Photosensitizer composition and application thereof

Abstract

The invention discloses a photosensitizer composition and application thereof, and belongs to the technical field of photodynamic antibiosis. The invention provides a photosensitizer composition. The photosensitizer composition comprises a component A and a component B, the component A and the component B can be gathered on bacteria at the same time, so that a fluorescence resonance energy transfer (FRET) effect can be generated. According to the application, the antibacterial effects of CPVBP3, TPP3, Methylene Blue (MB) and the combination of the CPVBP3, the TPP3 and the MB are researched, the CPVBP3 is found to have a synergistic antibacterial effect with the TPP3 and the MB respectively, and the antibacterial mechanism of the CPVBP3, the TPP3 and the MB is researched. According to the invention, multiple photosensitizers are gathered on bacteria at the same time (a bacteria targeting group can be added to the photosensitizers) for the first time, and the FRET effect is generated, so that the photodynamic antibacterial effect is improved.

Description

Technical Field

[0001] The present application belongs to the field of photodynamic antibacterial technology, and in particular relates to a photosensitizer composition and its application. Background Art

[0002] The abuse of antibiotics has led to the emergence of drug-resistant bacteria and the widespread spread of drug-resistant genes. In the absence of antibiotics, people have turned their attention to photodynamic antibacterial therapy. Photodynamic antibacterial therapy uses light of a specific wavelength to excite photosensitizers, causing them to react with oxygen to produce reactive oxygen species that are toxic to biological tissues to kill bacteria. Reactive oxygen species do not target specific tissues, and photosensitizers do not have dark toxicity. The duration of photodynamic therapy is short, so it is not easy for bacteria to develop resistance to photodynamic therapy.

[0003] Methods to improve the photodynamic antibacterial effect include: 1. Designing photosensitizers with high reactive oxygen production rate and photostability; 2. Optimizing the structure of photosensitizers to enhance their ability to contact or enter bacteria, because reactive oxygen species have a short lifetime and a limited range of action; 3. Increasing the photosensitizer's ability to absorb light; 4. Combining nanosystems with other substances to enhance the solubility, stability, bioavailability and bacterial targeting of photosensitizers, increase oxygen supply, and prevent aggregation of quenching photosensitizers, increase the photosensitizer's absorption of long-wavelength light for deep tissue antibacterial treatment; 5. Combining photosensitizers with other antibacterial drugs or bacteriophages, or combining photodynamic therapy with sonodynamic / photothermal / gas therapies, to synergize multiple antibacterial mechanisms.

[0004] The combination of two or three photosensitizers has been successfully applied to photodynamic therapy of tumors through multi-target treatment, which significantly enhances the therapeutic effect and reduces side effects. In contrast, there are far fewer studies on the combined use of multiple photosensitizers in photodynamic antibacterial therapy, and the mechanism of synergy is complex and not thoroughly studied. The most commonly used strategy is to combine type I and type II photosensitizers to destroy multiple bacterial targets by producing a variety of reactive oxygen species, ultimately enhancing the antibacterial effect. However, the combination of some photosensitizers did not show a synergistic antibacterial effect, and even stimulated bacterial growth and inhibited photodynamic therapy. Therefore, a new strategy is urgently needed to coordinate the antibacterial effects of multiple photosensitizers.

[0005] Fluorescence Resonance Energy Transfer (FRET) is a process of non-radiative resonant energy transfer between two interacting fluorescent molecules. The emission spectrum of the donor molecule overlaps with the excitation spectrum of the acceptor molecule. When they are close enough (<10nm), the donor molecule absorbs photons and transfers energy to the acceptor molecule, which increases the degree and range of spectral absorption of the photosensitizer as the acceptor. Usually, the two fluorescent molecules / photosensitizers that serve as donors and acceptors are combined to form nanoparticles, or co-encapsulated in polymers, and co-adsorbed on materials such as fibers. The FRET effect is used to enhance their ability to generate active oxygen to improve the antibacterial effect. However, this preparation method is relatively complicated, and the photosensitizer cannot enter or contact bacteria, thereby reducing the photodynamic bactericidal effect.

[0006] Multidrug-resistant Acinetobacter baumannii (MDR-Ab) is insensitive to the last line of antibiotics, desiccation, disinfectants, oxidative stress and complement-mediated sterilization methods, making it one of the most difficult hospital infection pathogens. Escherichia coli is also the second leading pathogen causing bacterial infectious deaths. They are all Gram-negative, have a thin peptidoglycan layer, and are surrounded by a lipopolysaccharide outer membrane, which acts as a protective barrier and makes Gram-negative bacteria less sensitive to photodynamic antimicrobial therapy. In the face of this challenge, people have been working hard to explore new strategies to enhance the efficacy of photodynamic therapy in killing Gram-negative bacteria. Summary of the invention

[0007] In order to solve the above technical problems, the present application provides a photosensitizer composition and its application.

[0008] In order to achieve the above-mentioned invention object, this application provides the following technical solutions:

[0009] In one aspect, the present application provides a photosensitizer composition, comprising component A and component B;

[0010] The component A and the component B can simultaneously aggregate on the bacteria to produce a fluorescence resonance energy transfer effect.

[0011] Optionally, the component A comprises CPVBP3;

[0012] The structural formula of the CPVBP3 is shown in Formula I:

[0013]

[0014]

[0015] Optionally, the component B comprises TPP3 and / or methylene blue;

[0016] The structural formula of the TPP3 is shown in Formula II:

[0017]

[0018] Optionally, the method for preparing TPP3 comprises the following steps:

[0019] (1) dissolving a mixture containing 1-(tert-butyloxycarbonyl)piperazine, 5-bromopentyltriethylammonium bromide, and iodine anion, stirring, extracting, and reducing pressure to obtain compound 1;

[0020] (2) dissolving the compound 1, adding iodomethane, stirring, and reducing the pressure to obtain the compound 2;

[0021] (3) dissolving the compound 2, adding hydrochloric acid, stirring, and reducing the pressure to obtain the compound 3;

[0022] (4) dissolving a mixture containing the compound 3, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin, benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, and N,N,-diisopropylethylamine, stirring, extracting, reducing pressure, and purifying in sequence to obtain TPP3.

[0023] Optionally, in step (1), the mixing mass ratio of 1-(tert-butyloxycarbonyl)piperazine, 5-bromopentyltriethylammonium bromide, and iodide anion is 700-900:1500-2000:3000-4000;

[0024] The source of the iodine anion includes potassium iodide;

[0025] The stirring temperature is 55-65°C;

[0026] The stirring time is 15 to 17 hours.

[0027] Optionally, in step (2), the mixing mass ratio of the compound 1 to methyl iodide is 600-650:500-600;

[0028] The stirring time is 15 to 17 hours.

[0029] Optionally, in step (3), the dosage ratio of the compound 2 to hydrochloric acid is 150-250 mg: 100-200 μL;

[0030] The molar concentration of the hydrochloric acid is 10-12M;

[0031] The stirring time is 15 to 17 hours.

[0032] Optionally, in step (4), the mixing mass ratio of the compound 3, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin, benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, and N,N,-diisopropylethylamine is 100-150:100-150:100-200:100-110;

[0033] The stirring time is 25 to 35 minutes.

[0034] Optionally, the molar concentration ratio of component A to component B is 1:0.1-10.

[0035] In a second aspect, the present application also provides the use of the above-mentioned photosensitizer composition in the preparation of photodynamic antibacterial drugs.

[0036] Compared with the prior art, this application has the following beneficial effects:

[0037] (1) The compound TPP3 provided in the present application is obtained by coupling a piperazine derivative with tetraphenylporphyrin, which can help tetraphenylporphyrin enter the outer membrane of Gram-negative bacteria and has an antibacterial effect under photodynamic conditions.

[0038] (2) The photosensitizer composition provided in the present application does not need to form nanoparticles or be co-encapsulated in polymers, nor does it need to be co-adsorbed on materials such as fibers. The components A and B included can simultaneously aggregate on bacteria to produce a fluorescence resonance energy transfer effect to achieve an antibacterial effect. The component A includes CPVBP3, and the component B includes compound TPP3 and / or methylene blue, wherein CPVBP3 is a photosensitizer with two positive charges, which can enter the outer membrane of Escherichia coli by self-promoting uptake to greatly improve its bactericidal effect. The compound TPP3 obtained by coupling piperazine derivatives with tetraphenylporphyrin also has the ability to target and enter the outer membrane of Gram-negative bacteria.

[0039] (3) This application studied CPVBP3, TPP3, Methylene Blue (MB), and their combined antibacterial effects, and found that CPVBP3, TPP3 and Methylene Blue have synergistic antibacterial effects, and studied the antibacterial mechanism. This application proposed for the first time that multiple photosensitizers can be simultaneously aggregated on bacteria (if necessary, bacteria targeting groups can be added to the photosensitizers), resulting in a FRET effect, thereby improving the photodynamic antibacterial effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 For this application, the photosensitizer is used with 10 8 coli at 37°C for 30 min and then illuminated with white light (400-700 nm, 20 mW / cm 2 ) Comparison of sterilization effects under 10 minutes of illumination (Note: a represents the sterilization effects of CPVBP3 and TPP3 at different concentrations on E. coli under 10 minutes of white light illumination; b represents the sterilization effects of CPVBP3, TPP3 at different concentrations and their combination on E. coli under 10 minutes of white light illumination and without illumination);

[0042] Figure 2 (a) UV-visible absorption graph (as shown in a) and fluorescence emission graph (as shown in b) of CPVBP3 and TPP3 of the present application and their combination on Escherichia coli (excitation light 420 nm);

[0043] Figure 3 This is the fluorescence imaging diagram of CPVBP3 and TPP3 combined on Escherichia coli under a laser confocal microscope of this application (excitation light 405nm, TPP3 channel fluorescence range 670-710nm, CPVBP3 channel fluorescence range 500-550nm, scale 5μm);

[0044] Figure 4 The fluorescence lifetime of CPVBP3 on E. coli when used alone and in combination with TPP3 in this application, 375nm light excitation, 610nm fluorescence detection;

[0045] Figure 5 For this application, the killing effects of different concentrations of CPVBP3, TPP3 and their combination on multidrug-resistant Acinetobacter baumannii under white light illumination for 10 minutes and without illumination;

[0046] Figure 6 The UV-visible absorption graph (as shown in a) and fluorescence emission graph (as shown in b) of CPVBP3 and MB in this application and their combination on Escherichia coli (excitation light 420 nm);

[0047] Figure 7 The fluorescence lifetime of CPVBP3 on E. coli when used alone and in combination with MB for this application, 375nm light excitation, 610nm fluorescence detection;

[0048] Figure 8 For this application, blue-violet light (415±10nm, 20mW / cm 2 ) The killing effects of CPVBP3, MB and their combination on Escherichia coli under illumination for 10 minutes and without illumination. DETAILED DESCRIPTION

[0049] The present application is further described below in conjunction with specific embodiments. The following are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application discloses the following preferred embodiments, they are not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the above disclosed technical content to make some changes or modifications are equivalent to equivalent implementation cases and are within the scope of the technical solution.

[0050] Unless otherwise specified, the raw materials in the examples of the present application were purchased from commercial sources and used directly without any special treatment.

[0051] Unless otherwise specified, the analysis methods in the examples all adopt conventional settings and conventional analysis methods of instruments or equipment.

[0052] Example 1

[0053] The preparation routes of CPVBP3 and TPP3 are as follows:

[0054]

[0055] Preparation of compound 1: A solution of 1-(tert-butyloxycarbonyl)piperazine (804 mg, 4 mmol), 5-bromopentyltriethylammonium bromide (1600 mg, 4.8 mmol), potassium carbonate (1100 mg, 8 mmol) and potassium iodide (3300 mg, 20 mmol) in acetonitrile (20 mL) was stirred at 60°C for 16 h, and then water and ethyl acetate were added for extraction. The ethyl acetate layer was discarded, and solid sodium chloride was added to the water layer until saturated, and then extracted with dichloromethane and the solvent was removed under reduced pressure to obtain a white solid 1, namely compound 1 (1857.8 mg, 96%). The nuclear magnetic resonance spectrum of the compound 1 is: 1 H NMR (400MHz, DMSO-d6) δ3.30-3.26(m, 2H), 3.25(q, J=7.2Hz, 6H), 3.13-3.08(m, 2H), 2.30-2.25(m , 6H), 1.61-1.52(m, 2H), 1.50-1.42(m, 2H), 1.38(s, 9H), 1.33-1.24(m, 2H), 1.17(t, J=7.2Hz, 9H); 13C NMR (100MHz, DMSO-d6) δ153.8, 78.7, 57.4, 56.0, 52.6, 52.0, 28.1, 25.5, 23.8, 20.8, 7.2.

[0056] Preparation of compound 2: Add iodomethane (554 mg, 3.9 mmol) to an acetone solution (15 mL) containing compound 1 (628 mg, 1.3 mmol), stir at room temperature for 16 h, and remove the solvent under reduced pressure to obtain a white solid 2, namely compound 2 (812 mg, 100%). The NMR spectrum of compound 2 is: 1 H NMR (400MHz, DMSO-d6) δ3.76-3.68 (m, 2H), 3.68-3.54 (m, 2H), 3.45-3.35 (m, 6H), 3.26 (q, J=7.2Hz, 6H), 3.15-3.10 (m, 2H), 3.09 (s, 3H), 1.77-1.68 (m, 2H), 1.68-1.57 (m, 2H), 1.42 (s, 9H), 1.35-1.27 (m, 2H), 1.20 (t, J=7.2Hz, 9H); 13 C NMR (100MHz, DMSO-d6) δ153.4, 80.0, 61.8, 58.5, 55.7, 52.1, 46.3, 27.9, 22.6, 20.7, 20.6, 7.3.

[0057] Preparation of compound 3: Slowly add concentrated hydrochloric acid (12M, 133 μL, 1.6 mmol) to a dichloromethane (5 mL) solution containing compound 2 (200 mg, 0.32 mmol), stir at room temperature for 16 h, and then remove the solvent under reduced pressure to obtain an oily liquid 3, namely compound 3 (181 mg, 100%). The NMR spectrum of compound 3 is: 1 H NMR (400MHz, DMSO-d6) δ10.02 (br, 2H), 3.79-3.75 (m, 1H), 3.70-3.52 (m, 3H), 3.52-3.45 (m, 4H), 3.38-3.28 (m, 3H), 3. 26 (q, J=7.2Hz, 6H), 3.15-3.08 (m, 4H), 1.81-1.71 (m, 2H), 1.65-1.52 (m, 2H), 1.39-1.30 (m, 2H), 1.19 (t, J=6.8Hz, 9H); 13 C NMR (100MHz, DMSO-d6) δ55.8, 55.0, 52.1, 47.5, 36.6, 22.8, 22.4, 20.5, 7.3.

[0058] Preparation of TPP3: A N,N-dimethylformamide solution (5 mL) containing 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (132 mg, 0.2 mmol), compound 3 (135 mg, 0.24 mmol), benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate (152 mg, 0.4 mmol), and N,N,-diisopropylethylamine (104 mg, 0.8 mmol) was stirred at room temperature for 30 min, and then dichloromethane and water were added for extraction. The dichloromethane layer was collected and the solvent was removed under reduced pressure to obtain a crude product, which was then purified by a neutral alumina column (dichloromethane / methanol = 8 / 2) to obtain a purple solid powder TPP3 (189.3 mg, 82%). The nuclear magnetic resonance spectrum of the TPP3 is: 1 H NMR (400MHz, DMSO-d6) δ8.93-8.83(m, 8H), 8.38(d, J=8.0Hz, 2H), 8.26-8.21(m, 6H), 7.93(d, J=8.0Hz, 2H), 7.88-7.81(m, 9H), 4.32-4.02(m, 4H), 3.71-3.63(m, 4H), 3.60- 3.54 (m, 2H), 3.30-3.21 (m, 9H), 3.20-3.14 (m, 2H), 1.88-1.77 (m, 2H), 1.73-1.63 (m, 2H), 1.42-1.35 (m, 2H), 1.22 (t, J = 6.8 Hz, 9H); high resolution mass spectrometry (ESI) m / e calculated value C61H65N7O (M-2I) / 2 + 455.7620, measured value 455.7627.

[0059] Preparation of compound 5: A mixed solution of water (30 mL) and ethylene glycol dimethyl ether (100 mL) containing tetrakis(triphenylphosphine)palladium (550 mg, 0.480 mmol), (4-(9-hydrogen-carbazole-9-yl)phenyl)boric acid (5.05 g, 17.58 mmol), 5-bromothiophene-2-carboxaldehyde (3.00 g, 15.99 mmol), sodium carbonate (5.00 g, 48 mmol) was stirred at 120°C for 2 h, and then water and ethyl acetate were added for extraction. The ethyl acetate layer was concentrated at 70°C and placed in a 4°C refrigerator to cool to precipitate light green crystals, which were filtered and dried to obtain compound 4 (5.10 g, 84.0%). Compound 4 (1.51 g, 4.29 mmol) and methyl 2-methyl-5-nitrobenzoate (1.35 g, 6.44 mmol) were dissolved in dimethyl sulfoxide (30 mL) and anhydrous potassium carbonate (1.77 g, 13 mmol) was added, and stirred at 80°C for 12 h. After cooling to room temperature, dichloromethane and water were added for extraction, and the dichloromethane layer was collected and the solvent was removed under reduced pressure to obtain a red solid 5, which was compound 5 (2.15 g, 97.1%). The nuclear magnetic resonance spectrum of the compound 5 is: 1 H NMR (400MHz, DMSO-d6) δ8.36 (d, J=2.8Hz, 1H), 8.27 (d, J=8.0Hz, 2H), 8.24 (d, J=16.4Hz, 1H), 8.04 (dd, J=8.8, 2.4Hz, 1H), 8.00 (d, J=8.4H z, 2H), 7.94 (d, J = 8.4Hz, 1H), 7.69 (d, J = 8.8Hz, 2H), 7.65 (d, J = 3.6Hz, 1H), 7.60 (d, J = 16.4Hz, 1H), 7.48-7.42 (m, 4H), 7.34-7.28 (m, 3H); 13 C NMR (100MHz, DMSO-d6) δ169.6, 146.4, 144.5, 143.7, 143.0, 141.7, 140.9, 137.2, 133.5, 130.7 , 128.2, 128.0, 127.8, 127.3, 126.5, 126.2, 126.0, 125.1, 123.8, 122.6, 121.6, 121.2, 110.7.

[0060] Preparation of CPVBP3: A solution of N,N-dimethylformamide (5 mL) containing compound 5 (103 mg, 0.2 mmol), compound 3 (153 mg, 0.24 mmol), benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate (152 mg, 0.4 mmol), and N,N,-diisopropylethylamine (104 mg, 0.8 mmol) was stirred at room temperature for 30 min, and then dichloromethane and water were added for extraction. The dichloromethane layer was collected and the solvent was removed under reduced pressure to obtain a crude product, which was then purified by a neutral alumina column (dichloromethane / methanol = 8 / 2) to obtain an orange-red solid powder CPVBP3 (176 mg, 86%). The nuclear magnetic resonance spectrum of the CPVBP3 is: 1 H NMR (400MHz, DMSO-d6) δ8.34-8.31 (m, 2H), 8.29 (d, J = 8.0Hz, 2H), 8.22 (d, J = 8.4Hz, 1H), 8.03 (d, J = 8.0Hz, 2H), 7 .90 (d, J=16.4Hz, 1H), 7.75-7.71 (m, 3H), 7.51-7.49 (m, 1H), 7.47 (d, J=3.6Hz, 4H), 7.35-7.29 (m, 2H), 6.91 (dd, J =16.0, 6.4Hz, 1H), 4.46 (br, 0.5H), 4.27 (br, 0.5H), 4.01 (br, 0.5H), 3.83 (br, 0.5H), 3.70-3.56 (m, 4H), 3.56-3 .42(m, 3H), 3.37-3.30(m, 1H), 3.28-3.06(m, 11H), 1.78(br, 2H), 1.64(br, 2H), 1.34(br, 2H), 1.20-1.09(m, 9H); 13 C NMR (100 MHz, DMSO-d6) δ 167.0, 146.7, 144.4, 141.8, 141.1, 140.7, 137.4, 135.3, 133.0, 132.1, 129.5, 128.1, 128.0, 127.5, 127.3, 126.4, 125.3, 123.8, 123.4, 122.6, 121.5, 121.2, 110.6, 65.0, 60.9, 59.5, 56.7, 53.0, 49.4, 46.1, 41.1, 36.3, 23.6, 21.7, 8.2; high resolution mass spectrometry (ESI) m / e calculated for C37H35N4O3S (M-2I) / 2 + 384.7007, measured value 384.7011.

[0061] Example 2

[0062] TPP3 and CPVBP3 prepared in Example 1 were used as photosensitizers and 10 8 coli at 37°C for 30 min and compared their activity under white light (400-700 nm, 20 mW / cm 2 ) Sterilization effect under 10 minutes of light. Figure 1 As shown. Figure 1 As can be seen from a in the figure, the antibacterial effects of CPVBP3 and TPP3 are both concentration-dependent. 20μM CPVBP3 can kill 2.9log10 E. coli, and 20μM TPP3 can kill 5.0log10 E. coli. When the concentration increases from 5μM to 10μM, the antibacterial effects of CPVBP3 and TPP3 are significantly improved. The combined antibacterial effects of these two concentrations are studied. Figure 1 As can be seen in b, the antibacterial effect of 5μM CPVBP3 and 5μM TPP3 (5.0log10) is significantly better than 5μM CPVBP3 (0.94log10), 5μM TPP3 (2.1log10) and 10μM CPVBP3 (2.3log10), and even significantly better than 10μM TPP3 (3.8log10), and close to the effect of 20μM TPP3, showing excellent synergistic antibacterial effect. However, in the absence of light, these groups of photosensitizers have no antibacterial effect, indicating that their antibacterial activity comes from photodynamics.

[0063] Example 3

[0064] In order to verify that the photosensitizer (TPP3, CPVBP3) prepared in Example 1 has a FRET effect on Escherichia coli, the present invention is to use Escherichia coli (10 8 CFU / mL, 10mL) were incubated with 5μM CPVBP3, 5μM TPP3 and their combination (5μM each) for 30 minutes, centrifuged at 5000rpm for 3 minutes, washed twice with phosphate buffer solution (PBS, pH=7.4, 1mL) to remove the photosensitizer that was not bound to the bacteria, and finally resuspended in 1mL of PBS. The light absorption, fluorescence emission and lifetime of these photosensitizers on Escherichia coli were studied, as well as fluorescence imaging under a laser confocal microscope. The results are shown in Figure 2 As shown. Figure 2 As can be seen from a in the figure, the light absorption when CPVBP3 and TPP3 are used together is roughly equal to the sum of their light absorption when used alone. However, the fluorescence intensity of CPVBP3 is significantly reduced when used together compared to when it is used alone ( Figure 2b), so it is speculated that the fluorescence of CPVBP3 on E. coli is absorbed by TPP3. The fluorescence emission range of CPVBP3 is basically consistent with the absorption range of TPP3 Q band, so CPVBP3 and TPP3 have an important condition for the FRET effect to occur. At the same time, under the laser confocal microscope, it was observed that the fluorescence of CPVBP3 and TPP3 on E. coli basically overlapped, forming a very thick aperture ( Figure 3 ). This shows that TPP3 and CPVBP3 have both entered the bacterial outer membrane, so they also have another condition for the FRET effect to occur, that is, the distance between them is very close. In order to further prove that CPVBP3 and TPP3 have a FRET effect on E. coli, this application studies the effect of the combined use of TPP3 on the fluorescence lifetime of CPVBP3 on E. coli. Figure 4 As shown, the fluorescence lifetime of CPVBP3 alone on E. coli is 0.98 ns, but in the presence of TPP3, the fluorescence lifetime of CPVBP3 on E. coli is reduced to 0.74 ns, proving that a FRET effect does occur between TPP3 and CPVBP3, with an efficiency of about 24%.

[0065] Example 4

[0066] In order to verify the universality of the combination of CPVBP3 and TPP3 to enhance photodynamic antibacterial efficacy, this application studied the antibacterial effect of this combination on multidrug-resistant Acinetobacter baumannii. Figure 5 As shown in the figure, in the absence of light, CPVBP3 and TPP3 have no bactericidal effect even at concentrations as high as 20 μM. After 10 minutes of white light illumination, 5 μM of CPVBP3 and TPP3 have no bactericidal effect, while their combination (5 μM each) can kill 1.2 log10 of Acinetobacter baumannii. When the concentration is increased to 10 μM, CPVBP3 (0.26 log10) and TPP3 (0.41 log10) begin to show weak antibacterial effects, and their combination (10 μM each) shows a very excellent antibacterial effect (4.1 log10). This effect is also significantly stronger than the antibacterial effects of CPVBP3 (2.5 log10) and TPP3 (1.3 log10) at 20 μM, showing a very strong synergistic antibacterial effect.

[0067] Example 5

[0068] In order to further verify the universality of the method that photosensitizers simultaneously aggregate on bacteria to produce FRET effect to enhance the antibacterial effect, this application studies the effect of the combined use of CPVBP3 and methylene blue (MB) on the photodynamic therapy of Escherichia coli. The light absorption of CPVBP3 (380-540nm) and MB (540-800nm) on Escherichia coli is basically non-overlapping, and the light absorption when combined is also a simple superposition of their light absorption when used alone ( Figure 6 a). In E. coli, the fluorescence emission range of CPVBP3 is (450~800nm, Figure 6 b) is basically consistent with the absorption range of MB. At the same time, the fluorescence of them on E. coli when used together is roughly the sum of their fluorescence when used alone minus the absorption of MB on E. coli ( Figure 6 b), that is, the fluorescence of CPVBP3 on E. coli was also absorbed by MB. In addition, in the presence of MB, the fluorescence lifetime of CPVBP3 on E. coli was reduced from 0.98ns when used alone to 0.92ns when used in combination ( Figure 7 ), which also proves that the FRET effect does occur between them, with an efficiency of about 6%. The low FRET efficiency may be because MB with a positive charge cannot enter the E. coli outer membrane in large quantities through self-promoting uptake like CPVBP3. This application uses 415±10nm, 20mW / cm 2 The combination of CPVBP3 and MB was tested against Escherichia coli (10 8 CFU / mL), because this wavelength of light can only excite CPVBP3, but not MB, which can better detect the bactericidal effect produced by the FRET effect. Figure 8 As shown in the data, under 10 minutes of illumination, CPVBP3 had a better bactericidal effect than MB at the same concentration. The antibacterial effect (4.6log10) of their combination (5 μM each) was also significantly better than that of the other groups (5 μM CPVBP3, 2.3log10; 5 μM MB, 1.2log10; 10 μM CPVBP3, 3.5log10; 10 μM MB, 2.3log10), which indeed showed a significant synergistic antibacterial effect.

[0069] In summary, the present application provides a method for enhancing the photodynamic antibacterial effect through the FRET effect, wherein the method is to appropriately select two photosensitizers, wherein the emission spectrum of one photosensitizer overlaps with the absorption spectrum of the other photosensitizer, and the two photosensitizers are simultaneously aggregated on bacteria (if necessary, bacterial targeting groups can be added to the photosensitizers), and the FRET effect occurs, thereby ultimately enhancing the antibacterial effect of the photosensitizer.

[0070] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A photosensitizer composition, characterized in that: The photosensitizer composition comprises component A and component B; The component A and the component B can simultaneously aggregate on the bacteria to produce a fluorescence resonance energy transfer effect.

2. A photosensitizer composition according to claim 1, characterized in that: The component A comprises CPVBP3; The structural formula of the CPVBP3 is shown in formula I:

3. A photosensitizer composition according to claim 1, characterized in that: The component B comprises TPP3 and / or methylene blue; The structural formula of the TPP3 is shown in formula II:

4. A photosensitizer composition according to claim 3, characterized in that: The preparation method of TPP3 comprises the following steps: (1) dissolving a mixture containing 1-(tert-butyloxycarbonyl)piperazine, 5-bromopentyltriethylammonium bromide, and iodine anion, stirring, extracting, and reducing pressure to obtain compound 1; (2) dissolving the compound 1, adding iodomethane, stirring, and reducing the pressure to obtain the compound 2; (3) dissolving the compound 2, adding hydrochloric acid, stirring, and reducing the pressure to obtain the compound 3; (4) dissolving a mixture containing the compound 3, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin, benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, and N,N,-diisopropylethylamine, stirring, extracting, reducing pressure, and purifying in sequence to obtain TPP3.

5. A photosensitizer composition according to claim 4, characterized in that: In step (1), the mixing mass ratio of 1-(tert-butyloxycarbonyl)piperazine, 5-bromopentyltriethylammonium bromide and iodide anion is 700-900:1500-2000:3000-4000; The source of the iodine negative ions includes potassium iodide; The stirring temperature is 55 to 65°C; The stirring time is 15 to 17 hours.

6. A photosensitizer composition according to claim 4, characterized in that: In step (2), the mixing mass ratio of the compound 1 to methyl iodide is 600-650:500-600; The stirring time is 15 to 17 hours.

7. A photosensitizer composition according to claim 4, characterized in that: In step (3), the dosage ratio of compound 2 to hydrochloric acid is 150-250 mg: 100-200 μL; The molar concentration of the hydrochloric acid is 10 to 12M; The stirring time is 15 to 17 hours.

8. A photosensitizer composition according to claim 4, characterized in that: In step (4), the mixing mass ratio of the compound 3, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin, benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, and N,N,-diisopropylethylamine is 100-150:100-150:100-200:100-110; The stirring time is 25 to 35 minutes.

9. The photosensitizer composition according to claim 1, characterized in that: The molar concentration ratio of component A to component B is 1:0.1-10.

10. Use of the photosensitizer composition according to any one of claims 1 to 9 in the preparation of photodynamic antibacterial drugs.

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