlled release and targeted therapeutic effects of CO, which can significantly improve the controllability and effectiveness of the treatment process (Photocatalyzing CO2 to CO for enhanced cancer therapy. Advanced Materials, 2017, 29(44): 1703822), providing important research value for achieving safe and controllable treatment of pathogenic bacterial infections. However, the limited production of endogenous CO2 will limit the therapeutic effect of CO to some extent. It is worth noting that polyethyleneimine (PEI), as a commonly used CO2 adsorbent, can capture CO2 from the air or surrounding environment by using the chemical reaction between its imino groups and CO2, achieving the purpose of stabilizing the CO2 load. When the system temperature rises, it can decompose back into imino groups and CO2 (Aminopolymer functionalization of boron nitridenanosheets for highly efficient capture of carbon dioxide. Journal of Materials Chemistry A, 2017, 5(31): 16241-16248). Therefore, the CO2 release rate can be controlled by adjusting the desorption temperature of PEI-CO2, demonstrating unique advantages in the field of CO2 storage and release. Thus, combining PEI as a CO2 adsorbent with a photocatalytic material provides an important research approach for the long-term controlled release of CO from photocatalytically reduced CO2. Summary of the Invention

[0005] Objective of the Invention: To address the problems existing in the prior art, this invention provides a method for preparing a red light-triggered long-acting controlled-release CO2 hydrogel dressing. Using highly biocompatible silk fibroin (SF) as the base material for the wound dressing, AgPCN@PEI@CO2 is mixed with SF to obtain an AgPCN@PEI@CO2 / SF hydrogel dressing. This invention is simple to prepare, safe and controllable, and less prone to inducing bacterial resistance, thus showing potential application prospects in the biomedical field.

[0006] Technical solution: This invention provides a method for preparing a red light-triggered long-lasting controlled-release CO2 hydrogel dressing, comprising the following steps:

[0007] S1. Preparation of Ag3PO4-supported PCN nanomaterials (AgPCN);

[0008] S2. Preparation of AgPCN@PEI: Polyethyleneimine was placed in an ethanol solution, stirred for the first time, AgPCN was added, stirred for the second time, centrifuged, and the lower precipitate was removed. The precipitate was added to an ethanol / water solution of glutaraldehyde, and stirred for the third time to obtain AgPCN@PEI.

[0009] S3. Preparation of AgPCN@PEI@CO2: After drying, AgPCN@PEI is placed in a glass adsorption column, and then CO2 gas is slowly blown into the adsorption column to obtain CO2-loaded AgPCN@PEI multi-component nanomaterial AgPCN@PEI@CO2;

[0010] S4. Preparation of AgPCN@PEI@CO2 / SF hydrogel dressing: An aqueous solution of N-lauroyl sarcosinate sodium was added to the mixed solution of AgPCN@PEI@CO2 and silk fibroin. The mixture was stirred evenly at room temperature to obtain an initial dispersion of the composite hydrogel. The initial dispersion was further freeze-dried to obtain AgPCN@PEI@CO2 / SF composite hydrogel.

[0011] Furthermore, in S4, the concentration of the mixed solution of AgPCN@PEI@CO2 and silk fibroin is 10~40 mg / mL;

[0012] And / or, in S4, the concentration of the N-lauroyl sarcosine sodium aqueous solution is 2-5 mg / mL.

[0013] Furthermore, the specific preparation method of the AgPCN is as follows:

[0014] Urea and dicyandiamide were ground and calcined in a muffle furnace. The calcined reactants were then washed sequentially with dilute nitric acid and water to obtain porous g-C3N4. The porous g-C3N4 was placed in deionized water and dispersed evenly. AgNO3 and Na2HPO4·12H2O solution were then added, stirred, irradiated with an Xe lamp, centrifuged, washed, and dried to obtain Ag3PO4-supported PCN nanomaterials AgPCN.

[0015] Furthermore, the mass ratio of urea to dicyandiamide is 2:1 to 4:1;

[0016] And / or, the mass ratio of the porous g-C3N4, AgNO3 and Na2HPO4·12H2O is 3:2:1 to 2:1:1;

[0017] And / or, the concentration of the dilute nitric acid is 0.1 mol·L⁻¹. -1 ;

[0018] Furthermore, the specific conditions for the calcination reaction are: reaction temperature 520-540 ℃, reaction time 4-5 h;

[0019] And / or, the Xe lamp irradiation specifically refers to: irradiation with a 300 W Xe lamp for 1~1.5 h;

[0020] And / or, the stirring time is 4~6 h;

[0021] And / or, the drying is specifically vacuum drying at a temperature of 60~80 °C.

[0022] Furthermore, in S2, the volume ratio of ethanol to water in the glutaraldehyde ethanol / water solution is 3:1 to 1:1;

[0023] And / or, in S2, the mass percentage of glutaraldehyde in the ethanol / water solution of glutaraldehyde is 0.5-2.0 wt%;

[0024] And / or, in S2, the mass ratio of the polyethyleneimine to the AgPCN is 2:1 to 1:1.

[0025] Furthermore, in S2, the first stirring time is 30-40 min;

[0026] And / or, in S2, the second stirring time is 24~48 h.

[0027] Furthermore, in S3, the drying process specifically involves vacuum drying at 105 °C for 12-24 h.

[0028] Furthermore, in S3, the time for blowing in CO2 gas is 1-12 h.

[0029] Beneficial Effects: Compared with existing technologies, this invention uses highly biocompatible silk fibroin (SF) as the base material for wound dressings, mixing AgPCN@PEI@CO2 with SF to obtain an AgPCN@PEI@CO2 / SF hydrogel dressing. In the AgPCN@PEI@CO2 / SF system, under red light irradiation (600-700 nm), the temperature of AgPCN increases (60-65 °C), causing thermal desorption of PEI-CO2 and releasing CO2. Simultaneously, AgPCN can reduce CO2 to CO under light irradiation for antibacterial and anti-inflammatory treatment. By controlling the irradiation time and power, this system can achieve a long-lasting and controllable CO antibacterial therapeutic effect. Attached Figure Description

[0030] Figure 1 Transmission electron microscope image of AgPCN@PEI@CO2 prepared in this invention;

[0031] Figure 2Infrared absorption spectra of AgPCN, AgPCN@PEI, and AgPCN@PEI@CO2 prepared in this invention;

[0032] Figure 3 Scanning electron microscope image of the AgPCN@PEI@CO2 / SF composite hydrogel prepared in this invention;

[0033] Figure 4 Photothermal experimental data of AgPCN@PEI@CO2 / SF composite hydrogels prepared in Embodiments 1-3 and SF hydrogels prepared in the comparative example;

[0034] Figure 5 The figures show the CO release kinetics data of the AgPCN@PEI@CO2 / SF composite hydrogels prepared in Examples 1-3 and the SF hydrogels prepared in the comparative example. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the embodiments.

[0036] Implementation method 1:

[0037] Step 1: Preparation of photocatalytic nanomaterial AgPCN: 3.75 g of urea and 1.25 g of dicyandiamide were ground for 4 h and then calcined in a muffle furnace at 530 ℃ for 4 h. The reaction was carried out sequentially with dilute nitric acid (0.1 mol·L⁻¹). -1 After washing with deionized water, porous g-C3N4 (PCN) was obtained. 500 mg of PCN was dispersed evenly in 100 mL of deionized water, and then 276 mg of AgNO3 and 100 mL of Na2HPO4·12H2O solution (2 mg·mL⁻¹) were added. -1 After stirring for 4 h, the mixture was irradiated with an Xe lamp for 1 h, centrifuged and washed, and then vacuum dried at 60 °C to obtain Ag3PO4-supported PCN nanomaterials (AgPCN).

[0038] Step 2, Preparation of AgPCN@PEI: Weigh 1 g of PEI and add it to 10 mL of ethanol. After stirring for 30 min, add 0.5 g of AgPCN and continue stirring for 24 h. Centrifuge to separate the lower precipitate and add the precipitate to 20 mL of glutaraldehyde in ethanol / water (v / v=3 / 1) solution (0.5 wt%). Stir at room temperature for a period of time to obtain AgPCN@PEI.

[0039] Step 3: Preparation of AgPCN@PEI@CO2: After drying AgPCN@PEI in a vacuum oven at 105 °C for 12 h, the sample was placed in a glass adsorption column. A vacuum was slowly created using a circulating water pump, and then CO2 gas was slowly blown into the adsorption column using a CO2 gas bag. This process was maintained for 10 h to obtain the AgPCN@PEI@CO2 sample. The infrared absorption spectrum of AgPCN@PEI@CO2 was measured using Fourier transform infrared spectroscopy to detect the successful CO2 loading. The morphology and structure of AgPCN@PEI@CO2 were observed using scanning electron microscopy.

[0040] Step 4: Preparation of AgPCN@PEI@CO2 / SF hydrogel dressing: Using sodium N-lauroyl sarcosinate (SNS) as a surfactant, 2 mL of an aqueous solution of SNS (4 mg / mL) was prepared and added to a mixed solution of AgPCN@PEI@CO2 and SF (10 mg / mL). The initial dispersion of the composite hydrogel was obtained at 25°C. Further freeze-drying yielded the AgPCN@PEI@CO2 / SF composite hydrogel.

[0041] Implementation Method 2:

[0042] This embodiment is largely the same as Embodiment 1, except that the concentration of the mixed solution of AgPCN@PEI@CO2 and SF added in this embodiment is 20 mg / mL.

[0043] Apart from the above, this implementation method is exactly the same as implementation method 1, and will not be described again here.

[0044] Implementation Method 3:

[0045] This embodiment is largely the same as Embodiment 1, except that the concentration of the mixed solution of AgPCN@PEI@CO2 and SF added in this embodiment is 30 mg / mL.

[0046] Apart from the above, this implementation method is exactly the same as implementation method 1, and will not be described again here.

[0047] Comparative example:

[0048] Sodium lauroyl sarcosinate (SNS) was used as a surfactant. 2 mL of an aqueous SNS solution (4 mg / mL) was added to 10 mL of SF solution, and the initial dispersion of the hydrogel was obtained at 25°C. Further freeze-drying yielded the SF hydrogel.

[0049] Photothermal effect test:

[0050] To study the photothermal properties of the samples, 630 nm red light (60 W) was used to irradiate the samples of Embodiment 1, Embodiment 2, Embodiment 3 and the comparative example, respectively, for 10 min. The temperature change of the samples was recorded every 2 min using a thermocouple thermometer.

[0051] CO release kinetics test:

[0052] The CO production of AgPCN@PEI@CO2 / SF composite gel was detected using the hemoglobin method. 1.5 mg of hemoglobin (Hb) was added to 5 mL of PBS solution, followed by 18 mg of sodium dithionite. After thorough stirring, the sample was added, and the mixture was bubbled under vacuum with N2 for 15 min. The solutions from Examples 1, 2, 3, and the comparative example were irradiated with 630 nm red light (60 W) for 10 min, and the absorption spectra of the Hb solution in the 350-600 nm range were measured every 2 min using a UV-Vis spectrophotometer. The conversion of Hb to HbCO was calculated using the absorption peak intensities of carboxyhemoglobin (HbCO) and Hb at 410 nm and 430 nm, respectively, indirectly calculating the CO release. The concentration of CO released (C...) was... CO Calculate using the following formula:

[0053]

[0054] In vitro antibacterial test:

[0055] Pseudomonas aeruginosa and Staphylococcus aureus were used as experimental strains in the in vitro antibacterial experiment. The revived bacteria were placed in liquid culture medium and shaken overnight on a 37°C constant temperature shaker. Samples from Embodiments 1, 2, 3, and the comparative example were placed in 12-well plates, and 500 µL of bacterial suspension was added dropwise to the sample surface for each.

[0056] After irradiating the samples with 630 nm red light (60 W) for 10 min, 1 mL of PBS solution was added to each group of samples. After sonication, 50 μL of bacterial culture was plated and placed on a shaker at 37℃ overnight. The number of bacterial colonies was then observed. The samples in the dark group were subjected to the same antibacterial experiment under light-protected conditions.

[0057] Transmission electron microscopy morphology data of AgPCN@PEI@CO2 prepared in this invention are as follows: Figure 1 As shown, the composite material exhibits a typical multi-component structure with a porous, layered substrate structure and Ag3PO4 nanoparticles loaded on the substrate surface, proving that the composite material was successfully prepared.

[0058] The infrared absorption spectra of AgPCN@PEI and AgPCN@PEI@CO2 prepared in this invention are as follows: Figure 2 As shown. Compared with AgPCN@PEI, AgPCN@PEI@CO2 at 2351 cm⁻¹ -1 A new absorption peak is observed, which is attributed to the asymmetric stretching vibration of the C=O bond in CO2, demonstrating the successful loading of CO2.

[0059] The scanning electron microscope morphology data of the AgPCN@PEI@CO2 / SF composite hydrogel prepared in this invention are as follows: Figure 3 As shown in the figure, the composite hydrogel exhibits a typical porous structure with pore sizes ranging from 1 to 5 μm. This porous structure enhances the material's water absorption and facilitates the generation and release of gas molecules. Furthermore, the surface of the composite hydrogel shows a significant distribution of nanoparticles, which is beneficial for CO generation during subsequent photocatalytic reactions, further contributing to improved antibacterial efficiency.

[0060] Photothermal experimental data such as Figure 4 As shown, under 630 nm red light irradiation, the temperature of the comparative sample did not change much with the irradiation time, while the temperature of the samples in Embodiments 1, 2 and 3 gradually increased, and their photothermal temperature gradually increased with the increase of AgPCN@PEI@CO2 doping amount, proving that the doping amount of AgPCN@PEI@CO2 has a significant impact on the photothermal temperature. This gel system mainly obtains the photothermal effect through AgPCN loading.

[0061] CO release kinetic data such as Figure 5 As shown, the CO production of the samples was tested under 630 nm red light irradiation. The results showed that the comparative sample showed no significant CO production under red light irradiation, while the CO production in the samples of Embodiments 1, 2, and 3 gradually increased with irradiation time. Furthermore, the CO release increased with increasing AgPCN@PEI@CO2 doping concentration, reaching 0.301 mM, 0.325 mM, and 0.351 mM respectively after 10 min of irradiation. These experimental results demonstrate that the AgPCN@PEI@CO2 / SF composite hydrogel achieves controlled CO release primarily through AgPCN@PEI@CO2 loading and red light irradiation.

[0062] The statistical data of plate colonies in the in vitro antibacterial experiment are shown in Tables 1 and 2. The results show that under 630 nm red light irradiation, Embodiments 1, 2, and 3 all exhibited effective antibacterial effects against Pseudomonas aeruginosa and Staphylococcus aureus, and the antibacterial efficiency significantly improved with increasing AgPCN@PEI@CO2 doping concentration. In contrast, the control group and the dark group showed no significant antibacterial effect. These results indicate that the antibacterial effect of this hydrogel system can be controlled by adjusting the AgPCN@PEI@CO2 doping concentration and red light irradiation conditions, thereby achieving safe and controllable treatment procedures.

[0063] Table 1. Bacterial survival rate results obtained under 630 nm red light irradiation for comparative examples and embodiments 1-3 of the present invention.

[0064] Implementation Method 1 Implementation Method 2 Implementation Method 3 Comparative Example Pseudomonas aeruginosa 13.9% 9.8% 1.2% 65.8% Staphylococcus aureus 17.3% 9.6% 1.5% 62.4%

[0065] Table 2. Bacterial survival rate results obtained under dark conditions in comparative examples and embodiments 1-3 of the present invention.

[0066] Implementation Method 1 Implementation Method 2 Implementation Method 3 Comparative Example Pseudomonas aeruginosa 68.2% 65.3% 69.8% 60.8% Staphylococcus aureus 61.1% 68.9% 60.7% 63.7%

[0067] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a red light-triggered long-lasting controlled-release CO2 hydrogel dressing, characterized in that, Includes the following steps: S1. Preparation of AgPCN: Urea and dicyandiamide were ground and calcined in a muffle furnace. The calcined reactants were then washed with dilute nitric acid and water to obtain porous g-C3N4. The porous g-C3N4 was placed in deionized water and dispersed evenly. AgNO3 and Na2HPO4·12H2O solution were added to the mixture, stirred, irradiated with an Xe lamp, centrifuged, washed, and dried to obtain Ag3PO4-supported PCN nanomaterial AgPCN. S2. Preparation of AgPCN@PEI: Polyethyleneimine was placed in an ethanol solution, stirred for the first time, AgPCN was added, stirred for the second time, centrifuged, and the lower precipitate was removed. The precipitate was added to an ethanol / water solution of glutaraldehyde, and stirred for the third time to obtain AgPCN@PEI. S3. Preparation of AgPCN@PEI@CO2: After drying, AgPCN@PEI is placed in a glass adsorption column, and then CO2 gas is slowly blown into the adsorption column to obtain CO2-loaded AgPCN@PEI multi-component nanomaterial AgPCN@PEI@CO2; S4. Preparation of AgPCN@PEI@CO2 / SF hydrogel dressing: Add N-lauroyl sarcosinate sodium aqueous solution to the mixed solution of AgPCN@PEI@CO2 and silk fibroin, stir evenly at room temperature to obtain the initial dispersion of composite hydrogel, and further freeze-dry the initial dispersion to obtain AgPCN@PEI@CO2 / SF composite hydrogel.

2. The method for preparing the red light-triggered long-lasting controlled-release CO2 hydrogel dressing according to claim 1, characterized in that: In S4, the concentration of the mixed solution of AgPCN@PEI@CO2 and silk fibroin is 10~40 mg / mL; And / or, in S4, the concentration of the N-lauroyl sarcosine sodium aqueous solution is 2-5 mg / mL.

3. The method for preparing the red light-triggered long-lasting controlled-release CO2 hydrogel dressing according to claim 1, characterized in that: In S1, the mass ratio of urea to dicyandiamide is 4:1 to 2:1; And / or, in S1, the mass ratio of the porous g-C3N4, AgNO3 and Na2HPO4·12H2O is 3:2:1 to 2:1:1; And / or, in S1, the concentration of the dilute nitric acid is 0.1 mol·L⁻¹. -1 .

4. The preparation method of the red light-triggered long-lasting controlled-release CO2 hydrogel dressing according to claim 1, characterized in that: In S1, the specific conditions for the calcination reaction are: reaction temperature 520-540 ℃, reaction time 4~5 h; And / or, in S1, the Xe lamp irradiation specifically refers to: irradiation with a 300 W Xe lamp for 1~1.5 h; And / or, in S1, the stirring time is 4~6 h; And / or, in S1, the drying is specifically vacuum drying at a temperature of 60~80 °C.

5. The method for preparing the red light-triggered long-lasting controlled-release CO2 hydrogel dressing according to claim 1, characterized in that: In S2, the volume ratio of ethanol to water in the glutaraldehyde ethanol / water solution is 3:1 to 1:

1. And / or, in S2, the mass percentage of glutaraldehyde in the ethanol / water solution of glutaraldehyde is 0.5-2.0 wt%; And / or, in S2, the mass ratio of the polyethyleneimine to the AgPCN is 2:1 to 1:

1.

6. The method for preparing the red light-triggered long-lasting controlled-release CO2 hydrogel dressing according to claim 1, characterized in that: In S2, the first stirring time is 30~40 min; And / or, in S2, the second stirring time is 24~48 h.

7. The method for preparing the red light-triggered long-lasting controlled-release CO2 hydrogel dressing according to claim 1, characterized in that: In S3, the drying process specifically involves vacuum drying at 105 °C for 12-24 h.

8. The method for preparing the red light-triggered long-lasting controlled-release CO2 hydrogel dressing according to claim 1, characterized in that: In S3, the time for blowing in CO2 gas is 1-12 h.

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