A polydopamine modified modified nanographene and a preparation method and application thereof

Abstract

The application belongs to the technical field of biological medical materials, and discloses a polydopamine modified modified nano-graphyne and a preparation method and application thereof. In the method, the polydopamine coating is combined with the nano-graphyne for the first time to construct a GDY@PDA composite system, and the core defects of the blocky graphyne, such as easy agglomeration, poor water solubility and insufficient biocompatibility, are solved. The graphyne-based material is applied to the near-infrared two-region photothermal regulation of neural cell calcium influx for the first time, the calcium ion channel is activated through the local thermal effect of the material, and precise, remote and reversible calcium influx regulation is realized; the limitation that the traditional biocompatibility modification is easy to fall off and difficult to functionalize is broken through, the polydopamine modification makes the material have both photothermal efficiency and biological safety, and the application of the graphyne in the treatment of neural diseases (such as neural cell injury repair) is expanded.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials technology, specifically relating to a polydopamine-modified nano-graphyne, its preparation method, and its application. Background Technology

[0002] Near-infrared II (NIR-II, 1000-1700nm) light has become an ideal light source for biomedical imaging and phototherapy due to its advantages such as deep tissue penetration, weak tissue scattering / absorption, and minimal photodamage. Photothermal materials, as the core carriers of NIR-II technology, directly determine the effectiveness of the technology. Currently available NIR-II photothermal materials mainly include noble metal nanoparticles (such as gold nanorods), sulfide quantum dots (such as CuInS2), and traditional carbon materials (such as graphene and carbon nanotubes). However, these materials have the following limitations: noble metal materials are costly and have poor biocompatibility; quantum dots pose a risk of heavy metal ion leakage; and traditional carbon materials such as graphene have low NIR-II absorption efficiency and their surface inertness easily leads to insufficient biocompatibility, making it difficult to meet the needs of clinical applications.

[0003] Graphdiyne, as a novel two-dimensional carbon nanomaterial, possesses unique sp-sp... 2 The hybrid carbon skeleton possesses abundant conjugated electron systems, a large specific surface area, and inherent absorption characteristics in the near-infrared II region, demonstrating significant potential for photothermal conversion. However, bulk graphyne exhibits strong interlayer van der Waals forces, making it prone to aggregation and resulting in poor dispersibility in aqueous solutions. Furthermore, its surface lacks bioactive groups, easily triggering inflammatory responses when directly interacting with cells, and hindering precise regulation of cellular functions (such as calcium influx in nerve cells), thus limiting its biomedical applications.

[0004] Calcium influx in nerve cells is a key physiological process for nerve signal transmission, synaptic plasticity, and cell survival. Abnormal calcium influx (such as calcium overload or deficiency) is one of the core pathological mechanisms of neurological diseases such as Alzheimer's disease and Parkinson's disease.

[0005] In the prior art, biocompatibility modification often uses polyethylene glycol (PEG) derivatives (such as DSPE-PEG), but these modifiers need to bind through hydrophobic interactions and are easily detached in the physiological environment; moreover, the surface of the modified material lacks active sites, making it difficult to further functionalize.

[0006] Therefore, developing a graphdiyne-based material that combines high near-infrared II photothermal efficiency, good biocompatibility, and precise calcium influx regulation capability is of great significance for promoting the development of neurological disease treatment technology. Summary of the Invention

[0007] To address the above-mentioned technical problems, the primary objective of this invention is to provide a method for preparing polydopamine-modified nano-graphyne. This method, for the first time, combines a polydopamine (PDA) coating with nano-graphyne (GDY) to construct a GDY@PDA composite system, solving the core defects of bulk graphyne, such as easy aggregation, poor water solubility, and insufficient biocompatibility. The polydopamine coating is firmly bonded to the surface of graphyne through both covalent and hydrogen bonds, retaining the inherent absorption characteristics of graphyne in the near-infrared II region while imparting good hydrophilicity and cell compatibility to the material, and reserving functionalization sites. The optimized ultrasonic-assisted liquid-phase exfoliation process, using ice-water bath temperature control, intermittent ultrasound, and differential centrifugation, achieves efficient preparation while avoiding structural oxidation and performance degradation. The mild dopamine self-polymerization modification process eliminates the need for chemical crosslinking agents, making it environmentally friendly and avoiding the introduction of toxic impurities, enabling large-scale production.

[0008] The second objective of this invention is to provide an application of polydopamine-modified graphynylene nanomaterials. For the first time, graphynylene-based materials are applied to near-infrared II region photothermal regulation of calcium influx in nerve cells. Calcium ion channels are activated through the local thermal effect of the material, achieving precise, remote, and reversible regulation of calcium influx. This overcomes the limitations of traditional biocompatible modifications, which are prone to detachment and difficult to functionalize. Polydopamine modification enables the material to possess both photothermal efficiency and biosafety, expanding the application of graphynylene in the treatment of neurological diseases (such as nerve cell damage repair).

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for preparing polydopamine-modified nano-graphyne includes the following steps:

[0011] S1. Preparation of nano-graphyne sheets:

[0012] Bulk graphyne was dispersed in a solvent and magnetically stirred until initial dispersion was achieved. Then, ultrasonic treatment was performed in an ice-water bath using an ultrasonic-assisted liquid phase exfoliation method. Differential centrifugation was used to remove unexfoliated bulk graphyne particles and graphyne sheets with a diameter of more than 200 nm, resulting in a dispersion containing nano-graphyne sheets. The solvent was then removed by drying to obtain nano-graphyne sheets.

[0013] S2. Preparation of polydopamine-modified nano-graphyne:

[0014] Nanographite dyne sheets were dispersed in buffer solution to prepare a nanographite dyne sheet dispersion with a mass concentration of 0.3~0.5 mg / mL.

[0015] Dopamine hydrochloride was added to the nano-graphyne sheet dispersion, and the mixture was magnetically stirred until completely dissolved. The pH of the system was then adjusted, and the reaction was carried out under constant temperature water bath. After the reaction was completed, the supernatant was discarded by centrifugation, and the mixture was purified to obtain polydopamine-modified nano-graphyne.

[0016] Preferably, in step S1, the solvent is a mixture of equal volumes of water and ethanol.

[0017] The bulk graphyne is dispersed in a solvent at a mass concentration of 0.1~1.2 mg / mL;

[0018] The magnetic stirring time is 25-30 minutes;

[0019] The ice water bath environment is 2~5℃;

[0020] The ultrasonic treatment conditions are as follows: using an ultrasonic instrument, at 200~600W, for 8~16 hours of ultrasonic treatment, and using an intermittent cyclic operation during the ultrasonic treatment process, specifically: working for 3 seconds and pausing for 1 second;

[0021] The differential centrifugation conditions are: centrifugation at 3000~5000 r / min for 5~20 min;

[0022] The diameter of the nano-graphyne sheets is 50~200nm.

[0023] Preferably, in step S2, the buffer solution is a Tris-HCl buffer solution with a molar concentration of 50-80 mmol / L and a pH of 8.3;

[0024] The mass ratio of the nano-graphyne sheets to dopamine hydrochloride is 1:4;

[0025] Furthermore, the purity of the dopamine hydrochloride is ≥98%;

[0026] The pH of the system was adjusted to 8.8-9 using a 0.8-1 mol / L Tris alkaline solution;

[0027] The stirring reaction conditions are as follows: stirring at a speed of 200-250 r / min for 10-12 hours in a constant temperature water bath at 35-37℃.

[0028] The conditions for discarding the supernatant after centrifugation are: centrifuge at 6000~8000 r / min for 20~25 min.

[0029] Preferably, in step S2, the purification process includes: redispersing the precipitate after centrifugation with ultrapure water, centrifuging at 6000~8000 r / min for 20~25 min, discarding the supernatant, and repeating the centrifugation purification step 3~4 times to remove unpolymerized dopamine hydrochloride monomer, thereby obtaining polydopamine-modified nano-graphyne.

[0030] A polydopamine-modified nano-graphyne is obtained by the preparation method described above.

[0031] The application of polydopamine-modified graphylene nanoparticles in the preparation of agents to improve neurological diseases, wherein the polydopamine-modified graphylene nanoparticles promote calcium influx into nerve cells through near-infrared II light response, and are used in the preparation of agents to improve nerve cell function.

[0032] The application of polydopamine-modified graphylene nanoparticles in the preparation of formulations for treating neurodegenerative diseases, wherein the polydopamine-modified graphylene nanoparticles induce apoptosis of abnormal nerve cells by regulating calcium ion overload in nerve cells, and are used in the preparation of formulations for treating neurodegenerative diseases.

[0033] The application of polydopamine-modified graphylene nanoparticles in the preparation of agents for the treatment of nerve damage repair, wherein the polydopamine-modified graphylene nanoparticles improve nerve cell activity by regulating calcium influx into nerve cells, and are used in the preparation of agents for the treatment of nerve damage repair.

[0034] Compared with the prior art, the present invention has at least the following technical effects:

[0035] This invention provides a method for preparing polydopamine-modified nano-graphyne. This method, for the first time, combines a polydopamine (PDA) coating with nano-graphyne (GDY) to construct a GDY@PDA composite system, solving the core defects of bulk graphyne, such as easy aggregation, poor water solubility, and insufficient biocompatibility. The polydopamine coating is firmly bonded to the surface of graphyne through both covalent and hydrogen bonds, retaining the inherent absorption characteristics of graphyne in the near-infrared II region while imparting good hydrophilicity and cell compatibility, and reserving functionalization sites. The optimized ultrasonic-assisted liquid-phase exfoliation process, using ice-water bath temperature control, intermittent ultrasound, and differential centrifugation, achieves efficient preparation and avoids structural oxidation and performance degradation. The mild dopamine self-polymerization modification process eliminates the need for chemical crosslinking agents, is environmentally friendly, avoids the introduction of toxic impurities, and allows for large-scale production.

[0036] The application of this polydopamine-modified graphylene nanomaterial marks the first time that graphylene-based materials have been used in the near-infrared II region for photothermal regulation of calcium influx in nerve cells. By activating calcium ion channels through the local thermal effect of the material, precise, remote, and reversible regulation of calcium influx is achieved. Overcoming the limitations of traditional biocompatible modifications that are easy to detach and difficult to functionalize, polydopamine modification enables the material to have both photothermal efficiency and biosafety, expanding the application of graphylene in the treatment of neurological diseases (such as nerve cell damage repair).

[0037] The polydopamine-modified nano-graphyne has the following advantages:

[0038] 1. Significant performance advantages: The polydopamine-modified nano-graphyne material prepared by this invention has high near-infrared II photothermal conversion efficiency; the water solubility and biocompatibility of the polydopamine-modified nano-graphyne are significantly better than those of the unmodified graphyne; and it achieves near-infrared II photothermal regulation of calcium influx into nerve cells.

[0039] 2. Advanced preparation process: The ultrasonic-assisted liquid phase exfoliation method does not require complex equipment, has low cost and high yield (100mL of nano-dispersion can be prepared in one batch); the polydopamine modification process is mild (37℃, pH=8.8), does not require chemical crosslinking agents, and avoids the introduction of toxic impurities; the entire preparation process is green and environmentally friendly and can be mass-produced.

[0040] 3. Broad application prospects: This material can remotely regulate the calcium influx into nerve cells through near-infrared II light. It can induce apoptosis of abnormal nerve cells through calcium ion overload, and improve nerve cell activity through moderate calcium influx (for nerve damage repair). At the same time, the polydopamine coating can be further coupled with targeting groups to achieve specific photothermal regulation. Attached Figure Description

[0041] Figure 1 Transmission electron microscopy (TEM) characterization of the nano-graphyne sheet material;

[0042] Figure 2 The ultraviolet-visible-near-infrared absorption spectrum of the nano-graphyne sheet material;

[0043] Figure 3 The near-infrared II region photothermal conversion efficiency diagram of the nano-graphyne sheet material;

[0044] Figure 4 This is a comparison chart of calcium ion concentrations in the experimental groups after 1064nm laser irradiation. Detailed Implementation

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is 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. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0046] One specific embodiment of the present invention is as follows:

[0047] A method for preparing polydopamine-modified nano-graphyne includes the following steps:

[0048] 1. Preparation of nano-graphite yttrium sheets

[0049] Take block graphyne and disperse it in a solvent (preferably a water / ethanol mixture, volume ratio 1:1) at a concentration of 0.1~1.2 mg / mL. Stir magnetically for 30 min before ultrasonic treatment to ensure initial dispersion.

[0050] A probe-type ultrasonic instrument is used, with a power setting of 200~600W, an ultrasound time of 8~16 hours, and an ultrasound interval of 3 seconds of operation and 1 second of pause to avoid local overheating.

[0051] Meanwhile, the reaction vessel was placed in an ice-water bath to control the system temperature at 2-5℃ to prevent graphylene oxidation.

[0052] After sonication, the dispersion is transferred to a centrifuge tube and centrifuged at 3000-5000 r / min for 5-20 min to remove the bottom precipitate. The upper dispersion is then dried to remove water and ethanol, thus obtaining nano-graphyne sheets.

[0053] The above-mentioned drying methods can include overnight drying, vacuum drying oven treatment, or freeze dryer treatment.

[0054] like Figure 1 The image shown is a transmission electron microscope (TEM) characterization of the nano-graphyne sheet material, with a scale bar of 200 nm.

[0055] Combination Figure 1 Transmission electron microscopy characterization shows that the sheet diameter is 50-200 nm.

[0056] Mechanism of preparation of nano-graphyne sheets:

[0057] The mechanical force generated by ultrasonic vibration can disrupt the van der Waals forces between the layers of bulk graphyne, achieving interlayer exfoliation; the use of a water / ethanol mixed solvent, utilizing the hydrogen bonding and polarity matching between solvent molecules and the graphyne surface, improves dispersion stability; and ice-water bath temperature control avoids sp-sp reactions of graphyne caused by ultrasonic heat. 2 The hybrid structure is disrupted to ensure its optical performance.

[0058] 2. Biocompatibility modification (polydopamine coating, i.e., preparation of polydopamine-modified nano-graphyne).

[0059] Take the nano-graphite dyne sheets obtained in step 1 and disperse them in 80 mmol / L Tris-HCl buffer solution (pH=8.3) to prepare a nano-graphite dyne sheet dispersion with a mass concentration of 0.3 mg / mL.

[0060] Add dopamine hydrochloride (purity ≥98%) at a mass ratio of 4:1 to graphyne and stir magnetically until completely dissolved.

[0061] The pH of the system was adjusted to 8.8 with 1 mol / L Tris base, and the mixture was placed in a constant temperature water bath at 37℃ and stirred at 250 r / min for 12 h.

[0062] After the reaction was completed, the mixture was centrifuged at 8000 r / min for 25 min, the supernatant was discarded, the precipitate was redispersed with ultrapure water, and the centrifugation purification was repeated 3 times to remove unpolymerized dopamine monomers, and polydopamine modified nanographyne sheets (denoted as GDY@PDA) were obtained.

[0063] Mechanism of action: Under alkaline conditions (pH=8.5-9.0), the catechol group in the dopamine molecule is oxidized to benzoquinone, which then forms a cross-linked polydopamine coating through self-polymerization; the amino and hydroxyl groups in the polydopamine molecule can form covalent bonds (such as CN bonds) and hydrogen bonds with the defect sites on the graphyne surface, achieving a strong bond; at the same time, the hydrophilic groups (-OH, -NH2) on the surface of the polydopamine coating can improve the water solubility of the material and reduce cytotoxicity.

[0064] Experimental Example 1: Characterization of Near-Infrared Photothermal Properties

[0065] Testing process:

[0066] 1.1 Absorption spectroscopy determination: The nano-graphyne sheet dispersion (concentration 0.1 mg / mL) was placed in a quartz cuvette and scanned using a UV-Vis-NIR spectrophotometer (wavelength range 200-1100 nm), and the absorption intensity in the 200-1100 nm range was recorded.

[0067] like Figure 2 The image shows the ultraviolet-visible-near-infrared absorption spectrum of the nano-graphyne sheet material.

[0068] Results combined Figure 2 It is known that graphdiene materials have a wide absorption range, with significant absorption around 1050 nm.

[0069] 1.2 Determination of photothermal heating curves: 1.0 mL of nano-graphyne sheet dispersion (concentrations of 0.4, 0.8, and 1.6 mg / mL) was placed in a 2 mL centrifuge tube and heated using a 1064 nm near-infrared laser (power density 1.5 W / cm²). 2 The liquid surface was vertically irradiated at a distance of 1 cm, and the temperature was recorded every 30 seconds using an infrared thermal imager (resolution 0.05℃) for 10 minutes. A temperature-time curve was plotted, and the maximum temperature change of the nanomaterial system under light irradiation (usually 10-25℃) was calculated. At the same time, a blank solvent control group was set up to exclude the photothermal effect of the solvent.

[0070] like Figure 3 The figure shows the near-infrared II region photothermal conversion efficiency of the nano-graphyne sheet material. In the figure, A is the photothermal heating curve of the nano-graphyne sheet dispersion under 1064nm near-infrared laser irradiation with different concentrations, and B is the photothermal heating curve of the nano-graphyne sheet dispersion under 1064nm near-infrared laser irradiation with different powers.

[0071] Results combined Figure 3 It is known that nano-graphitic dyne has excellent near-infrared II photothermal conversion performance.

[0072] Experiment Example 2: Verification of the Regulation of Calcium Influx in Nerve Cells

[0073] Experimental procedure:

[0074] Nerve cell culture: Rat pheochromocytoma PC12 nerve cells were cultured in RPMI 1640 medium containing 10% horse serum, 5% fetal bovine serum and 1% penicillin-streptomycin in an incubator at 37°C and 5% CO2.

[0075] Co-culture of materials: The GDY@PDA material was diluted to 0.2 mg / mL with culture medium and added to the cell culture plate, and cultured for another 6 h; a blank control group without material was set up.

[0076] Fluorescent probe loading: Remove the culture medium and add HBSS buffer solution (containing 0.02% Pluronic F-127) containing 5 μM Fluo-3AM fluorescent probe. Incubate at 37°C for 60 min to allow the probe to enter the cells and bind to calcium ions. Then wash three times with HBSS buffer solution to remove the extracellular free probe.

[0077] Photothermal irradiation and calcium concentration detection: The culture plate was placed under a laser confocal microscope and subjected to a 1064nm near-infrared laser (power density 1.0W / cm²). 2 Cells were irradiated for 5 minutes, and fluorescence images were acquired simultaneously (excitation wavelength 488nm, emission wavelength 525nm). Changes in fluorescence intensity before and after irradiation were recorded.

[0078] like Figure 4 The figure shown is a comparison of calcium ion concentrations in the experimental groups after 1064nm laser irradiation.

[0079] Results combined Figure 4 The results showed that the calcium ion concentration in the experimental group was significantly higher than that in the control group after irradiation, proving that the material can regulate the influx of calcium into nerve cells through photothermal effects.

[0080] Regulation mechanism: GDY@PDA generates a local thermal effect under near-infrared II laser irradiation (the temperature around the cell rises to 39-41℃). This temperature can activate temperature-sensitive calcium ion channels (such as TRPV1 channels) on the nerve cell membrane, promoting calcium ion influx. At the same time, the biocompatibility of the polydopamine coating can avoid cell damage caused by thermal effects, ensuring the safety and reversibility of regulation.

[0081] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing polydopamine-modified nano-graphyne, characterized in that, Includes the following steps: S1. Preparation of nano-graphyne sheets: Bulk graphyne was dispersed in a solvent and magnetically stirred until initial dispersion was achieved. Then, ultrasonic treatment was performed in an ice-water bath using an ultrasonic-assisted liquid phase exfoliation method. Differential centrifugation was used to remove unexfoliated bulk graphyne particles and graphyne sheets with a diameter of more than 200 nm, resulting in a dispersion containing nano-graphyne sheets. The solvent was then removed by drying to obtain nano-graphyne sheets. The solvent is a mixture of equal volumes of water and ethanol; The bulk graphyne is dispersed in a solvent at a mass concentration of 0.1~1.2 mg / mL; The magnetic stirring time is 25-30 minutes; The ice water bath environment is 2~5℃; The ultrasonic treatment conditions are as follows: using an ultrasonic instrument, at 200~600W, for 8~16 hours of ultrasonic treatment, and using an intermittent cyclic operation during the ultrasonic treatment process, specifically: working for 3 seconds and pausing for 1 second; The differential centrifugation conditions are: centrifugation at 3000~5000 r / min for 5~20 min; The diameter of the nano-graphyne sheets is 50~200nm; S2. Preparation of polydopamine-modified nano-graphyne: Nanographite dyne sheets were dispersed in buffer solution to prepare a nanographite dyne sheet dispersion with a mass concentration of 0.3~0.5 mg / mL. Dopamine hydrochloride was added to the nano-graphyne sheet dispersion, and the mixture was magnetically stirred until completely dissolved. The pH of the system was then adjusted, and the reaction was carried out under constant temperature water bath. After the reaction was completed, the supernatant was discarded by centrifugation, and the mixture was purified to obtain polydopamine-modified nano-graphyne. The buffer solution is a Tris-HCl buffer solution with a molar concentration of 50-80 mmol / L and a pH of 8.3; The mass ratio of the nano-graphyne sheets to dopamine hydrochloride is 1:4; Furthermore, the purity of the dopamine hydrochloride is ≥98%; The pH of the system was adjusted to 8.8-9 using a 0.8-1 mol / L Tris alkaline solution; The stirring reaction conditions are as follows: stirring at a speed of 200-250 r / min for 10-12 hours in a constant temperature water bath at 35-37℃. The conditions for discarding the supernatant after centrifugation are: centrifugation at 6000~8000 r / min for 20~25 min; The purification process includes: redispersing the precipitate after centrifugation with ultrapure water, centrifuging at 6000~8000 r / min for 20~25 min, discarding the supernatant, and repeating the centrifugation purification process 3~4 times to remove unpolymerized dopamine hydrochloride monomers, thereby obtaining polydopamine-modified nano-graphyne.

2. A polydopamine-modified nano-graphyne, characterized in that, It is obtained by the preparation method described in claim 1.

3. The application of the polydopamine-modified nanographite yttrium as described in claim 2 in the preparation of a formulation that promotes calcium influx into nerve cells.

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