Preparation method of guanidinated chitosan and application of guanidinated chitosan

A technology of chitosan and chitosan, which is applied in the field of functional polymer materials, can solve the problems affecting the inhibition of lysozyme, and achieve the effects of avoiding side reactions, good biocompatibility, and simple preparation process

Active Publication Date: 2017-06-30
JIANGSU ACADEMY OF AGRICULTURAL SCIENCES
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the surface layer of the cell wall of Gram-negative bacteria (G-) is covered with a l

Method used

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  • Preparation method of guanidinated chitosan and application of guanidinated chitosan
  • Preparation method of guanidinated chitosan and application of guanidinated chitosan
  • Preparation method of guanidinated chitosan and application of guanidinated chitosan

Examples

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Embodiment 1

[0029] Weigh 2.0 g of arginine and 4.84 g of N,N'-carbonyldiimidazole, dissolve them in 50 mL of anhydrous methanol, and stir at 0-5°C for 3 hours to obtain carboxyl-activated arginine for use. Weigh 2.7g of chitosan (viscosity average molecular weight 15kDa, degree of deacetylation 90%) and dissolve it in 100mL MES aqueous solution, and then add the carboxyl activated arginine prepared in the previous step directly to the chitosan solution, and the addition is complete Then, it was stirred at room temperature for 6h. The solvent was removed under vacuum, and the product was dissolved in ultrapure water, dialyzed (MWCO 6000) for 3 to 4 days, and freeze-dried. The infrared spectrum of the prepared guanidyl chitosan GCS1 is as figure 1 As shown in (b), elemental analysis shows that the guanidine group grafting rate is 34.8%.

Embodiment 2

[0031] Weigh 1.9 g of arginine and 3.72 g of N,N'-carbonyldiimidazole, dissolve in 100 mL of anhydrous methanol, and stir at 25° C. for 6 hours to obtain carboxyl-activated arginine for use. Weigh 1.6 g of chitosan (viscosity average molecular weight 8kDa, degree of deacetylation 88%) and dissolve it in 100 mL of MES aqueous solution, and then add the carboxyl activated arginine prepared in the previous step directly to the chitosan solution. After the addition is complete , Stir at room temperature for 20h. The solvent is removed under vacuum, the product is dissolved in ultrapure water, dialyzed (MWCO 3400) for 3 to 4 days, and freeze-dried. The infrared spectrum of the prepared guanidyl chitosan GCS2 is as figure 1 As shown in (c), elemental analysis shows that the guanidine group grafting rate is 45.2%.

Embodiment 3

[0033] An aqueous solution of guanidinated chitosan (viscosity average molecular weight 15kDa, guanidine grafting rate 34.8%) containing lysozyme was prepared, wherein the concentration of lysozyme was 1 mg / mL and the concentration of guanidinated chitosan was 1 mg / mL. Prepare 2mg / mL dextran sulfate aqueous solution. Using 2mL dextran sulfate as the base solution, use a syringe pump to add 0.8mL of guanidinated chitosan solution containing lysozyme at a rate of 10mL / h. The stirring speed of the base solution is 500rpm. Continue stirring after the addition is complete 10min. Settling naturally overnight, centrifuging at 4°C (rate 5000xg) for 20 minutes, removing the lower layer of precipitation, and freeze-drying to obtain antibacterial nanospheres. The lysozyme encapsulation rate of the nano microspheres is 45.78%, and the drug loading rate is 27.62%.

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Abstract

The invention provides a preparation method of guanidinated chitosan. By guanidination modification for chitosan, the biological alkalinity and the water solubility of the chitosan are improved, and the action capacity of the chitosan to an electronegative cell membrane is enhanced; the provided preparation method of the guanidinated chitosan aims to increase the grafting rate of chitosan guanidination and avoid side reaction. The invention further provides a method for preparing antibacterial nano microspheres from the guanidinated chitosan. The method comprises the steps of by taking dextran sulfate as a crosslinking agent, preparing the lysozyme-coated guanidinated chitosan nano microspheres; by the use of the puncture action of the guanidinated chitosan to the cell membrane, the stability of the outer membrane lipid structure of gram negative bacteria (G-) is destroyed to expose peptidoglycan on the inner wall layer, and the peptidoglycan is hydrolyzed through lysozyme; under the synergistic action of the guanidinated chitosan and the lysozyme-coated guanidinated chitosan nano microspheres, the inhibition effect on G- is enhanced.

Description

Technical field [0001] The invention relates to the field of functional polymer materials, in particular to a method for preparing guanidinated chitosan and a method for preparing antibacterial nano-microspheres by using guanidinated chitosan. Background technique [0002] Chitosan is a deacetylation product of chitin that exists widely in nature. The primary amine group (-NH 2 ) After protonation, it is positively charged, giving it antibacterial properties. Therefore, chitosan is also a natural antibacterial agent commonly used in food, medical, agricultural and other fields. Studies have shown that high-molecular-weight chitosan adsorbs on the surface of bacterial cells and can form a polymer film to prevent the transportation of nutrients into the cells, thus inhibiting the surface cell wall structure of Gram-positive bacteria (G+) The effect is remarkable; while the low molecular weight chitosan can penetrate the cell membrane into the bacterial cell and combine with the neg...

Claims

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Application Information

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IPC IPC(8): C08B37/08B01J13/02A01N47/44A01P1/00A01P3/00
CPCA01N47/44B01J13/02C08B37/003
Inventor 秦竹余刚史海健吴晓烽周忠凯刘建龙孙倩
Owner JIANGSU ACADEMY OF AGRICULTURAL SCIENCES
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