Porous composite phage hydrogel for promoting the regeneration repair of dermatitis

Abstract

The application discloses a porous composite bacteriophage hydrogel for promoting regeneration and repair of dermatitis, which is formed by mixing and cross-linking hydroxymethyl chitosan, sodium alginate and the like, and the porous composite formed by cross-linking hydroxymethyl chitosan and sodium alginate is used as a wrapping body to wrap bacteriophages, so that the hydrogel auxiliary material for promoting repair and inhibiting bacteria is prepared; the pore size of the bacteriophage hydrogel is 80-100 mu m, the bacteriophage hydrogel has the bacteriophage characteristics, and meanwhile, the bacteriophage hydrogel also has good moisturizing and anti-freezing properties, no biological toxicity and a long storage time. The porous composite bacteriophage hydrogel for promoting regeneration and repair of dermatitis improves the stability and slow-release property of the bacteriophage, effectively protects the activity of the bacteriophage through physical encapsulation of the hydrogel film, prolongs the survival time of the bacteriophage in the storage process, realizes controllable slow release of the bacteriophage, and ensures the sustained antibacterial effect of the bacteriophage on the surface of a wound.

Description

Technical Field

[0001] This invention relates to a porous composite phage hydrogel, specifically a porous composite phage hydrogel that promotes the regeneration and repair of dermatitis. Background Technology

[0002] Skin and ear infections are among the most common problems in companion animal clinical care. *Staphylococcus pseudointermedia*, a core opportunistic pathogen, has become a key conditional pathogen in various infections, such as otitis externa, pyoderma, wound infections, and postoperative wound infections. This bacterium not only exacerbates tissue damage by forming biofilms and producing various toxins and enzymes, but also continuously triggers and maintains a local inflammatory cascade, severely interfering with and delaying the normal healing process—including hindering granulation tissue formation, affecting epithelial regeneration, and orderly collagen deposition. This is a major reason for the persistent nature and poor prognosis of these infectious diseases. Currently, commonly used dressings or topical antibacterial agents in clinical practice often have single components and lack the dual ability to regulate pathogen clearance and excessive inflammatory responses, especially failing to intervene at the source of infection-related inflammatory storms. More seriously, the widespread and even inappropriate use of traditional antibiotics has led to the prevalence of multidrug-resistant strains against *Staphylococcus pseudointermedia*, resulting in limited treatment options and decreased efficacy in clinical practice. Therefore, there is an urgent need to develop a novel antibacterial strategy that can precisely kill bacteria, regulate the microenvironment, and is less likely to induce drug resistance.

[0003] Bacteriophages, as a class of viruses capable of specifically infecting and lysing host bacteria, exhibit unique advantages in this context: they possess high host specificity, enabling precise elimination of target pathogens without disrupting the symbiotic microbiota; they have self-replication potential, multiplying at the site of infection to enhance antibacterial efficacy; and being naturally derived, they are non-invasive to mammalian cells, resulting in high safety. Their antibacterial mechanism primarily involves recognizing and adsorbing onto bacterial surface receptors, injecting genetic material, utilizing the host bacterium's synthetic system to massively replicate progeny phages, and ultimately disrupting the cell wall through lysin-induced cell wall destruction, leading to bacterial death and thus interrupting the infection process. However, directly applying free bacteriophages to bacterial suppurative wounds still faces a series of key bottlenecks. First, temperature fluctuations, UV exposure, dehydration, pH shifts, and various proteases and immune factors in the wound environment can easily lead to denaturation of phage capsid proteins or degradation of nucleic acids, causing a rapid decline in their activity and making it difficult to maintain effective therapeutic concentrations during the healing period, which can last from several days to several weeks. Second, wound exudate, necrotic tissue, and early-formed biofilms severely hinder the penetration and diffusion of phages, preventing them from being evenly distributed and reaching all pathogen colonization areas, creating blind spots in sterilization. Finally, free phages are usually rapidly cleared by the body or inactivated locally, failing to achieve stable and continuous release. Their antibacterial effect often presents as a brief, "pulsating" burst, which is insufficient to meet the clinical need for long-term inhibition of pathogens. These factors collectively limit the reliability and widespread application of free phage therapy, highlighting the necessity of combining it with suitable carriers to achieve protected, controlled release, and targeted delivery.

[0004] To overcome the inherent drawbacks of free bacteriophages—such as easy inactivation, poor retention, and easy clearance in complex environments—immobilization and carrier encapsulation strategies have become a research focus, with the core objective of protecting phage activity and achieving controlled release. However, traditional microgel preparation processes (such as emulsion polymerization and microfluidic technology involving high temperatures or organic solvents) easily damage the phage structure. Therefore, developing mild loading methods (such as photocrosslinking and cold gelation) is a prerequisite for ensuring phage survival. Based on this, achieving efficient loading faces a dual challenge: increasing the carrier's loading capacity for active phages while simultaneously ensuring long-term stability, controlled release, and targeted proliferation at the infection site through material design, ultimately constructing a stable and intelligently releasing composite antibacterial system. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a porous composite phage hydrogel that promotes dermatitis regeneration and repair. This hydrogel not only maintains the biological activity of the phage and imparts high loading capacity, but also provides a large number of binding sites for the phage, increasing the contact opportunities between the phage and bacteria and improving antibacterial efficiency.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0007] A porous composite phage hydrogel that promotes dermatitis regeneration and repair is composed of a cross-linked mixture of hydroxymethyl chitosan, sodium alginate, etc. The porous composite formed by the cross-linking of hydroxymethyl chitosan and sodium alginate serves as an encapsulator, encapsulating the phage within it, thus preparing the hydrogel excipient that promotes repair and inhibits bacteria. The phage hydrogel has a pore size of 80-100 μm, possesses the phage phagocytic properties of phages, and also exhibits good moisturizing and antifreeze properties, non-biotoxicity, and a long storage time.

[0008] The preparation method of the porous composite phage hydrogel that promotes dermatitis regeneration and repair, as described above, includes the following steps:

[0009] (1) The host bacteria *Staphylococcus pseudointermedia*, which was isolated, identified and stored at -40℃, was revived by streaking on TSA solid medium. Then, single colonies on the plate were cultured in TSB liquid medium to obtain the host bacteria culture solution.

[0010] (2) The pseudo-Staphylococcus intermediate phage stored at 4℃ was mixed with the host bacteria culture obtained in step (1) in TSB liquid medium at a volume ratio of 1:1 to obtain the phage stock solution;

[0011] (3) Centrifuge the phage stock solution obtained in step (2), filter it with a filter and take the supernatant, which is the phage suspension. After determining the titer of the activated phage using the double-layer plate method, the phage suspension is stored at 4℃ for later use.

[0012] (4) After mixing sterilized glycerol with deionized water, heat it in a water bath, add carboxymethyl chitosan and mix quickly. Stir until the carboxymethyl chitosan and glycerol are evenly mixed. The resulting mixture is a pale yellow viscous colloid.

[0013] (5) Add the pale yellow viscous colloid obtained in step (4) to the phage suspension obtained in step (3), and then add sodium alginate while stirring. Use a glass stirring rod to evenly mix the sodium alginate in the system. After the sodium alginate is completely dissolved, a porous composite phage hydrogel that promotes dermatitis regeneration and repair is obtained. Store the hydrogel in a refrigerator at 4°C overnight. The prepared porous composite phage hydrogel has a shelf life of up to 28 days when stored at 4°C.

[0014] Preferably, in step (1), a single colony on the plate is incubated in TSB liquid medium at 37°C for 12 hours.

[0015] Preferably, in step (2), the mixture is cultured in 100 mL of TSB liquid medium for 10 hours; the mixing culture in step (2) is a mixing culture at 37°C for 10 hours.

[0016] Preferably, the pseudo-intermediate staphylococcus phage mentioned in step (2) is Staphylococcus pseudo-intermediate staphylococcus Phage vB_PTS_HC01, which was deposited at the China Center for Type Culture Collection on September 11, 2025, with accession number CCTCC NO: M 20252005.

[0017] Preferably, the centrifugation speed in step (3) is 8000 r / min, and the filtration using a filter is 0.22 μm filter membrane.

[0018] Preferably, in step (4), sterilized glycerol and deionized water are mixed at a volume ratio of 1:1; in step (4), 1g of carboxymethyl chitosan is added and mixed quickly.

[0019] Preferably, the temperature of the water bath in step (4) is 70°C; and the concentration of the carboxymethyl chitosan is 1% (w / v).

[0020] Preferably, the titer of the phage suspension in step (5) is 1×10⁻⁶. 6-7 pfu / mL; the concentration of sodium alginate is 2% (w / v); in step (5), 50 mL of the phage suspension obtained in step (3) is added to the pale yellow viscous colloid obtained in step (4), and then 2 g of sodium alginate is added while stirring.

[0021] The application of porous composite phage hydrogels that promote dermatitis regeneration and repair, as described above, in the preparation of products that promote the inhibition and repair of infectious dermatitis.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1) The porous composite phage hydrogel of this invention promotes dermatitis regeneration and repair, improves the stability and sustained release of phage, effectively protects the activity of phage through the physical encapsulation of the hydrogel membrane, prolongs its survival time during storage, and achieves controlled sustained release of phage, ensuring its continuous antibacterial effect on the wound surface.

[0024] 2) This invention promotes the regeneration and repair of dermatitis by enhancing the flexibility and mechanical properties of the porous composite phage hydrogel membrane, which also possesses excellent water absorption. The addition of glycerol significantly improves the elongation at break of the hydrogel membrane, making it more flexible and stretchable, thus meeting the actual needs of wounds. The three-dimensional hydrophilic network of the hydrogel can absorb and lock in a large amount of water, providing an ideal moist environment for wound healing or local treatment.

[0025] 3) The porous composite phage hydrogel of this invention promotes the regeneration and repair of dermatitis. It can effectively promote the regeneration and repair of infectious dermatitis, and is suitable for infection control and inflammation regulation of infectious dermatitis. It enhances anti-inflammatory and repair properties and provides a natural, precise and efficient repair solution for purulent bacterial wound infections.

[0026] Preservation Information

[0027] Staphylococcus pseudintermedius Phage vB_PTS_HC01 was deposited at the China Center for Type Culture Collection on September 11, 2025, with accession number CCTCC NO: M 20252005. Attached Figure Description

[0028] Figure 1 This invention is a porous composite phage hydrogel product that promotes dermatitis regeneration and repair.

[0029] Figure 2 This is a characterization of the porous composite phage hydrogel of the present invention that promotes dermatitis regeneration and repair.

[0030] Figure 3 This invention demonstrates the effect of using a porous composite phage hydrogel to promote dermatitis regeneration and repair.

[0031] Figure 4 The present invention relates to the in vitro biotoxicity of porous composite phage hydrogel that promotes dermatitis regeneration and repair.

[0032] Figure 5 This invention provides the stability, moisturizing and antifreeze properties of a porous composite phage hydrogel that promotes dermatitis regeneration and repair.

[0033] Figure 6 This invention demonstrates the therapeutic effect of the porous composite phage hydrogel that promotes dermatitis regeneration and repair. Detailed Implementation

[0034] The following detailed description, in conjunction with the accompanying drawings, outlines specific embodiments. However, it should be understood that the scope of protection of this invention is not limited to these specific embodiments. Unless otherwise specified, all raw materials and reagents used in the examples are commercially available.

[0035] The whole genome sequencing of the pseudo-intermediate staphylococcus phage Staphylococcus pseudintermedius Phage vB_PTS_HC01 of this invention has been completed by Sangon Biotech (Shanghai) Co., Ltd., and the sequence has been uploaded to the GenBank database with accession ID PX530545.

[0036] The host bacterium used in the experiment was the clinical strain of *Staphylococcus pseudointermediate* HCP21, which was isolated from an animal hospital in Hechi, Guangxi, and was co-deposited with the *Staphylococcus* bacteriophage of this invention at the China Center for Type Culture Collection.

[0037] SM buffer: Take 5.8 g sodium chloride, 2 g magnesium sulfate heptahydrate, 6.055 g Tris-HCl, add deionized water, and bring the volume to 1000 mL. After aliquoting, autoclave at 121℃ for 20 min and store at room temperature.

[0038] TSA solid culture medium: Weigh 40.0g of TSA solid culture medium powder. Dissolve it in 1000mL of distilled water by heating and stirring. Dispense into Erlenmeyer flasks and autoclave at 121℃ for 15 minutes.

[0039] TSB liquid culture medium: Weigh 30.0g of TSB liquid culture medium powder, heat and stir to dissolve in 1000mL of purified water, dispense into test tubes or other suitable containers, autoclave at 121℃ for 15 minutes, and set aside.

[0040] TSB semi-solid medium: Weigh 30.0g of TSB liquid medium powder and 3g of agar powder, heat and stir to dissolve in 1000mL of purified water, dispense into test tubes or other suitable containers, autoclave at 121℃ for 15 minutes, and set aside.

[0041] Example 1

[0042] Reviving host bacteria

[0043] The clinical strain of *Staphylococcus intermedia* HCP21, which was isolated, identified, and stored at -40℃, was revived by streaking on TSA solid medium (i.e., TSA plates). Then, single colonies from the plates were cultured in TSB liquid medium at 37℃ for 12 h to obtain the host bacterial culture solution for later use.

[0044] Example 2

[0045] Phage activation and titer assay

[0046] The pseudo-intermedius phage Staphylococcus pseudintermedius Phage vB_PTS_HC01 was taken from a 4°C refrigerator. 2 mL of the phage and 2 mL of the host bacterial culture prepared in Example 1 were placed in 100 mL of TSB liquid medium and shaken at 180 r / min and 37°C for 10 h in a constant temperature shaker. After centrifugation at 8000 r / min for 10 min, the co-culture solution was filtered through a 0.22 μm filter membrane. The supernatant was collected as the phage suspension and placed in a 4°C refrigerator for later use.

[0047] The titer of the prepared phage suspension was determined using the double-layer plate method: the phage suspension was serially diluted 10-fold. 100 μL of each appropriate dilution, 100 μL of the host culture medium prepared in Example 1, and 3.8 mL of TSB semi-solid medium (45-55℃) were mixed and poured into plates containing TSA solid medium. After solidification, the plates were incubated upside down at 37℃ for 4 h. The phage titer was calculated based on the number of plaques: Phage titer (PFU / mL) = number of plaques × dilution factor × 10, and the calculated titer was 1 × 10⁻⁶. 6-7 pfu / mL.

[0048] Example 3

[0049] Preparation of porous composite hydrogels loaded with bacteriophage vB_PTS_HC01

[0050] After autoclaving, glycerol was mixed with deionized water at a 1:1 ratio (25 mL:25 mL). The mixture was then heated in a 70°C water bath. 1 g of carboxymethyl chitosan (1% w / v) was added and rapidly stirred until the carboxymethyl chitosan and glycerol were evenly mixed, resulting in a pale yellow viscous colloid. 50 mL of the phage suspension prepared in Example 2 was added to the resulting pale yellow viscous colloid. Then, while stirring, 2 g of sodium alginate (2% w / v) was added, and the sodium alginate was evenly mixed into the system using a glass stirring rod. Once the sodium alginate was completely dissolved, a porous composite phage hydrogel for promoting dermatitis regeneration and repair was obtained. The porous composite phage hydrogel was stored at 4°C. See the finished product section below. Figure 1 The finished product is a mixture of light yellow, viscous colloids.

[0051] Preparation of blank hydrogel: The procedure is the same as above, except that no phage encapsulation is added to obtain a blank hydrogel for later use.

[0052] Example 4

[0053] Characterization of porous composite phage hydrogels that promote dermatitis regeneration and repair

[0054] To investigate the microstructural changes between the porous composite phage hydrogel for promoting dermatitis regeneration and repair prepared in Example 3 and the original hydrogel, the three-dimensional structure of the hydrogel was observed using scanning electron microscopy. The porous composite phage hydrogel for promoting dermatitis regeneration and repair prepared in Example 3 was first rapidly frozen in liquid nitrogen, and then freeze-dried using a vacuum freeze dryer. The two completely dried hydrogel samples were then fixed onto the SEM sample stage using conductive adhesive, and a thin gold film was uniformly deposited on the hydrogel surface. The microstructure of hydrogels with different proportions was observed using scanning electron microscopy, and the porosity of the prepared hydrogels was quantitatively analyzed using ImageJ software. The results are shown below. Figure 2The hydrogel's microstructure is a three-dimensional porous hydrophilic network that can absorb and lock in a large amount of water, providing multiple binding sites for bacteriophages.

[0055] Example 5

[0056] The effect of porous composite phage hydrogel on promoting dermatitis regeneration and repair

[0057] The antibacterial plaque morphology of the porous composite phage hydrogel for promoting dermatitis regeneration and repair prepared in Example 3 was observed using the spotting method. TSB semi-solid culture medium was heated until melted into a liquid, and after the temperature dropped to approximately 50°C, 20 mL was weighed and mixed with 300 μL of *S. pseudotermedius* bacterial suspension. The mixture was then poured into TSA plates and allowed to solidify. The porous composite phage hydrogel prepared in Example 3 and a blank hydrogel were then spotted onto double-layer plates and incubated at 37°C for 12 h. The presence of clear empty plaques (phage plaques) in the spotted areas was observed. The appearance of clear empty plaques indicated successful phage loading and that the phage hydrogel exhibited an antibacterial effect. A blank hydrogel was used as a negative control. Results are shown below. Figure 3 The results of spotting the negative control (left) and the phage hydrogel (right) show that the phage hydrogel group has clear empty spots, indicating that the phage was successfully loaded and that the phage hydrogel has an antibacterial effect.

[0058] Example 6

[0059] Porous composite phage hydrogel biotoxicity that promotes dermatitis regeneration and repair

[0060] Red blood cells were separated from fresh New Zealand white rabbit blood by centrifugation (4°C, 1500 rpm, 10 min), and the red blood cell particles were diluted with PBS to a final concentration of 2.5% (v / v). The prepared red blood cells were then immersed in the gel and incubated at 37°C for 2 h. 1% Triton X100 and PBS were used as positive and negative controls for the hemolysis test, respectively. Results are as follows: Figure 4 As shown, the red blood cells in the positive control Triton group and the ACK Lysis Buffer group were ruptured, and no normal cell morphology was observed under a microscope in the smears. The Hydrogel group (blank hydrogel), the Phage Hydrogel group (the porous composite phage hydrogel prepared in Example 3), and the Netagive Control group (negative control) all showed clear supernatant and intact cell morphology, indicating that the hydrogel prepared in this invention has no biological toxicity.

[0061] Example 7

[0062] Stability, moisturizing and antifreeze properties of porous composite phage hydrogels that promote dermatitis regeneration and repair.

[0063] To test the stability and freeze resistance of the phage hydrogel, the porous composite phage hydrogel for promoting dermatitis regeneration and repair prepared in Example 3 (with known added phage titer) was stored at 4°C and -20°C, respectively. 1 mL of the porous composite phage hydrogel stored at 4°C in Example 3 was taken out at 0 days, 7 days, 14 days, and 28 days, respectively. After rewarming, 9 mL of PBS buffer (pH=7.4) was added, and the mixture was incubated in a shaker at 37°C for 12 hours. The mixture was then extracted and the effect of the phage hydrogel was determined using the bilayer plate method.

[0064] The porous composite phage hydrogel stored at -20℃ was thawed and rewarmed after 14 days. The rewarmed hydrogel was then compared with the fresh porous composite phage hydrogel prepared in Example 3 in terms of physical morphology. If the fluidity and adhesion of the frozen hydrogel remained consistent with the original phage hydrogel after thawing, then the hydrogel exhibited good freeze resistance. Results are shown below. Figure 5 The hydrogels frozen for 7 days and 14 days maintained relatively consistent fluidity, adhesion and phage titer with the original phage hydrogel after thawing, proving that the phage hydrogel prepared by this invention has good stability and moisturizing and antifreeze properties.

[0065] Example 8

[0066] The therapeutic effect of porous composite phage hydrogel that promotes dermatitis regeneration and repair.

[0067] Twenty-five healthy male New Zealand white rabbits were randomly divided into five groups: a phage treatment group, a phage hydrogel treatment group, a hydrogel treatment group, a positive control group, and a negative control group (the positive control was used to test whether the bacterial dermatitis model was established, and the negative control consisted of only wounds without bacterial infection). Five rabbits were assigned to each group, and each group was randomly numbered from 1 to 5. After successful model establishment (day 4 of the experiment), the phage treatment group, the phage hydrogel treatment group, and the hydrogel treatment group were each given 3 mL of a solution with a titer of 10... 6 Phage suspension obtained in Example 2 with a PFU / mL or higher, porous composite phage hydrogel for promoting dermatitis regeneration and repair obtained in Example 3, and blank hydrogel were incubated on dermatitis wounds (3 mL was for single use). Results are shown in […]. Figure 6 The phage hydrogel group showed better therapeutic effects than the hydrogel group, phage group, and positive component group, and its recovery level was comparable to that of the negative group.

[0068] This invention requires only a single porous hydrogel template to simultaneously load bacteriophages and mold the material. This template functions as both a carrier and a reaction matrix, efficiently accommodating and immobilizing bacteriophages. Simultaneously, through a gentle physical cross-linking or in-situ gelation process, a structurally stable composite gel is formed in one step. This avoids complex multi-step reactions, the use of organic solvents, or stringent purification steps, significantly simplifying the process and reducing production barriers and time costs.

[0069] The phage-functionalized hydrogel prepared in this invention exhibits superior loading and delivery performance. Its core advantage lies in achieving efficient phage loading and activity protection through simple material design. Specifically, the hydrogel possesses a high porosity and interconnected hierarchical pore structure, which not only greatly increases the specific surface area, providing abundant physical adsorption and binding sites for phages, thus significantly enhancing physical loading capacity; more importantly, this porous matrix simulates a microenvironment conducive to phage residence, effectively increasing the probability of contact between the encapsulated phages and invading pathogens, and supporting limited local proliferation of phages, thereby achieving in-situ amplification and long-term maintenance of antibacterial activity. On the other hand, the hydrophilic three-dimensional network structure of the hydrogel, through its strong water retention and slow-release capabilities, can construct a stable environment for phages, effectively buffering external temperature fluctuations, preventing physical drying, and isolating the direct effects of some harmful enzymes or extreme pH, significantly improving the operational stability and storage life of phages in complex wound environments. In summary, this system not only solves the bottleneck of free bacteriophages being easily inactivated and difficult to persist, but also actively improves their bioavailability through the structural characteristics of the material, providing an innovative platform for developing next-generation local therapies against drug-resistant bacterial infections that combines high-efficiency loading, intelligent release, and strong protection.

[0070] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A porous composite phage hydrogel that promotes dermatitis regeneration and repair, characterized in that: The hydrogel excipient is a cross-linked mixture of hydroxymethyl chitosan and sodium alginate. The phage is encapsulated within a porous composite formed by the cross-linking of hydroxymethyl chitosan and sodium alginate, thus producing the hydrogel excipient that promotes repair and inhibits bacteria. The phage hydrogel has a pore size of 80-100 μm, possesses the phage characteristics of bacteriophage, and also exhibits good moisturizing and antifreeze properties, non-biotoxicity, and a long storage time.

2. The preparation method of the porous composite phage hydrogel for promoting dermatitis regeneration and repair as described in claim 1, characterized in that, Includes the following steps: (1) The host bacterium *Staphylococcus pseudointermedia* was revived by streaking on TSA solid medium, and then single colonies on the plate were cultured in TSB liquid medium to obtain the host bacterium culture medium. (2) Mix the pseudo-Staphylococcus intermediate phage with the host bacteria culture obtained in step (1) in TSB liquid medium at a volume ratio of 1:1 to obtain the phage stock solution; (3) Centrifuge the phage stock solution obtained in step (2), filter and take the supernatant, which is the phage suspension; (4) After mixing sterilized glycerol with water, heat it, add carboxymethyl chitosan and mix, stirring until the carboxymethyl chitosan and glycerol are mixed, and the resulting mixture is a viscous colloid; (5) Add the phage suspension obtained in step (3) to the viscous colloid obtained in step (4), and then add sodium alginate while stirring. Once the sodium alginate dissolves, a porous composite phage hydrogel that promotes dermatitis regeneration and repair is obtained.

3. The method for preparing the porous composite phage hydrogel for promoting dermatitis regeneration and repair according to claim 2, characterized in that: In step (1), a single colony on the plate is incubated in TSB liquid medium at 37°C for 12 hours.

4. The method for preparing the porous composite phage hydrogel for promoting dermatitis regeneration and repair according to claim 2, characterized in that: In step (2), the mixture is cultured in 100 mL of TSB liquid medium for 10 hours; the mixing culture in step (2) is a 37℃ mixing culture for 10 hours.

5. The method for preparing the porous composite phage hydrogel for promoting dermatitis regeneration and repair according to claim 2, characterized in that: The pseudo-intermediate phage mentioned in step (2) is Staphylococcus pseudintermedius Phage vB_PTS_HC01, which was deposited at the China Center for Type Culture Collection on September 11, 2025, with accession number CCTCC NO: M 20252005.

6. The method for preparing the porous composite phage hydrogel for promoting dermatitis regeneration and repair according to claim 2, characterized in that: The centrifugation speed in step (3) is 8000 r / min, and the filtration is filtration through a 0.22 μm filter membrane.

7. The method for preparing the porous composite phage hydrogel for promoting dermatitis regeneration and repair according to claim 2, characterized in that: In step (4), glycerol and water are mixed at a volume ratio of 1:1; in step (4), 1g of carboxymethyl chitosan is added and mixed quickly.

8. The method for preparing the porous composite phage hydrogel for promoting dermatitis regeneration and repair according to claim 2, characterized in that: The temperature of the water bath in step (4) is 70°C; the concentration of the carboxymethyl chitosan is 1% (w / v).

9. The method for preparing the porous composite phage hydrogel for promoting dermatitis regeneration and repair according to claim 2, characterized in that: The titer of the phage suspension mentioned in step (5) is 1×10⁻⁶. 6-7 pfu / mL; the concentration of sodium alginate is 2% (w / v); in step (5), 50 mL of the phage suspension obtained in step (3) is added to the viscous colloid obtained in step (4), and then 2 g of sodium alginate is added while stirring.

10. The use of the porous composite phage hydrogel for promoting dermatitis regeneration and repair as described in claim 1, or the porous composite phage hydrogel for promoting dermatitis regeneration and repair prepared by any of the methods of claims 2-9, in the preparation of products that promote the antibacterial and repair effects of infectious dermatitis.

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