Targeted antibacterial drug delivery system coated with pretreated macrophage membrane as well as preparation method and application of targeted antibacterial drug delivery system

Abstract

The invention discloses a pretreated macrophage membrane coated targeted antibacterial drug delivery system as well as a preparation method and application thereof. According to the targeted antibacterial drug delivery system, a photosensitizer serving as a carrier material and antibiotics form a drug-loaded nanosheet through an electrostatic binding effect, and a Toll-like receptor high-expression macrophage membrane serving as a surface modification material is loaded outside the drug-loaded nanosheet; through combined application of photodynamic therapy and antibiotics, efficient synergistic therapy on bacterial infection is realized, systemic toxic and side effects are effectively reduced, and the photodynamic effect of a nano material can peroxidize bacterial cell membrane lipid, improve the permeability of bacterial cell membranes and significantly enhance the sensitivity of bacteria to antibiotics; when the compound is applied to antibacterial drugs, the combined treatment mechanism not only strengthens the treatment effect of antibiotics, but also reduces the dosage of the antibiotics, so that more accurate and more efficient treatment is realized.

Description

Technical Field

[0001] The present invention relates to a targeted antibacterial drug delivery system, in particular to a targeted antibacterial drug delivery system coated with pretreated macrophage cell membranes, and also relates to the preparation method and application of the above targeted antibacterial drug delivery system. Background Art

[0002] Bacterial infections, as a widespread health threat, can cause various serious diseases such as urinary tract infections, osteomyelitis, endocarditis, sepsis, and wound infections, posing a severe challenge to the global public health system and economic development. Currently, antibiotics, as the main means of treating bacterial infections, mainly act by interfering with the growth and metabolic processes necessary for bacterial growth and survival. Antibiotics inhibit the synthesis of cell walls and cell membranes, block the synthesis pathways of DNA, RNA, and proteins, and disrupt the metabolic pathways of bacteria, thereby effectively inhibiting the growth and reproduction of bacteria. However, the over-reliance on antibiotics has led to the rapid emergence of multi-drug resistant bacteria, significantly reducing the therapeutic effect of antibiotics. In addition, antibiotics also face many challenges in clinical applications. Problems such as low bioavailability, fast in vivo clearance rate, poor tissue permeability, easy inactivation, and difficulty in crossing cell and biomembrane barriers limit the efficacy of antibiotics. Therefore, deeply exploring the complex mechanisms of bacterial infections, actively developing new antibacterial drugs and antibacterial materials, and constructing innovative antibacterial strategies to address the increasingly severe drug resistance problem and improve the treatment level of bacterial infections are the core tasks in the current field of bacterial infection research.

[0003] Photodynamic therapy (PDT) is a highly promising non-invasive antibacterial treatment method that can achieve precise control in terms of time and space at the cellular level. In PDT, photosensitive molecules absorb light energy and generate cytotoxic reactive oxygen species (ROS), which can effectively kill bacteria. However, problems such as the short half-life and diffusion distance of ROS make it difficult for PDT to achieve an ideal therapeutic effect.

[0004] Facing the dilemma of bacterial infection treatment, nanomaterials have shown great potential in the treatment of bacterial infections and the overcoming of drug resistance due to their unique physical and chemical properties. Nanomaterials such as gold nanoparticles, graphene and its derivatives, and various metal oxide nanomaterials can exhibit excellent antibacterial activity through their surface effects, quantum size effects, and high specific surface area, providing new ideas for the treatment of bacterial infections. These nanomaterials can penetrate bacterial cell membranes more effectively and interfere with their metabolic processes, thereby achieving the effect of rapid sterilization. The potential cytotoxicity, biocompatibility problems, and lack of precise targeting ability of existing nanocarriers limit their wide clinical application, and there is an urgent need to develop new antibacterial drugs with stronger targeting and better efficacy. Summary of the Invention

[0005] Objective of the Invention: The objective of the present invention is to provide a targeted antibacterial drug delivery system coated with pre-treated macrophage cell membrane by combining PDT and chemotherapy, and also to provide the preparation method and application of the above-mentioned targeted antibacterial drug delivery system.

[0006] Technical Solution: The present invention discloses a targeted antibacterial drug delivery system coated with pre-treated macrophage cell membrane. The targeted antibacterial drug delivery system consists of a photosensitizer and an antibiotic as carrier materials, which form a drug-loaded nanosheet through electrostatic binding, and the surface of the drug-loaded nanosheet is loaded with macrophage cell membrane with high expression of Toll-like receptor as a modification material.

[0007] Among them, the photosensitizer is violet phosphorus nanosheet (VPN), and the antibiotic is one of vancomycin (Van), norfloxacin, levofloxacin, moxifloxacin, imipenem, aztreonam or gentamicin.

[0008] Among them, the macrophage cell membrane with high expression of Toll-like receptor is obtained by co-incubating macrophages with methicillin-resistant Staphylococcus aureus, followed by ultrasonic disruption and separation of the cell membrane.

[0009] The preparation method of the above-mentioned targeted antibacterial drug delivery system includes the following steps:

[0010] (1) Preparation of drug-loaded nanosheet (Van / VPN): Grind violet phosphorus crystal (VP) and disperse it in absolute ethanol. After ultrasonic treatment, centrifugation and precipitation, VPN is obtained. Then, dropwise add the antibiotic solution, stir, and perform ultrafiltration centrifugation to obtain a photosensitizer drug-loaded nanosheet loaded with the antibiotic.

[0011] (2) Extraction of macrophage cell membrane with high expression of Toll-like receptor (Mm): After co-incubating macrophages with methicillin-resistant Staphylococcus aureus, wash with PBS buffer and perform ultrasonic disruption. Add sucrose solution, centrifuge to take the supernatant, and centrifuge again. After washing with TM buffer containing sucrose and centrifuging, collect the precipitate to obtain the macrophage cell membrane with high expression of Toll-like receptor.

[0012] (3) Preparation of targeted antibacterial drug delivery system (Van / VPN@M): After ultrasonic dispersion of the drug-loaded core and the macrophage cell membrane, co-extrude them through a liposome extruder, and centrifuge to remove the residual cell membrane to obtain a targeted antibacterial drug delivery system coated with pre-treated macrophage cell membrane.

[0013] Among them, in step (1), the mass ratio of the carrier material to the antibiotic is 1:1 - 3, the ultrasonic power is 500 - 1000W, the ultrasonic time is 12 - 24h; the centrifugation speed is 4000 - 12000rpm, and the centrifugation time is 10 - 30min.

[0014] Among them, in step (2), the number ratio of macrophages to methicillin-resistant Staphylococcus aureus is 1:3 - 5, the co-incubation time of bacteria and macrophages is 3 - 6 h, the power of macrophage ultrasonic disruption is 50 - 150 W, and the ultrasonic time is 10 - 30 min.

[0015] Among them, in step (3), the mass ratio of the drug-loaded core to the macrophage membrane is 1:1 - 3, and the number of co-extrusion times is 10 - 30 times.

[0016] The above-mentioned targeted antibacterial drug delivery system coated with pretreated macrophage membranes can also be used in the preparation of antibacterial drugs.

[0017] Among them, the application is that the targeted antibacterial drug delivery system combines PDT and chemotherapy. Specifically, the drug is accurately delivered through the targeting effect of the macrophage membrane, and cytotoxic reactive oxygen species are generated under the irradiation of 660 nm laser, synergistically enhancing the antibacterial effect with the chemotherapeutic drug.

[0018] Principle of the invention: The present invention uses macrophage membranes with high expression of Toll-like receptors to modify the VPN nanoplateform (Van / VPN) loaded with the antibiotic Van, enabling the nano-drug delivery system to accurately target the microenvironment of bacterial infection and specifically bind to the bacterial surface, significantly improving the bacterial targeting of antibacterial drugs. As a multifunctional nano-platform, this drug delivery system is injected into the body via intravenous injection, and the drug is accurately delivered through the targeting effect of the macrophage membrane. VPN generates cytotoxic ROS under the irradiation of 660 nm laser, thereby effectively killing bacteria. This synergistic effect enhances the antibacterial effect of Van and improves the treatment efficiency, providing new ideas and strategies for antibacterial treatment.

[0019] In vitro bacterial experiments first verified the effect of the macrophage membrane biomimetic nano-drug delivery system on colony-forming units, and secondly, the viability of bacteria was investigated by bacterial live / dead staining. The results showed that this biomimetic nano-drug delivery system has excellent antibacterial effects. In vivo animal experiments established wound healing models and subcutaneous abscess models of ICR female mice. To evaluate the treatment effect of the nano-drug delivery system, the recovery of skin damage in mice was closely monitored. H&E staining of organ tissue sections was used to investigate the in vivo biosafety of the nano-drug delivery system. The results showed that this nano-drug delivery system has good bacterial killing effects and biosafety.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following remarkable advantages: (1) The targeted antibacterial drug delivery system coated with pre-treated macrophage cell membranes of the present invention modifies the carrier with macrophage cell membranes with high expression of Toll-like receptors, improving the targeting of the delivery system to bacteria; adopting the non-invasive antibacterial treatment method PDT to achieve precise control in terms of time and space at the cellular level; realizing multi-modal synergistic treatment of phototherapy and chemotherapy to enhance the antibacterial effect; (2) The preparation method steps of the targeted antibacterial drug delivery system are clear, the operation is simple, and the technologies used in the preparation process (such as ultrasonic, centrifugation, extrusion, etc.) are all mature industrial production technologies, so the delivery system is easy to scale up production. In addition, the raw materials used (such as photosensitizer carrier materials, antibiotics, macrophages, etc.) are relatively easy to obtain, further reducing the difficulty and cost of large-scale production.. Description of the Drawings

[0021] Figure 1 It is the particle size and Zeta potential characterization result diagram of the nanoparticles in Example 1. Among them, Figure A is the particle size diagram of Van / VPN@M, and Figure B is the Zeta potential diagram of Van / VPN@M;

[0022] Figure 2 It is the 7-day stability of Van / VPN@M in DMEM medium containing serum in Example 1;

[0023] Figure 3 It is the release curve of Van in Example 1 (PH = 5.5, PH = 7.4);

[0024] Figure 4 It is the bacterial colony growth pictures after co-culturing different formulation groups with methicillin-resistant Staphylococcus aureus in Example 3;

[0025] Figure 5 It is the live / dead staining pictures of bacteria after co-culturing different formulation groups with methicillin-resistant Staphylococcus aureus in Example 4;

[0026] Figure 6 It is the skin monitoring situation and wound healing rate curve of each group in Example 5. Among them, Figure A is the skin wound image from day 0 to day 11, and Figure B is the wound healing rate curve graph of each group;

[0027] Figure 7 It is the abscess area curve graph of each group in Example 5;

[0028] Figure 8 It is the in vivo safety evaluation in Example 6, and it is the H&E staining result diagram of the heart, liver, spleen, lungs, and kidneys of mice. Detailed Embodiments

[0029] The technical solution of the present invention will be further described below in conjunction with embodiments. The test materials used in the embodiments can be obtained through conventional channels.

[0030] Example 1

[0031] For the targeted antibacterial drug delivery system coated with pretreated macrophage membrane of the present invention, the photosensitizer VPN is used as the carrier material, combined with the chemotherapeutic drug Van, and the surface is modified by pretreated macrophage membrane; specifically, it includes the following steps:

[0032] (1) Preparation of Van / VPN:

[0033] VP was ground with an agate mortar and dispersed in absolute ethanol. Ultrasonic treatment was carried out under ice bath conditions, and the pulse mode was on for 2 s and off for 2 s. The resulting dispersion was centrifuged to remove large particles of VP; the supernatant was centrifuged again to collect the precipitate VPN. The centrifuged product was washed three times with ultrapure water and then subjected to vacuum freeze-drying to finally obtain VPN powder. A certain concentration of VPN dispersion was added dropwise to the Van solution, stirred overnight, and then centrifuged using a 10 kDa ultrafiltration centrifugal tube to remove unbound Van, and Van / VPN was prepared.

[0034] (2) Preparation of Mm:

[0035] Macrophages were collected and resuspended in DMEM medium to a density of 2.5×10 7 cells / mL. The cells were co-incubated with 1×10 8 CFU methicillin-resistant Staphylococcus aureus, washed 3 times with PBS buffer, and ultrasonically disrupted. 0.25 mol / L sucrose solution was added to the obtained cell homogenate and centrifuged at 2000×g for 10 min. The supernatant was taken and centrifuged at 3000×g for 30 min to extract the macrophage membrane. Finally, the extracted macrophage membrane was centrifuged again at 3000×g for 30 min, washed with TM buffer containing 0.25 mol / L sucrose, and Mm was obtained.

[0036] (3) Preparation of Van / VPN@M

[0037] Mm was dissolved in PBS solution with pH = 7.4, mixed evenly with the Van / VPN solution in a certain proportion, and extruded 10 - 30 times using a liposome extruder to prepare the targeted antibacterial drug delivery system Van / VPN@M coated with pretreated macrophage membrane.

[0038] Example 2

[0039] Characterization of Van / VPN@M

[0040] (1) Hydrodynamic diameter and Zata potential

[0041] The nano - composite was dispersed in ultrapure water, and the hydrodynamic diameter and Zeta potential of Van / VPN@M were measured using a laser particle size analyzer. The results are shown in the appendix Figure 1 As shown, the average diameter of the nanoparticles was 165.26 ± 5.04 nm; the Zeta potential was - 24.42 ± 0.80 mV.

[0042] (2) Investigation of in vitro stability

[0043] Van / VPN@M was dispersed in DMEM medium containing 10% FBS, and its hydrodynamic diameter and polydispersity index (PDI) were measured on days 1 - 7 respectively to evaluate its stability. The results are shown in the appendix Figure 2 As shown. Dynamic light scattering showed that with the passage of time, the hydrodynamic diameter and PDI of the nano - composite did not change significantly, demonstrating its ability to maintain structural stability in serum - containing medium.

[0044] (3) Investigation of in vitro drug release

[0045] A dialysis bag (3500 Da) containing 1 mL of Van / VPN@M was placed in a 50 mL centrifuge tube, and pH buffer was poured in to immerse it. The centrifuge tube was placed in a water bath shaker at 37 °C. Samples of 1 mL were taken at 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 24 h, 36 h, and 48 h respectively, and 1 mL of pH buffer was added to each sample. The absorbance of the sample solution was measured using an enzyme - linked immunosorbent assay (ELISA) reader, and the release rate (TR%) and cumulative release rate (AR%) of Van at time T were calculated, and a curve of the cumulative release rate (AR%) of Van relative to time (t) was plotted.

[0046] The formulas for the release rate (TR%) and cumulative release rate (AR%) at time T are as follows:

[0047] TR1 = 10C1 / M × 100%

[0048] TR2 = (10C2 - 8C1) / M × 100%

[0049] TRt = (10Ct - 8Ct - 1) / M × 100%

[0050] ARt = ΣTRt

[0051] Where Ct represents the concentration of Van in the release medium at time t (μg / mL), M represents the mass of Van in 1 mL of the nanoparticle solution used for the in vitro release experiment (mg), TRt represents the release rate at time t, and ARt represents the cumulative release rate at time t. The results are shown in the appendix Figure 3As shown, when the pH is 7.4, the cumulative release amount of Van in Van / VPN@M is about 30%, which proves that the release of Van / VPN@M is relatively stable and slow in the normal physiological environment of the human body, and has good biosafety; under the weakly acidic condition similar to the bacterial microenvironment, the release rate of Van can reach more than 80%, showing excellent drug release bacterial selectivity.

[0052] Example 3

[0053] Investigation of the colony-forming units (CFU) of Van / VPN@M

[0054] Methicillin-resistant Staphylococcus aureus was incubated with shaking in LB medium under the constant temperature condition of 37°C. When subculturing, 50 μL of the original bacterial solution was inoculated into 5 mL of LB medium, and after 12 - 16 h of culture, the bacteria entered the logarithmic growth phase. Subsequently, the methicillin-resistant Staphylococcus aureus bacterial solution in the logarithmic phase was diluted to 1×106 CFU / ml, and the total volume was 1 mL. To explore the effects of different drugs on methicillin-resistant Staphylococcus aureus, the bacteria were divided into five groups: Group 1 was the blank control group, adding sterile PBS; Group 2 added Van; Group 3 added VPN; Group 4 added Van / VPN; Group 5 added Van / VPN coated with macrophage cell membrane (Van / VPN@M). After the bacteria in each group were co-cultured for 2 hours, they were further divided into a light irradiation group and a non-light irradiation group. The light irradiation group was irradiated with a laser with a wavelength of 660 nm and a power of 0.3 W / cm 2 for 10 min. Through the plate counting method, the antibacterial effects of the materials in each group were visually compared, that is, the number of surviving bacterial colonies was observed. The results are as shown in the appendix Figure 4 As shown, after laser irradiation, the number of bacteria in the VPN, Van / VPN, and Van / VPN@M treatment groups decreased significantly, and the antibacterial effect of unmodified Van / VPN was significantly weaker than that of the Van / VPN@M group coated with macrophage cell membrane, indicating that the modification of the macrophage cell membrane effectively improved the targeting ability of the delivery system to bacteria and achieved precise killing of bacteria.

[0055] Example 4

[0056] Live-dead staining experiment of bacteria

[0057] Take the methicillin-resistant Staphylococcus aureus bacterial solution in the logarithmic phase and dilute it to 1×10 6CFU / mL. According to the different drugs added, the bacteria were divided into five groups: Group 1 was the blank control group, to which sterile PBS was added; Group 2 was added with Van; Group 3 was added with VPN; Group 4 was added with Van / VPN; Group 5 was added with Van / VPN coated with macrophage cell membrane (Van / VPN@M). After co-culturing the bacteria with the drugs in each group for 2 h, the bacteria were gently washed 3 times with PBS buffer. Then, the bacteria were further divided into a light-irradiation group and a non-light-irradiation group. The light-irradiation group was irradiated with near-infrared laser with a wavelength of 660 nm and a power of 0.3 W / cm 2 for 10 min. Finally, after gently washing the bacteria in each group 3 times with PBS, a live / dead staining agent was added and incubated in the dark for 15 min. After washing away the excess dye, a confocal microscope was used to observe the survival of the bacteria and take pictures for recording. The results are as shown in Appendix Figure 5 . After staining with SYTO 9 and PI, under the confocal laser scanning microscope, live bacteria showed green fluorescence, while dead bacteria showed red fluorescence. The bacteria in the blank control group mainly showed green fluorescence with almost no red fluorescence, indicating that the bacteria in this group were basically live bacteria; while after the Van / VPN@M treatment group was irradiated with 660 nm laser, the stained bacteria showed red fluorescence after observation, indicating that the bacteria in this group were basically dead bacteria. This result shows that Van / VPN coated with macrophage cell membrane may specifically recognize bacteria through Toll-like receptors on the surface of macrophage cell membrane, thereby enhancing the photodynamic effect of VPN, promoting the combined killing effect of PDT and antibiotics on bacteria, and achieving a significant antibacterial effect.

[0058] Example 5

[0059] In vivo efficacy of Van / VPN@M

[0060] (1) Efficacy of Van / VPN@M in a mouse wound healing model

[0061] Female ICR mice aged 6 - 8 weeks and weighing 18 - 22 g were randomly divided into five groups: PBS, Van, VPN(+), Van / VPN(+), and Van / VPN@M(+). After anesthesia, the back skin of the mice was depilated and disinfected. A circular wound with a diameter of 1 cm was cut on the skin of each mouse, and methicillin-resistant Staphylococcus aureus (20 μL, 1×10 8 CFU / mL) was inoculated. According to the groups, PBS, Van, VPN, Van / VPN, and Van / VPN@M solutions were intravenously injected on the 1st, 3rd, 5th, 7th, and 9th days respectively. 12 h after intravenous injection, the mice in the VPN(+), Van / VPN(+), and Van / VPN@M(+) groups were irradiated with laser, with an irradiation wavelength of 660 nm and a power density of 0.3 W / cm 2, The irradiation time was 10 min. During the treatment, the skin wounds of the mice were photographed every day, and the wound healing rates of each group of mice were calculated. The results are shown in the appendix Figure 6 As shown, Figure A shows the monitored wound repair situation and is compared with the control group for intuitive evaluation of the efficacy differences among groups; Figure B is the wound healing rate curve of each group. The healing speed of the infected sites treated with PBS, Van, and VPN(+) groups was relatively slow, and the wound surface was the widest, indicating that the self-healing ability of the bacterially infected wound surface was poor; under the combined action of PDT and antibiotics in the experimental group, the tissue healed well, especially in the Van / VPN@M(+) group, where the wound surface was almost completely healed. This result strongly proves that the nanodrug delivery system not only has excellent antibacterial ability but also can effectively promote the healing of bacterially infected wounds.

[0062] (2) Efficacy of Van / VPN@M in a mouse subcutaneous abscess model

[0063] Female ICR mice aged 6 - 8 weeks and weighing 18 - 22 g were randomly divided into five groups: PBS, Van, VPN(+), Van / VPN(+), and Van / VPN@M(+). The back skin was depilated and disinfected, and methicillin-resistant Staphylococcus aureus bacterial solution (100 μL, 1×108 CFU / mL) was injected into the back of each mouse. According to the group, PBS, Van, VPN, Van / VPN, and Van / VPN@M solutions were intravenously injected every two days. 12 h after the injection, the mice in the VPN(+), Van / VPN(+), and Van / VPN@M(+) groups were irradiated with a laser (660 nm, 0.3 W / cm 2 , 10 min). During the treatment, the abscess area was recorded every day. The results are shown in the appendix Figure 7 As shown, compared with the PBS group, the abscess growth rate in the Van group and the VPN(+) group decreased slightly, but their growth could not be inhibited. However, the abscess areas in the Van / VPN(+) group and the Van / VPN@M(+) group were significantly reduced. On the 11th day after treatment, the abscess in the Van / VPN@M(+) group was almost cleared, indicating that it could effectively treat the abscess caused by bacteria and promote skin repair.

[0064] Example 6

[0065] In vivo safety evaluation of Van / VPN@M

[0066] To evaluate the in vivo biosafety of Van / VPN@M, the drug solution was intravenously injected into ICR mice, and an equal volume of PBS solution was used as the blank control group. 11 days after injecting the drug, the mice were sacrificed, and the heart, liver, spleen, lungs, and kidneys were taken and fixed with 4% paraformaldehyde. Paraffin embedding - sectioning - dewaxing to water - hematoxylin staining - eosin staining - dehydration and mounting - microscopic examination. The results are shown in the appendixFigure 8 As shown, compared with the control group, no histological abnormalities or inflammatory lesions were observed in each organ. The results indicate that intravenous injection of Van / VPN@M has good in vivo safety at the given drug dose. (Scale bar: 100μm)

[0067] Therefore, the targeted antibacterial drug delivery system coated with pre-treated macrophage membranes of the present invention uses the photosensitizer VPN as a carrier material, combines the chemotherapeutic drug Van, and is surface-modified with pre-treated macrophage membranes to enhance its biosafety and bacterial targeting ability, achieving the combined application of photodynamic therapy (PDT) and chemotherapy, thereby obtaining a synergistic therapeutic effect on bacterial infection. The combined application of PDT and antibiotics has achieved highly efficient synergistic treatment of bacterial infection while effectively reducing systemic side effects. The photodynamic effect of the nanomaterial can cause lipid peroxidation of the bacterial cell membrane, increase the permeability of the bacterial cell membrane, and significantly enhance the sensitivity of bacteria to antibiotics. This combined treatment mechanism not only strengthens the therapeutic effect of antibiotics but also reduces the dosage of antibiotics, achieving more precise and efficient treatment.

Claims

1. A targeted antimicrobial drug delivery system coated with pretreated macrophage membranes, characterized in that: The targeted antibacterial drug delivery system is composed of a photosensitizer as a carrier material and an antibiotic through electrostatic binding to form a drug-loaded nanosheet, and the surface of the nanosheet is loaded with a macrophage membrane with high expression of Toll-like receptors as a modification material.

2. The targeted antimicrobial drug delivery system according to claim 1, characterized in that: The photosensitizer is a purple phosphorus nanosheet, and the antibiotic is one of vancomycin, norfloxacin, levofloxacin, moxifloxacin, imipenem, aztreonam or gentamicin.

3. The targeted antimicrobial drug delivery system according to claim 1, characterized in that: The macrophage membrane with high expression of Toll-like receptors is obtained by co-incubating macrophages with methicillin-resistant Staphylococcus aureus and separating the cell membrane after ultrasonic disruption.

4. A method for preparing the targeted antimicrobial drug delivery system according to claim 1, characterized in that: The method comprises the following steps: (1) Preparation of drug-loaded nanosheets: grinding purple phosphorus crystals and dispersing them in anhydrous ethanol, ultrasonicating, centrifuging, and precipitating to obtain photosensitizer carriers, adding antibiotic solution dropwise, stirring, and ultrafiltration and centrifugation to obtain photosensitizer-loaded nanosheets loaded with antibiotics; (2) Extracting macrophage membranes with high expression of Toll-like receptors: After co-incubating macrophages with methicillin-resistant Staphylococcus aureus, the macrophages were washed with PBS buffer and ultrasonically disrupted; sucrose solution was added, the supernatant was centrifuged, and the supernatant was centrifuged again; the macrophage membranes with high expression of Toll-like receptors were obtained after washing with TM buffer containing sucrose, centrifuged, and the precipitate was collected; (3) Preparation of targeted antimicrobial drug delivery system: After ultrasonic dispersion of the drug-loaded nanosheets and macrophage membranes, the nanosheets were co-extruded using a liposome extruder, and the residual cell membranes were removed by centrifugation to obtain a targeted antimicrobial drug delivery system coated with pretreated macrophage membranes.

5. The method according to claim 4, characterized in that: In step (1), the photosensitizer carrier is purple phosphorus nanosheets, the ultrasonic power for preparing the photosensitizer carrier is 500-1000W, the ultrasonic time is 12-24h; the centrifugal speed is 4000-12000rpm, the centrifugal time is 10-30min; the mass ratio of the carrier material to the antibiotic is 1:1-3.

6. The method according to claim 4, characterized in that: In step (2), the ratio of the number of macrophages to methicillin-resistant Staphylococcus aureus is 1:3-5, the co-incubation time of bacteria and macrophages is 3-6 hours, the power of macrophage ultrasonic disruption is 50-150W, and the ultrasonic time is 10-30 minutes.

7. The method according to claim 4, characterized in that: In step (3), the mass ratio of the drug-loaded core to the macrophage membrane is 1:1-3, and the number of co-extrusions is 10-30 times.

8. Use of the pretreated macrophage membrane-coated targeted antibacterial drug delivery system according to claim 1 in the preparation of antibacterial drugs.

9. The use according to claim 8, characterized in that: The application is that the targeted antibacterial drug delivery system is combined with chemotherapy through photodynamic therapy.

10. The use according to claim 8, characterized in that: The application is specifically to accurately deliver drugs through the targeting effect of macrophage membranes, and produce cytotoxic reactive oxygen under laser irradiation conditions to enhance the antibacterial effect.

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