Lotus-like porous photocatalytic anticancer and antibacterial micro-nano material and preparation method thereof
By constructing Pt/TiO2@Lotus Janus Schottky heterojunctions on lotus pollen matrix and loading them with doxorubicin, the problems of insufficient ROS generation and insignificant GSH depletion in existing treatment strategies were solved. This enabled the synergistic photodynamic, photothermal, and chemotherapeutic effects of lotus-derived porous photocatalytic materials under near-infrared light, thereby improving the efficacy of antibacterial and tumor treatment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHEAST FORESTRY UNIV
- Filing Date
- 2026-03-03
- Publication Date
- 2026-05-12
AI Technical Summary
In existing antibacterial and tumor treatment strategies, single-modality therapy is difficult to completely eradicate stubborn bacteria or tumor cells, chemotherapy has the problem of poor targeting, photodynamic therapy has insufficient ROS generation and GSH depletion effect is not significant, and existing biomass-based platforms have failed to effectively integrate multimodal therapy.
Using lotus pollen as a matrix, a Pt/TiO2@Lotus Janus Schottky heterojunction was constructed and doxorubicin was loaded onto it, achieving efficient ROS generation, GSH depletion, and pH/near-infrared dual-response drug release, integrating photodynamic, photothermal, and chemotherapeutic effects.
Driven by near-infrared light, highly efficient antibacterial and tumor treatments were achieved, improving treatment precision, reducing off-target toxicity, and the material exhibited good biocompatibility.
Smart Images
Figure CN122005852A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biomedical materials and photocatalytic therapy technology, specifically relating to a lotus-derived porous photocatalytic material, a method for preparing the material, and its application in synergistic antibacterial and tumor photocatalytic therapy driven by near-infrared light. The material uses lotus pollen as the sole matrix material. Background Technology
[0002] Bacterial infections and tumors are major diseases that seriously threaten human health. Existing treatment strategies for both have many prominent shortcomings, resulting in limited treatment efficacy. Single-modality therapy is difficult to completely eradicate stubborn bacteria or tumor cells. Chemotherapy has the problem of poor targeting, which easily causes severe off-target toxicity, and non-responsive drug release cannot match the pathological microenvironment, reducing treatment precision. Photodynamic therapy (PDT) results in insufficient generation of reactive oxygen species (ROS) due to the rapid recombination of electron-hole pairs in photosensitizers. At the same time, the overexpression of glutathione (GSH) in pathogenic bacteria and tumor cells further clears intracellular ROS, significantly weakening the treatment effect.
[0003] To address these issues, researchers have explored using natural biomass-derived nanocarriers as therapeutic platforms. These carriers possess inherent biocompatibility, biodegradability, and porous structures, resolving the biocompatibility problems of synthetic nanocarriers. Lotus pollen, with its naturally spherical porous structure and large specific surface area, serves as a core potential template, enabling highly efficient drug adsorption and mass transfer. However, existing biomass-based platforms still lack integrated solutions. Most fail to simultaneously enhance ROS generation and GSH depletion, and very few integrate heterojunction-mediated PDT, photothermal conversion, and stimulus-responsive chemotherapy into a single system. Furthermore, the technology of constructing Schottky heterojunctions on lotus pollen matrices to promote charge separation has not been fully developed, limiting the synergistic potential of multimodal therapy.
[0004] Therefore, developing a lotus-based porous photocatalytic material that uses lotus pollen as the sole matrix to construct a heterojunction structure with efficient charge separation, while simultaneously achieving efficient ROS generation, GSH depletion, and stimulus-responsive drug release, enabling it to achieve synergistic photodynamic, photothermal, and chemotherapeutic effects under near-infrared light drive, thereby efficiently antibacterial and treating tumors, and possessing good biocompatibility, has become a pressing technical challenge in this field. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a lotus-derived porous photocatalytic material, its preparation method, and its antibacterial and anticancer applications. This material uses lotus pollen as the sole matrix to construct Pt / TiO2@Lotus Janus Schottky heterojunctions and load doxorubicin (DOX). Under near-infrared light irradiation, it can achieve efficient ROS generation and active depletion of intracellular GSH. It also has pH / near-infrared dual-response drug release characteristics, realizing the synergistic effects of photodynamic therapy (PDT), photothermal therapy (PTT), and chemotherapy. This invention solves the problems of insufficient ROS generation, GSH-mediated ROS clearance, poor targeting, and non-responsive drug release in existing antibacterial and tumor treatments. Furthermore, this material has excellent biocompatibility, a simple preparation process, and can achieve efficient in vitro and in vivo antibacterial and tumor treatments.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] A method for preparing a lotus-grown porous photocatalytic material, the method comprising the following steps:
[0008] Step 1: Pretreatment of lotus pollen
[0009] Lotus pollen was ground into a fine powder and then washed successively with anhydrous ethanol, ultrasonically cleaned with ultrapure water, and washed with acetone before being filtered to obtain pretreated lotus pollen.
[0010] Step 2: Synthesis of TiO2@Lotus micro / nanomaterials
[0011] Pretreated lotus pollen was dispersed in anhydrous ethanol, and TiCl3 solution was added dropwise while stirring in the dark. After centrifugation and washing, the mixture was calcined in an air atmosphere in a muffle furnace to obtain TiO2@Lotus micro / nano materials.
[0012] Step 3: Synthesis of Pt / TiO2@Lotus micro / nanomaterials
[0013] TiO2@Lotus micro / nanomaterials were dispersed in anhydrous ethanol to prepare a dispersion. The dispersion was uniformly coated onto a hydrophobic silicon wafer and sputtered with Pt using an ion sputtering instrument. Subsequently, the sputtered micro / nanomaterials were peeled off from the silicon wafer, centrifuged, washed, and dried to obtain Pt / TiO2@Lotus micro / nanomaterials.
[0014] Step 4: Preparation of Lotus-Grown Porous Photocatalytic Materials
[0015] Pt / TiO2@Lotus micro / nanomaterials were dispersed in an aqueous solution of doxorubicin. Electrostatic adsorption of doxorubicin was achieved by stirring in the dark. Unadsorbed free doxorubicin was removed by centrifugation and washing to obtain the porous photocatalytic material (Pt / TiO2-D@Lotus).
[0016] The advantages of this invention over the prior art are as follows:
[0017] (1) The pretreatment process effectively removes impurities from lotus pollen, preserves the integrity of the porous structure, and lays the foundation for subsequent functional component loading.
[0018] (2) The in-situ growth of TiO2 and the Pt sputtering process are used to accurately construct heterojunction structures, which solves the problem of low charge separation efficiency of traditional photocatalytic materials;
[0019] (3) Electrostatic adsorption method achieves high-efficiency loading of doxorubicin, and the dual-response release characteristic improves drug targeting and reduces off-target toxicity;
[0020] (4) The material integrates photodynamic, photothermal and chemotherapy synergistic functions, and has excellent biocompatibility, providing a new and efficient material for antibacterial and tumor treatment. Attached Figure Description
[0021] Figure 1 The image shows a scanning electron microscope (SEM) image of the Pt / TiO2@Lotus micro / nanomaterial obtained in the example.
[0022] Figure 2 The diagram shows the zeta potential variation of the Pt / TiO2-D@Lotus micro / nanomaterials obtained in the examples.
[0023] Figure 3 The UV-Vis spectra of different types of micro / nanomaterials obtained in the examples;
[0024] Figure 4 Infrared spectra of different types of micro / nano materials obtained in the examples;
[0025] Figure 5 The UV-Vis spectra of hydroxyl radicals in Pt / TiO2@Lotus micro / nanomaterials at different concentrations are shown in the examples.
[0026] Figure 6 The UV-Vis spectra of singlet oxygen in Pt / TiO2@Lotus micro / nanomaterials at different concentrations are shown in the examples.
[0027] Figure 7 The following are temperature-time curves of Pt / TiO2@Lotus micro / nanomaterials with different concentrations under near-infrared irradiation conditions in the examples;
[0028] Figure 8 The survival rate of L929 cells under near-infrared irradiation conditions using different concentrations of Pt / TiO2@Lotus micro / nanomaterials in the example;
[0029] Figure 9 The tumor weights of mice in different treatment groups obtained in the examples; Detailed Implementation
[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. However, the experimental conditions and setting parameters therein should not be regarded as limitations on the basic technical solution of the present invention. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and content of the technical solution of the present invention should be covered within the protection scope of the present invention.
[0031] A method for preparing a lotus-derived porous photocatalytic material, specifically comprising the following steps:
[0032] Step 1: Pretreatment of lotus pollen
[0033] The lotus pollen was ground into a fine powder. 20 g of the ground lotus pollen powder was added to 200 mL of anhydrous ethanol, vortexed for 5 min, and then stirred at 8000 r·min. -1 Centrifuge for 10 min and collect the precipitate. Repeat the ethanol washing process 3 times. Place the obtained precipitate in an ultrasonic cleaner and ultrasonically clean it with ultrapure water for 15 min. Centrifuge and collect the precipitate. Redisperse the precipitate in an appropriate amount of acetone, stir thoroughly for 5 min, and then vacuum filter. Repeat the acetone washing and vacuum filtration process 3 times to obtain pretreated lotus pollen for later use.
[0034] Step 2: Synthesis of TiO2@Lotus micro / nanomaterials
[0035] Pretreated lotus pollen was added to 100 mL of anhydrous ethanol solution, and 20 mL of TiCl3 reagent was slowly added dropwise under continuous stirring. After the addition was completed, the reaction was stirred in the dark for 15 h, followed by stirring at 8000 r·min. -1 Centrifuge for 10 min, and wash the collected precipitate twice with anhydrous ethanol; place the washed precipitate in a muffle furnace and incubate at 10 °C·min in air atmosphere. -1 The heating rate was increased from room temperature to 300 °C, and the material was calcined at 300 °C for 6 h. After the muffle furnace was allowed to cool naturally to room temperature, TiO2@Lotus micro / nanomaterials were obtained.
[0036] Step 3: Synthesis of Pt / TiO2@Lotus micro / nanomaterials
[0037] TiO2@Lotus micro / nanomaterials were dispersed in 5 mL of anhydrous ethanol and sonicated for 10 min to obtain a uniform dispersion. 100 μL of this dispersion was uniformly coated onto a pre-treated hydrophobic silicon wafer. The wafer was placed at a 9° angle, and after the ethanol evaporated naturally, a dense TiO2@Lotus monolayer formed on the wafer surface. The wafer was then transferred to an ion sputtering instrument equipped with a Pt target and sputtered with Pt for 1 min under an argon atmosphere to deposit a uniform thin Pt layer on the TiO2@Lotus surface. After sputtering, the wafer was immersed in ultrapure water and sonicated for 10 min to peel the Pt-deposited micro / nanomaterials from the wafer surface at 8000 r·min. -1 The precipitate was collected by centrifugation for 10 min, washed twice with anhydrous ethanol, and then vacuum dried overnight at 60 °C to obtain Pt / TiO2@Lotus micro / nano materials.
[0038] Step 4: Preparation of Lotus-Grown Porous Photocatalytic Materials
[0039] Take 10 mg of Pt / TiO2@Lotus micro / nanomaterial and add it to 5 mL of a solution with a concentration of 1 mg / mL. -1 In an aqueous solution of doxorubicin, the mixture was stirred at room temperature and in the dark for 48 h to achieve electrostatic adsorption loading of doxorubicin onto the surface of micro / nanomaterials. After stirring, the mixture was further loaded at 8000 r·min. -1 Centrifuge for 10 min to collect the precipitate, and wash the precipitate repeatedly with phosphate-buffered saline (PBS) at pH 7.4 until the supernatant becomes colorless to remove unadsorbed free doxorubicin and obtain the lotus porous photocatalytic material (Pt / TiO2-D@Lotus).
[0040] Example:
[0041] A porous lotus-derived photocatalytic anticancer and antibacterial material and its preparation method are disclosed, specifically comprising the following steps:
[0042] I. Pretreatment of Lotus Pollen
[0043] Take commercially available lotus pollen, grind it, weigh 20 g, and wash it with ethanol (3 times), ultrasonically clean it with ultrapure water (15 min), wash it with acetone and filter it (3 times) according to the method described in step one to obtain pretreated lotus pollen, which is then placed in a desiccator for later use.
[0044] II. Synthesis of TiO2@Lotus micro / nanomaterials
[0045] Pretreated lotus pollen was completely dispersed in 100 mL of anhydrous ethanol. 20 mL of TiCl3 reagent was slowly added dropwise under magnetic stirring. After reacting in the dark for 15 h, the precipitate was collected by centrifugation, washed twice with anhydrous ethanol, and then placed in a muffle furnace at 10 °C / min. -1 The temperature was raised to 300 °C, calcined for 6 h, and then naturally cooled to obtain white TiO2@Lotus micro / nanomaterials.
[0046] III. Synthesis of Pt / TiO2@Lotus micro / nanomaterials
[0047] 50 mg of TiO2@Lotus was dispersed in 5 mL of anhydrous ethanol and sonicated for 10 min to obtain a dispersion. 100 μL of the dispersion was coated onto a hydrophobic silicon wafer and placed at a 9° angle until the ethanol evaporated to form a monolayer. The silicon wafer was then placed in an ion sputtering instrument (E-1010, Hitachi) and sputtered with Pt for 1 min under an argon atmosphere. Subsequently, the wafer was ultrasonically peeled off, collected by centrifugation, washed twice with ethanol, and vacuum dried overnight at 60 °C to obtain gray-black Pt / TiO2@Lotus micro / nanomaterials.
[0048] IV. Preparation of Lotus-Grown Porous Photocatalytic Materials
[0049] Weigh 10 mg of Pt / TiO2@Lotus and add 5 mL of 1 mg·mL⁻¹ -1 Doxorubicin aqueous solution was stirred at room temperature in the dark for 48 h; the precipitate was collected by centrifugation and washed with pH 7.4 PBS buffer until the supernatant was free of red (characteristic color of doxorubicin). After freeze-drying, the lotus-grown porous photocatalytic material was obtained.
[0050] V. Structural Characterization of Materials
[0051] The morphology of pretreated lotus pollen, TiO2@Lotus, and Pt / TiO2@Lotus was observed using scanning electron microscopy (SEM). The results showed that the pretreated lotus pollen retained a spherical porous structure, with TiO2 nanoparticles uniformly anchored on the surface and pores of the pollen, and a Pt layer uniformly deposited on the TiO2 surface. The hierarchical porous structure of the material remained intact. The light absorption performance of the material was detected using ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS). The results showed that the absorption intensity of Pt / TiO2@Lotus was significantly enhanced in the visible and near-infrared regions, and the lotus-derived porous photocatalytic material (Pt / TiO2-D@Lotus) exhibited the characteristic absorption peak of doxorubicin at 480 nm. The chemical composition and crystal structure of the material were verified using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results confirmed that TiO2 is anatase phase, and Pt... Doxorubicin was successfully loaded via metallic deposition. The pore structure of the porous photocatalyst material (Pt / TiO2-D@Lotus) was analyzed using a nitrogen adsorption-desorption analyzer, revealing a specific surface area of 128 m²·g. -1 The pore size is approximately 4.2 nm, and the drug loading did not significantly block the pores.
[0052] VI. Doxorubicin Release Performance Testing
[0053] The porous photocatalytic material (Pt / TiO2-D@Lotus) was dispersed in PBS buffer at pH 5.0, 6.0, and 7.4. Near-infrared light irradiation (808 nm, 1.5 W·cm⁻², irradiation for 5 min) and no near-infrared light irradiation were established. Supernatants were collected at 0 h, 15 h, 30 h, 45 h, 60 h, and 75 h under mild shaking conditions at 37 ℃. The supernatants were replenished with fresh PBS buffer. The concentration of doxorubicin in the supernatant was detected at 480 nm using a UV-Vis spectrophotometer, and the drug release rate was calculated. The results showed that the material exhibited dual pH and near-infrared responsiveness in doxorubicin release. The release rate was significantly higher in the acidic environment (pH 5.0) than in the neutral environment (pH 7.4). Near-infrared light irradiation further enhanced the release rate, reaching 90% after 75 h under pH 5.0 + near-infrared light irradiation.
[0054] VII. ROS generation and GSH depletion capability testing
[0055] Methylene blue (MB), 1,3-diphenylisobenzofuran (DPBF), and terephthalic acid (TA) were used as probes to detect the total ROS, ¹O₂, and •OH generation capabilities of Pt / TiO₂@Lotus under near-infrared light irradiation using UV-Vis spectrophotometry and fluorescence spectrophotometry, respectively. Electron spin resonance (ESR) was used to directly verify the generation of •O₂⁻, •OH, and ¹O₂. 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) was used as a probe to detect the GSH depletion capability of Pt / TiO₂@Lotus using UV-Vis spectrophotometry. The results showed that Pt / TiO₂@Lotus could efficiently generate various ROS under near-infrared light irradiation, and the ROS generation increased with increasing material concentration and near-infrared light power. The material could achieve dose-dependent GSH depletion at 500 μg·mL⁻¹. -1 The GSH depletion rate reached 70%.
[0056] VIII. Photothermal conversion performance testing
[0057] Different concentrations (100, 200, 300, 400, 500 μg·mL) were used. -1 The Pt / TiO2@Lotus dispersion was irradiated with 808 nm near-infrared light (1.5 W·cm⁻²), and the temperature change was recorded in real time using an infrared thermal imager and thermometer. The photothermal stability of the material was tested by on / off cycle experiments, and the photothermal conversion efficiency was calculated according to the Roper method. The results showed that the temperature of the material increased with increasing concentration, with a maximum concentration of 500 μg·mL⁻¹. -1 The temperature can reach 52 ℃, and after 5 cycles, the temperature does not drop significantly, with a photothermal conversion efficiency of 55.4%.
[0058] IX. Application of Lotus-Grown Porous Photocatalytic Materials in Antibacterial Applications
[0059] (1) Bacterial culture: Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were inoculated into LB liquid medium and cultured in an air bath shaker at 37 ℃ and 180 rpm for 12 h. The bacterial concentration was adjusted to 10⁻⁶ with PBS at pH 7.4. 6 CFU / mL, for later use.
[0060] (2) Antibacterial effect was detected by plate colony counting method: The experiment was divided into 8 groups: blank control group (no material, no near-infrared light), near-infrared light control group (no material, 808 nm, 1.5 W·cm⁻² irradiation for 5 min), lotus pollen group (300 μg·mL⁻¹ pretreated lotus pollen, no near-infrared light), lotus pollen + NIR group (300 μg·mL⁻¹ pretreated lotus pollen + near-infrared light), TiO₂@Lotus group (300 μg·mL⁻¹, no near-infrared light), TiO₂@Lotus + NIR group (300 μg·mL⁻¹ + near-infrared light), Pt / TiO₂@Lotus group (300 μg·mL⁻¹, no near-infrared light), and Pt / TiO₂@Lotus + NIR group (300 μg·mL⁻¹ + near-infrared light). Mix 100 μL of bacterial culture with 100 μL of material suspension / buffer from each experimental group in a 96-well plate and incubate at 37 ℃ for 6 h. For the near-infrared light group, irradiate for 5 min during incubation. After incubation, perform 10... 5 The solution was serially diluted, and 20 μL of each diluted solution was evenly spread on LB agar plates. After incubation at 37 °C for 12 h, the number of colonies was counted, and the antibacterial efficiency was calculated according to the formula. The results showed that the antibacterial efficiency of Pt / TiO2@Lotus + NIR group against Staphylococcus aureus and Escherichia coli was >99%.
[0061] (3) CLSM (Confocal Laser Microscopy) live / dead staining assay for antibacterial effect: The bacterial treatment conditions for each experimental group were the same as those for plate colony counting. After treatment, the bacterial suspension was transferred to a 24-well plate containing sterile coverslips, and a mixed staining solution of DAPI (10 μg·mL⁻¹) and PI (5 μg·mL⁻¹) was added. Staining was performed at 37 ℃ in the dark for 30 min. After rinsing three times with PBS, bacterial fluorescence imaging was observed using CLSM. The results showed that the bacteria in the Pt / TiO₂@Lotus + NIR group exhibited a large amount of red fluorescence (dead bacteria), with a dead bacteria ratio of approximately 95%, confirming the excellent antibacterial effect of the material.
[0062] 10. Application of Lotus-Grown Porous Photocatalytic Materials in Tumor Treatment
[0063] (1) Normal cell compatibility test: L929 fibroblasts were subjected to a concentration of 1.0 × 10⁻⁶ cells / mL. 3Cells were seeded at a density of 1 cell / well in 96-well plates and cultured overnight. Then, culture medium containing different concentrations of Pt / TiO2@Lotus and Liansheng porous photocatalytic material (Pt / TiO2-D@Lotus) was added, and the plates were cultured at 37 ℃ and 5% CO2 for 24 h. Cell viability was assessed using the MTT assay. The results showed that cell viability was >85% at all concentrations, confirming the good biocompatibility of the material with normal cells.
[0064] (2) Tumor cytotoxicity test: HeLa cervical cancer cells were injected at 1.0 × 10⁻⁶. 3 The samples were seeded at a density of 100 cells / well in 96-well plates and cultured overnight. They were then divided into 8 groups, with blank medium, near-infrared light irradiation only, DOX, DOX + near-infrared light, Pt / TiO2@Lotus, Pt / TiO2@Lotus + near-infrared light, Pt / TiO2-D@Lotus porous photocatalyst material, and Pt / TiO2-D@Lotus porous photocatalyst material + near-infrared light added respectively. The samples were cultured at 37 ℃ and 5% CO2 for 24 h and 48 h. The near-infrared light irradiation conditions were 808 nm and 1.5 W·cm⁻¹. -2 Cell viability was assessed using the MTT assay after 5 minutes. CLSM staining was used to observe cell viability, the DCFH-DA probe was used to detect intracellular ROS levels, and flow cytometry was used to detect apoptosis rates. Results showed that the group using the lotus porous photocatalytic material (Pt / TiO2-D@Lotus) + NIR exhibited the lowest tumor cell viability (approximately 15%), the highest intracellular ROS levels, and an apoptosis rate of 85%, confirming that the material can achieve highly efficient in vitro tumor cell killing through synergistic photodynamic, photothermal, and chemoradiotherapy effects.
[0065] (3) In vivo antitumor therapy: S180 sarcoma cells were inoculated subcutaneously in the thigh of Kunming mice until the tumor volume reached approximately 100 mm. 3 Mice were randomly divided into 8 groups (n=5) and injected with PBS intratumorally, irradiated with near-infrared light only, DOX, DOX + near-infrared light, Pt / TiO2@Lotus, Pt / TiO2@Lotus + near-infrared light, Pt / TiO2-D@Lotus porous photocatalyst material, and Pt / TiO2-D@Lotus porous photocatalyst material + near-infrared light, with a material concentration of 300 μg·mL. -1 Injection volume 200 μL, near-infrared irradiation conditions 808 nm, 1.5 W·cm⁻ 2The mice were treated for 5 minutes. Body weight and tumor volume were measured every 2 days during the treatment period. After 14 days of treatment, the mice were sacrificed, and the tumors and major organs (liver, kidney, heart, lung, spleen) were removed. The tumor weight was measured, and the histological morphology of the tumors and organs was observed using hematoxylin-eosin (H&E) staining. The results showed that the tumor volume was smallest in the group treated with the porous photocatalytic material (Pt / TiO2-D@Lotus) + NIR, with a tumor inhibition rate of 92%. There was no significant decrease in mouse body weight, but significant necrosis of the tumor tissue was observed. The histological morphology of the major organs showed no significant pathological changes, confirming that the material has a highly efficient in vivo tumor-suppressing effect and no significant systemic toxicity.
Claims
1. A method for preparing a lotus-grown porous photocatalytic material, characterized in that, The material uses lotus pollen as the sole matrix, and the preparation steps include the following: Step 1: Pretreatment of lotus pollen Lotus pollen was ground into a fine powder and then washed with anhydrous ethanol, ultrasonically cleaned with ultrapure water, washed with acetone, and filtered to obtain pretreated lotus pollen. Step 2: Synthesis of TiO2@Lotus micro / nanomaterials Pretreated lotus pollen was dispersed in anhydrous ethanol, and TiCl3 solution was added dropwise while stirring in the dark. After centrifugation and washing, the mixture was calcined in an air atmosphere in a muffle furnace to obtain TiO2@Lotus micro / nano materials. Step 3: Synthesis of Pt / TiO2@Lotus micro / nanomaterials TiO2@Lotus micro / nanomaterials were dispersed in anhydrous ethanol to prepare a dispersion. The dispersion was uniformly coated on a hydrophobic silicon wafer and sputtered with Pt using an ion sputtering instrument. The sputtered micro / nanomaterials were then peeled off from the silicon wafer, centrifuged, washed, and dried to obtain Pt / TiO2@Lotus micro / nanomaterials. Step 4: Preparation of Lotus-Grown Porous Photocatalytic Materials Pt / TiO2@Lotus micro / nanomaterials were dispersed in an aqueous solution of doxorubicin. Electrostatic adsorption of doxorubicin was achieved by stirring in the dark. Unadsorbed free doxorubicin was removed by centrifugation and washing to obtain the porous photocatalytic material (Pt / TiO2-D@Lotus).
2. The method for preparing the lotus-grown porous photocatalytic material according to claim 1, characterized in that, In step one, the anhydrous ethanol washing is performed by vortex oscillation for 5 minutes followed by 8000 r·min. -1 Centrifuge for 10 min, repeat 3 times; ultrasonic cleaning with ultrapure water for 15 min; acetone washing and filtration process repeat 3 times.
3. The method for preparing the lotus-grown porous photocatalytic material according to claim 1, characterized in that, In step two, the volume of TiCl3 solution added is 20 mL, and the reaction time with stirring in the dark is 15 h; the heating rate for calcination is 10 ℃·min. -1 The calcination temperature was 300 ℃ and the calcination time was 6 h.
4. The method for preparing the lotus-grown porous photocatalytic material according to claim 1, characterized in that, In step three, the dispersion of the TiO2@Lotus micro / nano material is prepared by ultrasonic treatment for 10 min; the silicon wafer is pretreated with hydrophobicity, and after coating with the dispersion, the silicon wafer is placed at a 9° angle until the ethanol evaporates naturally; the Pt sputtering is carried out under an argon atmosphere for 1 min; the peeling process is ultrasonic treatment for 10 min, and the drying conditions are vacuum drying at 60 ℃ overnight.
5. The method for preparing the lotus-grown porous photocatalytic material according to claim 1, characterized in that, In step four, the concentration of the doxorubicin aqueous solution is 1 mg / mL. -1 The ratio of Pt / TiO2@Lotus micro / nanomaterials to doxorubicin aqueous solution was 10 mg: 5 mL; the stirring was carried out at room temperature for 48 h in the dark; the centrifugation and washing were performed using phosphate buffer at pH 7.4 until the supernatant was colorless.
6. The lotus-grown porous photocatalytic material prepared by any one of the preparation methods described in claims 1-5, characterized in that, This material uses lotus pollen as the sole matrix. TiO2 nanoparticles are uniformly anchored on the surface and internal pores of the lotus pollen. A Pt layer is uniformly deposited on the TiO2 surface to form a Pt-TiO2 Janus Schottky heterostructure. Doxorubicin is loaded onto the surface of the Pt / TiO2@Lotus micro / nanomaterial via electrostatic adsorption. The specific surface area of the material is 128 m². 2 ・g -1 It has an aperture of approximately 4.2 nm and a photothermal conversion efficiency of 55.4%.
7. The application of the lotus-derived porous photocatalytic material according to claim 6 in antibacterial applications, characterized in that, A treatment solution was prepared by dispersing Pt / TiO2@Lotus micro / nanomaterials or lotus-derived porous photocatalytic material (Pt / TiO2-D@Lotus) in a buffer solution. After being applied to bacteria, the solution was irradiated with 808 nm near-infrared light. The power density of the near-infrared light was 1.5 W·cm⁻², and the irradiation time was 5 min. The bacteria included Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli.
8. The application of the lotus-derived porous photocatalytic material according to claim 6 in tumor treatment, characterized in that, The porous photocatalytic material (Pt / TiO2-D@Lotus) was injected into the tumor site via intratumoral injection at a concentration of 300 μg·mL. -1 The injection volume was 200 μL, followed by irradiation with 808 nm near-infrared light at a power density of 1.5 W·cm⁻¹. -2 The irradiation time was 5 minutes; the tumor was an S180 sarcoma.
9. The application according to claim 7 or 8, characterized in that, The material can efficiently generate reactive oxygen species such as •O2⁻, •OH, and ¹O2 under near-infrared light irradiation, and can achieve dose-dependent glutathione depletion at 500 μg·mL⁻¹. -1 The glutathione depletion rate reached 70%.
10. The application according to claim 8, characterized in that, The material exhibits doxorubicin release characteristics with pH / near-infrared dual response, achieving a doxorubicin release rate of 90% after 75 h of irradiation under pH 5.0 + 808 nm near-infrared light.