Photoswitch-regulated pH response polymer as well as preparation method and application thereof

Abstract

The invention discloses an optical switch regulated and controlled pH response polymer and a preparation method and application thereof, the structural formula of the optical switch regulated and controlled pH response polymer is # imgabs0 #, and n1 and n2 are integers from 0 to 30; n3 is an integer from 8 to 50; a and b are integers from 1 to 100; and R is selected from one of # imgabs1 # imgabs2 #. According to the photoswitch regulated and controlled pH response polymer, self-assembly of the polymer is achieved through a coprecipitation method to form nano-micelles, the excellent biocompatibility is shown, the emission wavelength of 760 nm is achieved, the polymer is located in a visible light-near-infrared transition zone, the polymer is compatible with conventional visible light equipment, traditional visible light limitation is broken through, near-infrared level penetration and low interference are achieved, and the photoswitch regulated and controlled pH response polymer has good application prospects. And the background interference resistance and the tissue penetration depth are obviously improved. The micelle shows high-sensitivity fluorescence response to the pH value, accurate regulation and control can be achieved through illumination, and an efficient and accurate tool is provided for tumor diagnosis, drug delivery and real-time monitoring.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a pH-responsive polymer regulated by an optical switch, a preparation method thereof, and an application thereof. Background Art

[0002] Rhodamine derivatives are widely used in fluorescence sensing due to their excellent photophysical properties, including long absorption and emission wavelengths and large changes in absorption and fluorescence before and after spirolactam ring opening. Traditional rhodamine probes, which primarily absorb and emit light in the visible light range, are susceptible to interference from background fluorescence, have weak penetration, poor biocompatibility, and can cause some photodamage to organisms. In contrast, near-infrared fluorescent dyes have long excitation wavelengths, offering improved tissue penetration, minimal photodamage, and better protection against background interference.

[0003] Amphiphilic random copolymers can self-assemble in aqueous solution to form polymer micelles with a hydrophobic core and a hydrophilic shell. Therefore, polymer micelles are one of the earliest polymer self-assemblies to be applied. Over the past few decades, polymer micelles have garnered significant attention in the biopharmaceutical field as biocompatible drug carriers. Compared to traditional drug carriers, polymer micelles can enhance drug solubility, prolong drug circulation time in the blood, and improve pharmacokinetics and efficacy due to the EPR effect (enhanced permeation and retention).

[0004] To achieve targeted drug delivery and controlled release, stimuli-responsive polymer micelles (e.g., pH, temperature, light, redox potential, ultrasound, and enzyme responses) have been extensively studied. pH response has attracted considerable attention due to its ability to utilize the difference between the weakly acidic nature of the tumor microenvironment (pH ≈ 6.75) and normal tissue (pH ≈ 7.23) as an endogenous stimulus. Furthermore, light response, as a non-contact exogenous stimulus, offers unique advantages for the design of drug carriers, as its intensity, wavelength, and irradiation time can be precisely controlled remotely.

[0005] However, existing pH or light-responsive polymer micelles still face the following challenges: conventional visible light probes are difficult to achieve deep and precise imaging due to their insufficient tissue penetration depth and interference from biological background fluorescence, while near-infrared probes, although highly penetrating, rely on dedicated equipment and lack universality; a single response mechanism (only pH or light control) is susceptible to interference and lacks the ability to distinguish between tumors and normal tissues, resulting in blurred imaging background, which is not conducive to precise diagnosis and treatment. Summary of the Invention

[0006] In order to solve the problems raised in the above background technology, the purpose of the present invention is to provide a pH-responsive polymer regulated by an optical switch, and its preparation method and application. The pH-responsive polymer regulated by the optical switch of the present invention realizes the self-assembly of the polymer to form nano-micelles by a co-precipitation method, which not only shows excellent biocompatibility, but also has an emission wavelength of 760nm, which is in the visible light-near infrared transition zone, and has dual advantages: on the one hand, it is compatible with conventional visible light equipment, and on the other hand, it breaks through the limitations of traditional visible light, achieves near-infrared penetration and low interference, and significantly improves the anti-background interference ability and tissue penetration depth. In addition, the micelles show a highly sensitive fluorescence response to pH value and can be precisely regulated by light, providing an efficient and accurate tool for tumor diagnosis, drug delivery and real-time monitoring.

[0007] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a pH-responsive polymer regulated by a light switch, the structure of which is shown in formula (I):

[0008]

[0009] Wherein, n1, n2, and n3 are integers ranging from 0 to 30; n3 is an integer ranging from 8 to 50; a and b are integers ranging from 1 to 100;

[0010] R is selected from One of them.

[0011] In another aspect, the present invention provides a method for preparing the aforementioned photoswitch-controlled pH-responsive polymer, comprising the following steps:

[0012] S1: and Reaction, prepared

[0013] S2: S1 made With benzotriazol-1-yl-oxytripyrrolidinophosphine hexafluorophosphate, Reaction, prepared

[0014] S3: S2 made React with triethylamine and acryloyl chloride to prepare

[0015] S4: The S3 and Azobisisobutyronitrile was prepared by RAFT polymerization.

[0016] Furthermore, S1 specifically includes the following steps:

[0017] Will and Dissolve in a solvent, under nitrogen protection, stir and reflux at 80-100°C for 12-24h to obtain described The molar ratio is 1:(1~2).

[0018] Furthermore, S2 specifically includes the following steps:

[0019] The S1 was prepared Dissolve in a solvent, then add benzotriazole-1-yl-oxytripyrrolidinophosphine hexafluorophosphate (PyBOP), stir in an ice bath under nitrogen protection for 15 to 30 minutes; then slowly add Continue stirring under ice bath for 15-30 min and then move to room temperature to react for 2-6 h to obtain described Benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate and The molar ratio is 1:(1-1.5):(10-30).

[0020] Furthermore, S3 specifically includes the following steps:

[0021] S2 was prepared Dissolve in a solvent, add triethylamine, stir in an ice bath under nitrogen protection for 15 to 30 minutes; then slowly add acryloyl chloride dropwise, continue stirring in an ice bath for 15 to 30 minutes, then move to room temperature and react for 4 to 6 hours to obtain The compound The molar ratio of triethylamine to acryloyl chloride is 1:(10-30):(0.5-3).

[0022] Furthermore, S4 specifically includes the following steps:

[0023] The S3 was prepared Azobisisobutyronitrile is dissolved in a solvent, and the container is vacuumed and filled with nitrogen for several cycles under ice bath conditions, and then the temperature is quickly raised to 40-130°C and reacted for 5-7 hours to obtain described The molar ratio of azobisisobutyronitrile is (1-100):(50-800):(1-50):(0.1-10).

[0024] In another aspect, the present invention provides a pH-responsive polymer nanomicelle regulated by a light switch, which is prepared by the following method:

[0025] The pH-responsive polymer controlled by the optical switch is self-assembled in an aqueous solution by a co-precipitation method to prepare pH-responsive polymer nanomicelles controlled by the optical switch.

[0026] Further, it is prepared by the following method:

[0027] The pH-responsive polymer controlled by the optical switch is dissolved in a solvent to obtain a mixed solution, and the mixed solution is quickly added to water under ultrasonic conditions, and ultrasonication is continued for 10 to 30 minutes to obtain pH-responsive polymer nanomicelles controlled by the optical switch.

[0028] Furthermore, the solvent includes one of tetrahydrofuran, methanol and acetone.

[0029] In another aspect, the present invention provides a use of the aforementioned photoswitch-regulated pH-responsive polymer or any of the aforementioned photoswitch-regulated pH-responsive polymer nanomicelles in the preparation of a drug delivery carrier.

[0030] Furthermore, the drug is an anti-tumor drug.

[0031] Furthermore, the tumors include gastric cancer, colorectal cancer, and breast cancer.

[0032] Furthermore, the anti-tumor drugs include doxorubicin and paclitaxel.

[0033] In another aspect, the present invention provides a use of the aforementioned pH-responsive polymer regulated by a light switch or any of the aforementioned pH-responsive polymer nanomicelles regulated by a light switch in the preparation of a tumor diagnostic product or a real-time tumor monitoring product.

[0034] Furthermore, the tumors include gastric cancer, colorectal cancer, and breast cancer.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The pH-responsive polymer controlled by the optical switch of the present invention can achieve self-assembly of the polymer to form stable nanomicelles in aqueous solution through a co-precipitation method. It not only exhibits excellent biocompatibility but also has an emission wavelength of 760nm, which is in the visible light-near-infrared transition zone. It has dual advantages: on the one hand, it is compatible with conventional visible light equipment, and on the other hand, it breaks through the limitations of traditional visible light, achieving near-infrared penetration and low interference, significantly improving the ability to resist background interference and tissue penetration depth.

[0037] Furthermore, the photoswitchable pH-responsive polymer nanomicelles exhibited a highly sensitive fluorescence response to pH under UV irradiation, and their pH-responsive behavior could be precisely controlled by light. This light-controlled property transforms the traditional single passive pH response into a process that can be actively regulated by external light, providing a precisely controllable tool for drug delivery, tumor diagnosis, and real-time monitoring, expanding its potential for biomedical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0039] Figure 1 The high-resolution mass spectrum [M+H] of NIR-Rh-D prepared in Example 1 of the present invention is shown in FIG. + picture;

[0040] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of NIR-Rh-D prepared in Example 1 of the present invention;

[0041] Figure 3 The pH-responsive polymer P(PEG) regulated by the optical switch prepared in Example 1 of the present invention 44 -co-Rh4) H NMR spectrum;

[0042] Figure 4 The pH-responsive polymer P(PEG) regulated by the optical switch prepared in Example 1 of the present invention 44 -co-Rh4) gel permeation chromatogram;

[0043] Figure 5 TEM image of pH-responsive polymer nanomicelles NRs regulated by optical switches prepared in Example 1 of the present invention;

[0044] Figure 6 This is a graph showing the fluorescence emission spectra of the pH-responsive polymer nanomicelles NRs regulated by the optical switch prepared in Example 1 of the present invention after being irradiated with a 365nm UV lamp for 2 minutes in solutions with different pH values (λex = 640nm; slit: 5-5);

[0045] Figure 7 This is a fluorescence emission spectrum of the pH-responsive polymer nanomicelles NRs regulated by the optical switch prepared in Example 1 of the present invention, which changes with the irradiation time of a 365nm ultraviolet lamp in a solution with a pH of 3.5 (λex = 640nm; slit: 5-5);

[0046] Figure 8 Fluorescence emission spectra of the pH-responsive polymer nanomicelles NRs regulated by the optical switch prepared in Example 1 of the present invention after being irradiated with a 365nm UV lamp for 2 minutes in a solution with a pH of 3.5 and then placed under visible light for different times (λex = 640nm; slit: 5-5);

[0047] Figure 9 Fluorescence intensity graph at 760 nm (λex = 640 nm; slit: 5-5) of the pH-responsive polymer nanomicelles NRs regulated by the optical switch prepared in Example 1 of the present invention after reacting with other analytes in solutions at pH = 3.5 and 7.4 and then irradiated with a 365 nm UV lamp for 2 min;

[0048] Figure 10 The pH-responsive polymer P(PEG) regulated by the optical switch prepared in Example 3 of the present invention 47 -co-Rh3) H NMR spectrum;

[0049] Figure 11 The pH-responsive polymer P(PEG) regulated by the optical switch prepared in Example 3 of the present invention 47 -co-Rh3) gel permeation chromatogram;

[0050] Figure 12 This is a graph showing the changes in fluorescence emission spectra of the pH-responsive polymer nanomicelles NRt regulated by the optical switch prepared in Example 3 of the present invention after being irradiated with a 365nm ultraviolet lamp for 2 minutes in solutions with different pH values (λex=640nm; slit: 5-5). DETAILED DESCRIPTION

[0051] In order to better understand the content of the present invention, the content of the present invention is further described below in conjunction with specific implementation methods, but the protection content of the present invention is not limited to the following embodiments.

[0052] Example 1

[0053] The structure of the photoswitchable pH-responsive polymer is shown below:

[0054]

[0055] The preparation method of the photoswitch-controlled pH-responsive polymer is as follows:

[0056]

[0057] S1: Compound 1 (1.7 g, 4 mmol) and 4-diphenylaminobenzaldehyde (1.8 g, 6 mmol) were dissolved in 24 mL of glacial acetic acid. Under nitrogen protection, the mixture was stirred and refluxed at 90°C for 12 h. When the solution was observed to change from reddish brown to bluish black, the reaction was stopped and the solvent was removed by distillation under reduced pressure. The residue was washed with water, and the organic layer was collected and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:Me=10:1, v / v) and finally dried in vacuo to obtain 1.71 g of blue solid product Rh-TPA with a yield of 68%.

[0058] S2: The compound Rh-TPA (300 mg, 0.47 mmol) was dissolved in dichloromethane, and then PyBOP (247 mg, 0.47 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min. Then, ethylenediamine (0.6 mL, 9.40 mmol) was slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then the mixture was moved to room temperature for 2 h. The reaction was stopped and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 162 mg of a yellow solid product Rh-TPA-EDA with a yield of 50%.

[0059] S3: The compound Rh-TPA-EDA (100 mg, 0.15 mmol) was dissolved in dichloromethane, and triethylamine (0.5 mL, 3.59 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min, and then acryloyl chloride (12 μL, 0.14 mmol) was slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then the mixture was moved to room temperature for 5 h. The reaction was stopped and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 76 mg of a light yellow solid product NIR-Rh-D with a yield of 70%. 1 H NMR (400MHz, CDCl3) δ7.87 (d, J=7.1Hz, 1H), 7.55–7.43 (m, 2H), 7.33–7.18 (m, 9H) ,7.12(d,J=7.9Hz,4H),7.08–6.95(m,4H),6.37–6.17(m,3H),6.07(dd,J=17.1,1 0.2Hz,1H),5.56(d,J=10.1Hz,1H),3.49–3.16(m,8H),2.91–2.71(m,1H),2.71–2 .55(m,1H),1.66(d,J=15.3Hz,2H),1.58(d,J=6.5Hz,2H),1.16(t,J=7.1Hz,6H). MS (ESI): m / z 727.40 [M+H] + . High-resolution mass spectrum of NIR-Rh-D [M+H] + Figure Figure 1 The nuclear magnetic resonance hydrogen spectrum of NIR-Rh-D is shown as follows. Figure 2 shown.

[0060] S4: ATTC (3.6 mg, 0.01 mmol), PEGMA (333 mg, 0.67 mmol), NIR-Rh-D (36.3 mg, 0.1 mmol), and azobisisobutyronitrile (AIBN) (0.164 mg, 0.001 mmol) were dissolved in 2 mL of DMF. The mixture was vacuumed and filled with nitrogen for three cycles in a Shrek tube under ice bath conditions, and then the temperature was rapidly raised to 75 ° C for 6 h. After the reaction, the mixture was precipitated with ether and centrifuged six times. The supernatant was discarded and the precipitate was vacuum dried to obtain an oily light yellow photoswitch-controlled pH-responsive polymer P (PEG 44 -co-Rh4)116mg. (M n =20608 kDa, M w / M n =1.27). 1 H NMR (400 MHz, CDCl3) δ7.85 (s, 4H), 7.48 (s, 8H), 7.26 (s, 38H), 7.19–6.92 (m, 30H), 6.33 (s, 11H), 4.62 (s, 2H), 4.06 (s, 74H), 3.80 (s, 11H), 3.62 (s, 1150H), 3.54 (s, 110H), 3.46 (dp, J = 7.0, 3.5 Hz, 19H), 3.37 (s, 151H), 2.18–1.72 (m, 201H), 1.26–1.11 (m, 49H), 0.92 (d, J = 51.8 Hz, 137H). 44 -co-Rh4) as shown in the H NMR spectrum Figure 3 pH-responsive polymer P(PEG) regulated by optical switch 44 -co-Rh4) by gel permeation chromatography Figure 4 shown.

[0061] Preparation of pH-responsive polymer nanomicelles (NRs) regulated by optical switches: 10 mg P(PEG 44 -co-Rh4) was dissolved in 0.5 mL of tetrahydrofuran. The mixed solution was rapidly added to 10 mL of distilled water while sonicating for 10 minutes. The tetrahydrofuran was removed from the mixed solution by rotary distillation under reduced pressure at 30°C. The solution was then diluted to 10 mL with distilled water and filtered through a 0.22 μm filter to obtain 1 mg / mL of photoswitchable pH-responsive polymer nanomicelles (NRs).

[0062] The pH-responsive polymer nanomicelles NRs regulated by optical switches were characterized by TEM. Figure 5 As shown. Figure 5It can be seen that the pH-responsive polymer nanomicelles NRs regulated by the optical switch are uniformly distributed spherical particles with a particle size of about 400 nm.

[0063] Determination of the fluorescence spectrum of NRs for controllable pH detection: Take multiple 300 μL aliquots of 1 mg / mL NRs and add 2700 μL of BR buffer solution with different pH values (pH = 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.4, 8.0, 8.5, 9.0). After irradiation with 365 nm UV light for 2 minutes, the fluorescence spectrum is measured. The results are shown in the figure. Figure 6 As shown. Figure 6 It can be seen that NRs have a characteristic fluorescence emission peak at 760nm, and its intensity shows a significant correlation with pH value: when the pH of the solution is 3.5, the fluorescence intensity reaches a peak value. As the pH value deviates from 3.5 (whether increasing or decreasing), the fluorescence intensity shows a systematic decrease, but it can produce a significant signal in a wide acidic range (pH ≤ 7.0). Through molecular design, it can trigger a gradient response in the weak acid of the tumor microenvironment (pH 6.5-7.0) and is compatible with lysosomal strong acid detection (pH 4.5-5.5), combining wide-spectrum sensitivity and tumor targeting applicability. Based on this pH-responsive characteristic, NRs can show differentiated application potential in different physiological environments.

[0064] Fluorescence spectrum test of NRs after irradiation with 365nm UV lamp for different time periods: Take 300μL of 1mg / mL NRs, add 2700μL of pH=3.5 BR buffer solution, use 365nm UV lamp to irradiate for different time periods (test time is 0~180s, test once every 10s) at a distance of 0.5cm from the cuvette, and measure its fluorescence spectrum. The results are shown as follows: Figure 7 As shown. Figure 7 As can be seen, the reaction is complete after 2 minutes of irradiation with a 365nm UV lamp. Compared to traditional light-triggered systems that often require tens of minutes of UV radiation exposure, the present invention shortens the irradiation time to a clinically acceptable range, significantly reducing the risk of cumulative damage to biological tissues caused by UV light sources.

[0065] NRs were tested for recovery after 2 minutes of 365 nm UV irradiation: 300 μL of 1 mg / mL NRs was added to 2700 μL of pH 3.5 BR buffer solution. The sample was irradiated with 365 nm UV light at a distance of 0.5 cm from the cuvette for 2 minutes. The sample was then placed under visible light and fluorescence was measured every 30 minutes. The results are shown in the figure below. Figure 8 As shown. Figure 8It can be seen that its photoinduced ring opening can be maintained for 7 hours. Compared with traditional photoresponsive materials (usually maintained for tens of minutes to 2 hours), the 7-hour ring opening maintenance ability provides a sufficient time window for dynamic observation in vivo, which is especially suitable for biological processes that require long-term tracking (such as drug release kinetics and inflammatory microenvironment evolution).

[0066] NRs selectivity and anti-interference test for other common substances: 22 300 μL aliquots of 1 mg / mL NRs were added to BR buffer at pH 3.5. A certain amount of other common substances were then added to achieve a 0.1 mg / mL NRs concentration and a 10 mmol / L concentration of other common substances. Separately, 300 μL of 1 mg / mL NRs was added to BR buffer at pH 3.5 to obtain a 0.1 mg / mL NRs concentration, which served as a blank sample. 300 μL of 1 mg / mL NRs was added to BR buffer at pH 7.4 to obtain a 0.1 mg / mL NRs concentration and a 10 mmol / L concentration of other common substances. Separately, 300 μL of 1 mg / mL NRs was added to BR buffer at pH 7.4 to obtain a 0.1 mg / mL NRs concentration, which served as a blank sample. Other common substances referred to here include metal ions (K + , Ca 2+ 、Na + Mg 2+ 、Ba 2+ 、Zn 2+ 、Fe 3+ 、Fe 2+ 、Cu 2+ ), amino acids (Cys, Hcy), peptides (GSH) and common anions (PO4 3- 、HPO4 2- 、H2PO4 - 、HCO3 - 、HSO3 - 、SO4 2- 、CO3 2- 、NO3 - 、NO2 - 、Cl - The above samples were irradiated with a 365nm UV lamp at a distance of 0.5cm from the cuvette for two minutes and then the fluorescence spectrum was measured. The detection wavelength was 760nm and the excitation wavelength was 640nm. The data obtained are as follows Figure 9 As shown. Figure 9It can be seen that NRs exhibit excellent pH response selectivity and anti-interference ability in complex systems: when the environment is physiologically neutral (pH 7.4), even in the presence of multiple common interfering substances, its fluorescence signal at 760nm still maintains the baseline level, indicating that the molecular recognition unit of NRs has no specific response to non-target substances; when the pH is 3.5, the system produces a significantly enhanced fluorescence signal at 760nm, and the signal intensity is not interfered by coexisting substances, proving that its response mechanism is highly dependent on H + concentration rather than other environmental variables.

[0067] Example 2

[0068] The structure of the photoswitchable pH-responsive polymer is shown below:

[0069]

[0070] The preparation method of the photoswitch-controlled pH-responsive polymer is as follows:

[0071]

[0072] S1: Compound 1 (1.7 g, 4 mmol) and 4-diphenylaminobenzaldehyde (1.8 g, 6 mmol) were dissolved in 24 mL of glacial acetic acid. Under nitrogen protection, the mixture was stirred and refluxed at 90°C for 12 h. When the solution was observed to change from reddish brown to bluish black, the reaction was stopped and the solvent was removed by distillation under reduced pressure. The residue was washed with water, and the organic layer was collected and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 1.71 g of a blue solid product, Rh-TPA, with a yield of 68%.

[0073] S2: The compound Rh-TPA (300 mg, 0.47 mmol) was dissolved in dichloromethane, and then PyBOP (247 mg, 0.47 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min. Hydrazine hydrate (0.2 mL, 4.70 mmol) was then slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then the mixture was moved to room temperature for 2 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v), and finally dried in vacuo to obtain 168 mg of a yellow solid product Rh-TPA-EHA with a yield of 55%.

[0074] S3: The compound Rh-TPA-EHA (100 mg, 0.15 mmol) was dissolved in dichloromethane, and then triethylamine (0.5 mL, 3.59 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min, and then acryloyl chloride (12 μL, 0.14 mmol) was slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then moved to room temperature for 5 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v), and finally dried in vacuo to obtain a light yellow solid product NIR-Rh-H.

[0075] S4: ATTC (3.6 mg, 0.01 mmol), PEGMA (333 mg, 0.67 mmol), NIR-Rh-H (35.0 mg, 0.05 mmol), and azobisisobutyronitrile (AIBN) (0.164 mg, 0.001 mmol) were dissolved in 2 mL of DMF. The mixture was vacuumed and filled with nitrogen for three cycles in a Shrek tube under ice bath conditions, and then the temperature was rapidly raised to 75 ° C for 6 h. After the reaction, the mixture was precipitated with ether and centrifuged six times. The supernatant was discarded and the precipitate was vacuum dried to obtain an oily light yellow photoswitch-controlled pH-responsive polymer P (PEG 44 -co-Rh4).

[0076] Preparation of pH-responsive polymer nanomicelles (named NRh) regulated by optical switch: 10 mg P(PEG 44 -co-Rh4) was dissolved in 0.5 mL of tetrahydrofuran. The mixed solution was rapidly added to 10 mL of distilled water while sonicating for 10 minutes. The tetrahydrofuran was removed from the mixed solution by rotary distillation under reduced pressure at 30°C. The solution was then diluted to 10 mL with distilled water and filtered through a 0.22 μm filter to obtain 1 mg / mL of photoswitchable pH-responsive polymer nanomicelles NRh.

[0077] Example 3

[0078] The structure of the photoswitchable pH-responsive polymer is shown below:

[0079]

[0080] The preparation method of the photoswitch-controlled pH-responsive polymer is as follows:

[0081]

[0082] S1: Compound 1 (1.7 g, 4 mmol) and 4-diphenylaminobenzaldehyde (1.8 g, 6 mmol) were dissolved in 24 mL of glacial acetic acid. Under nitrogen protection, the mixture was stirred and refluxed at 90°C for 12 h. When the solution was observed to change from reddish brown to bluish black, the reaction was stopped and the solvent was removed by distillation under reduced pressure. The residue was washed with water, and the organic layer was collected and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 1.71 g of a blue solid product, Rh-TPA, with a yield of 68%.

[0083] S2: The compound Rh-TPA (1 g, 1.58 mmol) was dissolved in dichloromethane, and then PyBOP (823 mg, 1.58 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min. Diethylenetriamine (1.7 mL, 15.83 mmol) was then slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then the mixture was brought to room temperature for 3 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 500 mg of a yellow solid product, Rh-TPA-ETA, with a yield of 44%.

[0084] S3: The compound Rh-TPA-ETA (140 mg, 0.2 mmol) was dissolved in dichloromethane, and triethylamine (0.3 mL, 2.0 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min. Acryloyl chloride (33 μL, 0.4 mmol) was then slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then the mixture was moved to room temperature for 6 h. The reaction was stopped and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 92 mg of a light yellow solid product NIR-Rh-T with a yield of 60%.

[0085] S4: ATTC (3.6 mg, 0.01 mmol), PEGMA (333 mg, 0.67 mmol), NIR-Rh-T (41.2 mg, 0.05 mmol), and azobisisobutyronitrile (AIBN) (0.164 mg, 0.001 mmol) were dissolved in 2 mL of DMF. The mixture was vacuumed and filled with nitrogen for three cycles in a Shrek tube under ice bath conditions, and then the temperature was rapidly raised to 75 ° C for 6 h. After the reaction, the mixture was precipitated with ether and centrifuged six times. The supernatant was discarded and the precipitate was vacuum dried to obtain an oily light yellow light switch-controlled pH-responsive polymer P (PEG 47 -co-Rh3)97.6mg. (M n =22558 kDa, M w / M n=1.23). 1 H NMR(400MHz, CDCl3)δ8.00(s,1H),7.83(s,3H),7.48(s,6H),7.26(s,24H),7.21–6.68(m,22 H),6.36(s,9H),5.56(s,3H),4.63(s,2H),4.07(s,94H),3.81(s,14H),3.64(d,J=4.6Hz,128 9H),3.56–3.50(m,100H),3.45(s,15H),3.36(s,137H),2.56(s,1H),2.34–2.20(m,9H),2.05(d,J=6.7Hz,111H),1.82(d,J=40.8Hz,61H),1.51–1.11(m,48H),0.92(d,J=60.8Hz,126H). 47 -co-Rh3) is as follows Figure 10 pH-responsive polymer P(PEG) regulated by optical switch 47 -co-Rh3) by gel permeation chromatography Figure 11 shown.

[0086] Photosensitive pH-responsive polymer nanomicelles (NRt) were regulated by light switch. 10 mg P(PEG 47 -co-Rh3) was dissolved in 0.5 mL of tetrahydrofuran. The mixed solution was rapidly added to 10 mL of distilled water while sonicating for 10 minutes. The tetrahydrofuran was removed from the mixed solution by rotary distillation under reduced pressure at 30°C. The solution was then diluted to 10 mL with distilled water and filtered through a 0.22 μm filter to obtain 1 mg / mL of photoswitchable pH-responsive polymer nanomicelles NRt.

[0087] Determination of the fluorescence spectrum of NRt for controllable pH detection: Take multiple 300 μL aliquots of 1 mg / mL NRt and add 2700 μL of BR buffer solution with different pH values (pH = 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.4, 8.0, 8.5, 9.0). After irradiation with 365 nm UV light for 2 minutes, the fluorescence spectrum was measured. The results are shown in the figure. Figure 12 As shown. Figure 12It can be seen that NRt has a characteristic fluorescence emission peak at 760nm, and its intensity shows a significant correlation with pH value: when the pH of the solution is 3.5, the fluorescence intensity reaches a peak value. As the pH value deviates from 3.5 (whether increasing or decreasing), the fluorescence intensity shows a systematic decrease, but it can produce a significant signal in a wide acidic range (pH ≤ 7.0). Through molecular design, it can trigger a gradient response in the weak acid of the tumor microenvironment (pH 6.5-7.0) and is compatible with lysosomal strong acid detection (pH 4.5-5.5), combining wide-spectrum sensitivity and tumor targeting applicability. Based on this pH-responsive characteristic, NRt can show differentiated application potential in different physiological environments.

[0088] Example 4

[0089] The structure of the photoswitchable pH-responsive polymer is shown below:

[0090]

[0091] The preparation method of the photoswitch-controlled pH-responsive polymer is as follows:

[0092]

[0093] S1: Compound 1 (1.7 g, 4 mmol) and N,N-diethyl-4-aminobenzaldehyde (1.1 g, 6 mmol) were dissolved in 24 mL of glacial acetic acid. Under nitrogen protection, the mixture was stirred and refluxed at 90°C for 12 h. When the solution was observed to change from reddish brown to bluish black, the reaction was stopped and the solvent was removed by distillation under reduced pressure. The residue was washed with water, and the organic layer was collected and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 1.28 g of a blue solid product Rh-N with a yield of 60%.

[0094] S2: The compound Rh-N (250 mg, 0.47 mmol) was dissolved in dichloromethane, and then PyBOP (247 mg, 0.47 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min. Then, ethylenediamine (0.6 mL, 9.40 mmol) was slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then moved to room temperature for 2 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v), and finally dried in vacuo to obtain a yellow solid product Rh-N-EDA.

[0095] S3: The compound Rh-N-EDA (86 mg, 0.15 mmol) was dissolved in dichloromethane, and then triethylamine (0.5 mL, 3.59 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min, and then acryloyl chloride (12 μL, 0.14 mmol) was slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then moved to room temperature for 5 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v), and finally dried in vacuo to obtain a light yellow solid product NIR-Rh-N.

[0096] S4: ATTC (3.6 mg, 0.01 mmol), PEGMA (497 mg, 0.67 mmol), NIR-Rh-N (32.0 mg, 0.05 mmol), and azobisisobutyronitrile (AIBN) (0.164 mg, 0.001 mmol) were dissolved in 2 mL of DMF. The mixture was vacuumed and filled with nitrogen for three cycles in a Shrek tube under ice bath conditions, and then the temperature was rapidly raised to 75 ° C for 6 h. After the reaction, the mixture was precipitated with ether and centrifuged six times. The supernatant was discarded and the precipitate was vacuum dried to obtain an oily light yellow light switch-controlled pH-responsive polymer P (PEG 50 -co-Rh5).

[0097] Preparation of pH-responsive polymer nanomicelles (named NRn) regulated by optical switch: 10 mg P(PEG 50 -co-Rh5) was dissolved in 0.5 mL of tetrahydrofuran. The mixed solution was rapidly added to 10 mL of distilled water while sonicating for 10 minutes. The tetrahydrofuran was removed from the mixed solution by rotary distillation under reduced pressure at 30°C. The solution was then diluted to 10 mL with distilled water and filtered through a 0.22 μm filter to obtain 1 mg / mL of photoswitchable pH-responsive polymer nanomicelles NRn.

[0098] Example 5

[0099] The structure of the photoswitchable pH-responsive polymer is shown below:

[0100]

[0101] The preparation method of the photoswitch-controlled pH-responsive polymer is as follows:

[0102]

[0103] S1: Compound 1 (1.7 g, 4 mmol) and N,N-diethyl-4-aminobenzaldehyde (1.1 g, 6 mmol) were dissolved in 24 mL of glacial acetic acid. Under nitrogen protection, the mixture was stirred and refluxed at 90°C for 12 h. When the solution was observed to change from reddish brown to bluish black, the reaction was stopped and the solvent was removed by distillation under reduced pressure. The residue was washed with water, and the organic layer was collected and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain 1.28 g of a blue solid product Rh-N with a yield of 60%.

[0104] S2: The compound Rh-N (300 mg, 0.47 mmol) was dissolved in dichloromethane, and then PyBOP (247 mg, 0.47 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min. After that, hydrazine hydrate (0.2 mL, 4.70 mmol) was slowly added dropwise to the mixture, and stirring was continued in an ice bath for 30 min. The mixture was then moved to room temperature for 2 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v), and finally dried in vacuo to obtain a yellow solid product Rh-N-EHA.

[0105] S3: The compound Rh-N-EHA (82 mg, 0.15 mmol) was dissolved in dichloromethane, and then triethylamine (0.5 mL, 3.59 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min, and then acryloyl chloride (12 μL, 0.14 mmol) was slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then moved to room temperature for 5 h. The reaction was stopped and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain a light yellow solid product NIR-Rh-NH.

[0106] S4: ATTC (3.6 mg, 0.01 mmol), PEGMA (333 mg, 0.67 mmol), NIR-Rh-NH (30 mg, 0.05 mmol), and azobisisobutyronitrile (AIBN) (0.164 mg, 0.001 mmol) were dissolved in 2 mL of DMF. The mixture was vacuumed and filled with nitrogen for three cycles in a Shrek tube under ice bath conditions, and then the temperature was rapidly raised to 75 ° C for 6 h. After the reaction, the mixture was precipitated with ether and centrifuged six times. The supernatant was discarded and the precipitate was vacuum dried to obtain an oily light yellow photoswitch-controlled pH-responsive polymer P (PEG 30 -co-Rh6).

[0107] Preparation of pH-responsive polymer nanomicelles (named NRH) regulated by optical switch: 10 mg P(PEG 30-co-Rh6) was dissolved in 0.5 mL of tetrahydrofuran. The mixed solution was rapidly added to 10 mL of distilled water while sonicating for 10 minutes. The tetrahydrofuran was removed from the mixed solution by rotary distillation under reduced pressure at 30°C. The solution was then diluted to 10 mL with distilled water and filtered through a 0.22 μm filter to obtain 1 mg / mL of photoswitchable pH-responsive polymer nanomicelles (NRH).

[0108] Example 6

[0109] The structure of the photoswitchable pH-responsive polymer is shown below:

[0110]

[0111] The preparation method of the photoswitch-controlled pH-responsive polymer is as follows:

[0112]

[0113] S1: Compound 1 (1.7 g, 4 mmol) and 4-di-p-methoxyanilinobenzaldehyde (2.7 g, 8 mmol) were dissolved in 24 mL of glacial acetic acid. Under nitrogen protection, the mixture was stirred and refluxed at 90°C for 12 h. When the solution was observed to change from reddish brown to bluish black, the reaction was stopped and the solvent was removed by distillation under reduced pressure. The residue was washed with water, and the organic layer was collected and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v) and finally dried in vacuo to obtain a blue solid product Rh-O.

[0114] S2: The compound Rh-O (325 mg, 0.47 mmol) was dissolved in dichloromethane, and then PyBOP (247 mg, 0.47 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min, and then ethylenediamine (0.6 mL, 9.40 mmol) was slowly added dropwise to the mixture. The mixture was continued to be stirred in an ice bath for 30 min, and then moved to room temperature for 2 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v), and finally dried in vacuo to obtain a yellow solid product Rh-O-EHA.

[0115] S3: The compound Rh-O-EDA (110 mg, 0.15 mmol) was dissolved in dichloromethane, and then triethylamine (0.5 mL, 3.59 mmol) was added thereto. The mixture was stirred in an ice bath under nitrogen protection for 30 min, and then acryloyl chloride (12 μL, 0.14 mmol) was slowly added dropwise to the mixture. The mixture was stirred in an ice bath for 30 min, and then moved to room temperature for 5 h. The reaction was stopped, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography (DCM:MeOH=10:1, v / v), and finally dried in vacuo to obtain a light yellow solid product NIR-Rh-O.

[0116] S4: ATTC (3.6 mg, 0.01 mmol), PEGMA (497 mg, 0.67 mmol), NIR-Rh-O (40 mg, 0.05 mmol), and azobisisobutyronitrile (AIBN) (0.164 mg, 0.001 mmol) were dissolved in 2 mL of DMF. The mixture was vacuumed and filled with nitrogen for three cycles in a Shrek tube under ice bath conditions, and then the temperature was rapidly raised to 100 ° C for 6 h. After the reaction, the mixture was precipitated with ether and centrifuged six times. The supernatant was discarded and the precipitate was vacuum dried to obtain an oily light yellow photoswitch-controlled pH-responsive polymer P (PEG 44 -co-Rh7).

[0117] Preparation of pH-responsive polymer nanomicelles controlled by optical switch (named NRO): 10 mg P(PEG 44 -co-Rh7) was dissolved in 0.5 mL of tetrahydrofuran. The mixed solution was rapidly added to 10 mL of distilled water while sonicating for 10 minutes. The tetrahydrofuran was removed from the mixed solution by rotary distillation under reduced pressure at 30°C. The solution was then diluted to 10 mL with distilled water and filtered through a 0.22 μm filter to obtain 1 mg / mL of photoswitchable pH-responsive polymer nanomicelles NRO.

[0118] In summary, the pH-responsive polymer controlled by the optical switch of the present invention is an amphiphilic random copolymer based on a rhodamine backbone. Using a rhodamine dye scaffold as the matrix, the emission wavelength is increased to 760 nm by extending the conjugated chain length of the molecule and combining an effective donor-acceptor strategy (D-π-A), significantly enhancing the ability to resist background interference and tissue penetration depth. Synthetic small molecules are introduced into the polymer chain using RAFT polymerization technology, and the polymer can be self-assembled into polymer nanomicelles in aqueous solution by coprecipitation. These polymer nanomicelles have excellent biocompatibility and stability and exhibit ultraviolet light-controlled pH responsiveness, making them a novel drug controlled release carrier with excellent performance and unique functions. The polymer micelles exhibit a highly sensitive fluorescence response to pH under ultraviolet light irradiation, and their pH response behavior can be precisely controlled by light. This light-controlled property transforms the pH response from a single passive behavior to a process that can be actively controlled by external light. Based on this property, pH imaging of tumor sites under light control is achieved, providing a precise and controllable tool for tumor diagnosis and treatment.

[0119] The above description is only a specific embodiment of the present invention, not all embodiments. Any equivalent transformation of the technical solution of the present invention made by ordinary technicians in this field after reading the specification of the present invention is covered by the claims of the present invention.

Claims

1. A photoswitchable pH-responsive polymer, the structure of which is shown in formula (I): in, n1 and n2 are integers from 0 to 30; n3 is an integer from 8 to 50; a and b are integers from 1 to 100; R is selected from One of them.

2. The method for preparing a pH-responsive polymer controlled by a light switch according to claim 1, wherein: The following steps are involved: S1: Reaction, prepared S2: S1 made With benzotriazol-1-yl-oxytripyrrolidinophosphine hexafluorophosphate, Reaction, prepared S3: S2 made React with triethylamine and acryloyl chloride to prepare S4: The S3 and Azobisisobutyronitrile was prepared by RAFT polymerization.

3. The method for preparing a pH-responsive polymer controlled by an optical switch according to claim 2, wherein: S1 specifically includes the following steps: Will Dissolve in a solvent, under nitrogen protection, stir and reflux at 80-100°C for 12-24h to obtain described The molar ratio is 1:(1~2).

4. The method for preparing a pH-responsive polymer controlled by an optical switch according to claim 2, wherein: S2 specifically includes the following steps: The S1 was prepared Dissolve in a solvent, then add benzotriazole-1-yl-oxytripyrrolidinophosphine hexafluorophosphate, stir in an ice bath under nitrogen protection for 15 to 30 minutes; then slowly add dropwise Continue stirring under ice bath for 15-30 min and then move to room temperature to react for 2-6 h to obtain described Benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate and The molar ratio is 1:(1-1.5):(10-30).

5. The method for preparing a pH-responsive polymer controlled by an optical switch according to claim 2, wherein: S3 specifically includes the following steps: S2 was prepared Dissolve in a solvent, add triethylamine, stir in an ice bath under nitrogen protection for 15 to 30 minutes; then slowly add acryloyl chloride dropwise, continue stirring in an ice bath for 15 to 30 minutes, then move to room temperature and react for 4 to 6 hours to obtain described The molar ratio of triethylamine to acryloyl chloride is 1:(10-30):(0.5-3).

6. The method for preparing a pH-responsive polymer controlled by an optical switch according to claim 2, wherein: S4 specifically includes the following steps: The S3 was prepared Azobisisobutyronitrile is dissolved in a solvent, and the container is vacuumed and filled with nitrogen for several cycles under ice bath conditions, and then the temperature is quickly raised to 40-130°C and reacted for 5-7 hours to obtain described The molar ratio of azobisisobutyronitrile to azobisisobutyronitrile is (1-100):(50-800):(1-50):(0.1-10).

7. A pH-responsive polymer nanomicelle regulated by a light switch, characterized in that: Prepared by the following method: The pH-responsive polymer controlled by the optical switch according to claim 1 is self-assembled in an aqueous solution by a coprecipitation method to prepare pH-responsive polymer nanomicelles controlled by the optical switch.

8. The pH-responsive polymer nanomicelles controlled by optical switching according to claim 7, characterized in that: Prepared by the following method: The pH-responsive polymer controlled by the optical switch according to claim 1 is dissolved in a solvent to obtain a mixed solution, the mixed solution is quickly added to water under ultrasonic conditions, and the ultrasonication is continued for 10 to 30 minutes to obtain the pH-responsive polymer nanomicelles controlled by the optical switch.

9. Use of the photoswitch-controlled pH-responsive polymer of claim 1 or the photoswitch-controlled pH-responsive polymer nanomicelles of any one of claims 7 to 8 in the preparation of a drug delivery vehicle.

10. Use of the photoswitch-controlled pH-responsive polymer of claim 1 or the photoswitch-controlled pH-responsive polymer nanomicelles of any one of claims 7 to 8 in the preparation of tumor diagnostic products or real-time tumor monitoring products.

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