A universal method for synthesizing silica nanoparticles doped with dyes and drug molecules using a co-precipitation method.

Abstract

This invention relates to a universal method for synthesizing silica nanoparticles doped with dyes and drug molecules via co-precipitation. In the reaction system of this invention, tetraethyl orthosilicate is used as the synthetic raw material, and a universal method applicable to the doping of dye and drug molecules is proposed. This method demonstrates that 98 dyes and drug molecules can be directly doped into silica nanoparticles. The reaction is simple, and the substances involved have good biocompatibility, enabling efficient doping of dye and drug molecules into silica nanoparticles. By controlling the synthesis parameters, the synthesis ratio determined in this invention can ensure the morphology and a certain doping rate of the silica nanoparticles. This invention can serve as a safer and more efficient platform technology for doping various dye and drug molecules into silica nanoparticles. The unique microenvironment of silica nanoparticles further protects dye and drug molecules from damage caused by harsh environments.

Description

Technical Field

[0001] This invention relates to a universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules using a co-precipitation method, belonging to the field of dye molecule doping and drug molecule doping technology. Background Technology

[0002] Methods for doping dyes and drug molecules into silica are quite limited, and currently known methods are generally applicable to specific conditions. For dye doping, there are two main methods: covalent coupling and electrostatic attraction. The former involves direct bonding of the dye to a silane linker molecule, followed by co-precipitation of the resulting conjugate with silica. In the latter method, cationic dyes are directly incorporated using the Stöber method or microemulsion method. The release rate of drug molecules in the human body needs to be controlled within a suitable range; otherwise, it can lead to drug poisoning. Silica nanoparticles, with their high biocompatibility, are suitable as ideal carriers for drug molecules, and various silica-based drug sustained-release methods have been explored in recent years. Based on the structure of silica, there are currently two main methods for encapsulating drugs: the first is to directly encapsulate or embed the drug within silica for release; the second is to first synthesize silica (mainly mesoporous silica) and then encapsulate the drug within it through adsorption.

[0003] Among the many methods for doping dye and drug molecules with silica nanoparticles, covalent coupling is limited due to the need for expensive and limited quantities of dyes with specific coupling groups. Coprecipitation, on the other hand, is more suitable and universally applicable for cationic dye molecules. The excellent biocompatibility of silica nanoparticles also allows for their safe metabolism in biological environments and supports drug delivery, ensuring successful release.

[0004] However, the general methods applicable to dye and drug doping are not specifically described. The stability of dye molecules doped into silica nanoparticles remains a persistent issue due to differences in their inherent charge properties. Doxorubicin, a widely used antitumor drug with high targeting specificity for tumor treatment in vivo, exhibits particularly poor stability when doped into silica nanoparticles. To address this problem, researchers have employed various methods to improve the stability of dye and drug molecules. One such method involves nanoscale doping of dye and drug molecules to enhance their stability and prolong drug action time. Summary of the Invention

[0005] The technical problem solved by this invention is to propose a universal method for synthesizing silica nanoparticles doped with dyes and drug molecules using a co-precipitation method. This method enables the rapid doping of dye and drug molecules into silica nanoparticles in a simple reaction system for subsequent research and drug sustained release. Traditional methods involve complex reaction systems for doping silica with dye and drug molecules, often requiring multiple auxiliary substances that are difficult to completely remove during subsequent purification. In the reaction system of this invention, the water-soluble nature of tetraethyl orthosilicate, combined with its role as a raw material for synthesizing silica nanoparticles, simplifies the reaction system to the greatest extent, facilitating subsequent product purification. Furthermore, the substances used in the synthesis method of this invention possess strong biocompatibility, fundamentally ensuring the safety of the drugs for in vivo use. Silica nanoparticles effectively protect dye and drug molecules, improving their stability. The silica nanoparticles synthesized in this invention effectively protect dye and drug molecules from environmental damage. The synthesis method proposed in this invention can dope a large number of dye and drug molecules into silica nanoparticles and is applicable to most dye molecules, exhibiting high versatility. In the reaction system of this invention, compared to previous synthesis systems, the synthesis efficiency can be significantly improved, and it is applicable to most dye molecules. By adjusting the synthesis parameters, this invention can ensure a certain doping rate while maintaining the particle morphology at a defined synthesis ratio. Furthermore, this invention can serve as a safer and more efficient platform technology for doping drug molecules into silica nanoparticles, and holds promise for large-scale synthesis and in vivo drug delivery in the future.

[0006] To solve the technical problem of this invention, the specific technical solution proposed by this invention is: a universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules using a co-precipitation method, the specific steps of which are as follows:

[0007] Step (1): Prepare a mixed solution of isopropanol (IPA) and water for dye or drug molecules;

[0008] Step (2): Add tetraethyl orthosilicate (TEOS) and ammonia to step (1) to form a mixed solution and vortex rapidly and let stand. Dye@silica or drug@silica is formed by co-precipitation.

[0009] Step (3): After centrifuging the solution after the reaction, remove the supernatant to obtain the product, and wash and purify it with pure water multiple times to finally obtain purified dye@silica or drug@silica.

[0010] The specific method for preparing the isopropanol (IPA) and water mixed solution of dye molecules or drug molecules in step (1) is to dissolve the dye molecules or drug molecules in a mixed solution of isopropanol and water (volume ratio of 5:2) to prepare a 0.3mM dye molecule or drug molecule mixed solution.

[0011] The synthesis of dye@silica or drug@silica in step (2) is specifically carried out by taking 1.4 mL of the mixed solution in step (1) and adding 15 µL of ammonia water to the system, vortexing for 5 s, and then adding 3 µL of tetraethyl orthosilicate. After the addition is completed, the reaction system is placed in the dark and reacted at 500 rpm for 10 h on a magnetic stirrer to complete the co-precipitation process and form dye@silica or drug@silica.

[0012] Preferably, the dye molecule is phenolic saffron and the drug molecule is doxorubicin.

[0013] Preferably, the product purification process described in step (3) involves centrifuging the mixed solution after reaction at 12,000 rpm for 12 minutes, discarding the supernatant, dispersing the precipitated product in pure water, and continuing to centrifuge. This process is repeated three times to achieve the purpose of washing and purifying the product. The purified product can be dispersed in a specific solvent for subsequent characterization or application.

[0014] Preferably, the synthesis steps are as follows:

[0015] The specific method for preparing the isopropanol (IPA) and water mixed solution of dye molecules or drug molecules in step (1) is to dissolve the dye molecules or drug molecules in a mixed solution of isopropanol and water (volume ratio of 5:2) to prepare a 0.3mM dye molecule or drug molecule mixed solution.

[0016] The synthesis of dye@silica or drug@silica in step (2) is specifically carried out by taking 1.4 mL of the mixed solution in step (1) and adding 15 µL of ammonia water to the system, vortexing for 5 s, and then adding 3 µL of tetraethyl orthosilicate. After the addition is completed, the reaction system is placed in the dark and reacted at 500 rpm for 10 h on a magnetic stirrer to complete the co-precipitation process and form dye@silica or drug@silica.

[0017] The product purification process described in step (3) involves centrifuging the mixed solution after reaction at 12,000 rpm for 12 minutes, discarding the supernatant, dispersing the precipitated product in pure water, and continuing to centrifuge. This process is repeated three times to achieve the purpose of washing and purifying the product. The purified product can be dispersed in a specific solvent for subsequent characterization or application.

[0018] Preferably, the dye molecules are 98 dyes from 106 dyes in 12 series, including acridine series dyes, phenothiazine series dyes, Takagawa series dyes, arylmethane series dyes, phenazine series dyes, indole series dyes, phenothiazine series dyes, phthalocyanine series dyes, tetrazolium series dyes, benzothiazole series dyes, and other dyes, wherein R1, D11, D12, K7, K14, and K15 cannot be doped into silica nanoparticles;

[0019] A general method for synthesizing silica nanoparticles doped with dyes and drug molecules using coprecipitation includes:

[0020] Step (1): Prepare a mixed solution of 0.3 mM dye molecules or drug molecules in isopropanol and water (volume ratio of 5:2);

[0021] Step (2): Take 1.4 mL of the mixed solution from step (1) and add 15 µL of ammonia water to the system. After vortexing for 5 s, add 3 µL of tetraethyl orthosilicate. Place it in the dark and react at 500 rpm on a magnetic stirrer for 10 h to complete the co-precipitation process to form dye@silica or drug@silica.

[0022] Step (3): Purify the product dye@dilica or drug@silica with pure water.

[0023] The beneficial effects of this invention are:

[0024] (1) A platform technology for synthesizing silica nanoparticles doped with dye and drug molecules using a co-precipitation method has been established. This technology allows most cationic dye and drug molecules to be doped into silica nanoparticles, demonstrating high versatility. This invention can serve as a safer and more efficient platform technology for doping various dye and drug molecules into silica nanoparticles. The unique microenvironment of silica nanoparticles better protects dye and drug molecules from damage caused by harsh environments. This invention holds promise for large-scale synthesis in the future and is applicable to the doping of any cationic dye and drug molecules.

[0025] (2) The stability of dye molecules is improved by using silica nanoparticles to dope them. The synthesis method of this invention is applicable to most cationic dyes and has a high doping rate for most cationic dyes.

[0026] (3) It is applicable to the doping of a wide range of dye molecules, including 98 different dye molecules from 12 series such as acridine family, phenothiazine family, Takagawa series dyes, arylmethane family, phenazine series dyes, indole series dyes, phenothiazine family, phthalocyanine family, tetrazolium family, benzothiophene family, xanthene family and other families, and effectively controls their stability.

[0027] (4) This invention is applicable to the encapsulation of drug molecules, including neomycin (DOX), methylene blue (MB), etc. The synthesis method is simple and the synthesis efficiency is high. The silica nanoparticles provide a protective layer for the drug molecules, enabling the drug molecules to exist stably and be effectively released within a period of time.

[0028] (5) As can be seen from Example 2, PSF@silica obtained by doping with 0.3 mM phenol saffron did not precipitate, and the doping efficiency was about 1.86%. The morphology of the product was relatively uniform as observed by transmission electron microscopy. Figure 5 The nanoparticles were found to have a size of 57.95 ± 7.26 nm. Transmission electron microscopy revealed that they were uniformly spherical nanoparticles.

[0029] (6) As can be seen from Example 4, DOX@silica doped with 0.3 mM doxorubicin showed a significant neomycin absorption peak when detected by UV-Vis spectrophotometer. Figure 13 The doping efficiency of this method for neomycin was calculated to be approximately 34.1%. Furthermore, transmission electron microscopy revealed that the product morphology was relatively uniform. Figure 12 ).

[0030] (7) Comparative Example 1 shows that as the solvent ratio increases, the doping amount of PSF@silica for PSF gradually increases. Figure 6 In the synthesis, a solvent ratio of 5:2 for isopropanol and water is preferred, which neither damages the morphology of PSF@silica nanoparticles nor results in a high doping level.

[0031] (8) Comparative Example 2 shows that reducing the amount of ammonia water slows down the hydrolysis and condensation rate of TEOS. Figure 7 This results in a longer pairing time between the polysilicic acid produced by hydrolysis and the dye PSF, thus increasing the final amount of dye precipitation. When the amount of ammonia decreases to a certain level, it will severely affect the hydrolysis of TEOS, thereby reducing its precipitation amount, and the amount of dye precipitation will decrease. In the synthesis, a 15 μL amount of ammonia is preferred, which has a high doping amount but will not affect the hydrolysis of TEOS due to excessively low ammonia content.

[0032] (9) Comparative Example 3 shows that the greater the amount of TEOS, the more substances can precipitate the dye. Figure 8Therefore, the doping amount of dye will also increase accordingly. In the synthesis, the preferred volume of 3 μL of tetraethyl orthosilicate is one that does not damage the nanoparticle morphology of PSF@silica while achieving a high doping amount. Comparative Example 4: PSF@silica placed in a refrigerator was subjected to UV absorption testing again, and the absorption spectrum was compared with that of 7 days prior. Figure 9 The results showed no significant difference, indicating that PSF is stably doped into silicon oxide.

[0033] (10) Comparative Example 5 compares the UV absorption signals of phenolic saffron silica nanoparticles under the three reactions. Figure 10 The results showed no significant differences, indicating that the doping of phenolic saffron into silica nanoparticles has a certain degree of universality. Attached Figure Description

[0034] The present invention will be further described below with reference to the accompanying drawings.

[0035] Figure 1 This is a schematic diagram illustrating the mechanism of synthesizing nanoscale silica nanoparticles doped with dye molecules using the co-precipitation method;

[0036] Figure 2 The UV absorption spectra of phenolic saffron dye and phenolic saffron silica nanoparticles (PSF@silica) are shown.

[0037] Figure 3 The images show the UV absorption spectra and standard curves of silica nanoparticles (PSF@silica) doped with different concentrations of phenolic saffron red (PSF) dye.

[0038] Figure 4 These are transmission electron microscope images of phenolic saffron silica nanoparticles doped with different concentrations of phenolic saffron dye. (a) 0.1 mM phenolic saffron silica nanoparticles (PSF@silica) Phenolic saffron silica nanoparticles (PSF@silica) Phenolic saffron silica nanoparticles (PSF@silica).

[0039] Figure 5 These are transmission electron microscopy (TEM) images of silica nanoparticles (PSF@silica) doped with 0.3 mM phenol saffron dye, along with their corresponding particle size distribution (N=300).

[0040] Figure 6 This is the UV absorption spectrum of the solvent ratio relative to the dye doping amount of phenolic saffron silica nanoparticles (PSF@silica);

[0041] Figure 7These are transmission electron microscope images of phenolic saffron silica nanoparticles with different solvent ratios: (a) phenolic saffron silica nanoparticles with a solvent ratio of 5:1 (PSF@silica), (b) phenolic saffron silica nanoparticles with a solvent ratio of 5:2 (PSF@silica), and (c) phenolic saffron silica nanoparticles with a solvent ratio of 5:3 (PSF@silica).

[0042] Figure 8 The UV absorption spectrum of the amount of ammonia versus the dye doping amount of phenolic saffron silica nanoparticles (PSF@silica) is shown.

[0043] Figure 9 The images are (a) transmission electron microscope images of polysilicic acid precursors with tetramethyl orthosilicate (TMOS), (b) transmission electron microscope images of polysilicic acid precursors with tetraethyl orthosilicate (TEOS), (c) transmission electron microscope images of polysilicic acid precursors with tetrapropyl orthosilicate (TPOS), and (d) ultraviolet absorption spectra of different polysilicic acid precursors.

[0044] Figure 10 The UV absorption spectrum is a representation of the volume of tetraethyl orthosilicate versus the dye doping amount of phenolic saffron silica nanoparticles (PSF@silica).

[0045] Figure 11 These are transmission electron microscope images of phenolic saffron silica nanoparticles with different volumes of tetraethyl orthosilicate: (a) phenolic saffron silica nanoparticles with 1.5 μL tetraethyl orthosilicate (PSF@silica), (b) phenolic saffron silica nanoparticles with 2 μL tetraethyl orthosilicate (PSF@silica), (c) phenolic saffron silica nanoparticles with 3 μL tetraethyl orthosilicate (PSF@silica), and (d) phenolic saffron silica nanoparticles with 4 μL tetraethyl orthosilicate (PSF@silica).

[0046] Figure 12 The UV absorption spectra of phenolic saffron silica nanoparticles (PSF@silica) stored for different times are shown.

[0047] Figure 13 These are the UV absorption spectra of phenolic saffron silica nanoparticles (PSF@silica) with a doping amount of 0.3 mM from different batches.

[0048] Figure 14These are transmission electron microscope (TEM) images of some dye@silica nanoparticles prepared by the organic-inorganic coprecipitation method: (a) B3@silica, (b) B4@silica, (c) D7@silica, (d) D10@silica, (e) F1@silica, (f) F6@silica, (g) G2@silica, (h) G4@silica, (i) G6@silica, (j) J4@silica, (k) K9@silica, (l) K16@silica, (m) R6@silica, (n) R10@silica, and (o) R16@silica.

[0049] Figure 15 This is a transmission electron microscope image of doped with 0.3 mM doxorubicin (DOX);

[0050] Figure 16 (a) UV absorption spectra of neomycin and neomycin-doped silica nanoparticles (DOX@silica); (b) UV absorption spectra of silica nanoparticles (DOX@silica) doped with 0.3 mM doxorubicin (DOX); and (c) standard curve.

[0051] Figure 17 The images are (a) a comparison of the UV absorption spectra of DOX@silica before and after in a strong acid environment; (b) a comparison of the UV absorption spectra of DOX before and after in a strong acid environment; and (c) a transmission electron microscope image of DOX@silica in a strong acid environment.

[0052] Figure 18 These are (a) a comparison of the UV absorption spectra of DOX@silica before and after exposure to strong oxidizing conditions; (b) a comparison of the UV absorption spectra of DOX before and after exposure to strong oxidizing conditions; and (c) a transmission electron microscope image of DOX@silica under strong oxidizing conditions.

[0053] Figure 19 (a) are photos of DOX@silica before and after digestion; (b) is the UV-Vis absorption spectrum of the solution after DOX@silica digestion. Detailed Implementation

[0054] Example 1

[0055] Take 1.4 mL of a mixture of isopropanol and water (volume ratio 5:2), add 15 µL of ammonia, vortex for 5 s, then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the co-precipitation process and form silica nanoparticles. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product silica. Disperse the product in pure water. UV-Vis spectrophotometry was used to detect the UV absorption signal of the product, but no UV absorption signal peak was found. Figure 2 ).

[0056] Example 2

[0057] Take 1.4 mL of a mixed solution of phenol saffron dye (0.1 mM, 0.3 mM, 0.5 mM, and 0.7 mM) in isopropanol and water (volume ratio 5:2). Add 15 µL of ammonia to this system, vortex for 5 s, then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the coprecipitation process and form PSF@silica. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product PSF@silica. Disperse the product in pure water.

[0058] The UV absorption signal of the product was detected using a UV-Vis spectrophotometer and compared with that of phenolic saffron aqueous solution. A distinct molecular absorption peak of phenolic saffron was observed. Figure 2 ).

[0059] As the amount of dye PSF increased from 0.1 mM to 0.7 mM, the absorbance of the dye@silica gel gradually increased from 0.112 au to 0.807 au. Figure 3 This indicates that increasing the amount of dye promoted the doping of dye in silicon oxide.

[0060] Furthermore, no particle sedimentation was observed in PSF@silica doped with 0.1 mM and 0.3 mM, while particle sedimentation did occur in PSF@silica doped with 0.5 mM and 0.7 mM. This indicates that excessively high dye doping levels can lead to colloid instability. Since excessively high concentrations can cause particle sedimentation, we selected 0.3 mM, which does not cause particle sedimentation and has a relatively high concentration, as the optimal concentration for silicon oxide-doped phenolic saffron.

[0061] To synthesize PSF@silica nanoparticles with uniform size and a size of 57.95±7.26 nm, 15 µL of ammonia and 3 µL of tetraethyl orthosilicate were added to a 1.4 mL mixture of 0.3 mM phenol saffron in isopropanol and water (volume ratio 5:2). Figure 5 The UV-Vis absorption curve of silica was used as background and subtracted from the UV-Vis absorption curve of PSF@silica. The doping efficiency of this method for phenolic saffron was calculated to be approximately 1.86% using the relationship between the intensity of the characteristic absorption peak of the phenolic saffron solution and concentration. Transmission electron microscopy revealed that the morphology consisted of uniformly spherical nanoparticles. Figure 4 ).

[0062] Example 3

[0063] Take 1.4 mL of a mixture of isopropanol and water (volume ratio 5:2) containing different series of dyes (0.3 mM). Add 15 µL of ammonia to the system, vortex for 5 s, then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the co-precipitation process and form dye@silica. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product dye@silica. Disperse the product in pure water. Transmission electron microscopy reveals that its morphology is that of uniform spherical nanoparticles. Figure 14 ).

[0064] Under suitable synthesis conditions, 98 out of 106 dyes from 11 series of dyes, including acridine, phenothiazine, Takagawa, arylmethane, phenazine, indole, phenothiazine, phthalocyanine, tetrazolium, benzothiazole, and others, can be doped into silica nanoparticles and remain stable (Tables 1, 2, and 3). However, dyes R1, D11, D12, K7, K14, and K15 cannot be doped into silica nanoparticles.

[0065]

[0066] Table 1 Summary of Doping Amounts for Phenazine Series Dyes

[0067]

[0068] Table 2 Summary of Doping Amounts for Some Arylmethane Series Dyes

[0069]

[0070] Table 3 Summary of Doping Amounts of Some Dyes

[0071]

[0072] Example 4

[0073] Take 1.4 mL of a mixture of isopropanol and water (volume ratio 5:2) containing doxorubicin (DOX) (0.3 mM), add 15 µL of ammonia, vortex for 5 s, then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the co-precipitation process and form DOX@silica. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product DOX@silica. Disperse the product in pure water.

[0074] The ultraviolet absorption signal of neomycin was detected using a UV-Vis spectrophotometer, and a distinct neomycin absorption peak was observed. Figure 16 a, 16b). The UV-Vis absorption curve of silica was used as background and subtracted from the UV-Vis absorption curve of DOX@silica, and the relationship between the intensity of the characteristic absorption peak of neomycin solution and concentration was utilized. Figure 16 c) The calculated doping efficiency of this method for neomycin is approximately 34.1%. Transmission electron microscopy reveals that the nanoparticles exhibit a uniform spherical morphology. Figure 15 ).

[0075] Comparative Example 1

[0076] Take 1.4 mL of a mixed solution of 0.3 mM phenol saffron dye in isopropanol and water (volume ratios of 5:3, 5:2, and 5:1). Add 15 µL of ammonia to this system, vortex for 5 s, then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the co-precipitation process and form PSF@silica. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product PSF@silica. Disperse the product in pure water.

[0077] The ultraviolet absorption signal of phenolic saffron can be detected using a UV-Vis spectrophotometer. Figure 6The absorbance of PSF@silica was 0.263 au when the isopropanol to water ratio was 5:1, 0.398 au when the ratio was 5:2, and 0.561 au when the ratio was 5:3. As the solvent ratio increased, the PSF doping concentration in PSF@silica gradually increased, indicating that the solvent ratio affects the PSF doping concentration in PSF@silica. The morphology of PSF@silica under different solvent ratios could be observed using a scanning transmission microscope. Figure 7 When the solvent ratio of isopropanol to water was increased to 5:3, PSF@silica did not exhibit a uniform spherical nanoparticle morphology. Figure 7 c) indicates that a higher solvent ratio affects the uniform synthesis of nanoparticles, meaning that the resulting PSF@silica is inferior to that obtained with a lower solvent ratio. Therefore, in the synthesis, a solvent ratio of 5:2 for isopropanol to water is preferred, which neither damages the morphology of PSF@silica nanoparticles nor compromises the doping level.

[0078] Comparative Example 2

[0079] Take 1.4 mL of a mixed solution of 0.3 mM phenol saffron dye in isopropanol and water (volume ratio 5:2). Add 35 µL, 25 µL, 15 µL, and 5 µL of ammonia water to this system, respectively, and vortex for 5 s. Then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the coprecipitation process and form PSF@silica. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product PSF@silica. Disperse the product in pure water.

[0080] The ultraviolet absorption signal of phenolic saffron silica nanoparticles with different amounts of ammonia added can be detected using a UV-Vis spectrophotometer. Figure 8When the amount of ammonia in the reaction was gradually reduced from 35 μL to 5 μL, the final absorption values ​​of the precipitate were 0.239 au, 0.257 au, 0.408 au, and 0.389 au, respectively. The UV absorption signal first increased and then decreased, indicating that the amount of dye precipitated first increased and then decreased. It is generally believed that ammonia affects the hydrolysis process of TEOS. It is thought that reducing the amount of ammonia slows down the hydrolysis condensation rate of TEOS, which leads to a longer pairing time between the polysilicic acid produced by hydrolysis and the dye PSF, thus increasing the amount of dye precipitate. When the amount of ammonia is reduced to a certain extent, it will seriously affect the hydrolysis of TEOS, thereby reducing its precipitation amount, and the amount of dye precipitate will decrease. Therefore, in the synthesis, a 15 μL amount of ammonia is preferred, which has a high doping amount but does not affect the hydrolysis of TEOS due to excessively low ammonia content.

[0081] Comparative Example 3

[0082] Take 1.4 mL of a mixture of isopropanol and water (volume ratio 5:2) containing 0.3 mM phenol saffron dye. Add 15 µL of ammonia to this system, vortex for 5 s, and carry out four reactions under the same conditions. In each reaction, add a different polysilicic acid precursor: 3 µL of tetramethyl orthosilicate (TMOS), 3 µL of tetraethyl orthosilicate (TEOS), and 3 µL of tetrapropyl orthosilicate (TPOS). After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the coprecipitation process and form PSF@silica. After the reaction is completed, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product PSF@silica. Disperse the product in pure water.

[0083] The ultraviolet absorption signal of phenolic saffron silica nanoparticles with different polysilicic acid precursors can be detected using a UV-Vis spectrophotometer. Figure 9 d), and good absorption peaks can be seen in all of them. The nanostructures PSF@silica formed by adding different polysilicic acid precursors were observed using transmission electron microscopy. Figure 9 (a), (b), and (c) it can be observed that when the polysilicic acid precursor is tetramethyl orthosilicate (TMOS), silicon oxide nanoparticles cannot be synthesized well, and when the polysilicic acid precursor is tetrapropyl orthosilicate (TPOS), the resulting nanoparticles are not uniform. Therefore, tetraethyl orthosilicate, which has both a good doping amount and a relatively uniform nanoparticle morphology, is preferred in the synthesis.

[0084] Comparative Example 4

[0085] Take 1.4 mL of a mixture of isopropanol and water (volume ratio 5:2) containing 0.3 mM phenol saffron dye. Add 15 µL of ammonia to the system and vortex for 5 s. Then add 4 µL, 3 µL, 2 µL, and 1.5 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the coprecipitation process and form PSF@silica. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product PSF@silica. Disperse the product in pure water.

[0086] The ultraviolet absorption signal of phenol-saffron silica nanoparticles with different volume amounts of tetraethyl orthosilicate can be detected using a UV-Vis spectrophotometer. Figure 10 By adding different volumes of TEOS to the coprecipitation reaction solution, as the amount of TEOS gradually increased from 1.5 μL to 4 μL, the absorbance of PSF@silica gradually increased from 0.208 au to 0.451 au. This indicates that a higher amount of TEOS means more substances can precipitate the dye, thus increasing the amount of dye doping. The morphology of PSF@silica with different TEOS volumes can be observed under a scanning transmission microscope. Figure 11 When the volume of TEOS in the reaction solution increased to 4 μL, PSF@silica did not exhibit a uniform spherical nanoparticle morphology. Figure 11 (d) This indicates that adding a higher volume of TEOS to the reaction solution affects the uniform synthesis of nanoparticles, meaning that the resulting PSF@silica is inferior to that obtained with a lower volume of TEOS. Therefore, the preferred volume for synthesis is 3 μL of tetraethyl orthosilicate, which neither damages the morphology of the PSF@silica nanoparticles nor compromises the doping level.

[0087] Comparative Example 5

[0088] Take 1.4 mL of a mixture of isopropanol and water (volume ratio 5:2) containing 0.3 mM phenol saffron dye. Add 15 µL of ammonia to the system and vortex for 5 s. Then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the coprecipitation process and form PSF@silica. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product PSF@silica. Disperse the product in pure water.

[0089] After being placed in a refrigerator for 1 day and 7 days, the ultraviolet absorption signal of the phenolic saffron silica nanoparticles at different storage times could be detected using a UV-Vis spectrophotometer. Figure 12 After PSF@silica was stored in a refrigerator (4 °C) for 7 days, it was centrifuged, washed with water, and subjected to UV absorption testing. The absorption spectra were compared with those from 7 days prior, showing absorption values ​​of 0.372 au and 0.341 au, respectively, indicating that PSF can be stably doped into silicon oxide.

[0090] Comparative Example 6

[0091] Take 1.4 mL of a mixture of isopropanol and water (volume ratio 5:2) containing 0.3 mM phenol saffron dye. Add 15 µL of ammonia to the system and vortex for 5 s. Then add 3 µL of tetraethyl orthosilicate. After the addition is complete, place the reaction system in the dark and react at 500 rpm for 10 h on a magnetic stirrer to complete the coprecipitation process and form PSF@silica. Perform three identical reactions (a, b, and c) under the same conditions. After the reaction is complete, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, and wash the product precipitate three times with pure water to obtain the product PSF@silica. Disperse the product in pure water.

[0092] The UV absorption signals of phenol-saffron silica nanoparticles under three reactions can be detected using a UV-Vis spectrophotometer. Figure 13 The absorbance values ​​of PSF@silica were all around 0.483 au, indicating that the doping of phenolic saffron into silica nanoparticles has a certain degree of universality.

[0093] Experiment 1

[0094] 10 μL of hydrochloric acid solution (0.1 M, pH = 1) was added to 10 μL of DOX@silica (product of Example 5) dispersed in 10 μL of water. After waiting for 3 h, the UV absorption signal of the solution was detected using a UV-Vis spectrophotometer. Figure 17 a). Simultaneously, 10 μL of hydrochloric acid solution (0.1 M, pH = 1) was added to 10 μL of DOX aqueous solution, and the UV absorption signal of the solution was detected using a UV-Vis spectrophotometer as a control group. Figure 17b). It can be clearly observed that the characteristic UV absorption signal of free DOX is significantly weakened in the acidic environment of hydrochloric acid solution, indicating that the drug molecule structure is damaged; while DOX encapsulated in silica nanoparticles still exhibits the same UV absorption signal of DOX in the acidic environment, indicating that silica nanoparticles can effectively protect drug molecules from damage by the acidic environment. Simultaneously, transmission electron microscopy was used to observe the DOX@silica (…) after treatment with hydrochloric acid solution. Figure 17 (c) It can be seen that its nanostructure has not been damaged.

[0095] Experiment 2

[0096] 10 μL of 1% hydrogen peroxide solution was added to DOX@silica (product of Example 5) dispersed in 10 μL of water. After waiting for 3 h, the UV absorption signal of the solution was detected using a UV-Vis spectrophotometer. Figure 18 a). Simultaneously, 10 μL of 1% hydrogen peroxide solution was added to 10 μL of LDOX aqueous solution, and the UV absorption signal of the solution was detected using a UV-Vis spectrophotometer as a control group. Figure 18 b). It can be clearly observed that free DOX no longer exhibits characteristic UV absorption signals in the strong oxidizing environment of 1% hydrogen peroxide solution, indicating that the drug molecule structure has been damaged; however, DOX encapsulated in silica nanoparticles still shows a strong UV absorption signal in the 1% hydrogen peroxide solution environment, indicating that silica nanoparticles can effectively protect drug molecules from damage by strong oxidizing environments. Simultaneously, transmission electron microscopy was used to observe DOX@silica (…) after treatment with 1% hydrogen peroxide solution. Figure 18 (c) It can be seen that its nanostructure has not been damaged.

[0097] Experiment 3

[0098] DOX@silica (product of Example 5) was dispersed in an aqueous hydrofluoric acid solution (pH = 6) for a release experiment. During the release process, the product precipitate gradually dissolved and completely dissolved within approximately 1 hour. Figure 19 a) The solution changed from a turbid red colloidal state to a clear and transparent state. The UV absorption signal of the digested solution was detected using a UV-Vis spectrophotometer, revealing a distinct absorption peak for the doxorubicin drug molecule. Figure 19 (b) demonstrates that doxorubicin drug molecules encapsulated by silica nanoparticles can be released within a certain time period.

[0099] The present invention is not limited to the specific technical solutions described in the above embodiments. All technical solutions formed by equivalent substitutions are within the scope of protection claimed by the present invention.

Claims

1. A method for synthesizing silicon oxide nanoparticles doped with dyes or drug molecules using a co-precipitation method, characterized in that: The synthesis steps are as follows: Step (1): Dissolve the dye molecules or drug molecules in a 5:2 volume ratio of isopropanol and water to prepare a 0.3 mM solution of dye molecules or drug molecules; Step (2): 1.4 ml of the mixed solution from step (1), and add 15 ml of the mixture to the system. ammonia water, vortex for 5 seconds, then add 3 After adding tetraethyl orthosilicate, the reaction system was placed in the dark and reacted at 500 rpm for 10 h on a magnetic stirrer to complete the co-precipitation process and form dye@silica or drug@silica. Step (3): Centrifuge the mixed solution after reaction at 12000 rpm for 12 min, discard the supernatant, disperse the precipitate in pure water and continue centrifugation. Repeat this process three times to achieve the purpose of washing and purifying the product; The drug molecule is doxorubicin. Doxorubicin forms DOX@silica through steps (1)-(3). The UV-Vis absorption curve of silica is used as the background and subtracted from the UV-Vis absorption curve of DOX@silica. The doping efficiency of this method for doxorubicin is calculated to be about 34.1% by using the relationship between the intensity of the characteristic absorption peak of doxorubicin solution and the concentration. The morphology of the nanoparticles is observed to be uniform spherical through transmission electron microscopy; The dye molecule has the following specific structural formula: .

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