阅读说明：本技术 一种可德胶/埃洛石复合水凝胶及其应用和制备方法 (Curdlan/halloysite composite hydrogel and application and preparation method thereof ) 是由 孙燕 许衡 寿周翔 王磊 李伟东 陈夏伟 陈佳佳 金晓舒 费艺雯 季丹 于 2021-01-08 设计创作，主要内容包括：本发明公开了一种可德胶/埃洛石复合水凝胶及其应用和制备方法。现有多糖凝胶透气性及缓释效果差的问题,常规改性往往要添加化学助剂,增加了毒性。本发明可德胶/埃洛石复合水凝胶具备多孔状结构,所用材料包括可德胶和埃洛石,负载的药物为阿司匹林和普罗布考。本发明利用可德胶的低温可逆和高温不可逆的独特成胶特性,及其在水中能形成良好的分散体系与在碱溶液中良好溶解这三大特点,同时结合埃洛石特殊的管状结构,在碱性条件下形成具有良好载药效果的可德胶/埃洛石复合水凝胶。该款水凝胶材料所用材料都是天然材料,无毒无害,并可生物降解,可提高药物利用率,减轻毒副作用,在生物医用高分子材料具有良好的应用前景。(The invention discloses curdlan/halloysite composite hydrogel and an application and a preparation method thereof. The existing polysaccharide gel has poor air permeability and slow release effect, and chemical additives are usually added in conventional modification, so that the toxicity is increased. The curdlan/halloysite composite hydrogel has a porous structure, the used materials comprise curdlan and halloysite, and the loaded medicines are aspirin and probucol. The invention utilizes the unique gelling characteristics of curdlan that is reversible at low temperature and irreversible at high temperature, and the three characteristics that the curdlan can form a good dispersion system in water and can be well dissolved in an alkali solution, and simultaneously combines with a special tubular structure of halloysite to form curdlan/halloysite composite hydrogel with good drug loading effect under an alkali condition. The hydrogel material is made of natural materials, is non-toxic, harmless and biodegradable, can improve the utilization rate of the medicine, reduces toxic and side effects, and has good application prospect in biomedical polymer materials.)

1. A curdlan/halloysite composite hydrogel is characterized in that: including curdlan and halloysite; the halloysite and curdlan are crosslinked under the action of hydrogen bonds; the mass fraction of curdlan in the composite hydrogel is 0.5-2.5%, and the mass fraction of halloysite is 0.125-0.625%.

2. The curdlan/halloysite composite hydrogel of claim 1, wherein: also loaded with aspirin; the aspirin and halloysite were loaded in distilled water.

3. The curdlan/halloysite composite hydrogel according to claim 1 or 2, wherein: probucol is also loaded; the methylene dichloride solution of probucol is loaded with colloidal sol of curdlan and halloysite.

4. The use of a curdlan/halloysite composite hydrogel according to claim 1 or 2 as a wound dressing on the skin surface, or a drug slow-release carrier for enteric solution or a stent coating for treating and inhibiting restenosis after cardiac vasodilation.

5. The use of a curdlan/halloysite composite hydrogel according to claim 3 as a wound dressing on the skin surface, or a drug slow-release carrier for enteric solution or a stent coating for treating and inhibiting restenosis after cardiac vasodilation.

6. The method of claim 1, wherein the gel is prepared by the following steps: dispersing curdlan in an aqueous solution or dissolving the curdlan in an alkali solution to obtain a curdlan dispersion liquid or a curdlan solution;

step two, dropwise adding the halloysite solution into the stirred curdlan glue dispersion liquid or curdlan glue alkali solution to obtain a sol system; and then a sol system is utilized to obtain the curdlan/halloysite composite hydrogel.

7. The method for preparing curdlan/halloysite composite hydrogel according to claim 1, wherein the method comprises the following steps: in the first step, under the condition that the curdlan is dispersed in water, the mass concentration of the curdlan is 0.83-4.2%; under the condition that the curdlan is dissolved in the alkali solution, the mass ratio of the curdlan to the alkali solution is 1: 119-1: 23; continuously stirring the curdlan in the process of dispersing the curdlan in water or dissolving the curdlan in an alkali solution, wherein the stirring speed is 600-800 rpm; the alkaline solution adopts ammonia water, sodium hydroxide aqueous solution, trisodium phosphate aqueous solution or tricalcium phosphate aqueous solution, and the mass concentration of the alkaline solution is 0.0001-1.0%; the ratio of the halloysite to the curdlan in the second step is 1: 6-1: 2, and the stirring speed in the whole process is 600-800 rpm.

8. The method for preparing curdlan/halloysite composite hydrogel according to claim 1, wherein the method comprises the following steps: and in the second step, before the halloysite solution is mixed with the curdlan glue dispersion liquid or the curdlan glue alkali solution, adding the halloysite into the aspirin solution, so that the aspirin and the halloysite are loaded in the water solution at the temperature of 40-60 ℃ to obtain the aspirin-loaded halloysite solution.

9. The method for preparing curdlan/halloysite composite hydrogel according to claim 1, wherein the method comprises the following steps: after the sol is obtained in the second step, executing a third step and a fourth step; the method comprises the following specific steps:

step three, dissolving probucol in dichloromethane to prepare a dichloromethane solution of probucol, and then slowly dripping the dichloromethane solution into the sol obtained in the step two;

and step four, placing the sol obtained in the step three in a constant-temperature water bath at 70-80 ℃, placing for 6-24 hours, and fully volatilizing dichloromethane to obtain the probucol/aspirin-loaded curdlan/halloysite composite hydrogel.

10. The method for preparing curdlan/halloysite composite hydrogel according to claim 1, wherein the method comprises the following steps: the mass concentration of the methylene dichloride solution of the probucol in the step three is 5 mg/mL-25 mg/mL; the mass ratio of probucol to dichloromethane is 1: 264-1: 52, the dropwise addition is carried out gradually, and the dropwise addition is completed within 1-5 min; continuously stirring at the stirring speed of 200-500 rpm; the time required for the volatilization of the dichloromethane solvent is 0.5 to 2 hours, the heating temperature is controlled to be 70 to 85 ℃, and the mass fraction of curdlan in the composite gel is 0.5 to 2.5 percent.

Technical Field

The invention belongs to the technical field of composite materials, and particularly relates to a preparation method of probucol/aspirin-loaded curdlan/halloysite composite hydrogel and application of the probucol/aspirin-loaded curdlan/halloysite composite hydrogel in the biological field.

Background

Curdlan (Curdlan) is a microbial polysaccharide produced by fermentation of alcaligenes faecalis (alcaligenes faecalis). The curdlan is D-glucan formed by connecting beta- (1,3) glycosidic bonds, is the most distinctive one in a beta- (1-3) -D-glucan family, is neutral, has no branch, has simple repeating unit, and can be degraded and absorbed by human cells. Curdlan was also taught in 1964 by hoda uliginosa and its commercial production history is not long. Beginning in 1989 with martian corporation of japan, curdlan was certified by the united states Food and Drug Administration (FDA) in 1996 and can be used as an additive in food. Curdlan gel is unique in characteristic, is a thermoreversible low-strength gel, and is a thermoreversible high-strength gel formed at a temperature of more than 80 ℃. Halloysite is an inorganic mineral substance, and has the advantages of biocompatibility, low price, simple process and the like. In addition, the halloysite also has a unique nano-tubular structure and can load small-molecule drugs.

Aspirin and probucol are two antithrombotic medicaments with wide application and remarkable effect, and have good treatment effect on many common diseases. For example, the greatest problem in the oral administration process of aspirin is that local drug concentration is too high due to concentrated drug release, and the aspirin has stimulation effect on gastrointestinal mucosa after being hydrolyzed into salicylic acid in vivo, and even has the phenomena of edema, erosive ulcer and bleeding in severe cases.

Disclosure of Invention

The invention aims to provide preparation and application of aspirin/probucol loaded curdlan/halloysite composite hydrogel.

In a first aspect, the present invention provides a curdlan/halloysite composite hydrogel comprising a curdlan and a halloysite. The halloysite and curdlan are crosslinked under the action of hydrogen bonds. The mass fraction of curdlan in the composite hydrogel is 0.5-2.5%, and the mass fraction of halloysite is 0.125-0.625%.

Preferably, the curdlan/halloysite composite hydrogel also supports aspirin. Loading aspirin and halloysite in distilled water;

preferably, the curdlan/halloysite composite hydrogel is also loaded with probucol; the methylene dichloride solution of probucol is loaded with colloidal sol of curdlan and halloysite.

In a second aspect, the invention provides the use of the curdlan/halloysite composite hydrogel as a wound dressing on the surface of the skin, or a drug slow-release carrier of an enteric solution or a stent coating for treating and inhibiting restenosis after cardiac vasodilation (after PTCA). The curdlan/halloysite composite hydrogel has high strength, and the release time of the cardiovascular drug loaded on the curdlan/halloysite composite hydrogel is long, so that the sustained-release effect of the drug can be achieved.

In a third aspect, the invention provides a preparation method of the curdlan/halloysite composite hydrogel, which comprises the following specific steps:

dispersing curdlan in an aqueous solution or dissolving the curdlan in an alkali solution to obtain a curdlan dispersion liquid or a curdlan solution;

and step two, dropwise adding the halloysite solution into the stirred curdlan glue dispersion liquid or curdlan glue alkali solution to obtain a sol system. And then a sol system is utilized to obtain the curdlan/halloysite composite hydrogel.

Preferably, in the first step, when the curdlan is dissolved in the alkaline solution, the mass concentration of the curdlan is 0.83-4.2%; under the condition that the curdlan is dissolved in the alkali solution, the mass ratio of the curdlan to the alkali solution is 1: 119-1: 23; the process of dispersing the curdlan into water or dissolving the curdlan into an alkali solution is continuously stirred, and the stirring speed is 600-800 rpm. The alkaline solution adopts ammonia water, sodium hydroxide aqueous solution, trisodium phosphate aqueous solution or tricalcium phosphate aqueous solution, and the mass concentration of the alkaline solution is 0.0001-1.0%. The ratio of the halloysite to the curdlan in the second step is 1: 6-1: 2, and the stirring speed in the whole process is 600-800 rpm.

Preferably, in the second step, before the halloysite solution is mixed with the curdlan water dispersion or the curdlan alkali solution, the halloysite is added into the aspirin solution, so that the aspirin and the halloysite are loaded in the water solution at the temperature of 40-60 ℃, and the aspirin-loaded halloysite solution is obtained.

Preferably, the mass concentration of the aspirin solution in the step two is 5 mg/mL-25 mg/mL; the mass ratio of the halloysite to the aspirin is 1: 1-1: 5; the load temperature of the required distilled water is 40-60 ℃;

preferably, after the sol is obtained in the step two, the steps three and four are carried out; the method comprises the following specific steps:

and step three, dissolving the probucol in dichloromethane to prepare a dichloromethane solution of the probucol, and then slowly dripping the dichloromethane solution into the sol obtained in the step two.

And step four, placing the sol obtained in the step three in a constant-temperature water bath at 70-80 ℃, placing for 6-24 hours, and fully volatilizing dichloromethane to obtain the probucol-loaded curdlan/halloysite composite hydrogel.

Preferably, the mass concentration of the methylene dichloride solution of the probucol in the step three is 5 mg/mL-25 mg/mL; the mass ratio of probucol to dichloromethane is 1: 264-1: 52, the dropwise addition is carried out gradually, and the dropwise addition is completed within 1-5 min; and continuously stirring at a stirring speed of 200-500 rpm.

Preferably, in the fourth step, the solvent volatilization is dichloromethane solvent volatilization, the time required by the volatilization is 0.5 to 2 hours, the heating temperature is controlled to be 70 to 85 ℃, and the mass fraction of curdlan in the composite gel is 0.5 to 2.5 percent.

The invention has the beneficial effects that:

1. the invention utilizes different gel forming types of curdlan gel at different temperatures to prepare temperature response type gel by changing temperature conditions; the halloysite and the hydroxyl of curdlan gel form a hydrogen bond effect, and the rigid structure of the halloysite plays a role in physical crosslinking, so that the mechanical property of the curdlan gel is improved.

2. According to the invention, the oil-soluble solvent dichloromethane volatilizes to generate bubbles so as to form the porous composite hydrogel, the number of surface pores is up to 3.07/cm 2, so that the aerogel achieves good air permeability, and when the aerogel is used as a dressing or a stent coating, the air permeability can be effectively ensured, and the inflammation can be reduced.

3. The invention realizes the synergistic loading of the water/oil dual-property medicament by synergistically loading the water-soluble medicament aspirin and the oil-soluble medicament probucol into the curdlan/halloysite sustained-release system, can achieve the sustained-release effect, establishes a new sustained-release system, increases the medicament utilization rate and the synergistic action of the medicament, and simultaneously reduces toxic and side effects and burst release damage.

4. The synergistic probucol/aspirin-loaded curdlan/halloysite composite hydrogel obtained by the invention can be applied in various forms. When used as a surface coating, the coating can be applied to surface wound auxiliary materials to prevent pain and injury caused by material replacement; when used as a slow release material, the polymer can be applied to an enteric solution drug slow release carrier and a stent slow release coating for treating and inhibiting restenosis after cardiac vasodilator surgery (PTCA surgery).

5. The raw materials used in the invention have rich sources, are nontoxic, can be absorbed and degraded by human bodies, have low price, and meanwhile, the production condition is mild, the process is simple, the production efficiency is high, and the method is suitable for large-scale industrial production and has good economic benefit.

Drawings

FIGS. 1a to 1e are schematic views of drug-loaded composite hydrogels according to embodiments 1 to 5 of the present invention;

FIGS. 1a to 1e are schematic views of drug-loaded composite hydrogels according to embodiments 1 to 5 of the present invention;

FIG. 2 is a slow release curve diagram of aspirin and probucol in the composite hydrogel obtained in example 3 of the present invention.

Detailed Description

The preparation method of the curdlan/halloysite loaded water-oil amphoteric drug composite gel comprises the following specific steps:

the invention is further described below with reference to the accompanying drawings.

Example 1

Step one, dissolving 0.084g of curdlan (molecular weight is 5 ten thousand) in 0.0001% sodium hydroxide solution under stirring to obtain 0.83% by mass of curdlan sodium hydroxide solution, and the solution has good fluidity.

And step two, dissolving 0.05g of aspirin in 10mL of distilled water to prepare an aspirin solution of 5mg/mL, adding 0.025g of halloysite, and loading the aspirin and the halloysite in the distilled water of 40 ℃ to obtain drug-loaded slow-release particles, slowly adding the drug-loaded slow-release particles into a stirred curdlan sodium hydroxide solution, and uniformly dispersing the drug-loaded slow-release particles in the curdlan sodium hydroxide solution to obtain sol.

And step three, dissolving 0.025g of probucol in 5mL of dichloromethane to form a probucol dichloromethane solution with the concentration of 5mg/mL, slowly dripping the probucol dichloromethane solution into the sol obtained in the step two, stirring, and uniformly dispersing to obtain the composite sol.

And step four, placing the composite sol obtained in the step three in a water bath kettle at 70 ℃ for temperature control heating, and volatilizing dichloromethane to obtain the composite hydrogel carrying the medicine. The mass fraction of curdlan in the obtained composite hydrogel is 0.5%, and the maximum time for releasing the two drugs is 19 h.

Example 1 the final probucol/aspirin loaded curdlan/halloysite composite hydrogel formed a partial gel formation, forming a sol-gel system.

Example 2

Step one, dissolving 0.17g of curdlan (molecular weight is 20 ten thousand) in 0.001% sodium hydroxide solution under stirring to obtain 1.7% by mass of curdlan sodium hydroxide solution, and the solution has good fluidity.

And step two, dissolving 0.1g of aspirin in 10mL of distilled water to prepare a 10mg/mL solution, adding 0.05g of halloysite, loading the aspirin and the halloysite in the distilled water at 50 ℃ to obtain drug-loaded slow-release particles, slowly dripping the drug-loaded slow-release particles into the stirred curdlan sodium hydroxide solution, and uniformly dispersing the drug-loaded slow-release particles in the curdlan sodium hydroxide solution to obtain sol.

And step three, dissolving 0.05g of probucol in 5mL of dichloromethane to form a dichloromethane solution with the concentration of 10mg/mL of probucol, slowly dripping the dichloromethane solution into the sol obtained in the step two, stirring, and uniformly dispersing to obtain the composite sol.

And step four, heating the composite sol obtained in the step three in a water bath kettle at the temperature of 80 ℃, volatilizing dichloromethane, and enabling the upper surface to have fluidity. The mass fraction of curdlan in the obtained hydrogel was 1%, and a drug-loaded composite hydrogel was obtained.

Example 2 the shore durometer measurement of the finally obtained composite hydrogel was 55 degrees,2.95 air holes/cm²The diameter of the air hole is 1mm-4mm, and the air permeability is 0.128g/cm²H, the two drugs release time was 21 h.

Example 3

Step one, dissolving 0.26g of curdlan (molecular weight is 40 ten thousand) in 0.01% sodium hydroxide solution under stirring to obtain a curdlan sodium hydroxide solution with the mass fraction of 2.5%, wherein the solution mobility is poor.

And step two, dissolving 0.15g of aspirin in 10mL of distilled water to prepare a 15mg/mL solution, adding 0.075g of halloysite, and loading the aspirin and the halloysite in the distilled water at the temperature of 60 ℃ to obtain drug-loaded slow-release particles, slowly dripping the drug-loaded slow-release particles into the stirred curdlan sodium hydroxide solution, and uniformly dispersing the drug-loaded slow-release particles in the curdlan sodium hydroxide solution to obtain sol.

And step three, dissolving 0.075g of probucol in 5mL of dichloromethane to form a dichloromethane solution with the concentration of 15mg/mL of probucol, slowly dripping the dichloromethane solution into the sol obtained in the step two, stirring, and uniformly dispersing to obtain the composite sol.

And step four, heating the composite sol obtained in the step three in a water bath kettle at the temperature of 80 ℃, volatilizing dichloromethane, and enabling the upper surface to have fluidity. The mass fraction of curdlan in the obtained hydrogel was 1.5%, and a drug-loaded composite hydrogel was obtained.

Example 3 Shore durometer measurement of the finally prepared composite hydrogel was 43.5 degrees, with 3.07 pores/cm²The diameter of the air holes is 0.8mm-3mm, and the air permeability is 0.192g/cm²H. The release time of aspirin is about 25 hours, and the medicine release reaches a slow release platform which is the same as that of probucol later; wherein the burst release of aspirin is more pronounced than that of probucol and also shows multiple levels of procedural release; probucol shows better slow-release characteristics within 5-25h (the specific slow-release curve is shown in figure 2 of the specification)

Example 4

Step one, dissolving 0.35g of curdlan (molecular weight is 60 ten thousand) in 0.1% sodium hydroxide solution under stirring to obtain 3.4% by mass of curdlan sodium hydroxide solution, wherein the solution is generally viscous.

And step two, dissolving 0.2g of aspirin in 10mL of distilled water to prepare a 20mg/mL solution, adding 0.10g of halloysite, and loading the aspirin and the halloysite in the distilled water at the temperature of 60 ℃ to obtain drug-loaded slow-release particles, slowly dropping the drug-loaded slow-release particles into the stirred curdlan sodium hydroxide solution, and uniformly dispersing the drug-loaded slow-release particles in the curdlan sodium hydroxide solution to obtain sol.

And step three, dissolving 0.1g of probucol in 5mL of dichloromethane to form a dichloromethane solution with the concentration of 20mg/mL of probucol, slowly dripping the dichloromethane solution into the sol obtained in the step two, stirring, and uniformly dispersing to obtain the composite sol.

And step four, heating the composite sol obtained in the step three in a water bath kettle at 85 ℃ to volatilize dichloromethane, wherein the upper surface of the composite sol has fluidity. The mass fraction of curdlan in the obtained hydrogel was 2%, and a drug-loaded composite hydrogel was obtained.

Example 4 Shore durometer measurement of the finally prepared composite hydrogel has 26 pores, 2.77 pores/cm²The diameter of the air holes is about 0.5mm-2mm, and the air permeability is 0.128g/cm²And the slow release time of the two drugs is 24 hours.

Example 5

Step one, dissolving 0.44g of curdlan (molecular weight is 80 ten thousand) in a sodium hydroxide solution with the mass concentration of 1% under stirring to obtain a curdlan sodium hydroxide solution with the mass fraction of 4.2%, wherein the solution is sticky.

And step two, dissolving 0.25g of aspirin in 10mL of distilled water to prepare a solution of 25mg/mL, adding 0.125g of halloysite, and loading the aspirin and the halloysite in the distilled water at the temperature of 60 ℃ to obtain drug-loaded slow-release particles, slowly dropping the drug-loaded slow-release particles into the stirred curdlan sodium hydroxide solution, and uniformly dispersing the drug-loaded slow-release particles in the curdlan sodium hydroxide solution to obtain the sol.

And step three, dissolving 0.125g of probucol in 5mL of dichloromethane to form a dichloromethane solution with the concentration of 25mg/mL of probucol, slowly dripping the dichloromethane solution into the sol obtained in the step two, stirring and uniformly dispersing.

And step four, heating the composite sol obtained in the step three in a water bath kettle at 85 ℃ to volatilize dichloromethane, wherein the upper surface of the composite sol has fluidity. The mass fraction of curdlan in the obtained hydrogel was 2.5%, and a drug-loaded composite hydrogel was obtained.

The Shore durometer measurement value of the finally prepared composite hydrogel in example 5 is 7, and the number of pores is 1.92/cm²The diameter of the air hole is 0.2mm-1mm, and the air permeability is 0.064g/cm²And the slow release time of the two drugs is 23 h.