A nano-drug composition for photo-triggered pyroptosis and a preparation method and application thereof

Abstract

This invention proposes a photo-triggered pyroptosis nanomedicine composition, its preparation method, and its application, belonging to the field of pharmaceutical technology. The nanomedicine composition consists of spherical nanoparticles with a core-shell structure: an outer carrier (bovine serum albumin); a middle photothermal agent (poly(dithiophene-pyrrolopyrroledione); and a core demethylating agent (lipophilic demethylating agent RG108). This invention achieves successful triggering of pyroptosis and a sustained anti-tumor immune cycle with only a single dose and minimal light exposure, significantly improving the response rate of immunotherapy and providing a novel and highly innovative strategy for photo-immunotherapy of tumors.

Description

Technical Field

[0001] This invention relates to the field of nanomedicine technology, specifically to a photo-triggered pyrolysis nanomedicine composition, its preparation method, and its application. Background Technology

[0002] In the current field of cancer treatment, phototherapy based on nanomaterials (such as photothermal therapy, PTT) has become a promising technology. These photofunctional nanomaterials can not only efficiently convert light energy into heat energy to achieve precise physical ablation of tumor tissue, but their induced cell death process is also expected to serve as an effective signal to activate the host's own immune system.

[0003] However, existing nanomaterials for phototherapy still have significant limitations in their functional design. Typically, conventional photothermal nanoparticles have relatively simple functions, and their therapeutic effects mainly rely on the instantaneous physical killing effect under light irradiation. The resulting immune stimulation is limited and fails to generate a highly effective immune response. This over-reliance on external energy input not only increases the complexity of treatment and the burden on patients but also carries the risk of phototoxic damage to normal tissues.

[0004] The reason lies in the fact that the design of existing photothermal nanomaterials fails to deeply integrate photocontrolled local physical ablation with efficient systemic immune activation. Although these materials are excellent photothermal converters, they cannot regulate the subsequent biological effects of cell death, leading to the disruption of the anti-tumor immune response chain. Therefore, there is an urgent need in this field to design a novel multifunctional nanomaterial that can not only achieve efficient photothermal killing under light irradiation, but also actively induce a highly immunogenic programmed cell death mode—pyroptosis—thereby breaking through the bottleneck of existing technologies. Summary of the Invention

[0005] Based on the above-mentioned problems, the primary objective of this invention is to provide a photo-triggered pyroptosis nanomedicine composition. This composition can synergistically exert photothermal therapy and demethylation effects, lower the pyroptosis threshold, and transform photothermally induced local therapy into a systemic anti-tumor immune response.

[0006] A second objective of this invention is to provide a method for preparing the aforementioned nanomedicine combination. This method should be simple to operate, operate under mild conditions (such as ultrasonic emulsification based on protein self-assembly), be suitable for large-scale preparation, and possess good biocompatibility.

[0007] The third objective of this invention is to provide the application of the above-mentioned nanomedicine combination in the preparation of anti-tumor drugs and drugs that activate long-acting immune memory in the body.

[0008] This invention designs and constructs a nano-drug delivery platform with high biocompatibility that enables efficient co-delivery of near-infrared photothermal materials and epigenetic regulatory drugs (demethylated drugs).

[0009] The technical solution of this invention is implemented as follows:

[0010] This invention provides a photo-triggered pyrolysis nanomedicine composition, wherein the nanomedicine composition consists of spherical nanoparticles with a core-shell structure, the outer carrier being bovine serum albumin; the middle photothermal agent being poly(dithiophene-pyrrolopyrroledione); and the core demethylating agent being the lipid-soluble demethylating agent RG108.

[0011] As a further improvement of the present invention, the composition has a particle size distribution of 65-135 nm under transmission electron microscopy, a hydrated particle size of about 300-350 nm, and a polymer dispersibility index of 0.2-0.4; and has strong light absorption in the range of 600 nm to 900 nm, with a characteristic absorption peak located between 760-800 nm, and strong absorption of near-infrared light at 808 nm.

[0012] Preferably, the nanomedicine composition has a particle size distribution of 100±34nm under transmission electron microscopy (TEM), a hydrated particle size of about 320nm, and a polymer dispersibility index (PDI) of about 0.3; and exhibits strong light absorption in the range of 600nm to 900nm, with a characteristic absorption peak at about 780nm, and strong absorption of near-infrared light at 808nm.

[0013] This invention further protects a method for preparing the above-mentioned phototriggered pyrolysis nanomedicine composition, comprising the following steps:

[0014] Step 1: Preparation of the organic phase of the photothermal agent: Using chloroform as a solvent, the photothermal agent poly(dithiophene-pyrrolopyrroledione) is dissolved to obtain the organic phase of the photothermal agent;

[0015] Step 2: Preparation of the organic phase of the demethylated drug: Dichloromethane was used as a solvent to dissolve the lipid-soluble demethylated drug RG108 to obtain the organic phase of the demethylated drug;

[0016] Step 3: Preparation of the carrier aqueous phase: Bovine serum albumin is dissolved in an acidic aqueous solution to obtain the carrier aqueous phase;

[0017] Step 4: Ultrasonic Emulsification: Mix the photothermal agent organic phase, the demethylated drug organic phase, and the carrier aqueous phase, place them in an ice bath, and perform ultrasonic emulsification to obtain a homogeneous emulsion;

[0018] Step 5: Oil phase removal and purification: The organic solvent in the homogeneous emulsion is removed by vacuum evaporation to obtain a clear solution, which is then filtered to obtain the photo-triggered pyrolysis nanomedicine composition.

[0019] As a further improvement of the present invention, the mass-to-volume ratio of the photothermal agent poly(dithiophene-pyrrolopyrroledione) and chloroform in step 1 is 3-7:1 mg / mL.

[0020] As a further improvement of the present invention, the mass-to-volume ratio of the lipid-soluble demethylating drug RG108 and dichloromethane in step 2 is 1-3:0.1-0.3 mg / mL.

[0021] As a further improvement of the present invention, the pH value of the acidic aqueous solution in step 3 is 4.5-5.5.

[0022] As a further improvement of the present invention, the power of the ultrasonic emulsification process in step 4 is set to 550-650W, and a pulse mode of "2 seconds of ultrasonication, 1 second of off" is adopted, with a total ultrasonic time of 8-12 minutes.

[0023] Preferably, the ultrasonic power is set to 600W. Under this condition, the aqueous and oil phases form a uniform oil-in-water emulsion.

[0024] As a further improvement of the present invention, the filtration in step 5 uses a filter membrane with a pore size of 700 nm.

[0025] This invention further protects the application of the above-mentioned photo-triggered pyroptosis nanomedicine composition in the preparation of anti-tumor drugs and drugs that activate long-acting immune memory in the body.

[0026] After the DR@BSA nanomedicine of the present invention enters the tumor tissue, it induces pyroptosis under the activation of 808nm near-infrared light according to the following procedure.

[0027] The present invention has the following beneficial effects:

[0028] 1. Achieve long-lasting damage with a single light exposure, significantly reducing the frequency of treatment:

[0029] Existing photothermal therapies typically require repeated drug administration and light exposure. This invention creatively co-loads a photothermal agent (DPPT-TT / DPP-DTT) with a demethylating drug (RG108). A single 808nm laser irradiation is sufficient to not only recruit immune cells by inducing pyroptosis through the Caspase3 / GSDME pathway, but also to upregulate GSDME via RG108, enabling recruited immune cells to undergo pyroptosis through the granzyme / GSDME pathway.

[0030] 2. Strong photothermal conversion capability targeting deep tumors:

[0031] The absorption peak of the photo-triggered pyrolysis nanomedicine composition is around 780 nm, exhibiting extremely strong absorption of 808 nm near-infrared light. The 808 nm laser falls within the near-infrared absorption window of biological tissues, demonstrating strong tissue penetration. In an in vivo tumor model, only a low dose of 1.5 mg / kg and gentle light irradiation of 0.4 W / cm² for 10 minutes are required to rapidly raise the temperature of the tumor site to approximately 50 °C, exhibiting a photothermal conversion efficiency far exceeding that of conventional formulations. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the synthesis steps of the DR@BSA nanomedicine assembly of the present invention.

[0034] Figure 2 Transmission electron microscopy (TEM) images and particle size distribution histograms of the DR@BSA nanomedicine prepared in Example 1 of this invention; (a) TEM image of DR@BSA, scale bar: 1000 nm; (b) Statistical analysis of particle size distribution of DR@BSA in TEM image.

[0035] Figure 3 This is the UV-Vis absorption spectrum of the DR@BSA nanomedicine of this invention. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1: Preparation and morphology characterization of phototriggered pyrolysis nanomedicine compositions

[0038] This embodiment illustrates the specific preparation process of the core drug of this invention.

[0039] Preparation process: such as Figure 1As shown, an ultrasonic disruption emulsification method was employed. 5 mg of the photothermal agent DPPT-TT / DPP-DTT was completely dissolved in 1 mL of chloroform; 2 mg of the demethylating agent RG108 was completely dissolved in 200 μL of dichloroform; and 35 mg of BSA was completely dissolved in water with a pH of 5. The mixture was then placed in an ice bath and emulsified using an ultrasonic disruptor (600W power, 2 seconds sonication followed by 1 second off, total time 10 minutes). Subsequently, a rotary evaporator was used to remove the organic solvent (oil phase), and finally, the mixture was filtered through a 700 nm pore size filter membrane to remove free precipitate, yielding a clear DR@BSA aqueous solution.

[0040] Morphological characteristics: such as Figure 2 As shown, transmission electron microscopy (TEM) revealed that the prepared DR@BSA nanomedicine exhibited a uniform spherical structure. Particle size statistical analysis indicated an average particle size distribution of 100 ± 34 nm. This hydrated particle size facilitates excellent penetration and retention at tumor sites through high permeability and the efficient permeability-retention effect (EPR effect).

[0041] Example 2: Spectroscopic Validation of DR@BSA Nanomedicine

[0042] This embodiment verifies the physicochemical stability that the present invention must possess before clinical administration.

[0043] Spectral characteristics: such as Figure 3 As shown, the synthesized DR@BSA exhibits a clear, dark green color. UV-Vis absorption spectroscopy reveals strong absorption in the 600-900 nm near-infrared region, with an absorption peak around 780 nm, and retains the characteristic absorption peak of RG108 at 280 nm, confirming successful encapsulation of both drugs. In this embodiment, 808 nm near-infrared light was selected as the subsequent excitation source.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photo-triggered pyrolysis nanomedicine composition, characterized in that, The nanomedicine assembly consists of spherical nanoparticles with a core-shell structure. The outer carrier is bovine serum albumin; the middle photothermal agent is poly(dithiophene-pyrrolopyrroledione); and the core demethylating agent is the lipid-soluble demethylating agent RG108.

2. The photo-triggered pyrolysis nanomedicine composition according to claim 1, characterized in that, The composition has a particle size distribution of 65-135 nm under transmission electron microscopy, a hydrated particle size of about 300-350 nm, and a polymer dispersibility index of 0.2-0.4; it also has strong light absorption in the range of 600 nm to 900 nm, a characteristic absorption peak between 760-800 nm, and strong absorption of near-infrared light at 808 nm.

3. A method for preparing a phototriggered pyrolysis nanomedicine composition as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1: Preparation of the organic phase of the photothermal agent: Using chloroform as a solvent, the photothermal agent poly(dithiophene-pyrrolopyrroledione) is dissolved to obtain the organic phase of the photothermal agent; Step 2: Preparation of the organic phase of the demethylated drug: Dichloromethane was used as a solvent to dissolve the lipid-soluble demethylated drug RG108 to obtain the organic phase of the demethylated drug; Step 3: Preparation of the carrier aqueous phase: Bovine serum albumin is dissolved in an acidic aqueous solution to obtain the carrier aqueous phase; Step 4: Ultrasonic Emulsification: Mix the photothermal agent organic phase, the demethylated drug organic phase, and the carrier aqueous phase, place them in an ice bath, and perform ultrasonic emulsification to obtain a homogeneous emulsion; Step 5: Oil phase removal and purification: The organic solvent in the homogeneous emulsion is removed by vacuum evaporation to obtain a clear solution, which is then filtered to obtain the photo-triggered pyrolysis nanomedicine composition.

4. The preparation method according to claim 3, characterized in that, The mass-to-volume ratio of the photothermal agent poly(dithiophene-pyrrolopyrroledione) and chloroform in step 1 is 3-7:1 mg / mL.

5. The preparation method according to claim 3, characterized in that, In step 2, the mass-to-volume ratio of the lipid-soluble demethylating drug RG108 to dichloromethane is 1-3:0.1-0.3 mg / mL.

6. The preparation method according to claim 3, characterized in that, The pH value of the acidic aqueous solution mentioned in step 3 is 4.5-5.

5.

7. The preparation method according to claim 3, characterized in that, The power of the ultrasonic emulsification process in step 4 is set to 550-650W, and a pulse mode of "2 seconds of ultrasound, 1 second of off" is adopted, with a total ultrasound time of 8-12 minutes.

8. The preparation method according to claim 3, characterized in that, The filtration described in step 5 uses a filter membrane with a pore size of 700 nm.

9. The use of a photo-triggered pyroptosis nanomedicine composition as described in claim 1 or 2 in the preparation of antitumor drugs and drugs that activate long-acting immune memory in the body.

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