CN106975100A - A kind of nano composite material of cerium oxide/mesoporous silicon and its preparation method and application - Google Patents

Abstract

The present invention relates to a kind of nano composite material of cerium oxide/mesoporous silicon, the cerium oxide nanocrystal and amido modified nanometer particle changed comprising part, the cerium oxide nanocrystal of part conversion are modified in the surface of amido modified nanometer particle；The mass ratio of cerium oxide nanocrystal that part is changed and amido modified nanometer particle is 1~20；The cerium oxide nanocrystal of part conversion carries out part conversion using 2- bromo acids.The invention further relates to the preparation method of the nano composite material of cerium oxide/mesoporous silicon and its application in wound healing or tissue repair.The composite can balance the active oxygen radical level of the surface of a wound, reduce level of inflammation, and adhesive effect is played using nanometer bridge effect；And preparing reaction system gently, condition is controllable, and prepared material is respectively provided with good biocompatibility, with good clinical conversion possibility.

Description

A nanocomposite material of cerium oxide/mesoporous silicon and its preparation method and application

technical field

The invention relates to the field of preparation of cerium oxide/mesoporous silicon composite materials, in particular to a nanocomposite material of cerium oxide/mesoporous silicon and its preparation method and application.

Background technique

Chronic refractory skin wounds bring suffering to patients and a heavy burden on the healthcare system. Due to the high morbidity and mortality rates of chronic refractory trauma, it is urgent to develop new treatment methods to make up for the deficiencies of existing treatment methods. According to statistics, there are about 6.5 million chronic non-healing wound patients in the United States alone, and the annual expenditure on chronic non-healing wounds is more than 25 billion US dollars, and it can be predicted that with obesity, the incidence of diabetes is increasing high, and this number will continue to grow.

The functional loss or interference of various molecular and cellular signals necessary for the normal wound healing process is the root cause of chronic non-healing wounds. In addition, the continuous intrusion of microorganisms in the external environment into the wound will also lead to a chronic inflammatory response, which is even more detrimental to the healing of the wound. It has been reported in the literature that there is a certain correlation between chronic inflammatory response and tumor development. In addition to chronic refractory wounds, promoting the healing of wounds and the recovery of organ functions caused by visceral operations such as liver, kidney, lung, and heart is also a difficult medical problem at present. Surgical sutures and polymer adhesives are commonly used and effective treatments for wounds caused by visceral operations such as liver, kidney, lung, and heart. But for soft connective tissues such as liver and lung, surgical suturing will cause certain organ damage. Polymer binders are also limited in their scope of application because the conditions for controlling polymerization or crosslinking reactions in vivo are too complex and their effects in humid in vivo environments are limited.

In view of the soft and moist characteristics of some internal organs and many external and internal factors leading to chronic refractory wounds, some recent basic research and preclinical research have shown that nanoparticles have great potential in promoting wound healing caused by various reasons. The work of Ludwik Leibler et al. found that a drop of silicon nanoparticle solution can produce a fast and strong bond between two separate hydrogels at room temperature. The experimental results of Ludwik Leibler et al. on animal skin wounds and visceral surgical wound models showed that, consistent with the results on hydrogels, nanoparticle solutions can accelerate wound healing by means of a so-called nanobridging effect.

However, existing research results have shown that due to the lack of endogenous antioxidants such as glutathione and vitamin E, the inability to neutralize the elevated reactive oxygen species at the wound is the cause of chronic refractory wounds such as diabetes and aging. one. Therefore, in the prior art, only the nano-bridge effect is used to accelerate wound healing, and no antioxidant is used to balance the reactive oxygen species in the wound, so the effect of accelerating wound healing is not obvious.

Contents of the invention

The purpose of the present invention is to overcome the defects in the prior art, and provide a nanocomposite material of cerium oxide/mesoporous silicon, its preparation method and application.

The technical scheme provided by the invention is as follows:

A nanocomposite material of cerium oxide/mesoporous silicon, comprising ligand-switched cerium oxide nanocrystals and amino-modified mesoporous silicon nanoparticles, and the ligand-switched cerium oxide nanocrystals are modified on the amino-modified mesoporous The surface of silicon nanoparticles; the mass ratio of ligand-switched cerium oxide nanocrystals to amino-modified mesoporous silicon nanoparticles is 1 to 20; the ligand-switched cerium oxide nanocrystals utilize 2-bromoisobutyric acid Perform ligand switching.

The cerium oxide/mesoporous silicon nanocomposite material provided by the present invention can balance the level of active oxygen free radicals on the wound surface, reduce the level of inflammation, and utilize the nano-bridge effect to exert adhesion. First, mesoporous silicon nanoparticles have a nano-bridge effect, which can promote wound healing; second, cerium oxide nanocrystals can balance the elevated reactive oxygen species at the wound, thereby reducing the oxidation of reactive oxygen species to the cell membrane and protein in the surrounding environment of the wound Damage effect, the use of cerium oxide nanocrystals that can neutralize reactive oxygen species for wound repair can make up for the deficiency of endogenous antioxidants. In order to attach cerium oxide nanocrystals to the surface of mesoporous silicon nanoparticles in the form of stable covalent bonds, 2-bromoisobutyric acid was used to perform ligand conversion on cerium oxide nanocrystals, and then to the surface of mesoporous silicon nanoparticles. Amino modification is beneficial to the compounding between the two materials, and finally the performance of the two materials is further improved after compounding.

Preferably, the particle size of the ligand-switched cerium oxide nanocrystals is 1-10 nm, and the particle size of the amino-modified mesoporous silicon nanoparticles is 5-500 nm. The particle size range of the cerium oxide nanocrystals and the mesoporous silicon nanoparticles facilitates the uniform modification of the cerium oxide nanocrystals on the surface of the mesoporous silicon nanoparticles to obtain a composite material with excellent morphology and performance.

The present invention also provides a method for preparing a nanocomposite material of cerium oxide/mesoporous silicon, comprising the steps of:

1) adding cerium acetate hydrate and oleylamine to xylene, reacting at 85°C to 95°C for 3 to 6 hours, aging and precipitating to obtain cerium oxide nanocrystals;

2) For the cerium oxide nanocrystals obtained in step 1), use 2-bromoisobutyric acid to perform ligand conversion to obtain ligand-switched cerium oxide nanocrystals;

3) Then dissolve cetyltrimethylammonium chloride and triethanolamine in water, react at 90°C-100°C for 0.5-5h, and continue to add ethyl orthosilicate and 3-aminopropyltriethoxy Silane reaction for 0.5-5 hours, centrifugation, and washing to obtain amino-modified mesoporous silica nanoparticles;

4) Add ligand-converted cerium oxide nanocrystals and amino-modified mesoporous silicon nanoparticles to ethanol, and react at 45° C. to 55° C. for 8 to 15 hours to obtain a cerium oxide/mesoporous silicon nanocomposite material.

Using the above preparation method, a nanocomposite material of cerium oxide/mesoporous silicon can be prepared. The composite material can not only balance the active oxygen free radical level of the wound surface with the help of cerium oxide nanocrystals, reduce the inflammation level, but also use mesoporous silicon nanoparticles Therefore, the advantages of the two materials complement each other, which further improves the performance of the nanocomposite material of cerium oxide/mesoporous silicon.

Preferably, the mass ratio of cerium acetate hydrate to oleylamine in the step 1) is 1:7-9.

As a preference, the feed ratio of cetyltrimethylammonium chloride, triethanolamine, ethyl orthosilicate and 3-aminopropyltriethoxysilane in step 3) is: 1.5-2.5g: 0.03～0.05g: 1.4～1.6ml: 0.14～0.16ml.

Preferably, the mass ratio of ligand-switched cerium oxide nanocrystals to amino-modified mesoporous silicon nanoparticles in step 4) is 1-20. By adjusting the mass ratio between the two, the content of ligand-switched cerium oxide nanocrystals in the nanocomposite of cerium oxide/mesoporous silicon is controlled, so that the ligand-switched cerium oxide nanocrystals can be easily modified on the amino-modified mesoporous The surface of silicon nanoparticles is convenient for the regulation of morphology and the modification of cerium oxide nanocrystals.

As preferably, the ligand conversion in the described step 2) refers to that the cerium oxide nanocrystals, 2-bromoisobutyric acid and citric acid obtained in the step 1) are sequentially added to the mixture of chloroform and N-N dimethylformamide. Stir in the mixed solvent for 20-30h. Ligand switching is to attach cerium oxide nanocrystals to the surface of mesoporous silicon nanoparticles in the form of stable covalent bonds.

Preferably, the mass ratio of 2-bromoisobutyric acid to cerium oxide nanocrystals is 20-60.

The invention also provides the application of a cerium oxide/mesoporous silicon nanocomposite material in wound healing.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

(1) The new nanocomposite of cerium oxide/mesoporous silicon can balance the level of active oxygen free radicals on the wound surface, reduce the level of inflammation, and promote acute and chronic wound healing and tissue repair by using the nano-bridge effect to exert adhesion and other mechanisms.

(2) The present invention relates to a mild reaction system and controllable conditions, and the prepared materials all have good biocompatibility and good possibility of clinical transformation.

Description of drawings

Fig. 1 is the X-ray diffraction figure of the cerium oxide nanocrystal that the ligand conversion in embodiment 1;

Fig. 2 is the transmission electron micrograph of the cerium oxide nanocrystal of ligand conversion in embodiment 1;

Fig. 3 is the transmission electron micrograph of the mesoporous silicon nanoparticle of amino modification in embodiment 1;

Fig. 4 is the transmission electron micrograph of the nanocomposite material of cerium oxide/mesoporous silicon in embodiment 1;

Fig. 5 is the scanning transmission electron micrograph of the nanocomposite material of the cerium oxide/mesoporous silicon in embodiment 1;

Fig. 6 is the element distribution diagram of the nanocomposite material of cerium oxide/mesoporous silicon in embodiment 1;

Fig. 7 is the MTS cell activity quantitative analysis result figure of the nanocomposite material of the cerium oxide/mesoporous silicon in the application example;

Fig. 8 is the healing rate of SD rat wound model treated with different materials in the present invention, wherein MSN-ceria is a nanocomposite material of cerium oxide/mesoporous silicon, MSN is mesoporous silicon nanoparticles, and Control is a blank test;

Fig. 9 is a picture of SD rat trauma model treated with different materials in the present invention, wherein MSN-ceria is a nanocomposite material of cerium oxide/mesoporous silicon, MSN is mesoporous silicon nanoparticles, and Control is a blank test.

detailed description

The preparation of the cerium oxide/mesoporous silicon nanocomposite of the present invention and its application in promoting wound healing will be described in detail below in conjunction with specific examples and drawings.

Example 1

(1) Synthesis and ligand conversion of cerium oxide nanocrystals: 0.4 g of cerium acetate hydrate and 3.2 g of oleylamine were added to 15 ml of xylene, stirred at room temperature for 4 hours, and rapidly raised to 90 °C at a heating rate of 2 °C per minute. Celsius; inject 1ml of deionized water into the reaction system, age for three hours, precipitate with acetone, and centrifuge to obtain cerium oxide nanocrystals. Add the synthesized cerium oxide nanocrystals, 0.5g 2-bromoisobutyric acid and 0.05g citric acid to a mixed solvent of 7.5ml chloroform and 7.5ml N,N-dimethylformamide and stir for 24 hours to obtain .

X-ray diffraction was performed on the obtained ligand-converted cerium oxide nanocrystals, as shown in FIG. 1 ; and the morphology of the ligand-converted cerium oxide nanocrystals was characterized by transmission electron microscopy, as shown in FIG. 2 .

(2) Synthesis of amino-modified mesoporous silica nanoparticles: add 2g of cetyltrimethylammonium chloride and 0.02g of triethanolamine to 20ml of deionized water, stir and heat up to 95 degrees Celsius, add orthosilicic acid 1.5ml of ethyl ester and 150μL of 3-aminopropyltriethoxysilane were stirred and reacted for 0.5-1h. The amino-modified mesoporous silicon dioxide nanoparticles can be obtained by centrifuging and washing away the template agent with 1wt% sodium chloride methanol solution.

The morphology of the prepared amino-modified mesoporous silicon nanoparticles was characterized by a transmission electron microscope, as shown in FIG. 3 .

(3) Synthesis of nanocomposites of cerium oxide/mesoporous silicon: 5ml of ligand-switched ethanol solution of 0.6mM cerium oxide nanocrystals and 1ml of 0.5mg/ml amino-modified mesoporous silica nanoparticles A cerium oxide/mesoporous silicon nanocomposite can be obtained by reacting the ethanol solution at 45 degrees Celsius for 12 hours. Carry out transmission electron microscope and scanning transmission electron microscope to the nanocomposite material that obtains cerium oxide/mesoporous silicon, the obtained result is shown in Figure 4 and 5, the diameter of the nanocomposite material of cerium oxide/mesoporous silicon is 50～60nm; In addition Elemental analysis was also carried out, as shown in Figure 6, it can be seen that the gray balls refer to mesoporous silicon, and the white dots refer to cerium oxide.

Example 2

(1) Synthesis and ligand conversion of cerium oxide nanocrystals: Add 0.4 g of cerium acetate hydrate and 3.6 g of oleylamine to xylene, stir at room temperature for 6 hours, and raise the temperature to 95 degrees Celsius at a rate of 2 degrees Celsius per minute ; Inject 1ml of deionized water into the reaction system protected by an inert gas, age for three hours, precipitate acetone, and centrifuge to obtain cerium oxide nanocrystals. Add the synthesized oxidized nanocrystals, 0.5g 2-bromoisobutyric acid and 0.05g citric acid to a mixed solvent of 7.5ml chloroform and 7.5ml N,N-dimethylformamide and stir for 24 hours. .

(2) Synthesis of amino-modified mesoporous silica nanoparticles: Add 2.4 g of cetyltrimethylammonium chloride and 0.05 g of triethanolamine to 20 ml of deionized water, stir and heat up to 95 degrees Celsius, add orthosilicon 1.4ml of ethyl acetate and 160μL of 3-aminopropyltriethoxysilane were stirred and reacted. The amino-modified mesoporous silicon dioxide nanoparticles can be obtained by centrifuging and washing away the template agent with 1wt% sodium chloride methanol solution.

(3) Synthesis of nanocomposites of cerium oxide/mesoporous silicon: 8ml of ligand-switched ethanol solution of 0.6mM cerium oxide nanocrystals and 1ml of 0.5mg/ml amino-modified mesoporous silica nanoparticles The nanocomposite material of cerium oxide/mesoporous silicon can be obtained by reacting at 50 degrees Celsius for 12 hours in an ethanol system.

Example 3

(1) Synthesis and ligand conversion of cerium oxide nanocrystals: Add 0.4 g of cerium acetate hydrate and 2.8 g of oleylamine to xylene, stir at room temperature for 3 hours, and raise the temperature to 88 degrees Celsius at a rate of 2 degrees Celsius per minute ; Inject 1ml of deionized water into the reaction system protected by an inert gas, age for three hours, precipitate acetone, and centrifuge to obtain cerium oxide nanocrystals. Add the synthesized oxidized nanocrystals, 0.5g of 2-bromoisobutyric acid and 0.05g of citric acid into a mixed solvent of 7.5ml of chloroform and 7.5ml of N,N-dimethylformamide and stir for 24 hours. have to.

(2) Synthesis of amino-modified mesoporous silica nanoparticles: add 2g cetyltrimethylammonium chloride and 0.04g triethanolamine to 20ml deionized water, stir and heat up to 95 degrees Celsius, add orthosilicic acid 1.4ml of ethyl ester and 160μL of 3-aminopropyltriethoxysilane were stirred and reacted. Amino-modified mesoporous silica nanoparticles were obtained by centrifuging and washing away the template agent with 1wt% sodium chloride methanol solution.

(3) Synthesis of nanocomposites of cerium oxide/mesoporous silicon: 4ml of ligand-switched ethanol solution of 0.6mM cerium oxide nanocrystals and 1ml of 0.5mg/ml amino-modified mesoporous silica nanoparticles The nanocomposite material of cerium oxide/mesoporous silicon can be obtained by reacting in an ethanol system at 60 degrees Celsius for 12 hours.

Application example

Cerium oxide/mesoporous silicon nanocomposite used to promote skin wound healing in SD rats

In vitro biocompatibility evaluation: Human skin fibroblast cell line (HSF) was selected to investigate the in vitro biocompatibility of different concentrations of mesoporous silicon nanomaterials and cerium oxide/mesoporous silicon nanocomposites. The results of quantitative analysis of MTS cell activity are shown in Figure 7. The cell survival rates of different concentration groups were all above 80%, indicating that the mesoporous silicon nanomaterial (MSN) and the cerium oxide/mesoporous silicon nanocomposite (MSN-ceria) were both Has good in vitro biocompatibility.

Establishment of skin wound model and result analysis: SD rats were anesthetized by intraperitoneal injection of 10wt% chloral hydrate at a dose of 4ml/kg, the back hair was removed, and a 2 cm long full-thickness wound was drawn on the back. Rats were randomly divided into 3 groups, 5 in each group. Three groups of rats were given blank (control), 50 μL 10 mg/ml mesoporous silicon nanoparticle aqueous dispersion solution (MSN), 50 μL 10 mg/ml cerium oxide/mesoporous silicon nanocomposite aqueous dispersion solution (MSN- ceria). Record the recovery of wound length in each group at the designated time point. The repair rate of the wound is shown in Figure 8, and Figure 9 is the photos of the rat's back wound on the first day and the ninth day.

The above embodiments have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. All within the scope of the principles of the present invention Any modifications, supplements and equivalent replacements should be included within the protection scope of the present invention.

Claims (9)

1. A nanocomposite material of cerium oxide/mesoporous silicon, characterized in that, it comprises ligand-switched cerium oxide nanocrystals and amino-modified mesoporous silicon nanoparticles, and the ligand-switched cerium oxide nanocrystals are modified on the surface of amino-modified mesoporous silicon nanoparticles; the mass ratio of ligand-switched cerium oxide nanocrystals to amino-modified mesoporous silicon nanoparticles is 1 to 20; the ligand-switched cerium oxide nanocrystals use 2 -Bromoisobutyric acid for ligand switching. 2. The nanocomposite material of cerium oxide/mesoporous silicon according to claim 1, characterized in that, the particle size of the cerium oxide nanocrystals converted by the ligand is 1 to 10 nm, and the amino-modified mesoporous silicon The particle size of the porous silicon nanoparticles is 5-500 nm. 3. A preparation method of the nanocomposite material of cerium oxide/mesoporous silicon as claimed in claim 1 or 2, is characterized in that, comprises the steps: 1) adding cerium acetate hydrate and oleylamine to xylene, reacting at 85°C to 95°C for 3 to 6 hours, aging and precipitating to obtain cerium oxide nanocrystals; 2) For the cerium oxide nanocrystals obtained in step 1), use 2-bromoisobutyric acid to perform ligand conversion to obtain ligand-switched cerium oxide nanocrystals; 3) Then dissolve cetyltrimethylammonium chloride and triethanolamine in water, react at 90°C-100°C for 0.5-5h, and continue to add ethyl orthosilicate and 3-aminopropyltriethoxy Silane reaction for 0.5-5 hours, centrifugation, and washing to obtain amino-modified mesoporous silica nanoparticles; 4) Add ligand-converted cerium oxide nanocrystals and amino-modified mesoporous silicon nanoparticles to ethanol, and react at 45° C. to 55° C. for 8 to 15 hours to obtain a cerium oxide/mesoporous silicon nanocomposite material. 4. the preparation method of the nanocomposite material of cerium oxide/mesoporous silicon according to claim 3, it is characterized in that, described step 1) in the mass ratio of cerium acetate hydrate and oleylamine is 1:7～9 . 5. the preparation method of the nanocomposite material of cerium oxide/mesoporous silicon according to claim 3, is characterized in that, described step 3) in cetyltrimethylammonium chloride, triethanolamine, orthosilicon The feeding ratio of ethyl acetate to 3-aminopropyltriethoxysilane is: 1.5-2.5g: 0.03-0.05g: 1.4-1.6ml: 0.14-0.16ml. 6. the preparation method of the nanocomposite material of cerium oxide/mesoporous silicon according to claim 3, it is characterized in that, described step 4) in the cerium oxide nanocrystal of ligand conversion and the mesoporous silicon nanometer of amino modification The mass ratio of particles is 1-20. 7. The preparation method of the nanocomposite material of cerium oxide/mesoporous silicon according to claim 3, is characterized in that, described step 2) middle ligand conversion refers to, the cerium oxide nanometer that obtains in step 1) Crystalline, 2-bromoisobutyric acid and citric acid were sequentially added to a mixed solvent of chloroform and N-N dimethylformamide and stirred for 20-30 hours. 8. The preparation method of the nanocomposite material of cerium oxide/mesoporous silicon according to claim 7, characterized in that, the mass ratio of 2-bromoisobutyric acid to cerium oxide nanocrystals is: 20-60 . 9. The application of the nanocomposite material of cerium oxide/mesoporous silicon as claimed in claim 1 or 2 in wound healing.