Universal method for synthesizing silicon oxide nanoparticle doped dye and drug molecules by using coprecipitation method

Abstract

The invention relates to a universal method for synthesizing silicon oxide nanoparticle doped dye and drug molecules by utilizing coprecipitation. In the reaction system provided by the invention, tetraethyl orthosilicate is used as a synthetic raw material, and a universal method suitable for doping dye molecules and drug molecules is provided. The method shows that 98 dyes and drug molecules can be directly doped into the silicon oxide nanoparticles. The reaction is simple and convenient, substances involved in the reaction have good biocompatibility, dye molecules and drug molecules can be efficiently doped into the silicon oxide nanoparticles, and the morphology and a certain doping rate of the silicon oxide nanoparticles can be ensured by regulating and controlling synthesis parameters according to the determined synthesis proportion. The method can be used as a safer and more efficient platform technology to dope various dye molecules and drug molecules into the silicon oxide nanoparticles, and the special microenvironment of the silicon oxide nanoparticles can better protect the dye molecules and drug molecules from being damaged by a harsh environment.

Description

Technical Field

[0001] The invention relates to a universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation, belonging to the technical field of dye molecule doping and drug molecule doping. Background Art

[0002] There are very limited methods for doping dyes and drug molecules in silica, and the generally known methods are applicable to specific situations under certain conditions. There are two main methods for doping dye molecules: covalent coupling and electrostatic attraction. The former involves direct bonding of the dye to the silane linker molecule, and then co-precipitating the resulting conjugate with silica. In the latter method, the cationic dye is directly incorporated in the Stöber method or the microemulsion method. The release rate of drug molecules in the human body needs to be controlled within an appropriate range. If it is not appropriate, it will cause drug poisoning. Silica nanoparticles are suitable as ideal carriers for drug molecules due to their high compatibility with organisms. In recent years, various drugs based on silica have been tried for sustained release. According to the structure of silica, there are currently two main ways to encapsulate drugs: the first is to directly encapsulate or embed the drug in silica for release; the second is to first synthesize silica (mainly mesoporous silica), and then encapsulate the drug into silica by adsorption.

[0003] Among the many methods of doping dye molecules and drug molecules with silicon oxide nanoparticles, the covalent coupling method is limited because it requires expensive and small quantities of dyes with special coupling groups. The coprecipitation method is more suitable for dye molecules with cations. The good biocompatibility of silicon oxide nanoparticles also allows them to be safely metabolized in the biological environment and supports drug delivery to successfully complete the release.

[0004] However, there is no special description of the universal method for doping dye molecules and drug molecules. Among them, due to the difference in the charge properties of dye molecules, the problem of stability of dye molecules doped in silica nanoparticles continues to exist. Doxorubicin is a widely used anti-tumor drug molecule that has a high targeting effect on tumor treatment in vivo. The poor stability of doxorubicin doped with silica nanoparticles is particularly obvious. In order to solve this problem, researchers have adopted various methods to improve the stability of dye molecules and drug molecules. One of the methods is to dope dye molecules and drug molecules at the nanoscale to achieve the purpose of improving the stability of dye molecules and drug molecules and prolonging the duration of drug action. Summary of the invention

[0005] The technical problem solved by the present invention is to propose a universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method, which can realize the rapid doping of dye molecules and drug molecules into silicon oxide nanoparticles in a simple reaction system for subsequent research and drug sustained release. The reaction system of silicon oxide doped with dye molecules and drug molecules in the traditional method is relatively complicated, and a variety of substances are often required as auxiliary substances in the synthesis system, and these substances are difficult to be completely removed in the subsequent purification process. In the reaction system of the present invention, due to the property that ethyl orthosilicate is easily soluble in water, it is also used as a raw material for synthesizing silicon oxide nanoparticles, which simplifies the reaction system to the greatest extent and is conducive to the purification of subsequent products. In addition, the substances used in the synthesis method of the present invention all have strong biocompatibility, which fundamentally guarantees the safety of the drug used in the body. Silica nanoparticles can effectively protect dye molecules and drug molecules, improve the stability of dye molecules and drug molecules, and the silicon oxide nanoparticles doped with dye molecules and drug molecules synthesized by the present invention can effectively protect dye molecules and drug molecules from damage by the external environment. The synthesis method proposed by the present invention can dope a large number of dye molecules and drug molecules into silicon oxide nanoparticles, and is applicable to most dye molecules, with high universality. In the reaction system of the present invention, compared with the previous synthesis system, the synthesis efficiency of the reaction can be improved well and is applicable to most dye molecules. By regulating the synthesis parameters, the present invention can ensure a certain doping rate on the basis of ensuring the particle morphology under a determined synthesis ratio. At the same time, the present invention can be used as a safer and more efficient platform technology to dope drug molecules into silicon oxide nanoparticles, and it is expected to be synthesized on a large scale in the future and used for drug delivery in the body.

[0006] In order to solve the technical problem of the present invention, the specific technical solution proposed by the present invention is: a universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method, the specific steps are as follows

[0007] Step (1): preparing a mixed solution of isopropyl alcohol (IPA) and water containing dye molecules or drug molecules;

[0008] Step (2): in step (1), tetraethyl orthosilicate (TEOS) and ammonia water are added to form a mixed solution, which is rapidly vortexed and allowed to stand to form dye@silica or drug@silica by a coprecipitation method;

[0009] Step (3): The reaction solution is centrifuged to remove the supernatant to obtain the product, and the product is washed and purified with pure water for multiple times to finally obtain purified dye@silica or drug@silica.

[0010] The mixed solution of isopropyl alcohol (IPA) and water for preparing dye molecules or drug molecules in step (1) is specifically prepared by dissolving the dye molecules or drug molecules in a mixed solution of isopropyl alcohol and water (volume ratio of 5:2) to prepare a 0.3 mM mixed solution of dye molecules or drug molecules;

[0011] The synthesis of dye@silica or drug@silica in step (2) is as follows: 1.4 mL of the mixed solution in step (1) is added with 15 µL of aqueous ammonia, vortexed for 5 seconds, and then 3 µL of tetraethyl orthosilicate is added. After the addition is completed, the reaction system is placed in the dark and reacted on a magnetic stirrer at 500 rpm for 10 hours to complete the coprecipitation process and form dye@silica or drug@silica;

[0012] Preferably, the dye molecule is phenol safranin and the drug molecule is doxorubicin.

[0013] Preferably, the product purification process described in step (3) is specifically performed by centrifuging the mixed solution after the reaction at a speed of 12000 rpm for 12 minutes, discarding the supernatant, dispersing the precipitated product in pure water and continuing to centrifuge, and repeating the process 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 mixed solution of isopropyl alcohol (IPA) and water for preparing dye molecules or drug molecules in step (1) is specifically prepared by dissolving the dye molecules or drug molecules in a mixed solution of isopropyl alcohol and water (volume ratio of 5:2) to prepare a 0.3 mM mixed solution of dye molecules or drug molecules;

[0016] The synthesis of dye@silica or drug@silica in step (2) is as follows: 1.4 mL of the mixed solution in step (1) is added with 15 µL of aqueous ammonia, vortexed for 5 seconds, and then 3 µL of tetraethyl orthosilicate is added. After the addition is completed, the reaction system is placed in the dark and reacted on a magnetic stirrer at 500 rpm for 10 hours to complete the coprecipitation process and form dye@silica or drug@silica;

[0017] The product purification process described in step (3) is specifically performed by centrifuging the mixed solution after the reaction at a speed of 12000 rpm for 12 minutes, discarding the supernatant, dispersing the precipitated product in pure water and continuing to centrifuge, and repeating the process 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 of 106 dyes in 12 series of acridine dyes, phenothiazine dyes, kaochuan dyes, arylmethane dyes, phenazine dyes, indole dyes, phenoxazine dyes, phthalocyanine dyes, tetrazole dyes, benzothiazole dyes and other dyes, among which R1, D11, D12, K7, K14 and K15 cannot be doped into the silicon oxide nanoparticles;

[0019] A universal method for synthesizing silica nanoparticles doped with dyes and drug molecules by coprecipitation, including:

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

[0021] Step (2): Take 1.4 mL of the mixed solution in step (1), add 15 µL of ammonia water to the system, vortex for 5 seconds, add 3 µL of tetraethyl orthosilicate, and react on a magnetic stirrer at 500 rpm for 10 hours in the dark to complete the coprecipitation process to form dye@silica or drug@silica;

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

[0023] Beneficial effects of the present invention:

[0024] (1) A platform technology for synthesizing silica nanoparticles doped with dye molecules and drug molecules using the coprecipitation method has been established. Under this technology, most cationic dye molecules and drug molecules can be doped into silica nanoparticles, which has high universality. The present invention can be used as a safer and more efficient platform technology to dope various dye molecules and drug molecules into silica nanoparticles. The special microenvironment of silica nanoparticles can better protect dye molecules and drug molecules from damage caused by harsh environments. This invention is expected to be synthesized on a large scale in the future and be applicable to the doping of any cationic dye molecules and drug molecules.

[0025] (2) Silicon oxide nanoparticles are used to dope dye molecules, thereby improving the stability of dye molecules. The synthesis method of the present invention is applicable to most cationic dyes and has a high doping rate for most cationic dyes.

[0026] (3) It is suitable for the doping of many dye molecules, including 98 different dye molecules from 12 series, including acridine family, phenothiazine family, Gaochuan series dyes, arylmethane family, phenazine series dyes, indole series dyes, phenoxazine family, phthalocyanine family, tetrazole family, benzothiophene family, xanthene family and other families, and effectively controls their stability.

[0027] (4) The present invention is suitable for encapsulation of drug molecules, including neomycin (DOX), methylene blue (MB), etc. The synthesis method is simple and the synthesis efficiency is high. The silicon oxide nanoparticles provide a protective layer for the drug molecules so that the drug molecules can exist stably and can be effectively released within a period of time.

[0028] (5) It can be seen from Example 2 that the PSF@silica obtained by doping with 0.3 mM phenol safranin did not precipitate, and the doping efficiency was about 1.86%. The product morphology was relatively uniform as observed by transmission electron microscopy ( Figure 5 ), and its size is 57.95±7.26nm nm. Through transmission electron microscopy, it can be observed that its morphology is uniform spherical nanoparticles.

[0029] (6) As can be seen from Example 4, the DOX@silica obtained by doping with 0.3 mM doxorubicin has an obvious neomycin absorption peak detected by UV-visible spectrophotometer ( Fig.13 ). It was calculated that the doping efficiency of this method for neomycin is about 34.1%. And through transmission electron microscopy, it can be observed that the product morphology is relatively uniform ( Fig.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 of isopropanol to water is preferred, which does not destroy the nanoparticle morphology of PSF@silica and has a high doping amount.

[0031] (8) Comparative Example 2 shows that reducing the amount of ammonia water will slow down the hydrolysis and condensation rate of TEOS ( Figure 7 ), resulting in a longer pairing time between the polysilicic acid produced by hydrolysis and the dye PSF, so the final amount of dye precipitation increases. When the amount of ammonia water is reduced to a certain extent, it will seriously affect the hydrolysis of TEOS, thereby reducing its precipitation amount, and the amount of dye precipitation decreases. In the synthesis, it is preferred to use 15μL of ammonia water, which has a high doping amount but does not affect the hydrolysis of TEOS due to too low ammonia content.

[0032] (9) Comparative Example 3 shows that the greater the amount of TEOS, the more substances that can precipitate dyes ( Figure 8), so the doping amount of the dye will also increase accordingly. In the synthesis, it is preferred that the volume of tetraethyl orthosilicate, which does not destroy the nanoparticle morphology of PSF@silica and has a high doping amount, is 3μL. Comparative Example 4 The PSF@silica placed in the refrigerator was tested for UV absorption again and compared with its absorption spectrum 7 days ago ( Fig. 9 ), and found that there was no significant difference, indicating that PSF was stably doped into silicon oxide.

[0033] (10) Comparative Example 5 The ultraviolet absorption signals of phenol safranin silicon oxide nanoparticles under three reactions were compared ( Fig.10 ), and found that there was no significant difference, which shows that the doping of phenol safflower in silicon oxide nanoparticles has a certain universality. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0035] Figure 1 It is a mechanism diagram of synthesizing nano-sized silica nanoparticles doped with dye molecules by co-precipitation method;

[0036] Figure 2 is the UV absorption spectra of phenol safranine dye and phenol safranine silica nanoparticles (PSF@silica);

[0037] Figure 3 It is the UV absorption spectra of silica nanoparticles (PSF@silica) doped with different concentrations of phenol safranin (PSF) dye and the standard curve;

[0038] Figure 4 It is the transmission electron microscopy images of phenol safranin silica nanoparticles doped with different concentrations of phenol safranin dye, (a) 0.1mM phenol safranin silica nanoparticles (PSF@silica) phenol safranin silica nanoparticles (PSF@silica) phenol safranin silica nanoparticles (PSF@silica);

[0039] Figure 5 is the transmission electron microscopy (TEM) image of silica nanoparticles doped with 0.3 mM phenol safranin dye (PSF@silica) and the corresponding particle size distribution (N=300);

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

[0041] Figure 7These are transmission electron micrographs of phenol safranin silica nanoparticles at different solvent ratios, (a) phenol safranin silica nanoparticles (PSF@silica) at a solvent ratio of 5:1, (b) phenol safranin silica nanoparticles (PSF@silica) at a solvent ratio of 5:2, and (c) phenol safranin silica nanoparticles (PSF@silica) at a solvent ratio of 5:3.

[0042] Figure 8 is the UV absorption spectrum of the amount of ammonia water for the dye doping amount of phenol safranin silica nanoparticles (PSF@silica);

[0043] Fig. 9 (a) Transmission electron micrograph of polysilicate precursor being tetramethyl orthosilicate (TMOS), (b) Transmission electron micrograph of polysilicate precursor being tetraethyl orthosilicate (TEOS), (c) Transmission electron micrograph of polysilicate precursor being tetrapropyl orthosilicate (TPOS), (d) UV absorption spectra of different polysilicate precursors;

[0044] Fig.10 is the UV absorption spectrum of the volume amount of tetraethyl orthosilicate for the dye doping amount of phenol safranin silica nanoparticles (PSF@silica);

[0045] Fig.11 These are transmission electron micrographs of phenol safflower silica nanoparticles at different volumes of tetraethyl orthosilicate, (a) 1.5 μL tetraethyl orthosilicate with phenol safflower silica nanoparticles (PSF@silica), (b) 2 μL tetraethyl orthosilicate with phenol safflower silica nanoparticles (PSF@silica), (c) 3 μL tetraethyl orthosilicate with phenol safflower silica nanoparticles (PSF@silica), (d) 4 μL tetraethyl orthosilicate with phenol safflower silica nanoparticles (PSF@silica);

[0046] Fig.12 is the UV absorption spectra of phenol safranin silica nanoparticles (PSF@silica) stored at different times;

[0047] Fig.13 It is the UV absorption spectra of phenol safranin silicon oxide nanoparticles (PSF@silica) with a doping amount of 0.3mM under different batches;

[0048] Fig.14These are transmission electron micrographs of some dye@silica nanoparticles prepared by organic-inorganic coprecipitation method, including TEM images of (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] Fig.15 is a transmission electron microscopy image doped with 0.3 mM doxorubicin (DOX);

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

[0051] Fig.17 (a) Comparison of UV absorption spectra of DOX@silica before and after strong acid environment; (b) Comparison of UV absorption spectra of DOX before and after strong acid environment; and (c) Transmission electron microscopy image of DOX@silica in strong acid environment;

[0052] Fig.18 (a) Comparison of UV absorption spectra of DOX@silica before and after strong oxidizing environment; (b) Comparison of UV absorption spectra of DOX before and after strong oxidizing environment; and (c) Transmission electron microscopy image of DOX@silica under strong oxidizing environment;

[0053] Fig.19 (a) is a photo of DOX@silica before and after digestion; (b) is the UV-visible absorption spectrum of the solution after DOX@silica digestion. DETAILED DESCRIPTION

[0054] Example 1

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

[0056] Example 2

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

[0058] The UV absorption signal of the product was detected by UV-visible spectrophotometer and compared with the aqueous solution of phenol safflower red, and an obvious absorption peak of phenol safflower red molecule was found ( Figure 2 ).

[0059] As the amount of dye PSF increased from 0.1 mM to 0.7 mM, the absorbance of the final dye@colloid oxide gradually increased from 0.112 au to 0.807 au ( Figure 3 ), indicating that the increase in the amount of dye promoted the doping of the dye in silicon oxide.

[0060] The PSF@silica obtained by doping with 0.1 mM and 0.3 mM did not have any particle sedimentation, while the PSF@silica obtained by doping with 0.5 mM and 0.7 mM had particle sedimentation, which indicates that when the dye doping amount is too high, the colloid will become unstable. Since too high a concentration will cause the problem of particle sedimentation, we selected 0.3 mM as the optimal concentration of silica doped phenol safranin without particle sedimentation and with a higher concentration.

[0061] 15 µL of ammonia and 3 µL of tetraethyl orthosilicate were added to 1.4 mL of a 0.3 mM phenol safranin solution of isopropanol and water (volume ratio 5:2) to synthesize PSF@silica with uniform size of 57.95 ± 7.26 nm ( Figure 5 ). The UV-visible absorption curve of silica was used as the background to deduct from the UV-visible absorption curve of PSF@silica, and the relationship between the characteristic absorption peak intensity of phenol safranine solution and the concentration was used to calculate that the doping efficiency of this method for phenol safranine was about 1.86%. Through transmission electron microscopy, it can be observed that the morphology is uniform spherical nanoparticles ( Figure 4 ).

[0062] Example 3

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

[0064] Under universal synthesis conditions, 98 dyes out of 106 dyes in 11 series, including acridine dyes, phenothiazine dyes, kaochuan dyes, arylmethane dyes, phenazine dyes, indole dyes, phenoxazine dyes, phthalocyanine dyes, tetrazole dyes, benzothiazole dyes and other dyes, can be doped into silicon oxide nanoparticles and exist stably (Table 1, Table 2, Table 3). Among them, R1, D11, D12, K7, K14 and K15 cannot be doped into silicon oxide nanoparticles.

[0065]

[0066] Table 1 Summary of doping amounts of phenazine series dyes

[0067] Table 2 Summary of doping levels of some arylmethane dyes

[0068] Table 3 Summary of doping amounts of some dyes

[0069] Example 4

[0070] Take 1.4mL of a mixed solution of doxorubicin (DOX) (0.3mM) in isopropanol and water (volume ratio of 5:2), add 15µL of ammonia water to the system, vortex for 5s, then add 3µL of tetraethyl orthosilicate. After the addition, place the reaction system in the dark and react on a magnetic stirrer at 500 rpm for 10h to complete the coprecipitation process and form DOX@silica. After the reaction, centrifuge the reaction system at 12000 rpm for 12min, remove the supernatant, wash and purify the product precipitate with pure water three times to obtain the product DOX@silica, and disperse the product in pure water.

[0071] The UV absorption signal of neomycin was detected by UV-visible spectrophotometer and an obvious neomycin absorption peak was found ( Fig.16 a, 16b). The UV-visible absorption curve of silica was used as the background to deduct from the UV-visible absorption curve of DOX@silica, and the relationship between the characteristic absorption peak intensity of neomycin solution and the concentration was used ( Fig.16 c) The calculated doping efficiency of neomycin by this method is about 34.1%. Through transmission electron microscopy, it can be observed that the morphology of the nanoparticles is uniform and spherical ( Fig.15 ).

[0072] Comparative Example 1

[0073] Take 1.4mL of a mixed solution of phenol safranin dye (0.3mM) in isopropanol and water (volume ratio of 5:3, volume ratio of 5:2, volume ratio of 5:1), add 15µL of ammonia water to the system, vortex for 5s, then add 3µL of tetraethyl orthosilicate, after the addition is completed, place the reaction system in the dark and react on a magnetic stirrer at 500 rpm for 10h 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, wash and purify the product precipitate with pure water three times to obtain the product PSF@silica, and disperse the product in pure water.

[0074] The UV absorption signal of phenol safranin can be detected by UV-visible spectrophotometer ( Figure 6), that is, when the ratio of isopropanol to water is 5:1, the absorbance of PSF@silica is 0.263au, when the ratio of isopropanol to water is 5:2, the absorbance of PSF@silica is 0.398au, when the ratio of isopropanol to water is 5:3, the absorbance of PSF@silica is 0.561au. As the solvent ratio increases, the doping amount of PSF in PSF@silica gradually increases, indicating that the solvent ratio will affect the doping of PSF in PSF@silica. The morphology of PSF@silica under different solvent ratios can be observed under a scanning transmission microscope ( Figure 7 ). When the solvent ratio of isopropanol to water was increased to 5:3, PSF@silica did not present a uniform spherical nanoparticle morphology ( Figure 7 c), indicating that a higher solvent ratio will affect the uniform synthesis of nanoparticles, that is, the obtained PSF@silica is inferior to that of a lower solvent ratio. Therefore, in the synthesis, a solvent ratio of 5:2 of isopropanol to water is preferred, which does not destroy the nanoparticle morphology of PSF@silica and has a higher doping amount.

[0075] Comparative Example 2

[0076] Take 1.4mL of a mixed solution of phenol safranin dye (0.3mM) in isopropanol and water (volume ratio of 5:2), add 35µL, 25µL, 15µL, and 5µL of ammonia water to the system, vortex for 5s, then add 3µL of tetraethyl orthosilicate. After the addition, place the reaction system in the dark and react on a magnetic stirrer at 500 rpm for 10h to complete the coprecipitation process and form PSF@silica. After the reaction, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, wash and purify the product precipitate with pure water three times to obtain the product PSF@silica, and disperse the product in pure water.

[0077] The UV absorption signal of phenol safranin silica nanoparticles under different ammonia water addition can be detected by UV-visible spectrophotometer ( Figure 8). When the amount of ammonia water in the reaction is gradually reduced from 35 μL to 5 μL, the absorption of the final precipitation is 0.239 au, 0.257 au, 0.408 au, and 0.389 au, respectively. The ultraviolet absorption signal first increases and then decreases, that is, the amount of dye precipitation first increases and then decreases. It is generally believed that ammonia water will affect the hydrolysis process of TEOS. It is believed that the reduction in the amount of ammonia water slows down the hydrolysis and condensation rate of TEOS, which causes the polysilicic acid produced by hydrolysis to pair with the dye PSF for a longer time, so the final amount of dye precipitation increases. When the amount of ammonia water is reduced to a certain extent, it will seriously affect the hydrolysis of TEOS, thereby reducing its precipitation amount, and the amount of dye precipitation will decrease. Therefore, in the synthesis, it is preferred to use 15 μL of ammonia water, which has a higher doping amount but does not affect the hydrolysis of TEOS due to too low ammonia content.

[0078] Comparative Example 3

[0079] Take 1.4mL of a mixed solution of phenol safranin dye (0.3mM) in isopropanol and water (volume ratio of 5:2), add 15µL of ammonia water to the system, vortex for 5s, and perform four reactions under the same conditions. Different polysilicic acid precursors are added to each reaction, namely 3µL of tetramethyl orthosilicate (TMOS), 3µL of tetraethyl orthosilicate (TEOS), and 3µL of tetrapropyl orthosilicate (TPOS). After the addition, the reaction system is placed in the dark and reacted on a magnetic stirrer at 500 rpm for 10h to complete the coprecipitation process and form PSF@silica. After the reaction, the reaction system is centrifuged at 12000 rpm for 12 min, and after removing the supernatant, the product precipitate is washed and purified three times with pure water to obtain the product PSF@silica, and the product is dispersed in pure water.

[0080] The UV absorption signal of phenol safranin silica nanoparticles with different polysilicic acid precursors can be detected by UV-visible spectrophotometer ( Fig. 9 d), we can see that they all have good absorption peaks. The nanostructured PSF@silica ( Fig. 9 a, 9b, 9c), it can be found 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 formed nanoparticles are uneven. Therefore, tetraethyl orthosilicate is preferred in the synthesis because it has a better doping amount and a more uniform nanoparticle morphology.

[0081] Comparative Example 4

[0082] Take 1.4mL of a mixed solution of phenol safranin dye (0.3mM) in isopropanol and water (volume ratio of 5:2), add 15µL of ammonia water to the system, vortex for 5s, then add 4µL, 3µL, 2µL, and 1.5µL of tetraethyl orthosilicate. After the addition, place the reaction system in the dark and react on a magnetic stirrer at 500 rpm for 10h to complete the coprecipitation process and form PSF@silica. After the reaction, centrifuge the reaction system at 12000 rpm for 12 min, remove the supernatant, wash and purify the product precipitate with pure water three times to obtain the product PSF@silica, and disperse the product in pure water.

[0083] The UV absorption signal of phenol safranin silica nanoparticles with different volume of tetraethyl orthosilicate can be detected by UV-visible spectrophotometer ( Fig.10 ). By adding different volumes of TEOS to the coprecipitation reaction solution, as the amount of TEOS gradually increased from 1.5μL to 4μL, the absorption value of PSF@silica gradually increased from 0.208 au to 0.451 au, indicating that the more TEOS, the more substances that can precipitate the dye, and therefore the amount of dye doping will also increase accordingly. The morphology of PSF@silica under different TEOS volumes can be observed under a scanning transmission microscope ( Fig.11 ). When the volume of TEOS in the reaction solution was increased to 4 μL, PSF@silica did not present a uniform spherical nanoparticle morphology ( Fig.11 d), indicating that adding a higher volume of TEOS to the reaction solution will affect the uniform synthesis of nanoparticles, that is, the obtained PSF@silica is inferior to that of TEOS with a lower volume. Therefore, in the synthesis, the preferred volume of tetraethyl orthosilicate is 3 μL, which will not destroy the nanoparticle morphology of PSF@silica and has a higher doping amount.

[0084] Comparative Example 5

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

[0086] After being placed in the refrigerator for 1 day and 7 days, the UV absorption signals of the phenol safranin silica nanoparticles at different storage times can be detected using a UV-visible spectrophotometer ( Fig.12 ). After PSF@silica was stored in a refrigerator (4 ℃) for 7 days, it was centrifuged and washed again and subjected to UV absorption test. The absorption spectrum was compared with that 7 days ago. The absorption before and after was 0.372 au and 0.341 au, indicating that PSF can be stably doped into silicon oxide.

[0087] Comparative Example 6

[0088] Take 1.4mL of a mixed solution of phenol safranin dye (0.3mM) in isopropanol and water (volume ratio of 5:2), add 15µL of ammonia water to the system, vortex for 5s, then add 3µL of tetraethyl orthosilicate. After the addition, place the reaction system in the dark and react on a magnetic stirrer at 500 rpm for 10h to complete the coprecipitation process and form PSF@silica. Under this condition, three identical reactions a, b, and c were carried out. After the reaction, the reaction system was centrifuged at 12000 rpm for 12 min. After removing the supernatant, the product precipitate was washed and purified three times with pure water to obtain the product PSF@silica, and the product was dispersed in pure water.

[0089] The UV absorption signals of phenol safranin silica nanoparticles under three reactions can be detected by UV-visible spectrophotometer ( Fig.13 ). The absorption values ​​of PSF@silica are all around 0.483 au, which indicates that the doping of phenol safranin into silicon oxide nanoparticles has a certain universality.

[0090] Experiment 1

[0091] 10 μL of hydrochloric acid solution (0.1 M, pH = 1) was added to DOX@silica (product of Example 5) dispersed in 10 μL of water, and the UV absorption signal of the solution was detected by UV-visible spectrophotometer after waiting for 3 h ( Fig.17 a). At the same time, 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 by UV-visible spectrophotometer as a control group ( Fig.17b). It can be clearly observed that the characteristic ultraviolet absorption signal of free DOX in the acidic environment of hydrochloric acid solution is greatly weakened, indicating that the molecular structure of the drug has been destroyed; while the DOX encapsulated in the silica nanoparticles still has the same ultraviolet absorption signal of DOX in the acidic environment, indicating that the silica nanoparticles can effectively protect the drug molecules from being destroyed by the acidic environment. At the same time, the transmission electron microscope was used to observe the DOX@silica treated with hydrochloric acid solution ( Fig.17 c) It can be found that its nanostructure has not been destroyed.

[0092] Experiment 2

[0093] 10 μL of 1% hydrogen peroxide solution was added to DOX@silica (product of Example 5) dispersed in 10 μL of water, and the UV absorption signal of the solution was detected by UV-visible spectrophotometer after waiting for 3 h ( Fig.18 a). At the same time, 10 μL of 1% hydrogen peroxide solution was added to the 10 μL DOX aqueous solution, and the UV absorption signal of the solution was detected by UV-visible spectrophotometer as a control group ( Fig.18 b). It can be clearly observed that the free DOX no longer has characteristic UV absorption signals in the strong oxidative environment of 1% hydrogen peroxide solution, indicating that the drug molecular structure has been destroyed; while the DOX encapsulated in the silica nanoparticles still shows a strong UV absorption signal of DOX in the 1% hydrogen peroxide solution environment, indicating that the silica nanoparticles can effectively protect the drug molecules from being destroyed by the strong oxidative environment. At the same time, the DOX@silica treated with 1% hydrogen peroxide solution was observed by transmission electron microscopy ( Fig.18 c) It can be found that its nanostructure has not been destroyed.

[0094] Experiment 3

[0095] DOX@silica (product of Example 5) was dispersed in a hydrofluoric acid aqueous solution (pH = 6) for release experiments. During the release process, the product precipitate gradually dissolved and was completely digested within about 1 hour ( Fig.19 a), the solution changed from a turbid red colloidal state to a clear and transparent state, and the UV absorption signal of the solution after product digestion was detected by UV-visible spectrophotometer, and an obvious absorption peak of doxorubicin drug molecules was found ( Fig.19 b) It proves that the doxorubicin drug molecules encapsulated by silica nanoparticles can be released within a certain period of time.

[0096] The present invention is not limited to the specific technical solutions described in the above embodiments, and all technical solutions formed by equivalent replacement are within the protection scope required by the present invention.

Claims

1. A universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation, the specific steps are as follows Step (1): preparing a mixed solution of isopropyl alcohol (IPA) and water for dye molecules or drug molecules; the mixed solution of isopropyl alcohol (IPA) and water for dye molecules or drug molecules in step (1) is prepared by dissolving the dye molecules or drug molecules in a mixed solution of isopropyl alcohol and water in a volume ratio of 5:1 to 5:3 to prepare a mixed solution of 0.1 to 0.7 mM dye molecules or drug molecules; Step (2): in step (1), a polysilicic acid precursor and ammonia water are added to form a mixed solution, which is rapidly vortexed and allowed to stand to form dye@silica or drug@silica by a coprecipitation method; 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), adding 15-35 µL of ammonia water to the system, vortexing for 5-10 seconds, and then adding 1.5-3 µL of polysilicic acid precursor. After the addition is completed, the reaction system is placed in the dark and reacted on a magnetic stirrer at 500 rpm for 10 hours to complete the coprecipitation process and form dye@silica or drug@silica; Step (3): The reaction solution is centrifuged to remove the supernatant to obtain the product, which is then washed and purified with pure water for multiple times to finally obtain purified dye@silica or drug@silica.

2. The universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method according to claim 1, characterized in that: The dye molecule is phenol safranin, and the drug molecule is doxorubicin.

3. The universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method according to claim 1, characterized in that: The polysilicic acid precursor is tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS) or tetrapropyl orthosilicate (TPOS).

4. The universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method according to claim 1, characterized in that: The dye molecules are 98 dyes of 106 dyes in 12 series including acridine dyes, phenothiazine dyes, kaochuan dyes, arylmethane dyes, phenazine dyes, indole dyes, phenoxazine dyes, phthalocyanine dyes, tetrazole dyes, benzothiazole dyes and other dyes, among which R1, D11, D12, K7, K14 and K15 cannot be doped into silicon oxide nanoparticles. 。 5. The universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method according to claim 1, characterized in that: The product purification process described in step (3) is specifically performed by centrifuging the mixed solution after the reaction at a speed of 12000 rpm for 12 minutes, discarding the supernatant, dispersing the precipitated product in pure water and continuing to centrifuge, and repeating the process 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.

6. The universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method according to claim 1, characterized in that: The synthesis steps are as follows: The mixed solution of isopropyl alcohol (IPA) and water for preparing the dye molecule or drug molecule in step (1) is specifically prepared by dissolving the dye molecule or drug molecule in a mixed solution of isopropyl alcohol and water (volume ratio is 5:2) to prepare a 0.3 mM mixed solution of the dye molecule or drug molecule; The synthesis of dye@silica or drug@silica in step (2) is as follows: 1.4 mL of the mixed solution in step (1) is added with 15 µL of aqueous ammonia, vortexed for 5 seconds, and then 3 µL of tetraethyl orthosilicate is added. After the addition is completed, the reaction system is placed in the dark and reacted on a magnetic stirrer at 500 rpm for 10 hours to complete the coprecipitation process and form dye@silica or drug@silica; The product purification process described in step (3) is specifically performed by centrifuging the mixed solution after the reaction at a speed of 12000 rpm for 12 minutes, discarding the supernatant, dispersing the precipitated product in pure water and continuing to centrifuge, and repeating the process 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.

7. The universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method according to claim 1, characterized in that: The synthesis steps are as follows: Step (1): prepare a mixed solution of 0.3 mM dye molecules or drug molecules in isopropanol and water (volume ratio is 5:2); Step (2): Take 1.4 mL of the mixed solution in step (1), add 15 µL of ammonia water to the system, vortex for 5 seconds, add 3 µL of tetraethyl orthosilicate, and react on a magnetic stirrer at 500 rpm for 10 hours in the dark to complete the coprecipitation process to form dye@silica or drug@silica; Step (3): Purify the product dye@dilica or drug@silica with pure water.

8. The universal method for synthesizing silicon oxide nanoparticles doped with dyes and drug molecules by coprecipitation method according to claim 1, characterized in that: A universal method is adopted, which is suitable for the doping of most cationic dyes in silica micropores, which increases the doping amount of most cationic dyes in silica and has a certain stability; silica nanoparticles are used as a protective layer to protect drug molecules, which can effectively protect drug molecules from damage in acidic environments and strong oxidant environments. At the same time, the drug molecules doped with silica nanoparticles can be released within a certain period of time.

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