Sodium alginate dressing with in-situ photo-thermal conversion function and preparation method thereof

Abstract

The invention discloses a sodium alginate dressing with an in-situ photo-thermal conversion function and a preparation method of the sodium alginate dressing, and belongs to the technical field of dressings. The sodium alginate dressing with the in-situ photo-thermal conversion function is prepared by the following steps: mixing sodium alginate and an azobenzene quaternary ammonium salt compound containing an N-benzyl structure in a water and ethanol solution system; stirring and mixing to form an ion compound precipitate, and carrying out centrifugal separation, water washing purification and freeze drying treatment on the obtained ion compound precipitate to obtain the photo-induced phase change dressing. The sodium alginate dressing with the in-situ photo-thermal conversion function prepared by the invention has high energy storage density and good biocompatibility, and can realize long-time heat energy release under light stimulation. The sodium alginate dressing with the in-situ photo-thermal conversion function prepared by the invention can be used as a wound dressing to effectively promote the healing process of a wound, and can be applied to the field of preparation of medicines for treating wound healing.

Description

Technical Field

[0001] The present invention belongs to the technical field of dressings, and in particular relates to a sodium alginate dressing with in-situ photothermal conversion function and a preparation method thereof. Background Art

[0002] The healing process of wound tissue requires a suitable physiological environment, and gentle thermal stimulation is crucial for vascular and skin regeneration. Among energy sources capable of providing thermal stimulation, light energy and low-temperature thermal energy are bio-friendly and less harmful to biological tissue. Medical dressings that convert light and low-temperature thermal energy into controllable heat can provide a spa-like thermal environment for wound tissue, effectively promoting the wound healing process.

[0003] Light energy and low-temperature thermal energy are two widely occurring energy sources in nature, and their storage and utilization are of great significance. In recent years, energy storage materials based on organic photoswitch molecules have attracted widespread attention. These energy storage materials can achieve efficient conversion of light energy into thermal energy through the photoisomerization of organic photoswitch molecules. Furthermore, the photoisomerization of some photoswitch molecules can also serve as a driving force for phase transitions in the material, enabling the material to effectively utilize low-temperature thermal energy through phase changes. For example, under room temperature ultraviolet light irradiation, some azobenzene-based photoinduced phase change energy storage materials can undergo trans-to-cis molecular isomerization and solid-to-liquid phase transition, storing light energy and ambient low-temperature thermal energy within the material. Under visible light irradiation, they can undergo cis-to-trans molecular isomerization and liquid-to-solid phase transition, releasing the stored energy as thermal energy, thereby effectively utilizing both light energy and low-temperature thermal energy.

[0004] For azobenzene-based energy storage materials, energy storage density, controllable heating time and biocompatibility are important considerations in practical applications. When designing azobenzene energy storage materials with high energy storage density, the phase change ability of the material is often sacrificed, making the energy storage method of this type of material more complicated, which is not conducive to the practical application of this type of material in the field of wound treatment. At the same time, due to its limited single energy storage, azobenzene energy storage materials cannot provide a long-term warming effect under visible light irradiation. In addition, the lack of biocompatibility of simple azobenzene energy storage materials also makes it difficult to use them as medical dressings. Therefore, how to combine biomolecules with good biocompatibility with azobenzene energy storage materials to develop photothermal conversion materials with high energy storage density, simple energy storage method, long heating time and high biosafety is of great significance for expanding the application of molecular switch materials in basic scientific research and medical dressings. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention proposes a sodium alginate dressing with in-situ photothermal conversion function and a preparation method thereof.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] The present invention provides a sodium alginate dressing with in-situ photothermal conversion function. The raw materials of the dressing include sodium alginate and an azobenzene quaternary ammonium salt compound containing an N-benzyl structure.

[0008] Azobenzene molecules undergo a cis-trans isomerization reaction under light conditions. When irradiated with light of a specific wavelength, the azobenzene molecules undergo electronic transitions and molecular structural rearrangements, resulting in a transition between the two isomers. This structural change, accompanied by changes in physical properties such as molecular polarity, molecular size, and steric hindrance, provides a foundation for photothermal conversion. During the photothermal conversion process, light energy is first absorbed by the azobenzene molecules. The excited state energy is then released as heat through non-radiative transitions, thereby increasing the material's temperature. The azobenzene groups in azobenzene quaternary ammonium salt compounds containing N-benzyl structures can efficiently absorb light energy and convert it into heat, thereby improving the photothermal conversion efficiency of sodium alginate dressings. Quaternary ammonium salts are cationic surfactants with excellent water solubility and adsorption properties. The quaternary ammonium groups in azobenzene quaternary ammonium salt compounds containing N-benzyl structures can electrostatically interact with functional groups such as carboxyl groups in the sodium alginate molecule, enabling the compounds to be evenly dispersed or adsorbed on the alginate dressing. This good compatibility and dispersibility help improve the uniformity and efficiency of photothermal conversion. The quaternary ammonium salt structure can also enhance the stability and mechanical properties of the sodium alginate dressing, allowing it to maintain good structural integrity during the photothermal conversion process, thereby improving the service life and performance stability of the dressing. The N-benzyl structure can reduce the bulk density of the surfactant, helping to improve the stability of the compound in the dressing and the photothermal conversion performance. Sodium alginate is a natural polysaccharide with good biocompatibility and biodegradability. When an azobenzene quaternary ammonium salt compound containing an N-benzyl structure is combined with a sodium alginate dressing, the photothermal conversion performance of the dressing is significantly improved. Under light conditions, the dressing can quickly convert light energy into heat energy, and can continuously convert light energy into heat energy under visible light irradiation, thereby achieving long-term in situ photothermal therapy. When an azobenzene quaternary ammonium salt compound containing an N-benzyl structure is combined with a sodium alginate dressing, a synergistic effect may be produced between the two. When combined with sodium alginate, azobenzene quaternary ammonium salt compounds containing an N-benzyl structure undergo simultaneous trans-cis isomerization and cis-trans isomerization under visible light irradiation, thereby converting visible light into heat energy. This synchronous transformation enables a long-term photothermal conversion effect. Therefore, the sodium alginate dressing of the present invention, which has an in-situ photothermal conversion function, achieves photothermal conversion in a completely solvent-free manner, and it is an in-situ photothermal conversion of visible light.

[0009] Furthermore, the sodium alginate is a mixture of polysaccharide polymers with a molecular formula of (C6H7O6Na)n.

[0010] Furthermore, the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is selected from one of N,N-dimethyl-N-benzyl-4-(4-((4-methoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide, N,N-dimethyl-N-benzyl-4-(4-((4-n-butoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide and N,N-dimethyl-N-benzyl-4-(4-((4-n-octyloxyphenyl)diazenyl)phenoxy)n-butylammonium bromide.

[0011] The present invention also provides a method for preparing the sodium alginate dressing with in-situ photothermal conversion function, comprising the following steps:

[0012] An aqueous solution of sodium alginate is mixed with a water-ethanol solution of an azobenzene quaternary ammonium salt compound containing an N-benzyl structure, the mixed solution is stirred, the stirred mixed solution is centrifuged, the supernatant is discarded, and the obtained precipitate product is washed with water and freeze-dried to prepare the sodium alginate dressing with in-situ photothermal conversion function.

[0013] Furthermore, based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na, the molar ratio of sodium alginate in the aqueous solution of sodium alginate to the azobenzene quaternary ammonium salt compound containing an N-benzyl structure in the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is 1:1.

[0014] Furthermore, the aqueous solution of sodium alginate has a concentration of 20 to 30 mmol / L, based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na;

[0015] And / or, the concentration of the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is 5 to 10 mmol / L.

[0016] Furthermore, in the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure, the volume ratio of water to ethanol is 3:1.

[0017] Furthermore, the stirring treatment time is 30 minutes.

[0018] Furthermore, the freeze-drying treatment time is 12 hours.

[0019] The present invention also provides use of the sodium alginate dressing with in-situ photothermal conversion function in the preparation of a medicine for treating wound healing.

[0020] The sodium alginate dressing prepared by the present invention has an in-situ photothermal conversion function and can undergo phase change (photoinduced phase change) under light induction at room temperature and can release heat for a long time under visible light irradiation.

[0021] In the present invention, the photoinduced phase change process of the sodium alginate dressing with in-situ photothermal conversion function includes: ultraviolet light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to undergo a solid-to-liquid transition; visible light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to undergo a liquid-to-liquid state transition.

[0022] For example, in the photoinduced phase change process of the sodium alginate dressing with in situ photothermal conversion function, the ultraviolet irradiation conditions are: wavelength 365nm, intensity 10-50mW / cm 2 The visible light irradiation conditions are: wavelength 520nm, intensity 50 ~ 100mW / cm 2 , time 10 minutes.

[0023] Illustratively, the process of long-term heat release of a sodium alginate dressing with in-situ photothermal conversion function under visible light irradiation includes: ultraviolet light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to undergo a solid-to-liquid transition; continuous visible light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to continuously release heat energy, and the continuous heat energy release time is 4 hours.

[0024] The present invention also provides a medicine for preparing a wound healing treatment, the active ingredient of which is the sodium alginate dressing with in-situ photothermal conversion function.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] 1. The sodium alginate dressing with in-situ photothermal conversion function obtained by the present invention is a solid material formed by electrostatic force between sodium alginate and an azobenzene quaternary ammonium salt compound containing an N-benzyl structure.

[0027] 2. The sodium alginate dressing obtained by the present invention has an in-situ photothermal conversion function and can produce phase transition under the stimulation of ultraviolet light and visible light.

[0028] 3. The sodium alginate dressing obtained by the present invention has the function of in-situ photothermal conversion and can continuously release heat energy under continuous irradiation of visible light.

[0029] 4. The sodium alginate dressing with in situ photothermal conversion function obtained by the present invention has good biocompatibility.

[0030] 5. The sodium alginate dressing obtained by the present invention with in-situ photothermal conversion function can be used as a medical dressing in wound healing treatment and other related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 Comparison of small-angle X-ray scattering patterns of the sodium alginate dressing with in-situ photothermal conversion function prepared in Example 1 before and after ultraviolet light irradiation.

[0033] Figure 2 This is a polarizing microscope image of the sodium alginate dressing with in-situ photothermal conversion function prepared in Example 1 under visible light irradiation.

[0034] Figure 3 This is the differential scanning calorimetry analysis spectrum of the sodium alginate dressing with in-situ photothermal conversion function prepared in Example 1 before and after ultraviolet light irradiation.

[0035] Figure 4 These are the cytotoxicity test results of the sodium alginate dressing with in situ photothermal conversion function prepared in Example 1 at different mass concentrations.

[0036] Figure 5 When the sodium alginate dressing with in situ photothermal conversion function prepared in Example 1 was used as a medical dressing, the healing rates of mouse wounds on the 9th and 14th days were shown.

[0037] Figure 6 This is the differential scanning calorimetry analysis spectrum of the sodium alginate dressing with in-situ photothermal conversion function prepared in Example 2 before and after ultraviolet light irradiation.

[0038] Figure 7 This is the differential scanning calorimetry analysis spectrum of the sodium alginate dressing with in-situ photothermal conversion function prepared in Example 3 before and after ultraviolet light irradiation.

[0039] Figure 8 This is the temperature change of the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 1 within 10 minutes of visible light irradiation.

[0040] Figure 9 This is the temperature change of the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 2 within 10 minutes of visible light irradiation. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0042] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0043] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0044] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0045] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0046] An embodiment of the present invention provides a sodium alginate dressing with in-situ photothermal conversion function, the raw materials of which include sodium alginate and an azobenzene quaternary ammonium salt compound containing an N-benzyl structure.

[0047] The principle of the present invention is as follows: the sodium alginate dressing with in-situ photothermal conversion function of the present invention is an ion complex formed by sodium alginate and an azobenzene quaternary ammonium salt compound containing an N-benzyl structure through electrostatic force. The sodium alginate molecule can effectively adjust the packing density of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure through electrostatic force, providing spatial freedom for the photoisomerization of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure. After the sodium alginate dressing with in-situ photothermal conversion function of the present invention is irradiated with ultraviolet light, the azobenzene quaternary ammonium salt compound containing an N-benzyl structure will undergo trans-cis structural isomerization, inducing the sodium alginate dressing with in-situ photothermal conversion function to undergo a phase change from an ordered crystal structure to a disordered fluid structure. The sodium alginate dressing with in-situ photothermal conversion function can store light energy and low-temperature heat energy in the environment through the trans-cis structural isomerization of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure and the phase change of the material. Under visible light irradiation, the azobenzene quaternary ammonium salt compound containing an N-benzyl structure contained in the sodium alginate dressing with an in-situ photothermal conversion function of the present invention undergoes cis-trans structural isomerization, and induces the sodium alginate dressing with an in-situ photothermal conversion function of the present invention to undergo a phase change from a disordered fluid structure to an ordered liquid crystal state. The sodium alginate dressing with an in-situ photothermal conversion function can release stored light energy and low-temperature thermal energy in the environment in the form of thermal energy through the cis-trans structural isomerization of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure and the phase change of the material. The sodium alginate dressing with an in-situ photothermal conversion function of the present invention forms a liquid crystal state through light induction, which can provide spatial freedom for photoisomerization of an azobenzene quaternary ammonium salt compound containing an N-benzyl structure under visible light irradiation, so that the azobenzene quaternary ammonium salt compound containing an N-benzyl structure contained in the sodium alginate dressing with an in-situ photothermal conversion function of the present invention can simultaneously undergo trans-cis structural isomerization and cis-trans structural isomerization under visible light irradiation, so that the sodium alginate dressing with an in-situ photothermal conversion function of the present invention has an in-situ photothermal conversion function under visible light irradiation.

[0048] In an embodiment of the present invention, sodium alginate is a mixture of polysaccharide polymers with a molecular formula of (C6H7O6Na)n.

[0049] In an embodiment of the present invention, the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is selected from one of N,N-dimethyl-N-benzyl-4-(4-((4-methoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide, N,N-dimethyl-N-benzyl-4-(4-((4-n-butoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide and N,N-dimethyl-N-benzyl-4-(4-((4-n-octyloxyphenyl)diazenyl)phenoxy)n-butylammonium bromide.

[0050] An embodiment of the present invention also provides a method for preparing a sodium alginate dressing with in-situ photothermal conversion function, comprising the following steps: mixing an aqueous solution of sodium alginate with a water-ethanol solution of an azobenzene quaternary ammonium salt compound containing an N-benzyl structure at room temperature, stirring the mixture for 30 minutes, centrifuging the stirred mixture, discarding the supernatant, washing the obtained precipitate three times with water for purification, and freeze-drying for 12 hours to obtain a sodium alginate dressing with in-situ photothermal conversion function.

[0051] The sodium alginate dressing with in-situ photothermal conversion function of the present invention is a photoinduced phase change dressing obtained by mixing sodium alginate and an azobenzene quaternary ammonium salt compound containing an N-benzyl structure in a water and ethanol solution system, stirring and mixing to form an ion complex precipitate, and subjecting the obtained ion complex precipitate to centrifugal separation, water washing purification and freeze-drying. The sodium alginate dressing with in-situ photothermal conversion function prepared by the present invention has high energy storage density and good biocompatibility, and can achieve long-term heat energy release under light stimulation. The sodium alginate dressing with in-situ photothermal conversion function prepared by the present invention can be used as a wound dressing to effectively promote the wound healing process, and can be applied to the field of preparing wound healing drugs.

[0052] In an embodiment of the present invention, based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na, the molar ratio of sodium alginate in the aqueous solution of sodium alginate to the azobenzene quaternary ammonium salt compound containing an N-benzyl structure in the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is 1:1.

[0053] In an embodiment of the present invention, the concentration of the aqueous solution of sodium alginate is 20 to 30 mmol / L, based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na; the concentration of the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is 5 to 10 mmol / L.

[0054] In an embodiment of the present invention, the volume ratio of water to ethanol in the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is 3:1.

[0055] The sodium alginate dressing with in-situ photothermal conversion function provided by the embodiment of the present invention can be used to prepare a medicine for treating wound healing.

[0056] The sodium alginate dressing prepared by the present invention has an in-situ photothermal conversion function and can undergo phase change (photoinduced phase change) under light induction at room temperature and can release heat for a long time under visible light irradiation.

[0057] In the present invention, the photoinduced phase change process of the sodium alginate dressing with in-situ photothermal conversion function includes: ultraviolet light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to undergo a solid-to-liquid transition; visible light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to undergo a liquid-to-liquid state transition.

[0058] For example, in the photoinduced phase change process of the sodium alginate dressing with in situ photothermal conversion function, the UV irradiation conditions are: wavelength 365nm, intensity 10-50mW / cm 2 , time 10 minutes; visible light irradiation conditions are: wavelength 520nm, intensity 50~100mW / cm 2 , time 10 minutes.

[0059] Illustratively, the process of long-term heat release of a sodium alginate dressing with in-situ photothermal conversion function under visible light irradiation includes: ultraviolet light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to undergo a solid-to-liquid transition; continuous visible light irradiation, inducing the sodium alginate dressing with in-situ photothermal conversion function to continuously release heat energy, and the continuous heat energy release time is 4 hours.

[0060] An embodiment of the present invention further provides a drug for preparing a wound healing treatment, wherein the active ingredient of the drug is the sodium alginate dressing having the in-situ photothermal conversion function.

[0061] Unless otherwise specified, the room temperature in the present invention is 25±2°C.

[0062] All raw materials used in the examples of the present invention were purchased from commercial sources.

[0063] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0064] The technical solution of the present invention is further illustrated by the following examples.

[0065] Example 1

[0066] This embodiment provides a method for preparing a sodium alginate dressing with in-situ photothermal conversion function, and the steps are as follows:

[0067] At room temperature, 0.8 mL of a 25 mmol / L sodium alginate aqueous solution (calculated based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na) and a 5 mmol / L water-ethanol solution of N,N-dimethyl-N-benzyl-4-(4-((4-methoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide (3 mL-1 mL, i.e., the volume of water is 3 mL and the volume of ethanol is 1 mL, the same below) were mixed, the mixture was stirred for 30 minutes, the evenly stirred mixture was placed in a centrifuge, centrifuged at a relative centrifugal force of 6124 g for 5 minutes, the supernatant was discarded, the obtained precipitate was washed three times with water for purification, and finally the precipitate was freeze-dried for 12 hours to prepare a sodium alginate dressing with in situ photothermal conversion function.

[0068] The sodium alginate dressing with in-situ photothermal conversion function prepared in this example was tested before and after ultraviolet irradiation (365 nm, 30 mW / cm 2 ) X-ray small angle scattering test spectrum after 10 minutes of irradiation is as follows Figure 1 As shown, it can be concluded that the sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment can produce a phase transition from ordered crystals (solid) to disordered fluid (liquid) under ultraviolet light stimulation.

[0069] The sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment was subjected to a photothermal treatment at a wavelength of 365 nm and an intensity of 30 mW / cm 2 After 10 minutes of ultraviolet irradiation, the material was in a disordered fluid state; the material was in a disordered fluid state after 10 minutes of ultraviolet irradiation with a wavelength of 520nm and an intensity of 50mW / cm 2 After irradiation with visible light for 10 minutes, the sodium alginate dressing with in-situ photothermal conversion function can be transformed from a disordered fluid state to an ordered liquid crystal state (such as Figure 2 As shown). Under continuous irradiation with visible light, the sodium alginate dressing with in-situ photothermal conversion function of this embodiment can achieve continuous heat release for 4 hours through the in-situ photothermal conversion function.

[0070] The sodium alginate dressing with in-situ photothermal conversion function prepared in this example was tested before and after ultraviolet irradiation (365 nm, 30 mW / cm 2 ) The differential scanning calorimetry analysis spectrum after irradiation for 10 minutes is as follows Figure 3 As shown, it can be concluded that the prepared sodium alginate dressing with in situ photothermal conversion function can achieve a phase change energy storage density and a light energy storage density of 310.1 J / g and 70.5 J / g respectively through ultraviolet light irradiation, that is, the sodium alginate dressing with in situ photothermal conversion function prepared in this embodiment can achieve a total energy storage density of 380.6 J / g through ultraviolet light irradiation.

[0071] In the cytotoxicity analysis, the cytotoxicity test results of sodium alginate dressing with in situ photothermal conversion function at different mass concentrations are as follows: Figure 4 As shown, it can be concluded that the sodium alginate dressing with in situ photothermal conversion function prepared in this embodiment has good in vitro biosafety.

[0072] Taking the wound healing treatment of mice as an example, the effect of sodium alginate dressing with in situ photothermal conversion function as a medical dressing was tested. The specific experimental process is as follows: a wound with a diameter of 1 cm was cut on the back of Balb / c mice and divided into four groups. The group without any dressing and light conditions was recorded as the control group + darkness, the group without any dressing and repeated ultraviolet light irradiation for 10 minutes + visible light irradiation for 60 minutes from the first to the third day was recorded as the control group + light, the group with sodium alginate dressing with in situ photothermal conversion function and no light conditions was recorded as dressing + darkness, and the group with sodium alginate dressing with in situ photothermal conversion function and repeated ultraviolet light irradiation for 10 minutes + visible light irradiation for 60 minutes from the first to the third day was recorded as dressing + light, where the ultraviolet light had a wavelength of 365nm and an intensity of 30mW / cm 2 , visible light has a wavelength of 520nm and an intensity of 50mW / cm 2 The healing rates of mouse wounds on days 9 and 14 were as follows: Figure 5 As shown, it can be concluded that the wound healing rate under light conditions reached 65% on the 9th day, and the wound healing rate under light conditions reached 10% on the 14th day. The above results prove that the sodium alginate dressing with in situ photothermal conversion function prepared by the present invention can effectively promote wound healing by providing a mild thermal environment.

[0073] Example 2

[0074] This embodiment provides a method for preparing a sodium alginate dressing with in-situ photothermal conversion function, and the steps are as follows:

[0075] At room temperature, 0.8 mL of a 25 mmol / L sodium alginate aqueous solution (based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na) and a 5 mmol / L water-ethanol solution (3 mL-1 mL) of N,N-dimethyl-N-benzyl-4-(4-((4-n-butoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide) were mixed, and the mixture was stirred for 30 minutes. The stirred mixture was placed in a centrifuge and centrifuged for 5 minutes at a relative centrifugal force of 6124 g. The supernatant was discarded, and the resulting precipitate was washed three times with water for purification. Finally, the precipitate was freeze-dried for 12 hours to obtain a sodium alginate dressing with in situ photothermal conversion function.

[0076] The differential scanning calorimetry analysis spectrum of the sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment before and after ultraviolet irradiation is as follows: Figure 6 As shown in the figure, the sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment can undergo phase change under the irradiation of ultraviolet light and visible light. The sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment is first subjected to a wavelength of 365nm and an intensity of 30mW / cm 2 After 10 minutes of ultraviolet irradiation, the samples were then irradiated at a wavelength of 520 nm and an intensity of 50 mW / cm 2 Under continuous irradiation of visible light, it can achieve continuous heat release through in-situ photothermal conversion function.

[0077] The sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment is subjected to a wavelength of 365nm and an intensity of 30mW / cm 2 The phase change energy storage density and light energy storage density that can be achieved by ultraviolet light irradiation are 303.8 J / g and 25.4 J / g, respectively. That is, the sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment can achieve a total energy storage density of 329.2 J / g by ultraviolet light irradiation.

[0078] Example 3

[0079] This embodiment provides a method for preparing a sodium alginate dressing with in-situ photothermal conversion function, and the steps are as follows:

[0080] At room temperature, 0.8 mL of a sodium alginate aqueous solution with a concentration of 25 mmol / L (based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na) and a water-ethanol solution (3 mL-1 mL) of N,N-dimethyl-N-benzyl-4-(4-((4-n-octyloxyphenyl)diazenyl)phenoxy)n-butylammonium bromide with a concentration of 5 mmol / L were mixed, and the mixture was stirred for 30 minutes. The stirred mixture was placed in a centrifuge and centrifuged for 5 minutes under a relative centrifugal force of 6124 g. The supernatant was discarded, and the obtained precipitate was washed three times with water for purification. Finally, the precipitate was freeze-dried for 12 hours to obtain the sodium alginate dressing with in situ photothermal conversion function of the present invention.

[0081] The differential scanning calorimetry analysis spectrum of the sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment before and after ultraviolet irradiation is as follows: Figure 7 As shown in the figure, the sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment can undergo phase change under the irradiation of ultraviolet light and visible light. The sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment can undergo phase change under the irradiation of ultraviolet light and visible light. 2After 10 minutes of ultraviolet irradiation at a wavelength of 520 nm and an intensity of 50 mW / cm 2 Under continuous irradiation of visible light, it can achieve continuous heat release through in-situ photothermal conversion function.

[0082] The sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment is subjected to a wavelength of 365nm and an intensity of 30mW / cm 2 The phase change energy storage density and light energy storage density that can be achieved by ultraviolet light irradiation are 288.5 J / g and 19.2 J / g, respectively. That is, the sodium alginate dressing with in-situ photothermal conversion function prepared in this embodiment can achieve a total energy storage density of 307.7 J / g by ultraviolet light irradiation.

[0083] Comparative Example 1

[0084] At room temperature, 0.8 mL of a 25 mmol / L sodium alginate aqueous solution (based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na) and a 5 mmol / L N,N-dimethyl-N-(4-(4-((4-n-octyloxyphenyl)diazenyl)phenoxy)n-butyl)-3,6,9,12-tetraoxatridecylammonium bromide water-ethanol solution (3 mL-1 mL) were mixed, and the mixture was stirred for 30 minutes. The stirred mixture was placed in a centrifuge and centrifuged at a relative centrifugal force of 6124 g for 5 minutes. The supernatant was discarded, and the resulting precipitate was washed three times with water for purification. Finally, the precipitate was freeze-dried for 12 hours to obtain a sodium alginate material containing an azobenzene surfactant.

[0085] After testing, it was found that the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 1 did not have the ability to continuously release heat after being irradiated with ultraviolet light for 10 minutes and then continuously irradiated with visible light.

[0086] Figure 8 The temperature change of the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 1 within 10 minutes of visible light irradiation proves that the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 1 cannot effectively release heat energy under visible light irradiation.

[0087] Comparative Example 2

[0088] At room temperature, 0.8 mL of a 25 mmol / L sodium alginate aqueous solution (based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na) and a 5 mmol / L water-ethanol solution (3 mL-1 mL) of N,N,N-trimethyl-4-(4-((4-n-octyloxyphenyl)diazenyl)phenoxy)n-butylammonium bromide) were mixed. The mixture was stirred for 30 minutes. The stirred mixture was placed in a centrifuge and centrifuged at a relative centrifugal force of 6124 g for 5 minutes. The supernatant was discarded, and the resulting precipitate was washed three times with water for purification. Finally, the precipitate was freeze-dried for 12 hours to obtain a sodium alginate material containing an azobenzene surfactant.

[0089] After testing, it was found that the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 2 did not have the ability to continuously release heat after being irradiated with ultraviolet light for 10 minutes and then continuously irradiated with visible light.

[0090] Figure 9 The temperature change of the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 2 within 10 minutes of visible light irradiation proves that the sodium alginate material containing azobenzene surfactant prepared in Comparative Example 2 cannot effectively release heat energy under visible light irradiation.

[0091] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A sodium alginate dressing with in-situ photothermal conversion function, characterized in that: The raw materials include sodium alginate and an azobenzene quaternary ammonium salt compound containing an N-benzyl structure.

2. The sodium alginate dressing with in-situ photothermal conversion function according to claim 1, characterized in that: The azobenzene quaternary ammonium salt compound containing an N-benzyl structure is selected from one of N,N-dimethyl-N-benzyl-4-(4-((4-methoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide, N,N-dimethyl-N-benzyl-4-(4-((4-n-butoxyphenyl)diazenyl)phenoxy)n-butylammonium bromide and N,N-dimethyl-N-benzyl-4-(4-((4-n-octyloxyphenyl)diazenyl)phenoxy)n-butylammonium bromide.

3. A method for preparing a sodium alginate dressing with in-situ photothermal conversion function according to any one of claims 1 to 2, characterized in that: The following steps are involved: An aqueous solution of sodium alginate is mixed with a water-ethanol solution of an azobenzene quaternary ammonium salt compound containing an N-benzyl structure, the mixed solution is stirred, the stirred mixed solution is centrifuged, and the obtained precipitated product is washed with water and freeze-dried to prepare the sodium alginate dressing with in-situ photothermal conversion function.

4. The method for preparing a sodium alginate dressing with in-situ photothermal conversion function according to claim 3, characterized in that: Based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na, the molar ratio of the sodium alginate in the aqueous solution of sodium alginate to the azobenzene quaternary ammonium salt compound containing an N-benzyl structure in the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is 1:

1.

5. The method for preparing a sodium alginate dressing with in-situ photothermal conversion function according to claim 4, characterized in that: The aqueous solution of sodium alginate has a concentration of 20 to 30 mmol / L, based on the repeating monosaccharide unit of sodium alginate being C6H7O6Na; And / or, the concentration of the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure is 5 to 10 mmol / L.

6. The method for preparing a sodium alginate dressing with in-situ photothermal conversion function according to claim 5, characterized in that: In the water-ethanol solution of the azobenzene quaternary ammonium salt compound containing an N-benzyl structure, the volume ratio of water to ethanol is 3:

1.

7. The method for preparing a sodium alginate dressing with in-situ photothermal conversion function according to claim 3, characterized in that: The stirring time is 30 minutes.

8. The method for preparing a sodium alginate dressing with in-situ photothermal conversion function according to claim 3, characterized in that: The freeze-drying treatment lasted for 12 hours.

9. Use of the sodium alginate dressing with in-situ photothermal conversion function according to any one of claims 1 to 2 in the preparation of a medicament for treating wound healing.

10. A medicine for treating wound healing, characterized in that: The active ingredient is the sodium alginate dressing with in-situ photothermal conversion function as described in any one of claims 1-2.

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