HYDROXYBUTYL CHITIN, HYDROXYBUTYL CHITIN HYDROGEL AND PREPARATION METHODS THEREOF

Abstract

Disclosed in the present disclosure are a hydroxybutyl chitin, a hydroxybutyl chitin hydrogel and a preparation method thereof. Chitin is subjected to pulverization, dissolution, modification with epoxybutane, and purification to obtain a final product, namely the hydroxybutyl chitin. The hydroxybutyl chitin prepared by the method has good solubility in purified water, and a hydrogel with a low solid content can be formed. The hydroxybutyl chitin hydrogel will have a wide application aspect in biomedicine, absorbable materials, and other fields.

Claims

1. A method for preparing a hydroxybutyl chitin, comprising the following steps: (1) subjecting chitin to dispersion in an alkaline aqueous solution at low temperature; (2) adding epoxybutane to a chitin aqueous phase system, and conducting stirring for a reaction; and (3) after the reaction is completed, conducting dialysis and freeze-drying to obtain the hydroxybutyl chitin.

2. The method for preparing a hydroxybutyl chitin according to claim 1, wherein in step (2), the epoxybutane is added to the chitin alkaline aqueous solution, and stirred for a reaction at 0° C.-45° C. for 1-7 days.

3. The method for preparing a hydroxybutyl chitin according to claim 1, wherein in step (2), before being added to the chitin alkaline aqueous solution, the epoxybutane is diluted with a mixed reagent to adjust a gelatination effect of the hydroxybutyl chitin; and the mixed reagent comprises one or more of methanol, ethanol, isopropanol and n-butanol, purified water, one or more of sodium dodecyl sulfate, sodium iodide and potassium iodide, and one or more of lithium chloride, sodium chloride, potassium chloride and cesium chloride.

4. The method for preparing a hydroxybutyl chitin according to claim 3, wherein all alcohol reagents account for 20%-80% of a volume fraction of the mixed reagent; the purified water accounts for 20%-80% of the volume fraction of the mixed reagent; the one or more of the sodium dodecyl sulfate, the sodium iodide and the potassium iodide have a total concentration of 0-0.1 g/mL in the mixed reagent; and the one or more of the lithium chloride, the sodium chloride, the potassium chloride and the cesium chloride have a total concentration of 0-0.1 g/mL in the mixed reagent.

5. The method for preparing a hydroxybutyl chitin according to claim 1, wherein in step (3), after the reaction is completed, the system is diluted 1-20 times with purified water, followed by dialysis and freeze-drying.

6. A method for preparing a hydroxybutyl chitin hydrogel, comprising the following preparation steps: adding the hydroxybutyl chitin prepared by the preparation method according to claim 1 to purified water, and conducting stirring at 0° C.-30° C. for complete dissolution to form the hydroxybutyl chitin hydrogel.

7. A hydroxybutyl chitin prepared by the preparation method according to claim 1.

8. A hydroxybutyl chitin hydrogel prepared by a preparation method comprising the preparation steps according to claim 6.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a diagram showing the infrared spectrum of a hydroxybutyl chitin prepared in the present disclosure.

[0028] FIG. 2 is an effect diagram showing aqueous phase systems of 4 kinds of hydroxybutyl chitins with a mass fraction of 1%. From left to right, a hydroxybutyl chitin 1, a hydroxybutyl chitin 2, a hydroxybutyl chitin 3, and a hydroxybutyl chitin 4 are shown in sequence.

[0029] FIG. 3 is an effect diagram showing aqueous phase systems of 4 kinds of hydroxybutyl chitins with a mass fraction of 2%. From left to right, a hydroxybutyl chitin 1, a hydroxybutyl chitin 2, a hydroxybutyl chitin 3, and a hydroxybutyl chitin 4 are shown in sequence.

[0030] FIG. 4 is an effect diagram showing aqueous phase systems of 4 kinds of hydroxybutyl chitins with a mass fraction of 2.5%. From left to right, a hydroxybutyl chitin 1, a hydroxybutyl chitin 2, a hydroxybutyl chitin 3, and a hydroxybutyl chitin 4 are shown in sequence.

DETAILED DESCRIPTION

[0031] In order to further understand the present disclosure, a preparation method of highly dispersed chitin in aqueous phase provided in the present disclosure will be specifically described below with reference to embodiments. But the present disclosure is not limited to these embodiments. Non-essential improvements and adjustments made by a person skilled in the art under the core guiding ideology of the present disclosure still fall within the protection scope of the present disclosure.

[0032] Example 1 Preparation of a chitin solution [0033] (1) Preparation of a chitin powder 20.00 g of chitin was weighed, and put in a Chinese medicine pulverizer for grinding for 2-5 minutes. Ground chitin was taken out, and sequentially sifted through a 20-mesh sieve and a 50-mesh sieve to obtain a chitin powder. [0034] (2) Preparation of an alkaline aqueous solution 129.42 g of NaOH was accurately weighed, and slowly added to 1 L of purified water for several times. After the NaOH was completely dissolved and the temperature of the system was lowered to normal temperature, 47.06 g of urea was added to an obtained solution, stirred for dissolution, and cooled to room temperature. [0035] (3) Dissolution and dispersion of the chitin powder 1.85 g of the chitin powder was added to 1 L of the alkaline aqueous solution, and stirred for dispersion. The whole system was soaked in a low-temperature medium for treatment at −2° C. for 24 hours. The system was taken out, recovered to room temperature, stirred for 1 hour, and then soaked in a low-temperature medium for standing at a low temperature of −20° C. for 20 days. The system was taken out, and recovered to room temperature to obtain a chitin alkaline aqueous solution with good dispersibility and high viscosity.

Example 2 Preparation of Hydroxybutyl Chitins

[0036] 4 kinds of chitin modification reagents were prepared by changing a volume ratio of epoxybutane to a mixed reagent. The 4 kinds of reagents sequentially include: a modification reagent 1 (including the epoxybutane with a volume ratio of 100% and the mixed reagent with a volume ratio of 0%), a modification reagent 2 (including the epoxybutane with a volume ratio of 75% and the mixed reagent with a volume ratio of 25%), a modification reagent 3 (including the epoxybutane with a volume ratio of 25% and the mixed reagent with a volume ratio of 75%), and a modification reagent 4 (including the epoxybutane with a volume ratio of 0% and the mixed reagent with a volume ratio of 100%).

[0037] The mixed reagent includes the following ratios of components: an alcohol reagent accounting for 60% of a volume of the mixed reagent (the volume ratio of each reagent to the mixed reagent is as follows), including 20% of isopropanol, 20% of ethanol, and 20% of methanol; purified water with a volume ratio of 40%; sodium chloride with a concentration of g/mL; and sodium iodide with a concentration of 0.01 g/mL.

[0038] With the modification reagent 2 as an example, a method for preparing the reagent is as follows. 30 mL of epoxybutane was accurately weighed, and 2 mL of isopropanol, 2 mL of ethanol, and 2 mL of methanol were sequentially added, and stirred uniformly. 0.1 g of sodium chloride and 0.1 g of sodium iodide were weighed, sequentially added to 4 mL of purified water, and stirred for dissolution. A purified aqueous solution of the sodium chloride and the sodium iodide was dropped to a mixed solution of the epoxybutane and the alcohols, and stirred uniformly to obtain the mixed reagent 2. The modification reagents 1-4 were prepared according to the above method.

[0039] The 4 kinds of modification reagents (with 5 mL of each reagent) were separately dropped to 50 mL of the chitin solution prepared in Example 1, and stirred for a reaction at 4° C. for 2 days. A corresponding relationship between the modification reaction and resulting products is as follows: the product modified with the modification reagent 1 is a hydroxybutyl chitin 1, the product modified with the modification reagent 2 is a hydroxybutyl chitin 2, the product modified with the modification reagent 3 is a hydroxybutyl chitin 3, and the product modified with the modification reagent 4 is a hydroxybutyl chitin 4.

[0040] Example 3 Purification of a hydroxybutyl chitin [0041] (1) An aqueous phase system in Example 2 was taken out, and 150 mL of purified water was added and stirred uniformly. [0042] (2) An insoluble substance in the system was filtered out, and the system was subjected to dialysis with a cellulose ester dialysis bag to remove low molecular polysaccharide below 5,000 Da, where 5 L of purified water was used for the dialysis each time. The water was continuously changed every 4 hours for 4 times, and then continuously changed every 12 hours for 6 times. [0043] (3) After the dialysis was completed, a liquid in the bag was taken out, and freeze-dried to obtain a hydroxybutyl chitin. Infrared data of the hydroxybutyl chitin 2 are as shown in FIG. 1.

[0044] Example 4 Preparation of hydroxybutyl chitin hydrogel Certain amounts of the 4 kinds of hydroxybutyl chitins were weighed, and 3.5 mL of purified water was added. 4 kinds of hydroxybutyl chitin systems with a mass fraction of 1%, 2%, and 2.5% were separately prepared. The systems were shaken at room temperature for 3 minutes, and put in a refrigerator for standing at 4° C. for 0.5 hour. Samples were taken out, and stirred at 4° C. for 15 hours to obtain stable hydroxybutyl chitin aqueous phase systems. The time for dissolution and dispersion of the hydroxybutyl chitin 1 is longer than 12 hours, and the time for dispersion and dissolution of other hydroxybutyl chitins is 5-8 hours.

[0045] As shown in FIG. 2, when the mass fraction is 1%, a viscous liquid is formed by the hydroxybutyl chitin 1, and solutions with good fluidity are formed by the hydroxybutyl chitins 2, 3, and 4. After placement at room temperature for 14 days, a flocculent precipitate is formed in the hydroxybutyl chitin 4 system.

[0046] As shown in FIG. 3, when the mass fraction is 2%, hydrogel is formed by the hydroxybutyl chitins 1 and 2, and solutions with good fluidity are formed by the hydroxybutyl chitins 3 and 4. The time for dispersion of the hydroxybutyl chitin 1 is long (about 12 hours). After placement at room temperature for 14 days, a small amount of purified water permeates through the hydroxybutyl chitin 1 hydrogel, and the gel has low stability; and a flocculent precipitate is formed in the hydroxybutyl chitin 4 system.

[0047] As shown in FIG. 4, when the mass fraction is continuously increased to 2.5%, hydrogel is formed by the hydroxybutyl chitins 1, 2, and 3, and a solution with good fluidity is formed by the hydroxybutyl chitin 4. The time for dispersion of the hydroxybutyl chitin 1 is still long (about 12 hours). After placement at room temperature for 14 days, a small amount of purified water permeates through the hydroxybutyl chitin 1 hydrogel, and the gel has unsatisfactory stability; and a flocculent precipitate is formed in the hydroxybutyl chitin 4 system.

[0048] The dispersion time, solid content, and hydrogel stability of the hydroxybutyl chitins are comprehensively considered, the hydroxybutyl chitin 2 has better performance. When the solid content is 2%-2.5%, a hydroxybutyl chitin hydrogel is formed in 5-8 hours.

CONCLUSION

[0049] In the present disclosure, the chitin is dispersed to obtain a chitin alkaline aqueous phase system with good dispersibility. The chitin is modified by adding the epoxybutane or the diluted epoxybutane. A novel hydroxybutyl chitin is obtained by dilution, dialysis, and freeze-drying of a sample system. A uniform and stable physical cross-linked hydrogel can be formed by the hydroxybutyl chitin with a solid content of 2%-2.5%. The hydroxybutyl chitin hydrogel will be further developed into a novel tissue engineering scaffold and other degradable materials to play an important role in the field of Class III medical apparatuses and instruments.