Prodrug composition and method for catalytic activation of drug by radiation

Abstract

A prodrug composition comprising a precatalyst and a predrug molecule. The precatalyst consists of a carrier and a coordination molecule, wherein the coordination molecule is a divalent palladium salt. The prodrug molecule comprises alkenyl or alkynyl. After being irradiated, the precatalyst can be induced to be reduced into zero-valent palladium, and the zero-valent palladium catalyzes the prodrug molecule to produce an active drug. A method for catalytic activation of a drug by radiation.

Description

A prodrug composition and a method for activating a drug by radiation catalysis

[0001] Cross-references

[0002] This application claims priority to Chinese Patent Application No. 2023118567491, filed on December 29, 2023, entitled “A Prodrug Composition and Method for Radiation-Catalyzed Drug Activation,” the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to the field of radiation chemistry technology, and in particular to a prodrug composition and a method for activating a radiation-catalyzed drug. Background Art

[0004] According to the World Health Organization, cancer cases and deaths are rapidly increasing, and cancer is projected to become the leading cause of death worldwide in the 21st century. Chemotherapy and radiotherapy are effective treatments for inhibiting the continued growth of tumor cells. However, chemotherapy drugs circulate in the blood and are distributed throughout most organs and tissues in the body, resulting in poor selectivity. Radiotherapy can also damage normal cells near tumor cells, resulting in significant side effects. Furthermore, the sensitivity of tissues in the irradiated area decreases, making secondary chemotherapy impossible. Due to the complex and variable nature of cancer, traditional single-treatment approaches are no longer sufficient. To address these challenges, researchers have proposed a variety of methods to improve the effectiveness of tumor treatment.

[0005] Photodynamic therapy (PDT) and photothermal therapy (PTT) are currently the main novel cancer treatments, which eliminate cancer cells by generating reactive oxygen species (ROS) or increasing the temperature at the lesion site. Significant progress has been made in understanding the biological effects of PDT and PTT at the cellular, vascular, and tumor microenvironmental levels, as well as in their clinical translation. There is also substantial evidence that PDT and PTT can exert synergistic effects through distinct mechanisms of action, and their non-overlapping toxicity profiles make this combination potentially effective. PDT can protect surrounding collagen structures and nerves. Furthermore, due to the short diffusion distance of ROS, PDT can be used to target both invasive and non-expandable tumor components. For some photosensitizers, accumulation in the eye and skin may cause photosensitivity, compromising safety. Unlike PDT, PTT's selectivity relies primarily on localized light delivery, which inevitably generates temperature gradients. The lack of a thermal confinement mechanism can lead to additional thermal damage, increasing the risk of adverse reactions. Another important difference between PDT and PTT is the type of light source required. Because PDT uses low fluence rates and total flux, it can be used with various light-emitting diodes, relatively inexpensive low-power lasers, and even sunlight to excite the photosensitizer. PTT, on the other hand, requires more expensive, higher-energy lasers, complex fiber-optic cooling, and online temperature monitoring. However, both PDT and PTT are affected by the depth of illumination, resulting in poor therapeutic effects within the body. Therefore, they are more commonly used clinically for superficial skin treatments.

[0006] Currently, research is leveraging the advantages of organometallic chemistry to utilize transition metals for bond cleavage reactions. Compared to other methods, metals offer enhanced tissue / cell penetration, are less susceptible to reactive oxygen species formation, exhibit lower cytotoxicity, and exhibit higher selectivity. In recent years, transition metals have seen numerous applications in the life sciences. Palladium, a relatively low-toxic transition metal, can successfully activate caged molecules, including fluorescent compounds, drugs, and the acid side chains of intact proteins, enabling the synthesis of bioactive drugs within living cells. The mechanism of zero-valent palladium depropylation has been reported in the literature, with the traditional Tsuji-Trost reaction being one of its primary mechanisms. This mechanism involves oxidative addition, reaction with water, and reductive elimination, ultimately generating active palladium for subsequent catalytic conversion. In 2011, Bradley et al. reported the use of cell-transmembrane-capable resin microspheres loaded with pre-prepared zero-valent palladium nanoparticles as catalysts for the hydrolysis of allyl carbamates. In 2022, Gu Zhen's research group developed smart microneedles containing titanium dioxide nanosheets loaded with zero-valent palladium particles, which catalyze the detachment of tumor drugs from the skin, thereby activating the release of drugs at the tumor site.

[0007] In 2020, Professor Zhibo Liu of Peking University reported a decaging reaction induced by radiation-generated hydroxyl radicals, and used it for radiotherapy-targeted activation of rhodamine molecules, anticancer drugs MMAE, etc. The Mark Bradley team used X-ray irradiation to mediate the activation of cancer prodrugs, achieving synchronous chemotherapy and radiotherapy and local activation of prodrugs by radiotherapy. They used ionizing radiation to release sulfonated azide and phenyl azide prodrugs of pazopanib and doxorubicin for real-time drug degradation at the tumor site. In 2022, Professor Zhibo Liu's team developed a delivery strategy using X-ray-induced hydrated electrons to activate nitrogen oxide drugs, as well as a strategy for prodrug activation through radiation-induced cleavage of quaternary ammonium groups. The main limiting factor of this type of strategy is the active species generated by radiation in water, including hydrated electrons, hydroxyl radicals, etc., which usually have low yields, which fundamentally restricts the sensitivity of its radiation response and determines that it requires a higher radiation dose.

[0008] However, the existing technology still has the following technical problems: (1) Problems with phototherapy include: limited penetration depth, which is effective for the treatment of epidermal tumors, but cannot treat deep parts; there is skin phototoxicity, and drugs released in non-tumor areas will cause damage to the skin. (2) Problems with palladium catalysis: materials circulating in the blood may activate drugs in non-tumor areas to detach from the cage, causing the drugs to harm normal tissues. The reduction of metal ions to nanoparticles will increase the surface energy as the particle size decreases, which usually leads to severe aggregation of small particles. In order to avoid aggregation, various stabilizers, such as polymers and different types of ligands, are used as capping agents to stabilize palladium nanoparticles. However, they may severely limit catalytic activity and biodegradability leads to bioaccumulation and long-term toxicity. In addition, the method of using chemical reducing agents has poor spatiotemporal controllability, which is not conducive to targeted therapy. (3) Low-dose radiation has limited therapeutic effect on tumors, and high-dose radiation is difficult for the human body to withstand, so there is a certain contradiction in tumor treatment. (4) Previous strategies usually focus on radiation chemistry in water. Water radiolysis generates reactive species such as free radicals, hydrated electrons, and H₂O₂, which participate in or induce secondary reactions, further causing changes in the system. The main limitation of this type of strategy is that the yield of reactive species generated by water radiation is generally low, which fundamentally restricts the sensitivity of its radiation response.

[0009] In view of this, the present invention is proposed. Summary of the Invention

[0010] The purpose of the present invention is to provide a prodrug composition and a method for radiation-catalyzed drug activation. By combining radiation chemistry and catalytic chemistry, the problem of high-dose ionizing radiation and the limitations of transition metal reduction catalysis can be solved. Drug release can be controlled at lower radiation doses, achieving spatially and temporally controllable activation, thereby greatly reducing systemic cytotoxicity and minimizing potential side effects of the drug.

[0011] The specific technical solutions of the present invention are as follows:

[0012] In a first aspect, the present invention provides a prodrug composition comprising: a procatalyst and a prodrug molecule; wherein the procatalyst is composed of a carrier and a coordination molecule; the coordination molecule is a divalent palladium salt, and the prodrug molecule contains an alkenyl group or an alkynyl group;

[0013] The procatalyst can be induced to be reduced to zero-valent palladium after being irradiated, and then the zero-valent palladium catalyzes the prodrug molecule to catalytically generate an active drug.

[0014] Utilizing the controlled dissociation of chemical bonds induced by medical radiotherapy to release or activate them is a promising strategy for radiotherapy-induced targeted chemotherapy. However, conventional radiotherapy-chemotherapy combinations currently employ a prodrug approach in which a functional molecule is released upon irradiation to unleash biological activity. For example, patent CN114539320A discloses a radiation-activated tetravalent platinum complex and its uses. This approach uses high-energy radiation as an external trigger for activating a precursor ligand. Because the radiation-induced chemical reaction can be controlled spatially and temporally, the area, time, and dose over which the precursor ligand is converted to its active form can be precisely controlled. However, this method utilizes hydrated electrons—primary active species generated by radiation—to undergo chemical reactions, and the ability to activate the platinum complex still directly depends on the radiation dose. Due to the low yield of hydrated electrons generated by radiation (280 nM / Gy), the radiation dose required for this method remains relatively high. The minimum dose used in this invention is 4 Gy, which is still higher than the 2 Gy daily dose available for clinical radiotherapy patients.

[0015] The present invention, by combining radiation chemistry and catalytic chemistry, proposes a novel concept of radiation-driven catalysis: ionizing radiation activates procatalytic centers, catalyzing the activation of prodrug compounds or the release of drugs, thereby producing active drugs and reducing or avoiding the limitation of radiation-generated primary active species. Using the prodrug compositions and methods of the present invention, 1 Gy of irradiation can produce significant cytotoxicity.

[0016] Specifically, a high-molecular-weight polymer is used as a carrier to coordinately load transition metal ions, achieving radioreduction of the transition metal and activation of its catalytic activity under the action of ionizing radiation. High-energy radiation irradiation can generate active species in water, such as hydrated electrons, hydroxyl radicals, hydrogen radicals, and hydrogen peroxide. Hydrated electrons or hydrogen radicals have low reduction potentials and can be reduced to produce catalytically active zero-valent palladium. Zero-valent palladium can catalyze the deprotection of allyloxycarbonyl or propargyloxycarbonyl groups, activating drug release only at the tumor site, improving the therapeutic effect at the tumor site and reducing damage to normal tissue. Furthermore, zero-valent palladium can catalyze reactions such as cross-coupling. Furthermore, the present invention utilizes biocompatible and bioorthogonal palladium as a catalyst for radioactive bond cleavage, thereby reducing the minimum irradiation dose required and providing a new material for concurrent chemoradiotherapy.

[0017] Preferably, the prodrug molecule has the structure shown in the figure:

[0018] The D is an imaging agent or a therapeutic agent for treating cancer, including but not limited to rhodamine, coumarin, luciferin, 5-fluorouracil, gemcitabine, doxorubicin hydrochloride, monomethyl auristatin E, monomethyl auristatin F, mitoxantrone or protein degradation targeting chimera (PROTAC); the M is a chemical group that can be catalyzed by palladium, including but not limited to: The D and the M can be combined arbitrarily.

[0019] Preferably, the mass ratio of the procatalyst to the prodrug molecule is 1 to 230:1; more preferably, the mass ratio of palladium to the prodrug molecule is 0.1 to 2:1; further preferably, the mass ratio of palladium to the prodrug molecule is 1 to 1.5:1.

[0020] In the present invention, the carrier can be a nitrogen-containing small molecule, such as a small molecule without aromatic rings and aromatic heterocycles: ammonia, methylamine, ethylamine, propylamine, dimethylamine, trimethylamine, acetyleneamine, urea, pentamethylenediamine, acridine, thiazole, acridinedione, imidazole, pyridone, acridinol, thiazoline, acridinone, imidazolone, pyridazinol, acridinone, pentanoneamine, acridinesulfonamide, pyridazinamine alcohol, acridinium methanol, pentamethylenediamine ketone, imidazolinone, pentanolamine, thiazoloneamine, propylamine ketone, etc.; nitrogen-containing aromatic and heteroaromatic groups: aminophenyl, methyleneaniline, dimethylaminophenyl, pyridyl, pyridazinyl, imidazolyl, acridinyl, pyranyl, pyrrolyl, quinolyl, pyrimidinyl, acridanyl, pyridazin ... The alkyl ligands include pyridinedione, carbazole, quinolinone, acridone, pyridazinone, pyridinemethanol, pyridazinesulfonyl, acridone, imidazolinone, acridone methyl ester, pyridazinyl methyl ester, imidazolinedione, pyridone, thienyl, acryldione, pyrone, cyanurea, isocyanuric acid, triazinol, diethylene glycol triazine, triazinone, triazinamine, triazine ester, triazine sulfide, triazinemethanol, etc., and some nitrogen-containing multidentate organic ligands, the structural formula of which is shown below; it can also be some polymers, such as metal organic frameworks (MOFs), covalent organic frameworks (COFs), molecular sieves, mesoporous materials, porous polymers, etc., which are not limited here.

[0021] The structural formula of the nitrogen-containing multidentate organic ligand is shown below:

[0022] Among them, 1a: R = benzyl (TBTA); 1b: R = tert-butyl (TTTA); 1c: R = CH2CH2CH2OH (THPTA); 1d: R = CH2CH2CO2H; 1e: R = CH2C8H4CO2H;

[0023] Among them, 4a: R=OH; 4b: R=OBn.

[0024] Preferably, the carrier is a porous organic polymer, and the pore size of the porous organic polymer is

[0025] In the present invention, the reduced zero-valent Pd gradually aggregates from small nanoclusters into nanoparticles, and then gradually forms larger microparticles. This aggregation weakens the catalytic activity of the zero-valent Pd. Therefore, the present invention uses a porous polymer to stabilize the Pd nanoparticles, reduce particle aggregation, and enhance the catalytic ability of the zero-valent Pd.

[0026] Preferably, the mass ratio of the porous organic polymer to palladium is 1:(1-1.5).

[0027] In a second aspect, the present invention provides a method for radiation-catalyzed drug activation, comprising:

[0028] The prodrug composition is irradiated using a radiation source to induce reduction of the procatalyst to zero-valent palladium, and then the zero-valent palladium catalytically activates the prodrug molecule.

[0029] Preferably, the method for radiation-catalyzed drug activation comprises: first irradiating the procatalyst in the prodrug composition to induce its reduction to zero-valent palladium, and then catalytically activating the prodrug molecule with the zero-valent palladium.

[0030] In the present invention, the radiation-catalyzed drug activation method is not only applicable to palladium-catalyzed hydrolysis reactions or decaging reactions, but can also be used for coupling reactions, such as palladium-catalyzed Suzuki coupling reactions, Sonogashira coupling reactions, etc.

[0031] Preferably, the method for activating the radiation-catalyzed drug comprises: incubating cancer cells in a culture medium, adding the procatalyst, water and the prodrug molecule to the culture medium, continuing to culture, and then subjecting the cells to ionizing radiation;

[0032] More preferably, the method for activating the radiation-catalyzed drug is performed in the following order:

[0033] S1: incubating cancer cells in a culture medium, adding the procatalyst and water to the culture medium and continuing to culture, and then subjecting the cells to ionizing radiation;

[0034] S2: adding the prodrug molecule to the culture medium for reaction.

[0035] The present invention has found that following the above-mentioned sequence of operations, i.e., adding the prodrug molecule after ionizing radiation, is conducive to efficiently obtaining highly active zero-valent palladium and effectively catalytically activating the prodrug molecule.

[0036] Further preferably, after the ionizing radiation in S1, the propyl group-containing prodrug molecule is added within 24 to 28 hours, which can effectively ensure the catalytic activity of zero-valent palladium and is conducive to the activation of the prodrug compound or the release of the drug.

[0037] Preferably, the radiation source includes α rays, β rays or γ rays produced by the decay of radioactive nuclides; or X-rays, γ rays, high-energy electrons, protons, heavy ions or α particles produced by boron neutron capture therapy generated by external radiation sources, and other possible exogenous or endogenous radiation.

[0038] More preferably, the irradiation dose of the radiation source is 0.1 to 100 Gy; further preferably, the irradiation dose of the radiation source is 1 to 20 Gy.

[0039] Preferably, the method for activating the radiation-catalyzed drug further comprises: adding isopropanol or DMSO to the culture medium.

[0040] Preferably, the catalytic activation time is 20 to 30 hours.

[0041] In a third aspect, the present invention provides application of the above-mentioned method for activating a radiation-catalyzed drug in the treatment of cancer.

[0042] In a fourth aspect, the present invention provides use of the above-mentioned prodrug composition in treating cancer.

[0043] Based on the above technical solution, the beneficial effects of the present invention are:

[0044] By combining radiation chemistry with catalytic chemistry, this method leverages the precision of radiation and the potent cytotoxicity of chemotherapy drugs to control drug release at lower radiation doses, achieving spatial and temporal control. This significantly reduces systemic cytotoxicity and potential drug side effects, potentially promising promising clinical applications. Furthermore, combining radiotherapy with chemotherapy facilitates controlled drug release, minimizing the damage caused by drug toxicity. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] FIG1 is a synthesis route diagram of the porous organic polymer POP in Example 1 provided by the present invention;

[0047] Figure 2 a is a transmission electron micrograph of the porous organic polymer POP material in Example 1 provided by the present invention; Figure 2 b is a transmission electron micrograph of the POP / Pd material before γ-ray irradiation in Example 1 provided by the present invention; Figure 2 c is a transmission electron micrograph of the POP / Pd material after γ-ray irradiation in Example 1 provided by the present invention;

[0048] FIG3 is a diagram showing the element distribution test results of the POP / Pd material in Example 1 provided by the present invention; FIG3 a is a HAADF-STEM image and element distribution diagram; FIG3 b is an energy spectrum analysis element result diagram;

[0049] FIG4 is a synthetic route diagram of N-allyloxycarbonylrhodamine 110 in Example 1 provided by the present invention;

[0050] FIG5 is a diagram of N-allyloxycarbonyl rhodamine 110 in Example 1 provided by the present invention. 1 H NMR spectrum;

[0051] FIG6 is a fluorescence standard curve diagram of different concentrations of Rhodamine 110 in Example 1 provided by the present invention.

[0052] FIG7 is a fluorescence spectrum of catalytic detachment induced by different doses of irradiation in Example 1 provided by the present invention;

[0053] FIG8 shows the results of the catalytic effect of radiation in Example 1 provided by the present invention; FIG8 a shows the results of catalytic detachment of POP and Pd by radiation at different mass ratios, FIG8 b shows the results of fluorescence detachment with the addition of different quenchers, FIG8 c shows the results of the effects of three different conditions on fluorescence detachment, and FIG8 d shows the results of the effects of three different conditions on fluorescence detachment over time;

[0054] Figure 9 a is a flowchart of the intracellular irradiation catalysis experiment in Example 2 provided by the present invention; Figure 9 b is a confocal image of fluorescence uncaging at different doses in cells in Example 2 provided by the present invention; Figure 9 c is a fluorescence quantitative analysis diagram in Figure b;

[0055] FIG10 is a flowchart of irradiated drug activation in Example 3 provided by the present invention;

[0056] FIG11 is a graph showing the cytotoxicity test results of POP / Pd, Pro-DOX, and DOX at different concentrations on A549 cells in Example 3 provided by the present invention; FIG11 a is a graph showing the cytotoxicity test results of POP / Pd at different concentrations on A549 cells, and FIG11 b is a graph showing the cytotoxicity test results of Pro-DOX and DOX at different concentrations on A549 cells;

[0057] Figure a in Figure 12 is a graph showing the cell activity results of the prodrug catalytically activated by different influencing factors in Example 3 provided by the present invention; Figure b in Figure 12 is a graph showing the effects of different doses of irradiation on cell activity in Example 3 provided by the present invention. DETAILED DESCRIPTION

[0058] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0059] Unless otherwise specified, the various raw materials used in the examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0060] Example 1: Irradiation-catalyzed POP / Pd verification of Pro-Rh110 fluorescence detachment

[0061] This embodiment first provides a method for activating a radiation-catalyzed drug, which specifically includes the following steps:

[0062] 1. Synthesis of porous polymer / palladium material (POP / Pd)

[0063] In this embodiment, the aperture is selected as A porous organic polymer was used as a carrier for divalent Pd coordination and zero-valent Pd nanoparticles. Equal amounts of triphenylaldehyde and p-phenylenediamine were dissolved in 1,4-dioxane under nitrogen protection. Acetic acid at a concentration of 3M was added dropwise and allowed to react for three days, yielding a yellow solid, a porous organic polymer (POP). The synthesis route is shown in Figure 1. POP was then used as a palladium carrier, with palladium acetate selected as the coordination molecule. Pd acetate and POP were stirred in a mass ratio of 1.5:1 to form a coordination bond, yielding a POP / Pd solid.

[0064] Transmission electron microscopy (TEM) revealed a layered structure of POP, as shown in Figure 2(a). This is due to the π-π stacking interactions between adjacent layers, forming coplanar aggregates. After Pd coordination, the layered morphology remained unchanged, as shown in Figure 2(b). After irradiation with 20 Gy of gamma rays, a distinct granular structure was observed, as shown in Figure 2(c). This is due to the hydrated electrons generated by the irradiation reducing the divalent Pd to zero-valent Pd nanoparticles.

[0065] Even at a low dose of 1 Gy, the formation of Pd nanoparticles was observed using scanning transmission electron microscopy, and elemental distribution was tested. As shown in Figure 3, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and POP / Pd elemental mapping confirmed that C, N, and Pd were uniformly distributed in the POP material, and energy dispersive spectrometer (EDS) analysis revealed the presence of all three elements. The Pd content of the irradiated sample was determined using inductively coupled plasma mass spectrometry (ICP-MS), yielding a Pd content of 5.74 wt%.

[0066] 2. Synthesis of caged molecule N-allyloxycarbonylrhodamine (Pro-Rh110)

[0067] Rhodamine 110 (Rh110) (50 mg) and pyridine (70 μL) were dissolved in 700 μL of ultra-dry dimethylformamide (DMF) and sonicated for complete dissolution. The reaction mixture was then purged with nitrogen and placed in an ice bath at 0°C. Allyl chloroformate (52 μL) was added to the solution, and the resulting reaction solution was warmed to room temperature and stirred overnight. After 24 hours, ethyl acetate was added to the solution, and the product was washed twice with an equal volume of 5% hydrochloric acid solution and twice with saturated sodium bicarbonate solution. The ethyl acetate phase was collected, dried over anhydrous MgSO4, and concentrated on a rotary evaporator. The resulting oily liquid was collected in ethyl acetate and purified on a silica gel column using petroleum ether / ethyl acetate (2:1) as the eluting solvent. The collected fraction was concentrated to dryness to yield Pro-Rh110 as a white solid (22.6%).

[0068] The synthetic route is shown in Figure 4. 1 H NMR is shown in Figure 5.

[0069] 3. Catalytic properties of in vitro irradiation

[0070] In order to verify the radiation-catalyzed deallyl reaction, Pro-Rh110 molecules were decaged to form fluorescent Rh110 molecules, where the mass ratio of POP / Pd to Pro-Rh110 was 1:1.2. POP / Pd was dispersed in ultrapure water and used 60 The cells were irradiated with different doses of Co gamma rays, and the detachment rate was determined according to the standard curve, as shown in FIG6 .

[0071] The results show that the fluorescence intensity increases with increasing irradiation dose, as shown in Figure 7. This is because the amount of hydrated electrons generated in water increases with increasing irradiation dose, which in turn increases the amount of reduced zero-valent Pd and the amount of Pro-Rh110 decaged. Therefore, the fluorescence changes in the fluorescence spectrum also increase with increasing dose. Furthermore, it was found that even at a low dose of 1 Gy, the decaged fluorescent molecules can still be catalyzed. This is likely because the size of the pores in the POP material limits the size of the irradiated Pd nanoparticles. As the particles decrease in size, the specific surface area of ​​the Pd catalyst increases, enhancing its catalytic activity.

[0072] 4. Factors affecting irradiation catalysis

[0073] This example verifies that different conditions exist in the reaction of catalytic fluorescence detachment. As shown in Figure 8 a, the Pd content has a very significant effect on the results of irradiation catalytic detachment. After reducing the mass ratio of POP and Pd, the fluorescence detachment within 48 hours decreased significantly. In subsequent experiments on irradiation catalytic detachment, a POP / Pd mass ratio of POP to Pd of 1:1.5 was used. According to the principle of irradiation catalytic detachment, hydrated electrons are very important in the process of irradiation reduction. However, during the process of irradiation of water, oxidizing hydroxyl radicals are generated, which will affect the process of hydrated electron reduction of divalent Pd. In order to explore the effects of hydrated electrons and hydroxyl radicals on the irradiation detachment process, potassium nitrate (KNO3), a hydrated electron quencher, and isopropyl alcohol (IPA), a hydroxyl radical quencher, were added respectively to measure the catalytic detachment fluorescence results. As shown in Figure 8 b, after the addition of KNO3, due to the quenching of hydrated electrons, the reduced zero-valent Pd is reduced, thereby reducing the fluorescence detachment. As for IPA, quenching hydroxyl radicals produces IPA radicals, which can reduce divalent Pd, increasing the fluorescence of catalytic decaging. The effects of three influencing factors on catalytic decaging were compared, as shown in Figures c and d of Figure 8. Only when all three factors are present does radiation-catalyzed decaging yield the best results, and this finding persists even after 48 hours. This is likely due to the fact that POP, as a porous material, disperses the Pd nanoparticles, reducing their size and increasing their catalytic effectiveness.

[0074] Example 2 Intracellular irradiation catalysis

[0075] For the catalytic cell detachment test, A549 cells were used for cell testing. DMEM basal medium was added with 10% fetal bovine serum and 1% penicillin-streptomycin. 5,000 cells were first plated on a confocal microplate and incubated overnight in a 37°C, 5% carbon dioxide incubator. Afterwards, POP / Pd solids dispersed in water were added to the culture medium and incubated for 24 hours. Then, PBS was used to wash away the solids that were not swallowed by the cells. 60 The cells were irradiated with Co gamma rays. After irradiation, the cells were placed in an incubator overnight. Finally, a Pro-Rh110 solution (final concentration 30 μM) was added to the culture medium. After 24 hours of reaction, the uncaging effect was measured. The mass ratio of POP / Pd to Pro-Rh110 was 1:1.

[0076] Extracellular irradiation catalysis experiments demonstrated that POP / Pd could catalyze the decaged Pro-Rh110 under irradiation conditions. Next, the irradiation-mediated catalytic properties were investigated intracellularly. As shown in Figure 9 (a), A549 cells were incubated in a culture medium containing 30 μg / mL of POP / Pd. After reduction with varying doses of gamma rays, fluorescence changes were measured by the addition of 30 μM Pro-Rh110. Laser confocal microscopy revealed that the fluorescence of the irradiated cells increased with increasing dose. In the absence of irradiation, in the presence of POP / Pd and Pro-Rh110, no fluorescence signal was generated, as shown in Figures 9 (b) and (c). These results demonstrate that gamma ray irradiation, in the presence of POP / Pd and Pro-Rh110, catalyzes the activation of Pro-Rh110 and the production of fluorescent rhodamine intracellularly.

[0077] Example 3 Intracellular chemoradiotherapy synergy

[0078] Based on the results of irradiation-catalyzed fluorescent molecule detachment, the present invention further verifies the in vitro activation of prodrugs to treat cancer. Doxorubicin (DOX) is used clinically for cancer treatment; it works by binding to DNA and initiating enzyme-mediated chain breaks. Caged doxorubicin (Pro-DOX) is obtained by caged doxorubicin's primary amine with an allyl carbamate group. Pro-DOX has a weak ability to bind to DNA structures. Due to the reduction of the positive charge of the six-carbon aminosugar part, the DNA-drug intercalation complex is unstable, which can provide a prodrug with lower activity. The test was performed as shown in Figure 10.

[0079] A549 cells were used for cell viability assay, and the results are shown in Figure 11. Among Pro-DOX, DOX, and POP / Pd, the toxicity of DOX increased with increasing concentration, while the toxicity of Pro-DOX was much lower. The toxicity of Pro-DOX (half maximal inhibitory concentration (IC50) = 14.7 μM) was 1 / 122 of that of DOX (IC50 = 0.12 μM).

[0080] Pro-DOX was then subjected to an irradiation detachment experiment. A549 cells were used for cell testing using DMEM basal medium supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin. First, 5,000 cells / dish were plated on a confocal microplate and incubated overnight in a 37°C, 5% CO2 incubator. Then, POP / Pd solids dispersed in water were added to the culture medium and incubated for another 24 hours. Then, PBS was used to remove the solids not taken up by the cells. At different doses, the cells were washed with PBS to remove the solids. 60Irradiation was performed under Co gamma rays. After irradiation, the cells were allowed to stand in an incubator overnight. Finally, Pro-DOX solution (final concentration 1 μM) was added to the culture medium, and after 24 hours of reaction, the cell activity was measured, wherein the mass ratio of POP / Pd to Pro-DOX was 24:1. As shown in Figure 12, cell viability was measured under different conditions. Only in the presence of POP / Pd, Pro-DOX, and gamma rays could there be obvious cytotoxicity, indicating that irradiated reduced Pd can catalyze the activation of Pro-DOX prodrug, and also verify the feasibility of synergistic radiotherapy and chemotherapy. Under different irradiation doses, the uncaging of Pro-DOX prodrug also increased with increasing dose. Under low-dose irradiation of 1Gy, it can still catalyze the uncaging of Pro-DOX prodrug.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention. Industrial Applicability

[0082] The present invention provides a prodrug composition and a method for radiation-catalyzed drug activation. The prodrug composition comprises a procatalyst and a prodrug molecule; wherein the procatalyst is composed of a carrier and a coordination molecule; the coordination molecule is a divalent palladium salt, and the prodrug molecule contains an alkenyl or alkynyl group; the procatalyst can be induced to reduce to zero-valent palladium after irradiation, and the zero-valent palladium then catalyzes the prodrug molecule to produce an active drug. By combining radiation chemistry and catalytic chemistry, the present invention utilizes the precision of radiation rays and the potent cytotoxicity of chemotherapy drugs to control drug release at low radiation doses, achieving spatial and temporal control, thereby significantly reducing systemic cytotoxicity and minimizing potential drug side effects. This method has the potential to have good economic value and application prospects in clinical applications.

Claims

1. A prodrug composition, characterized in that, Comprising: A precatalyst and a prodrug molecule; wherein, the precatalyst is composed of a carrier and a coordination molecule; the coordination molecule is a divalent palladium salt, and the prodrug molecule contains an alkenyl group or an alkynyl group; After being irradiated, the precatalyst can be induced to be reduced to zero-valent palladium, and then the zero-valent palladium catalyzes the prodrug molecule to generate an active drug.

2. The prodrug composition according to claim 1, wherein The prodrug molecule has the structure shown in the figure: The D is an imaging agent or a therapeutic agent for treating cancer, including rhodamine, coumarin, luciferin, 5-fluorouracil, gemcitabine, doxorubicin hydrochloride, monomethyl auristatin E, monomethyl auristatin F, mitoxantrone or a protein degradation targeting chimera; the M is a chemical group that can be catalyzed by palladium, including: The D and the M can be combined arbitrarily.

3. The prodrug composition according to claim 1 or 2, characterized in that, The mass ratio of the precatalyst to the prodrug molecule is 1 to 230:1; preferably, the mass ratio of palladium to the prodrug molecule is 0.1 to 2:

1.

4. The prodrug composition according to any one of claims 1 to 3, characterized in that, The carrier is a porous organic polymer, and the pore size of the porous organic polymer is 5. A method for activating a radiation-catalyzed drug, characterized in that, Comprising: Irradiating the prodrug composition according to any one of claims 1 to 4 with a radiation source to induce the reduction of the precatalyst to zero-valent palladium, and then the zero-valent palladium catalytically activates the prodrug molecule; preferably, first irradiating the precatalyst in the prodrug composition to induce its reduction to zero-valent palladium, and then the zero-valent palladium catalytically activates the prodrug molecule.

6. The method for activating a radiation-catalyzed drug according to claim 5, characterized in that, Comprising: Incubating cancer cells in a culture medium, then adding the precatalyst, water and the prodrug molecule into the culture medium for continuous culture, and then performing ionizing radiation; Preferably, the method for activating a drug by radiation catalysis comprises: S1: Incubating cancer cells in a culture medium, then adding the precatalyst and water into the culture medium for continuous culture, and then performing ionizing radiation; S2: Adding the prodrug molecule into the culture medium for reaction.

7. The method for activating a radiation-catalyzed drug according to claim 6, wherein After the ionizing radiation in S1, the prodrug molecule is added after controlling for 24 to 28 h.

8. The method for activating a radiation-catalyzed drug according to any one of claims 5 to 7, characterized in that The radiation source includes α rays, β rays or γ rays generated by the decay of a radionuclide; or, X rays, γ rays, high-energy electrons, protons, heavy ions generated by an external radiation source, or α particles generated by boron neutron capture therapy; Preferably, the irradiation dose of the radiation source is 0.1 to 100 Gy; more preferably, the irradiation dose of the radiation source is 1 to 20 Gy.

9. The method for activating a radiation-catalyzed drug according to any one of claims 6 to 8 further comprises: Adding isopropanol or DMSO into the culture medium.

10. The method for activating a radiation-catalyzed drug according to any one of claims 6 to 9, characterized in that, The time for catalytic activation is 20 to 30 h.

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