Optoacoustic nanorobot and preparation method and application thereof

Abstract

This invention specifically discloses a photoacoustic nanorobot, its preparation method, and its applications, relating to the field of atherosclerotic plaque imaging technology, and particularly to a photoacoustic imaging agent for atherosclerotic plaques. The photoacoustic nanorobot provided by this invention uses the plaque's unique high-lipid environment as a signal "switch," targets unwinding collagen—which is directly related to plaque mechanical stability—as the imaging target, and combines active chemotactic movement capabilities to achieve targeted penetration and heterogeneity analysis, thereby realizing specific enhanced imaging of vulnerable plaques.

Description

Technical Field

[0001] This invention relates to the field of atherosclerotic plaque imaging technology, and in particular to photoacoustic imaging agents for atherosclerotic plaques. Background Technology

[0002] Currently, clinical assessment of carotid plaque vulnerability mainly relies on imaging methods to determine plaque size and degree of stenosis. However, this method fails to reflect the biological composition of the plaque, leading to misdiagnosis of vulnerable plaques. While existing molecular imaging probes can target specific molecules within the plaque, they still have the following limitations: (1) Poor specificity: Most probes target upstream factors (such as ROS and proteases) in the plaque inflammatory microenvironment. Vascular inflammation (such as thrombosis and vasculitis) that is not plaque factor can also activate these probes, leading to false positive results.

[0003] (2) Difficulty in reflecting heterogeneity: Existing probes are mostly evaluated based on global signal intensity, ignoring the spatial heterogeneity of molecular markers within the plaque. Since plaque heterogeneity is closely related to the risk of rupture, this global averaging evaluation method will underestimate the vulnerability of the plaque.

[0004] (3) Poor tissue penetration: Traditional probes have difficulty penetrating deep into plaques in complex vascular environments (blood flow, vasoconstriction and vasodilation), resulting in low binding efficiency with targets and limiting the accuracy of imaging. Summary of the Invention

[0005] (a) Technical problems to be solved Therefore, one of the main objectives of this invention is to provide a photoacoustic nanorobot, its preparation method, and its applications. Utilizing the unique high-lipid environment of plaques as a signal "switch," and targeting unwinding collagen, which is directly related to plaque mechanical stability, as an imaging target, and combining active chemotactic movement capabilities to achieve targeted penetration and heterogeneity analysis, this invention enables specific enhanced imaging of vulnerable plaques.

[0006] (II) Technical Solution To achieve the above objectives, the present invention provides a photoacoustic nanorobot composed of composite micelles formed by the self-assembly of a first polymer and a second polymer. The first polymer comprises lipids, arginine, unwound collagen hybrid peptides, and a hemicyanine backbone; The second polymer comprises lipids and metalloporphyrins.

[0007] In one embodiment, the mass ratio of the first polymer to the second polymer is 1:1 to 10:1.

[0008] In one embodiment, the mass ratio of the first polymer to the second polymer is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0009] In one embodiment, the mass ratio of the first polymer to the second polymer is 2:1 to 10:1.

[0010] In one embodiment, the mass ratio of the first polymer to the second polymer is 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, or 6:1.

[0011] In one embodiment, the mass ratio of the first polymer to the second polymer is 4:1.

[0012] In one embodiment, the sequence of the unwound collagen hybrid peptide is (GPO). n n is a natural number from 1 to 10; preferably, n is 1, 2, 3, 4, 5, 6, 7, 8, or 9; preferably, n is 9.

[0013] In one embodiment, the lipids include phospholipids.

[0014] In one embodiment, the metal includes manganese, zinc, palladium, and copper; preferably, the metal is manganese.

[0015] In another aspect, the present invention provides a method for preparing the above-mentioned photoacoustic nanorobots, comprising: S1: Reaction of lipids with arginine derivatives yields lipid-arginine intermediates; S2: The lipid-arginine intermediate is reacted with collagen hybrid peptide to obtain the lipid-arginine-collagen hybrid peptide intermediate; S3: The first polymer (DAGH) is obtained by reacting the lipid-arginine-collagen hybrid peptide intermediate with a hemicyanine derivative. S4: The lipid is reacted with a metalloporphyrin derivative to obtain the second polymer (DM). S5: The first polymer and the second polymer are self-assembled to form the photoacoustic nanorobot.

[0016] In one embodiment, the lipid in S1 is a phospholipid.

[0017] In one embodiment, the arginine derivative in S1 is BOC-arginine (Boc-Arg-OH).

[0018] In one embodiment, the lipids and arginine derivatives in S1 are dissolved in an organic solvent to react.

[0019] In one embodiment, the organic solvent includes dichloromethane, chloroform, N,N-dimethylformamide, and / or dimethyl sulfoxide.

[0020] In one embodiment, S1 further includes a condensing agent and an organic base.

[0021] In one embodiment, the condensing agent includes HBTU, HOBT, EDC, NHS, and / or DCC.

[0022] In one embodiment, the condensing agent comprises HBTU and / or HOBT.

[0023] In one embodiment, the organic base includes DIPEA, triethylamine, and / or pyridine.

[0024] In one embodiment, the organic base comprises DIPEA.

[0025] In one embodiment, the reaction conditions for S1 are: 0~40℃, 4~48h.

[0026] In one embodiment, the lipid-arginine intermediate in S2 reacts with the collagen hybrid peptide in a solvent.

[0027] In one embodiment, the solvent is water, phosphate buffer, and / or Tris-HCl buffer.

[0028] In one embodiment, S2 further includes a condensing agent.

[0029] In one embodiment, the condensing agent includes HBTU, HOBT, EDC, NHS, and / or DCC.

[0030] In one embodiment, the condensing agent includes EDC and NHS.

[0031] In one embodiment, the S2 reaction conditions are: 4~50℃, 6~48h.

[0032] In one embodiment, the lipid-arginine-collagen hybrid peptide intermediate in S3 reacts with the hemicyanine derivative dissolved in a solvent.

[0033] In one embodiment, the solvent is water, phosphate buffer, and / or Tris-HCl buffer.

[0034] In one embodiment, the solvent is water.

[0035] In one embodiment, S3 further includes a condensing agent.

[0036] In one embodiment, the condensing agent includes HBTU, HOBT, EDC, NHS, and / or DCC.

[0037] In one embodiment, the condensing agent comprises NHS.

[0038] In one embodiment, the S3 reaction conditions are: 4~50℃, 6~48h.

[0039] In one embodiment, the lipid in S4 is a phospholipid.

[0040] In one embodiment, the metalloporphyrin derivative in S4 is manganese porphyrin.

[0041] In one embodiment, in S4, lipids and metalloporphyrin derivatives are dissolved in an organic solvent to react.

[0042] In one embodiment, the organic solvent includes dichloromethane, chloroform, N,N-dimethylformamide, and / or dimethyl sulfoxide.

[0043] In one embodiment, S4 further includes a condensing agent and an organic base.

[0044] In one embodiment, the condensing agent includes HBTU, HOBT, EDC, NHS, and / or DCC.

[0045] In one embodiment, the condensing agent comprises HBTU and / or HOBT.

[0046] In one embodiment, the organic base includes DIPEA, triethylamine, and / or pyridine.

[0047] In one embodiment, the organic base comprises DIPEA.

[0048] In one embodiment, the S4 reaction conditions are: 0~40℃, 4~48h.

[0049] In one embodiment, in step S5, the first polymer and the second polymer are dissolved in a solvent to react.

[0050] In one embodiment, the solvent is water, phosphate buffer, and / or Tris-HCl buffer.

[0051] In one embodiment, the reaction conditions for S5 are: 4~50℃, 6~48h.

[0052] In one embodiment, the reaction conditions for S5 are: 20~30℃, 12~24h.

[0053] In another aspect, the present invention also provides a photoacoustic nanorobot obtained by the above-described preparation method.

[0054] In another aspect, the present invention also provides the application of the above-mentioned photoacoustic nanorobots as probes for atherosclerotic plaques.

[0055] In one embodiment, the plaque is a vulnerable plaque.

[0056] In one embodiment, the atherosclerotic plaque is accompanied by inflammation.

[0057] In one embodiment, the inflammation includes pneumonia, arthritis, aneurysm, and thrombosis.

[0058] In one embodiment, the inflammation is pneumonia.

[0059] (III) Beneficial Effects This invention provides a photoacoustic nanorobot, its fabrication method, and its application. Compared with existing technologies, it has the following advantages: 1. Dual Specificity: Through the dual protection of "lipid activation" and "collagen recognition", it ensures high imaging specificity and avoids false positive interference from non-plaque inflammation.

[0060] 2. Active targeting and deep penetration: By utilizing the chemotactic motion driven by the iNOS concentration gradient, nanorobots are endowed with the ability to actively and efficiently penetrate and permeate plaques, overcoming the problem of low efficiency in passive diffusion of traditional probes.

[0061] 3. Heterogeneity Quantification: For the first time, the gray-level co-occurrence matrix image analysis method is applied to photoacoustic imaging to quantify the heterogeneity of dissociated collagen from multiple dimensions, providing a more comprehensive and accurate indicator for plaque vulnerability assessment.

[0062] 4. Component tunability: By adjusting the incorporation ratio of the two polymers, the lipid response threshold of the nanorobot can be flexibly controlled to adapt to the blood lipid levels of different patients and avoid premature activation of the signal in the blood. Attached Figure Description

[0063] 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.

[0064] Figure 1 This is a schematic diagram of the synthesis of the first polymer; Figure 2 This is a schematic diagram of the synthesis of the second polymer; Figure 3 These are the 1H NMR spectra of HD and DSPE / Arg; Figure 4This is a diagram showing the synthesis and characterization of photoacoustic nanorobots; Figure 5 This is a diagram showing the lipid response effect of photoacoustic nanorobots; Figure 6 This is a diagram showing the imaging performance of photoacoustic nanorobots. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0066] Terms and Definitions As used in this article, “containing,” “having,” or “including” includes “containing,” “mainly composed of,” “substantially composed of,” and “composed of”; “mainly composed of,” “substantially composed of,” and “composed of” are subordinate concepts of “containing,” “having,” or “including.”

[0067] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the reagents, methods and equipment used are conventional reagents, methods and equipment in this technical field.

[0068] Example 1: Fabrication of photoacoustic nanorobots: 1. Preparation of the first polymer: Phospholipid (DSPE) and BOC-arginine (0.2 mmol, Shanghai Maclean Biochemical Technology Co., Ltd., catalog number B801401, specification 98%) were dissolved in the organic solvent DMF (DMF, 2 ml, Sinopharm Chemical Reagent Co., Ltd., catalog number 330628-04-1, specification AR). In the presence of condensing agent (HOBT and HBTU: HOBT, 0.3 mmol, Shanghai Maclean Biochemical Technology Co., Ltd., catalog number H810970, specification ≥97%; HBTU, 0.3 mmol, Shanghai Maclean Biochemical Technology Co., Ltd., catalog number 94790-37-1, specification 99%) and organic base (DIPEA, 1.148 mmol, Shanghai Maclean Biochemical Technology Co., Ltd., catalog number N807281, specification 99%), a first amidation reaction was carried out at 0~40℃ for 4~48 hours to obtain the DSPE-arginine intermediate.

[0069] The DSPE-arginine intermediate and collagen hybrid peptide (sequence (GPO)9) were dissolved in an aqueous medium and subjected to a second amidation reaction at 4-50°C for 6-48 hours in the presence of a condensing agent (EDC and NHS: EDC, 0.003 mmol, Shanghai Maclean Biochemical Technology Co., Ltd., catalog number 1363481-45-1, specification 98%; NHS, 0.003 mmol, Shanghai Aladdin Biochemical Technology Co., Ltd., catalog number N164052) to obtain the DSPE-arginine-collagen hybrid peptide intermediate.

[0070] The DSPE-arginine-collagen hybrid peptide intermediate and a hemicyanine derivative (HD, 0.003 mmol, Beijing Oukenas Biochemical Technology Co., Ltd.) were dissolved in an aqueous medium and subjected to a third amidation reaction at 4–50 °C in the presence of a condensing agent (NHS) for 6–48 hours. The resulting product was purified by dialysis or chromatography to obtain the first polymer (DAGH). The preparation process is as follows: Figure 1 As shown.

[0071] 2. Preparation of the second polymer: Phospholipid (DSPE) and manganese porphyrin derivative were dissolved in an organic solvent and subjected to an amidation reaction at 0–40 °C for 4–48 hours in the presence of a condensing agent (HBTU) and an organic base (DIPEA). The reaction was followed by extraction, washing, and drying purification to obtain the second polymer (DM). The preparation process is as follows: Figure 2 As shown.

[0072] 3. Fabrication of photoacoustic nanorobots: The first polymer and the second polymer prepared above were mixed at a mass ratio of 1:1 to 10:1 and dispersed in an aqueous medium. The mixture was stirred at 4-50°C for 6-48 hours to allow them to self-assemble into composite micelles. Unassembled polymer monomers were removed by dialysis to obtain the photoacoustic nanorobots.

[0073] Example 2 Characterization of photoacoustic nanorobots: Characterization of the synthetic compounds and products by proton nuclear magnetic resonance spectroscopy and near-infrared spectroscopy. Figure 3 and Figure 4 (A in the middle).

[0074] The critical micelle concentrations of DAGH and DM, determined by pyrene fluorescence spectrometry, were 50–100 μg / mL and 0.5–5 μg / mL, respectively. Figure 4 (B in the middle).

[0075] In pure DAGH polymer solutions, pure DM polymer solutions, and mixed DAGH and DM polymer solutions (mass ratios DAGH:DM = 1:1, 2:1, 4:1, 10:1) at concentrations above the critical micelle concentration, the polymers were allowed to self-assemble. Figure 4 (C in the middle).

[0076] Transmission electron microscopy showed that these amphiphilic polymers could all form spherical nanoparticles. Figure 4 (D in the figure) proves the feasibility of constructing photoacoustic nanorobot composite micelles based on amphiphilic polymers.

[0077] Figure 4 In the image, A: Near-infrared spectra of DAGH and DM; B: Critical micelle concentrations of the two amphiphilic polymers determined by pyrene fluorescence method; C: Schematic diagram of the self-assembly of the two amphiphilic polymers to form composite micelles; D: Transmission electron microscopy images of micelles formed in different polymer solution systems (scale bar: 200 nm).

[0078] Example 3: Lipid-responsive properties of photoacoustic nanorobots: 1. The motion trajectory of photoacoustic nanorobots was studied using single-particle tracking trajectory analysis in normal / inflammatory cellular environments. Motion and chemotactic behavior characterization: RAW264.7 cells were treated with or without lipopolysaccharide (LPS, 1 μg / mL, Shanghai Yuanye Biotechnology Co., Ltd., catalog number S11060) for 24 hours. DAGH photoacoustic motors, Cy5-labeled DM nanoparticles, and a series of DAGH / DM photoacoustic motors were added to the cell culture supernatant, respectively. Motion behavior was observed using a fluorescence microscope at 10 frames per second, and the motion trajectory was analyzed using ImageJ software.

[0079] like Figure 5 As shown in Figure A, in a normal cellular environment (with virtually no iNOS expression), trajectory analysis revealed that all nanomicelles primarily exhibited Brownian motion behavior with no significant displacement in any direction. However, in an inflammatory cellular environment (with significantly high iNOS expression), the photoacoustic nanorobots produced significant displacement in different directions, demonstrating an enhanced diffusion effect. The average velocity of the particles was at least 6 times higher than in the normal cellular environment, showing a statistically significant difference. Figure 5 The sample containing DAGH (i.e., nanomicelles composed of pure DM) still exhibited Brownian motion, while the sample without DAGH (i.e., nanomicelles composed of pure DM) showed no significant increase in motion speed. This verifies that the incorporation of DAGH can endow the composite micelles with enhanced motion capabilities.

[0080] 2. Verify the lipid responsiveness of photoacoustic nanorobots in buffer solutions containing different concentrations of mixed lipids (including cholesterol esters and free cholesterol). Figure 5(C and D in the text). Lipid responsiveness characterization: Anhydrous ethanol and deionized water were mixed at different volume ratios (volume / volume) to prepare ethanol-water solutions with concentration gradients (%). When preparing buffer solutions containing mixed lipids, esterified cholesterol (CE, Shanghai Maclean Biotechnology Co., Ltd., catalog number 19485-76-8) and free cholesterol (CF, Shanghai Maclean Biotechnology Co., Ltd., catalog number C804517) were added to a 10% serum albumin aqueous solution at a mass ratio of 2:1. After heating and sonication-assisted dissolution, lipid buffer solutions with concentration gradients (mg / dL) were obtained. For lipid responsiveness testing, 10 μL of LDM nanoparticles and DAGH were mixed with a series of photoacoustic nanorobot aqueous solutions (2 mg / mL) and 90 μL of ethanol-water solution or lipid buffer solution.

[0081] Absorption spectroscopy showed that pure DM-based nanomicelles did not exhibit a distinct HD characteristic absorption peak (at 695 nm); while the five nanomicelles containing DAGH but with different DM doping ratios all showed HD characteristic absorption peaks.

[0082] As the concentration of the mixed lipids gradually increased from 0 mg / dL to 2000 mg / dL, the nanomicelles composed of pure DAGH did not show any change in absorption spectrum. The photoacoustic nanorobots obtained by incorporating DM with a higher proportion of DAGH (DAGH:DM ratio of 1:1 and DAGH:DM ratio of 2:1) first showed enhanced light absorption at 695 nm, with lipid response thresholds of approximately 200 mg / dL and 300 mg / dL, respectively (close to the total cholesterol level in hyperlipidemia). Compared with the mixed lipid concentration of 0 mg / dL, the absorbance was significantly different.

[0083] The photoacoustic nanorobots obtained by incorporating DM at lower ratios (DAGH:DM ratio of 4:1 and DAGH:DM ratio of 10:1) did not show significant changes in absorption spectra in environments with mixed lipid concentrations of 0–500 mg / dL. However, when the mixed lipid concentrations were 1000 mg / dL and 1500 mg / dL, respectively, the absorbance showed significant changes compared to when the mixed lipid concentration was 0 mg / dL.

[0084] These results demonstrate that the lipid-responsive behavior of photoacoustic nanorobots is component-incorporation ratio-dependent. Photoacoustic nanorobots with higher DM incorporation ratios (DAGH:DM ratios of 1:1 and 2:1) may prematurely activate signaling in the hyperlipidemic blood of patients with carotid plaques due to their lower lipid response threshold. In contrast, photoacoustic nanorobots with lower DM incorporation ratios (DAGH:DM ratios of 4:1 and 10:1) are more reliably kept "off" in the blood due to their higher lipid response threshold.

[0085] Furthermore, compared with the photoacoustic nanorobot with the lowest DM incorporation ratio (DAGH:DM = 10:1), the DAGH:DM ratio of 4:1 showed enhanced light absorption in an environment with a lipid concentration of 1000 mg / dL (close to the total cholesterol level of asymptomatic carotid plaques reported in the literature), suggesting that the DAGH:DM ratio of 4:1 is more reasonable.

[0086] Photoacoustic imaging also showed that the photoacoustic nanorobots at this doping ratio (DAGH:DM = 4:1) could maintain the photoacoustic signal "off" in a low-concentration lipid environment, while being rapidly activated in a high-concentration lipid environment. Figure 5 (E in the text).

[0087] Figure 5 In the table, A and B: Trajectory analysis (n=10 particles) and average velocity analysis (n=15 particles) of nanomicelles and photoacoustic nanorobots formed in different polymer solution systems in normal and inflammatory cell environments; C and D: Absorption spectra and absorbance statistics at 695 nm (n=3) of nanomicelles and photoacoustic nanorobots formed in different polymer solution systems in mixed lipid solutions of different concentrations; E: Photoacoustic imaging images and quantitative analysis of photoacoustic nanorobots (DAGH:DM = 4:1) in mixed lipid solutions of different concentrations. Data are expressed as Mean ± SD.

[0088] Example 4: In vitro imaging performance evaluation of photoacoustic nanorobots: When preparing cell seeding coverslip samples, RAW264.7 cells were cultured on round coverslips (Biosharp, catalog number BS-14RC).

[0089] To induce the generation of inflammatory cells, RAW264.7 cells were stimulated with lipopolysaccharide (1 μg / mL) for 36 hours.

[0090] To induce foam cells, RAW264.7 cells were first stimulated with lipopolysaccharide (1 μg / mL) for 12 hours, and then co-incubated with lipopolysaccharide (1 μg / mL) and oxidized low-density lipoprotein (80 μg / mL).

[0091] These pretreated cells were co-incubated with a DAGH photoacoustic motor or a DAGH / DM photoacoustic motor (20 μg / mL) for 30 minutes.

[0092] For cell suspension samples, inflammatory cells and foam cells were collected and co-incubated with a DAGH / DM photoacoustic motor (20 μg / mL) for 30 minutes. The inflammatory cells were then resuspended in dimethyl sulfoxide, and the foam cells were resuspended in phosphate-buffered saline.

[0093] For human carotid artery plaque samples, frozen tissue sections were incubated overnight with a DAGH / DM photoacoustic motor (100 μg / mL). Photoacoustic imaging of cell-inoculated coverslips, silicone tubes containing cell suspension, and tissue sections was performed using a preclinical mouse imaging system.

[0094] Photoacoustic images were acquired under 705 nm laser illumination, and the data were reconstructed and analyzed using 3D Slicer software.

[0095] Compared to normal cells, photoacoustic nanorobots showed increased uptake in inflammatory cells, and uptake in foam cells (which exhibit both inflammatory characteristics and are rich in lipids) was comparable to that in inflammatory cells. Figure 6 (A in the figure) This corroborates that photoacoustic nanorobots can promote cellular uptake through chemotactic movement.

[0096] Photoacoustic imaging results from cell smears showed that the photoacoustic signal of the photoacoustic nanorobots was stronger in foam cells than in inflammatory cells. Figure 6 (B in the text) suggests that photoacoustic nanorobots can responsively activate their own photoacoustic signals in a lipid-rich intracellular environment.

[0097] At the ex vivo tissue level, co-incubation of photoacoustic nanorobots with pathologically stained sections of vulnerable human carotid artery plaques demonstrated that the photoacoustic nanorobots could penetrate into the plaque interior, and that the distribution pattern of their photoacoustic signals was highly consistent with the pathological staining results. Figure 6 (C in the middle).

[0098] Example 5: In vivo imaging performance evaluation of photoacoustic nanorobots: At the in vivo level, a mouse model of simple atherosclerosis (stable plaque) and an artificially unstable mouse model of atherosclerosis plaque complicated by pneumonia (vulnerable plaque) were established.

[0099] Mice were intravenously injected with DAGH or photoacoustic nanorobots (500 μg / kg, 500 μg / kg, 50 μg / ml). Photoacoustic imaging was performed using a preclinical mouse imaging system before and 1 hour after injection. Photoacoustic images were acquired under 705 nm laser irradiation, and the data were reconstructed and analyzed using 3D Slicer software.

[0100] Photoacoustic imaging cross-sectional images near the aortic arch plane showed that, compared with before injection, the photoacoustic signal in the aortic region was enhanced in a mouse model of simple atherosclerosis after intravenous injection of photoacoustic nanorobots. Figure 6 In the D and E of the plaque artificial instability mouse model, the enhancement was more pronounced.

[0101] By extracting the photoacoustic signal intensity ratio of the aortic region in the image (post-injection / pre-injection) Figure 6 F in the figure), and second-order features based on the gray-level co-occurrence matrix (including angular second moment, inverse difference and entropy) Figure 6 By comparing the results with pathological staining, it was preliminarily confirmed that the enhanced signal intensity and increased signal distribution disorder of the photoacoustic nanorobots were correlated with increased plaque vulnerability.

[0102] These results at the cellular, ex vivo tissue, and in vivo levels preliminarily demonstrate that photoacoustic nanorobots respond to high concentrations of lipids in plaques to activate signals and reflect plaque vulnerability.

[0103] Figure 6 In the image, A: Cellular uptake laser confocal images and quantitative analysis of fluorescently labeled photoacoustic nanorobots (scale bar: 50 μm); B: Photoacoustic imaging three-dimensional reconstruction after co-incubation of photoacoustic nanorobots with cell slides treated with different methods; C: Gross image, transmission electron microscopy image (scale bar: 500 nm), Oil Red O staining and Masson staining images of tissue sections of human carotid artery plaques (scale bar: 5 mm), and photoacoustic imaging of tissue sections; D and E: Cross-sectional images of photoacoustic imaging near the aortic arch plane 1 h after intravenous injection of photoacoustic nanorobots into mice with simple atherosclerosis (D) or atherosclerosis complicated with pneumonia (E) (scale bar: 2 mm) and Oil Red O staining images of aortic arch tissue sections (scale bar: 500 μm); FI: Quantitative analysis of the photoacoustic signal intensity ratio (post-injection / pre-injection) and second-order texture features of the gray-level co-occurrence matrix in the aortic region. Data are expressed as Mean ± SD. The simple atherosclerosis group had n=4 mice, and the atherosclerosis combined with pneumonia group had n=3 mice. Independent samples t-test was used for analysis.

[0104] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photoacoustic nanorobot, characterized in that, Composed of composite micelles formed by the self-assembly of the first polymer and the second polymer; The first polymer comprises lipids, arginine, unwound collagen hybrid peptides, and a hemicyanine backbone; The second polymer comprises lipids and metalloporphyrins.

2. The photoacoustic nanorobot according to claim 1, characterized in that, The mass ratio of the first polymer to the second polymer is 1:1 to 10:

1.

3. The photoacoustic nanorobot according to claim 2, characterized in that, The mass ratio of the first polymer to the second polymer is 2:1 to 10:

1.

4. The photoacoustic nanorobot according to claim 3, characterized in that, The mass ratio of the first polymer to the second polymer is 4:

1.

5. The photoacoustic nanorobot according to claim 1, characterized in that, The sequence of the unwound collagen hybrid peptide is (GPO). n n is a natural number from 1 to 10; preferably, n is 9.

6. The photoacoustic nanorobot according to claim 1, characterized in that, The lipids include phospholipids.

7. The photoacoustic nanorobot according to claim 1, characterized in that, The metal includes manganese, zinc, palladium, and copper; preferably, the metal is manganese.

8. A method for preparing the photoacoustic nanorobot according to any one of claims 1 to 7, characterized in that, include: S1: Reaction of lipids with arginine derivatives yields lipid-arginine intermediates; S2: The lipid-arginine intermediate is reacted with collagen hybrid peptide to obtain the lipid-arginine-collagen hybrid peptide intermediate; S3: The first polymer is obtained by reacting the lipid-arginine-collagen hybrid peptide intermediate with a hemicyanine derivative; S4: The lipid is reacted with a metalloporphyrin derivative to obtain the second polymer; S5: The first polymer and the second polymer are self-assembled to form the photoacoustic nanorobot.

9. A photoacoustic nanorobot, characterized in that, It is obtained by the preparation method described in claim 8.

10. The application of the photoacoustic nanorobot of any one of claims 1 to 7 or the photoacoustic nanorobot of claim 9 as a probe for atherosclerotic plaques.

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