Agarose Le isolated in nature has a high phase transition temperature, which limits the application of Agarose Le in biomedicine and other fields. According to the temperature response mechanism of Agarose Le, changing the hydrogen bond interaction between the inside/outside of the Agarose Le structural unit and with the water molecules around the structural unit, and regulating the formation of the Agarose Le double helix structure, can effectively reduce its phase transition temperature and improve the Agarose Le. Sugar use performance.
A method for modifying Agarose Le, the method is:
Add 0.1 g of low melting point Agarose Le and 100 mL of deionized water to a round-bottomed flask and heat to fully dissolve the Agarose Le. Cool to 50°C, add 0.5g sodium hydroxide (NaOH) and 1.6mL epichlorohydrin, react at 30°C for 2h, add 5mL containing 0.025g methoxypolyethylene glycol amine (mPEG-NH2) (molecular weight is 20k) deionized water, wherein the mass ratio of Agarose Le and methoxy polyethylene glycol amine is 1:0.25; after reacting at 30 ° C for 72h, the reaction solution is transferred into a dialysis bag, and the molecular weight cut-off of the dialysis bag is 50k , dialyzed for 3 days, changed the water every 12h, and lyophilized. The polymer prepared in this example is: Agarose-g-PEG20k-1.
In this method, through alkalization reaction and nucleophilic substitution reaction, sodium hydroxide and epichlorohydrin are added to low-melting Agarose Le aqueous solution at 30 °C for 2 h, and methoxypolyethylene glycol amine of different quality is added at 30 °C. After 72 hours of reaction, after dialysis and freeze-drying, agarose-graft-polyethylene glycol monomethyl ether polymer (Agarose-g-mPEG) was prepared. The method can destroy the formation of the agarose double helix structure, lower the phase transition temperature of the agarose, and reduce the immune response of the human body to the drug. Moreover, the agarose phase transition temperature is effectively adjusted according to the PEG reaction ratio.