High-efficiency bactericidal phthalocyanine-carboxymethyl chitosan nanomaterial, preparation method thereof and application thereof in antibiosis

Abstract

This invention relates to highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials, their preparation methods, and their applications in antibacterial applications. The phthalocyanine-carboxymethyl chitosan composite material (I) is a nanoscale complex formed by covalent bonds. This composite material not only exhibits high singlet oxygen yield and high superoxide radical yield, but also demonstrates excellent photothermal response in the near-infrared region, along with superior bactericidal effects. In vitro antibacterial experiments show that this composite material has significant bactericidal effects, requires mild preparation conditions, has a simple process, and has a wide range of applications.

Description

Highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials, their preparation methods, and their applications in antibacterial applications Technical Field

[0001] This invention relates to highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials, their preparation methods, and their application in antibacterial applications, belonging to the category of functional materials. Background Technology

[0002] The increasing resistance of bacteria poses a significant challenge to antibiotic treatment of bacterial infections. Phototherapy, however, has gained considerable attention due to its effective antibacterial properties without inducing bacterial resistance. Photodynamic therapy and photothermal therapy are collectively referred to as phototherapy. Compared to traditional treatments, phototherapy offers advantages such as being minimally invasive, having very low toxicity, and allowing for repeated treatments. The principle of photodynamic therapy is that under light irradiation, a photosensitizer gains energy and transitions from its ground state to an excited state, generating reactive oxygen species (ROS) through intersystem crossing, thus killing bacteria. The principle of photothermal therapy is that molecules that have transitioned to the excited state return to their ground state through vibrational relaxation, releasing energy as heat, causing localized heating and killing bacteria.

[0003] Phthalocyanines are a class of planar macrocyclic molecules that have been widely used in photodynamic and photothermal therapy for cancer treatment. Compared to metallic phthalocyanines, silicon phthalocyanines exhibit better biocompatibility and also possess advantages such as longer absorption wavelengths and higher extinction coefficients. The six-coordinate structure of silicon atoms allows for axial reactions in silicon phthalocyanines. Therefore, by introducing different groups at the axial positions of silicon phthalocyanines to increase steric hindrance and reduce aggregation, it is possible to overcome the fluorescence and ROS quenching caused by the π-π stacking of metallic phthalocyanines in solution. This has great potential for application in phototherapy. Currently, most reported methods involve introducing groups at the axial positions of silicon phthalocyanines to reduce aggregation. However, due to the influence of molecular structure, aggregation still occurs at high concentrations.

[0004] Carboxymethyl chitosan is a long-chain polysaccharide prepared by carboxylation of chitosan. Due to its antibacterial and non-toxic properties, it is widely used in biopharmaceuticals and food factories. To date, organic photothermal materials are primarily formed as nanomaterials in a molecular aggregate state, which suffers from poor biostability and low photothermal conversion efficiency. Furthermore, the aggregated state reduces fluorescence quenching and photodynamic properties, failing to achieve the synergistic effect of photodynamic and photothermal action. Moreover, it cannot pinpoint bacteria or track therapeutic effects, resulting in weak bactericidal efficacy.

[0005] Therefore, developing drugs that are non-aggregating, have highly efficient bactericidal effects, and possess good photodynamic and photothermal synergistic antibacterial effects in the near-infrared region is of paramount importance. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials, their preparation methods, and their applications in antibacterial applications.

[0007] This invention obtains covalently linked phthalocyanine-carboxymethyl chitosan nanomaterials by bonding the carboxylic acid groups on the carboxymethyl chitosan chain to the amino groups on the aminosilicon phthalocyanine long chain. This ensures the fluorescence emission performance of silicon phthalocyanine while also guaranteeing excellent photodynamic and photothermal effects, good biocompatibility, and highly efficient bactericidal effect.

[0008] The technical solution of the present invention is as follows:

[0009] A highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterial, wherein the nanomaterial is obtained by bonding carboxylic acid groups on a carboxymethyl chitosan chain to amino groups on an aminosilicon phthalocyanine long chain, and has the structure described in Formula I:

[0010]

[0011] In Formula I, n = 0 to 10, m = 3 to 20.

[0012] According to the present invention, preferably, in Formula I, n = 1-2 and m = 5-10.

[0013] According to the present invention, the preparation method of the above-mentioned highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterial includes the following steps:

[0014] Phthalocyanine II, sodium carboxymethyl chitosan III, carboxyl activator, carboxyl condensing agent and organic base were dissolved in a mixed solvent of deionized water and organic solvent, and reacted under nitrogen atmosphere to obtain highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials.

[0015]

[0016] In the structural formula of phthalocyanine II, n is the same as in formula I, and in the structural formula of carboxymethyl chitosan III, m is the same as in formula I.

[0017] According to the present invention, preferably, the mass ratio of sodium carboxymethyl chitosan salt III to phthalocyanine II is 1:1 to 5, and more preferably, the ratio is 1:1 to 2.

[0018] According to the present invention, preferably, the carboxyl activator is N-hydroxysuccinimide, the mass ratio of sodium carboxymethyl chitosan salt III to the carboxyl activator is (18-22):(22-26), the carboxyl condensing agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and the molar ratio of the carboxyl activator to the carboxyl condensing agent is 1:1.

[0019] According to the present invention, preferably, the organic base is N,N-diisopropylethylamine, and the mass ratio of N,N-diisopropylethylamine to phthalocyanine II is 5 to 10:1, preferably 5 to 7:1.

[0020] According to the present invention, preferably, the organic solvent is N,N-dimethylformamide, dimethyl sulfoxide, methanol or ethanol, and more preferably N,N-dimethylformamide.

[0021] According to the present invention, preferably, the volume ratio of deionized water to organic solvent in the mixed solvent of deionized water and organic solvent is 1:1 to 3, more preferably 1:1 to 1.5.

[0022] According to the present invention, preferably, the mass ratio of the organic solvent to phthalocyanine II is 1:4 to 10, more preferably 1:4 to 6.

[0023] According to the present invention, preferably, the reaction time is 12 to 96 hours, and more preferably 18 to 24 hours.

[0024] After the reaction is complete, the product is separated and purified. The specific steps are as follows: the obtained reaction mixture is dialyzed and freeze-dried to obtain highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials.

[0025] According to the present invention, preferably, the dialysis is performed by using a dialysis bag with a molecular weight cutoff of 1000 to 10000 Da, first dialyzing with N,N-dimethylformamide for 1 to 5 days, and then dialyzing with deionized water for 1 to 5 days.

[0026] More preferably, the molecular weight cutoff of the dialysis bag is 2000-3000 Da, the dialysis time with N,N-dimethylformamide is 2-3 days, and the dialysis time with deionized water is 1-2 days.

[0027] According to the present invention, preferably, the freeze-drying is carried out at a freeze-drying temperature of -60℃ to -40℃ for 1 to 5 days.

[0028] Further preferred, the freeze-drying temperature is -60℃ to -50℃, and the freeze-drying time is 1 to 2 days.

[0029] Unless otherwise specified, the present invention shall be performed in accordance with conventional practices in the art.

[0030] According to the present invention, the preparation method of the phthalocyanine II is prior art and can be obtained by referring to patent document CN111166882A. The carboxymethyl chitosan can be commercially available or prepared according to existing methods.

[0031] Taking the bonding of one carboxymethyl chitosan monomer to two aminosilylphthalocyanines as an example, the reaction route of this invention is as follows:

[0032]

[0033] This invention covalently bonds organoaminosilylphthalocyanine II and carboxymethyl chitosan III to obtain phthalocyanine-carboxymethyl chitosan composite nanomaterials. The carboxylic acid groups on the carboxymethyl chitosan chains are bonded to the amino groups on the long chains of the organoaminosilylphthalocyanine. The presence of the long carboxymethyl chitosan chains makes the molecular structure more three-dimensional and less prone to planar stacking. Even at high concentrations, the organoaminosilylphthalocyanine does not aggregate. It not only exhibits high singlet oxygen yield and high superoxide radical yield, but also excellent photothermal response in the near-infrared region, making it a material with synergistic photodynamic and photothermal therapeutic effects. A novel nanomaterial with highly efficient bactericidal effect has been experimentally demonstrated that, compared with aminosilyl phthalocyanine II, the photodynamic effect of phthalocyanine-carboxymethyl chitosan nanomaterial is basically the same, while the photothermal conversion efficiency is significantly improved. This is because some of the energy emitted in the form of fluorescence is converted into heat energy, thus improving the photothermal effect. In addition, carboxymethyl chitosan itself has a bactericidal effect and good biocompatibility. Its introduction into the molecular structure greatly enhances the bactericidal effect of the nanomaterial, exhibiting excellent bactericidal effect under low concentration conditions. The bactericidal effect is significantly better than that of carboxymethyl chitosan and other phthalocyanine composite nanomaterials.

[0034] Based on this, the present invention provides the application of the phthalocyanine-carboxymethyl chitosan nanomaterial.

[0035] The above-mentioned phthalocyanine-carboxymethyl chitosan nanomaterials are used in the preparation of antibacterial drugs for photodynamic therapy and photothermal therapy.

[0036] An antibacterial pharmaceutical composition for photodynamic therapy and photothermal therapy, comprising the above-mentioned phthalocyanine-carboxymethyl chitosan nanomaterial, and pharmaceutically acceptable excipients and / or carriers.

[0037] The beneficial effects of this invention are as follows:

[0038] 1. This invention obtains phthalocyanine-carboxymethyl chitosan nanomaterials by bonding the carboxylic acid groups on the carboxymethyl chitosan chain to the amino groups on the aminosilicon phthalocyanine long chain. Due to the presence of the carboxymethyl chitosan long chain, the molecular structure is more three-dimensional and less prone to planar stacking. Even at high concentrations, the organoaminosilicon phthalocyanine will not aggregate. It not only has high singlet oxygen yield and high superoxide radical yield, but also has excellent photothermal response in the near-infrared region, and has excellent bactericidal effect.

[0039] 2. The phthalocyanine-carboxymethyl chitosan nanomaterial of the present invention showed a good bacterial inhibition effect in in vitro antibacterial experiments. After light treatment, the survival rate of bacteria was greatly reduced. It can kill bacteria efficiently at low concentrations (see Figures 8 and 9), showing a highly efficient bactericidal effect and good application prospects. It is a multifunctional antibacterial drug.

[0040] 3. This invention improves near-infrared absorption by introducing carboxymethyl chitosan into aminosilyl phthalocyanine (II) with different chain lengths, exhibiting good photodynamic and photothermal effects, and also has good biocompatibility. Attached Figure Description

[0041] Figure 1 is the UV-Vis absorption spectrum of phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in N,N-dimethylformamide solution, where the horizontal axis represents wavelength and the vertical axis represents absorption intensity.

[0042] Figure 2 is the fluorescence spectrum of phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in N,N-dimethylformamide solution, where the horizontal axis is wavelength and the vertical axis is fluorescence intensity.

[0043] Figure 3 is the fluorescence lifetime spectrum of phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in N,N-dimethylformamide solution (30 μg / mL), where the horizontal axis is time and the vertical axis is fluorescence intensity.

[0044] Figure 4 shows the UV-Vis spectrum of singlet oxygen measured using DPBF as a quencher, where phthalocyanine-carboxymethyl chitosan prepared in Example 1 is dispersed in N,N-dimethylformamide solution (10 μg / mL). The horizontal axis represents wavelength, and the vertical axis represents absorption intensity.

[0045] Figure 5 shows the superoxide radical fluorescence spectrum of phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in N,N-dimethylformamide solution, measured with DHE as a fluorescent probe. The horizontal axis represents wavelength and the vertical axis represents fluorescence intensity.

[0046] Figure 6 shows the temperature change curve of phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in deionized aqueous solution under 808nm laser irradiation, where the horizontal axis represents time and the vertical axis represents temperature.

[0047] Figure 7 shows the photothermal response curve of phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in deionized aqueous solution under 808nm laser irradiation, where the horizontal axis represents time and the vertical axis represents temperature.

[0048] Figure 8 shows the effects of photodynamic therapy, photothermal therapy, and the synergistic effect of the phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in deionized aqueous solution on its anti-Staphylococcus aureus activity. The horizontal axis represents concentration, and the vertical axis represents survival rate.

[0049] Figure 9 shows the effects of photodynamic therapy, photothermal therapy, and the synergistic effect of the phthalocyanine-carboxymethyl chitosan prepared in Example 1 dispersed in deionized water on anti-Escherichia coli treatment. The horizontal axis represents concentration, and the vertical axis represents survival rate. Detailed Implementation

[0050] The invention will be further illustrated below with reference to specific examples and accompanying drawings, but is not limited thereto.

[0051] All raw materials used in this invention are commercially available analytical grade reagents.

[0052] The phthalocyanine I used in the examples can be prepared with reference to patent document CN111166882A.

[0053] Example 1

[0054] The preparation method of phthalocyanine-carboxymethyl chitosan composite nanomaterials, where phthalocyanine n=1, is as follows:

[0055] (1) Dissolve sodium carboxymethyl chitosan (20.4 mg) in 10 mL of deionized water, disperse by ultrasonication, add 5 μL of concentrated hydrochloric acid to the solution to acidify -COONa to -COOH, and obtain solution a;

[0056] (2) 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (38 mg), N-hydroxysuccinimide (24 mg), N,N-diisopropylethylamine (525 μL) and aminosilylphthalocyanine (n = 1, 37.5 mg) were dissolved in 10 mL of N,N-dimethylformamide to obtain solution b;

[0057] (3) Add solution b dropwise to solution a, stir at room temperature, react for 12 h under nitrogen atmosphere, dialyze the product, freeze dry, and obtain 38.1 mg of product, of which 17.7 mg is aminosilyl phthalocyanine and 20.4 mg is carboxymethyl chitosan.

[0058] The reaction route and product structure of this embodiment are as follows:

[0059]

[0060] Example 2

[0061] Taking aminosilylphthalocyanine n=2 as an example

[0062] As described in Example 1, the difference is that aminosilylphthalocyanine (n=1, 37.5 mg) was replaced with an equal amount of aminosilylphthalocyanine (n=2).

[0063] Example 3

[0064] As described in Example 1, the difference is:

[0065] Replace aminosilyl phthalocyanine (n=1, 37.5 mg) with 20.4 mg aminosilyl phthalocyanine (n=1).

[0066] Experimental Example

[0067] 1. Ultraviolet-Visible Absorption Spectroscopy

[0068] The phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 were dissolved in N,N-dimethylformamide to prepare solutions with concentrations of 10 μg / mL, 20 μg / mL, 30 μg / mL, 40 μg / mL, and 50 μg / mL, respectively. The UV-Vis absorption spectra were then tested, and the results are shown in Figure 1. As can be seen from Figure 1, the nanomaterials have excellent solubility and remain in a monomeric state, without aggregation even at high concentrations.

[0069] 2. Fluorescence spectroscopy test

[0070] The phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 were dissolved in N,N-dimethylformamide to prepare solutions with concentrations of 2 μg / mL, 4 μg / mL, 6 μg / mL, 8 μg / mL, and 10 μg / mL, respectively. The fluorescence emission was then tested, and the results are shown in Figure 2. As can be seen from Figure 2, the initial fluorescence emission of the nanomaterials increased with increasing concentration.

[0071] 3. Fluorescence lifetime

[0072] The phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 were dissolved in N,N-dimethylformamide at a concentration of 30 μg / mL. The excitation wavelength was 455 nm, the emission wavelength was 675 nm, and the fluorescence lifetime was in the nanosecond range. The results are shown in Figure 3. The average fluorescence lifetime of the nanomaterials was 5.20 ns, which showed good luminescence efficiency.

[0073] 4. Singlet oxygen test

[0074] The ability of the phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 to generate singlet oxygen was tested using 1,3-diphenylisobenzofuran as a quencher. A 150W halogen lamp equipped with a 610nm cutoff filter (λ > 610nm) was used as the light source.

[0075] First, a 40 μM solution of 1,3-diphenylisobenzofuran in N,N-dimethylformamide was prepared. Then, the phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 were added to this solution to achieve a concentration of 10 μg / mL. 3 mL of the solution was transferred to a quartz cuvette, and the solution was irradiated with a light source at 5-second intervals to test the UV-Vis spectrum. The test results are shown in Figure 4. The 10 μg / mL phthalocyanine-carboxymethyl chitosan nanomaterials exhibited good singlet oxygen yield.

[0076] 5. Superoxide radical test

[0077] A solution of N,N-dimethylformamide containing 250 μg / mL fish sperm DNA and 10 μM DHE dye was prepared. Phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 were added to this solution to achieve a concentration of 30 μg / mL. The solution was irradiated with a 150W halogen lamp equipped with a 610 nm cutoff filter (λ > 610 nm) for 0, 5, 10, and 20 minutes, and the fluorescence emission intensity of the solution was measured. The test results are shown in Figure 5. With increasing irradiation time, the yield of superoxide radicals increased.

[0078] 6. Photothermal response effect test

[0079] The phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 were dissolved in deionized water to prepare solutions with concentrations of 10 μg / mL, 20 μg / mL, 30 μg / mL, 40 μg / mL, and 50 μg / mL. An 808 nm laser (3 W / cm²) was then used to treat the solutions. 2 Irradiate for 10 minutes. Take pictures every 30 seconds using an infrared thermal imager. The temperature change is shown in Figure 6. When the power density is constant, the temperature of the solution increases with the increase of concentration.

[0080] 7. Photothermal conversion efficiency test

[0081] The phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1 were dissolved in deionized water to prepare a 40 μg / mL solution. 3 mL of this solution was transferred to a cuvette and incubated at 808 nm (1.5 W / cm²). 2 The laser irradiation lasted for 20 minutes, followed by natural cooling for 20 minutes. The temperature was recorded every 30 seconds using an infrared thermal imager. The results are shown in Figure 7.

[0082] Calculations show that the phthalocyanine-carboxymethyl chitosan nanomaterial of this embodiment has a very high photothermal conversion efficiency, reaching 26.8% under 808nm laser irradiation.

[0083] 8. Staphylococcus aureus test

[0084] 100 μL of a 0.85% NaCl solution containing Staphylococcus aureus was added, along with different amounts of the phthalocyanine-carboxymethyl chitosan nanomaterials prepared in Example 1, to obtain solutions of different concentrations. The solutions were incubated at 37°C for 10 min to absorb the drug, and divided into four groups. The first group was irradiated with a 660 nm LED lamp (PDT) for 5 min; the second group was irradiated with an 808 nm LED lamp (5 min, 5 W / cm²) for 5 min. 2 Laser irradiation (PPT); The third group was first irradiated with a 660nm LED lamp (5min), followed by irradiation with an 808nm lamp (5min, 5W / cm²). 2The first group was subjected to laser irradiation (PDT+PPT); the fourth group was the light-protected group (control). Bacteria were spread on nutrient plates and incubated at 37°C for 24 hours, and CFU were counted. The phthalocyanine-carboxymethyl chitosan nanomaterials obtained in Example 1 demonstrated high killing efficiency against Staphylococcus aureus, as shown in Figure 8. The figure shows that the bactericidal rate against Staphylococcus aureus gradually increases with increasing concentration of the phthalocyanine-carboxymethyl chitosan nanomaterials.

[0085] 9. Escherichia coli test

[0086] 100 μL of a 0.85% NaCl solution containing Escherichia coli (EC.) was added, along with different amounts of the phthalocyanine-carboxymethyl chitosan nanomaterial prepared in Example 1, to obtain solutions of different concentrations. The solutions were incubated at 37°C for 10 min to absorb the drug. The solutions were divided into four groups: the first group was irradiated with a 660 nm LED lamp (PDT) for 5 min; the second group was irradiated with an 808 nm LED lamp (5 min, 5 W / cm²) for 5 min. 2 Laser irradiation (PPT); The third group was first irradiated with a 660nm LED lamp (5min), followed by irradiation with an 808nm lamp (5min, 5W / cm²). 2 The first group was subjected to laser irradiation (PDT+PPT); the fourth group was the light-protected group (control). Bacteria were spread on nutrient plates and incubated at 37°C for 24 hours, and CFU were counted. The product of Example 1, phthalocyanine-carboxymethyl chitosan composite nanomaterials, demonstrated high killing efficiency against *E. coli*, as shown in Figure 9. The figure shows that the bactericidal rate of *E. coli* gradually increased with increasing concentration of phthalocyanine-carboxymethyl chitosan nanomaterials.

[0087] Obviously, those skilled in the art can make various modifications and variations to the complex and preparation method of the present invention, such as replacing the long chain in the aminosilyl phthalocyanine, changing the synthesis conditions and processes, without departing from the essence and scope of the present invention. All such modifications and variations should fall within the protection scope of the present invention.

Claims

1. A highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterial, wherein the nanomaterial is obtained by bonding carboxylic acid groups on the carboxymethyl chitosan chain with amino groups on the aminosilicon phthalocyanine long chain. The presence of the carboxymethyl chitosan long chain makes the molecular structure more three-dimensional and less prone to planar stacking. Even at high concentrations, the organoaminosilicon phthalocyanine does not aggregate. It not only exhibits high singlet oxygen yield and high superoxide radical yield, but also excellent photothermal response in the near-infrared region, possessing the structure described in Formula I: In Formula I, n = 1-2, m = 5-10; it is prepared by the following method: phthalocyanine II, sodium carboxymethyl chitosan III, carboxyl activator, carboxyl condensing agent and organic base are dissolved in a mixed solvent of deionized water and organic solvent, and reacted under nitrogen atmosphere to obtain highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials. In the structure of phthalocyanine II, n is the same as in formula I; in the structure of carboxymethyl chitosan III, m is the same as in formula I; the mass ratio of sodium carboxymethyl chitosan III to phthalocyanine II is 1:1 to 2; the carboxyl activator is N-hydroxysuccinimide, and the mass ratio of sodium carboxymethyl chitosan III to the carboxyl activator is (18-22):(22-26); the carboxyl condensing agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; the molar ratio of the carboxyl activator to the carboxyl condensing agent is 1:

1.

2. The highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterial according to claim 1, characterized in that, The organic base is N,N-diisopropylethylamine, and the mass ratio of N,N-diisopropylethylamine to phthalocyanine II is 5 to 7:

1.

3. The highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterial according to claim 1, characterized in that, The organic solvent is N,N-dimethylformamide, dimethyl sulfoxide, methanol, or ethanol; in the mixed solvent of deionized water and organic solvent, the volume ratio of deionized water to organic solvent is 1:1 to 3, the mass ratio of organic solvent to phthalocyanine II is 1:4 to 10, and the reaction time is 12 to 96 h.

4. The highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterial according to claim 1, characterized in that, After the reaction is completed, the product is separated and purified. The specific steps are as follows: the obtained reaction mixture is dialyzed and then lyophilized to obtain highly efficient bactericidal phthalocyanine-carboxymethyl chitosan nanomaterials; the dialysis is performed by using a dialysis bag with a molecular cutoff of 1000-10000 Da, first dialyzing with N,N-dimethylformamide for 1-5 days, and then dialyzing with deionized water for 1-5 days; the lyophilization is performed by lyophilizing at a temperature of -60℃ to -40℃ for 1-5 days.

5. The use of the phthalocyanine-carboxymethyl chitosan nanomaterial according to claim 1 in the preparation of antibacterial drugs for photodynamic therapy and photothermal therapy.

6. An antibacterial pharmaceutical composition for photodynamic therapy and photothermal therapy, comprising the phthalocyanine-carboxymethyl chitosan nanomaterial of claim 1, and pharmaceutically acceptable excipients and / or carriers.

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