A photothermal-regulated anaerobic sclera cross-linking nanocomposite material, a preparation method and application thereof

Abstract

The application discloses a kind of photo-thermal regulation's anaerobic sclera crosslinking nano-composite material and its preparation method and application, for the technical bottleneck of lacking anaerobic crosslinking agent for the inhibition of myopia development of sclera collagen crosslinking technology, develop a kind of not dependent on oxygen, photo-thermal regulation's nano-composite crosslinking agent PHIONs-GQDs-AIBI nano system.Based on the good photo-thermal performance and synergistic effect of mesoporous iron oxide nanoparticles (PHIONs) and graphene quantum dots (GQDs), the near-infrared excitation light energy is efficiently converted into heat energy, and the heat energy is efficiently transmitted to the free radical initiator (AIBI) through the excellent thermal conductivity of GQDs. Make AIBI decompose to produce an anaerobic radical under high heat excitation, that is, alkyl radical, for the crosslinking of sclera collagen.

Description

A photothermally regulated anaerobic scleral crosslinked nanocomposite material, its preparation method and application Technical Field

[0001] This invention relates to the field of biomedical technology, specifically to a photothermally regulated anaerobic scleral crosslinking nanocomposite material, its preparation method, and its application. Background Technology

[0002] High myopia has been listed as a major cause of blindness, leading to serious blinding diseases such as retinal detachment, macular degeneration, glaucoma, and cataracts. The exact causes of myopia are still unclear, but they can be broadly categorized into two main factors: genetics and environment. Research has found that when using the eyes for close work, the brain senses farsighted focusing information, thereby regulating dopamine, reducing blood supply to the choroid, leading to scleral hypoxia and thinning, and subsequently, under the influence of intraocular pressure, elongating the axial length of the eye. This indicates that the progression of myopia is closely related to the thinning and decreased mechanical properties of the sclera. Improving the mechanical properties of the sclera through scleral cross-linking to prevent the progression of myopia—that is, cross-linking scleral collagen to form new connections within and between collagen molecules—is a novel method for treating myopia.

[0003] Current scleral crosslinking techniques mainly include chemical crosslinking and physical crosslinking. Chemical crosslinking uses chemical crosslinking agents (such as glutaraldehyde, genipin, and glyceraldehyde) to crosslink collagen; however, the crosslinking effect is unstable, easily producing toxic side effects such as exogenous crosslinking, and the degree of crosslinking cannot be controlled by adjusting the reaction time. Physical crosslinking mainly uses specific wavelengths of light, such as ultraviolet / blue light, to irradiate riboflavin and generate reactive oxygen species, catalyzing the crosslinking of scleral collagen. This method requires the consumption of oxygen between tissues. However, the sclera in myopia may already be in a hypoxic state, resulting in low crosslinking efficiency and limited effectiveness in inhibiting myopia progression. Therefore, this patent aims to solve the problem of how to achieve efficient collagen crosslinking in a hypoxic state of the sclera, namely, by developing an oxygen-independent, photothermally regulated nanocomposite crosslinking agent to achieve efficient crosslinking of myopia-related scleral collagen in a hypoxic state.

[0004] This patent reports a novel nanocomposite crosslinking agent composed of mesoporous hollow iron oxide nanoparticles (PHIONs), graphene quantum dots (GQDs), and the free radical initiator 2,2'-azabis(2-imidazoline) dihydrochloride (AIBI). PHIONs possess excellent photothermal effects, converting light energy of specific wavelengths into heat energy. Graphene quantum dots, with their excellent photothermal effects and superior thermal conductivity, can synergistically enhance the photothermal effect of PHION-based nanomaterials and efficiently transfer heat energy to AIBI. Under high-temperature excitation, AIBI decomposes to generate alkyl free radicals, a non-oxygen free radical, which are used for the crosslinking of scleral collagen to achieve efficient crosslinking of hypoxic scleral collagen, thereby effectively treating myopia progression. Summary of the Invention

[0005] To address the shortcomings and deficiencies of existing technologies, this invention develops a photothermally regulated oxygen-free scleral crosslinking nanocomposite material, composed of nanoparticles, GQDs quantum dots, and AIBI free radical initiator. It can achieve oxygen-independent scleral crosslinking through photothermal regulation to treat the progression of myopia.

[0006] The technical solution adopted in this invention is: a photothermally regulated oxygen-free scleral crosslinking nanocomposite material, wherein the nanocomposite material is composed of mesoporous iron oxide nanoparticles (PHIONs), graphene quantum dots (GQDs) and alkyl radical initiator AIBI.

[0007] The initiator for the alkyl radical is 2,2'-azabis(2-imidazoline) dihydrochloride (AIBI).

[0008] A method for preparing a photothermally regulated, oxygen-free scleral crosslinking nanocomposite material PHIONs-GQDs-AIBI includes the following steps:

[0009] (1) Hydrothermal synthesis of PHIONs: Weigh anhydrous ferric chloride, sodium citrate dihydrate and urea, add them to deionized water one after another, mix and stir for half an hour until they are evenly dissolved; add polyacrylamide slowly in portions to the above solution, stirring continuously during the addition process; after the polyacrylamide is evenly dissolved, transfer the above solution to a stainless steel reactor, and then put the reactor into an oven and react at a high temperature of 200℃ for 12 hours; after the reaction is completed, wait for the reactor to cool to room temperature, take out the mixture after the reaction, centrifuge and discard the supernatant, take the precipitate, wash with anhydrous ethanol to remove excess polyacrylamide, and then wash with deionized water 3 times to finally obtain purified PHIONs, redisperse them in water, and store them in a refrigerator at 4℃ for later use;

[0010] (2) Preparation of functionalized mesoporous iron oxide nanomaterials PHIONs-GQDs-AIBI: PHIONs, GQDs and AIBI solutions were mixed in a certain mass ratio and stirred for 5 hours. After stirring, the mixture was centrifuged and washed with water multiple times to remove excess GQDs and AIBI, and purified PHIONs-GQDs-AIBI nanomaterials were obtained.

[0011] Application of a photothermally regulated anaerobic scleral crosslinking nanocomposite material in the preparation of scleral collagen crosslinking drugs.

[0012] The concentration of PHIONs-GQDs-AIBI in the scleral collagen crosslinking drug is 200-300 μg / mL.

[0013] The laser power density induced by the cross-linking of the scleral collagen cross-linking drug is 0.5-0.8 W / cm². 2 .

[0014] The scleral collagen crosslinking drug can decompose to generate alkyl free radicals at a temperature of 39℃-46℃.

[0015] A method for crosslinking scleral collagen includes the following steps: adding the prepared nanocomposite system PHIONs-GQDs-AIBI solution to the scleral tissue and irradiating it with an 808 nm laser emission instrument for 10 minutes to complete the scleral collagen crosslinking operation.

[0016] The beneficial effects of this invention are as follows: This invention provides a photothermally regulated oxygen-free scleral crosslinking nanocomposite material, its preparation method, and its application. Based on the excellent photothermal effect of PHIONs, light energy of a specific wavelength (808 nm) is converted into heat energy. Based on the excellent photothermal effect and superior thermal conductivity of GQDs, the photothermal performance of PHIONs-based nanomaterials is improved through synergistic effects, and the heat energy is rapidly and efficiently transferred to AIBI. This allows for controllable thermal excitation of AIBI, causing it to decompose and generate a non-oxygen free radical, namely an alkyl free radical, for crosslinking of scleral collagen. Attached Figure Description

[0017] Figure 1(a) and (b) are TEM images of PHIONs before and after loading GQDs and AIBI, respectively.

[0018] Figure 2 shows the photothermal conversion capability of PHIONs-GQDs-AIBI under different concentrations and laser power densities; where a and b are the photothermal curves at different concentrations and their corresponding temperature increases; and c and d are the photothermal curves at different laser power densities and their corresponding temperature increases.

[0019] Figure 3 shows the biomechanical parameters of the porcine sclera in the material + NIR group, the NIR group, and the material group; where NIR: NIR group; PHIONs-GQDs-AIBI: material group; PHIONs-GQDs-AIBI + NIR: material + NIR group. a: Stress-strain curves of different groups (strain range 0~8%); b, c, and d: Comparison of scleral thickness, elastic modulus at 8% strain, and ultimate stress of different groups, respectively. Detailed Implementation

[0020] 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 a part of the embodiments of the present invention, and not all of the 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.

[0021] Example 1: Synthesis of PHIONs

[0022] The synthesis of PHIONs utilizes anhydrous ferric chloride as the iron source and is achieved via a hydrothermal synthesis method. The specific steps are as follows:

[0023] 1) Weigh 0.648 g of anhydrous ferric chloride, 2.06 g of sodium citrate dihydrate and 0.72 g of urea into 80 mL of deionized water and stir for half an hour until dissolved.

[0024] 2) Add 0.5 g of polyacrylamide slowly in portions to the above solution. Stir continuously during the addition process to prevent the polyacrylamide from agglomerating. This addition process takes about 2 hours.

[0025] 3) After the polyacrylamide has dissolved evenly, transfer the solution to a stainless steel reactor, then place the reactor in an oven and react at 200°C for 12 hours.

[0026] 4) After the reaction is complete, wait for the reaction vessel to cool to room temperature, take out the reaction mixture, centrifuge at high speed for 10-15 minutes, discard the supernatant and take the precipitate, first wash with anhydrous ethanol to remove excess polyacrylamide, then wash with deionized water 3 times to finally obtain purified PHIONs, redisperse them in water and store them in a refrigerator at 4°C for later use.

[0027] Example 2: Preparation of PHIONs-GQDs-AIBI

[0028] To obtain better photothermal performance, we explored the synthesis ratio of PHIONs and GQDs. PHIONs and GQDs dispersions were mixed at a mass ratio of 1:0.1 to 1:0.5, and PHIONs and AIBI solutions were mixed at a mass ratio of 1:4 to 1:6. After stirring for 5 hours, the mixture was centrifuged and washed with water multiple times to remove excess GQDs and AIBI, resulting in a purified PHIONs-GQDs-AIBI nanosystem.

[0029] Experimental results

[0030] Figure 1(a) shows that the synthesized PHIONs are typical mesoporous nanomaterials, in which each sphere has a bright central region that contrasts with the dark edges, indicating that these spheres are hollow. Figure 1(b) shows that the originally bright central region of the PHION mesoporous material loaded with GQDs and AIBI turns black, indicating that AIBI and GQDs were successfully loaded into the cavities of the PHIONs.

[0031] Figure 2 shows the effect of different concentrations and laser power densities on the photothermal conversion capability of PHIONs-GQDs-AIBI. As the concentration of PHIONs-GQDs-AIBI increases, the corresponding temperature increase also increases. Under the same concentration conditions, PHIONs-GQDs-AIBI exhibits different temperature rise capabilities after irradiation with lasers of different power densities. Figures c and d show that at a power density of 2.0 W / cm², the temperature rise is significantly higher. 2 Under laser irradiation, the heating capacity of PHIONs-GQDs-AIBI is significantly improved, with a maximum temperature change of up to 53.9℃.

[0032] Figure 3(a) shows the overall trend of biomechanical parameters of porcine sclera treated with PHIONs-GQDs-AIBI. As shown in Figure 3(b), there was no statistically significant difference in scleral thickness among the three groups, indicating that PHIONs-GQDs-AIBI had no significant effect on scleral thickness after contact or interaction with the porcine sclera. As shown in Figure 3(c), there was a statistically significant difference in stress values ​​at 8% strain among the three groups (p<0.01). Pairwise comparisons between groups revealed that the material plus near-infrared (NIR) group was significantly higher than the pure NIR group (p<0.001) and the pure material group (p<0.05), and the pure material group was also slightly higher than the pure NIR group (p<0.01). This may be because after the PHIONs-GQDs-AIBI nanomaterials came into contact with the porcine sclera, the material particles penetrated between the scleral collagen fibers, possibly filling the gaps between the scleral collagen fibers and locally strengthening its tensile strength. The cross-linking effect of PHIONs-GQDs-AIBI is essential for further enhancing its biomechanical properties. The elastic modulus results at 8% strain (Figure 3d) show statistically significant differences among the three groups (p<0.05). Specifically, the material + NIR group showed significantly higher modulus than the NIR group (p<0.01), while there was no statistically significant difference between the material + NIR group and the material group (p>0.05), nor between the material group and the NIR group (p>0.05). This corresponds to the stress values ​​at 8% strain, further indicating that the tensile strength enhancement of the porcine sclera in the material group is only localized. Regarding the ultimate stress value, there was no statistically significant difference among the three groups (p>0.05).

[0033] In summary, this invention addresses the challenge of scleral collagen crosslinking techniques for inhibiting myopia progression—specifically, the bottleneck of achieving efficient collagen crosslinking under hypoxic conditions in the sclera. It develops an oxygen-independent, photothermally regulated nanocomposite crosslinking agent, the PHIONs-GQDs-AIBI nanosystem, for efficient crosslinking of scleral collagen under hypoxic conditions. The synergistic effect of PHIONs and GQDs efficiently converts near-infrared excitation light into heat energy, which is then efficiently transferred to AIBI via GQDs. This causes AIBI to decompose under high-heat excitation, generating alkyl free radicals that are used for scleral collagen crosslinking, resulting in significantly improved biomechanical properties in animal models.

[0034] Please note to all technical personnel: Although the present invention has been described according to the specific embodiments above, the inventive concept of the present invention is not limited to this invention. Any modifications that utilize the inventive concept will be included within the scope of protection of this patent.

[0035] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A photothermally regulated oxygen-free scleral crosslinking nanocomposite material, characterized in that, The nanocomposite material is composed of mesoporous iron oxide nanoparticles (PHIONs) supported on graphene quantum dots (GQDs) and alkyl radical initiator AIBI, wherein the mass ratio of PHIONs to GQDs ranges from 1:0.1 to 1:0.5, and the mass ratio of PHIONs to AIBI ranges from 1:4 to 1:

6.

2. A method for preparing a photothermally regulated oxygen-free scleral crosslinking nanocomposite material, characterized in that, Includes the following steps: (1) Hydrothermal synthesis of PHIONs: Weigh anhydrous ferric chloride, sodium citrate dihydrate and urea, and add them to deionized water one after another. Mix and stir for half an hour until they are evenly dissolved. Add polyacrylamide slowly in portions to the above solution. Stir continuously during the addition process to prevent polyacrylamide from agglomerating. After the polyacrylamide is evenly dissolved, transfer the above solution to a stainless steel reactor. Then place the reactor in an oven and react at a high temperature of 200°C for 12 hours. After the reaction is completed, let the reactor cool to room temperature, take out the mixture after the reaction, centrifuge at high speed for 10-15 minutes, discard the supernatant and take the precipitate. Wash with anhydrous ethanol to remove polyurethane. The remaining polyacrylamide was washed three times with deionized water to obtain purified PHIONs, which were then redispersed in water and stored in a 4°C refrigerator for later use. (2) Preparation of PHIONs-GQDs-AIBI nanomaterials: PHIONs, GQDs and AIBI solutions were mixed at a mass ratio of PHIONs to GQDs of 1:0.1 to 1:0.5 and a mass ratio of PHIONs to AIBI of 1:4 to 1:6, respectively. After stirring for 5 hours, the mixture was centrifuged and washed with water multiple times to remove excess GQDs and AIBI, and purified PHIONs-GQDs-AIBI nanomaterials were obtained.

3. The preparation method according to claim 2, characterized in that, The process of slowly adding polyacrylamide in step (1) lasts for 2 hours.

4. The application of the photothermally regulated anaerobic scleral crosslinking nanocomposite material according to claim 1 in the preparation of scleral collagen crosslinking drugs.

5. The application according to claim 4, characterized in that, The concentration of PHIONs-GQDs-AIBI in the scleral collagen crosslinking drug is 200-300 μg / mL.

6. The application according to claim 4, characterized in that, The laser power density induced by the cross-linking of the scleral collagen cross-linking drug is 0.5-0.7 W / cm². 2 .

7. The application according to claim 4, characterized in that, The scleral collagen crosslinking drug can decompose to generate alkyl free radicals at a temperature of 39℃-46℃.

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