PH-sensitive hydrogen and its production

Abstract

The invention relates to a pH-sensitive hydrogel and a preparation method thereof. The hydrogel is composed of carboxymethyl chitosan, polymethyl vinyl ether, crosslinking agent glutaraldehyde and water, wherein the molar ratio of carboxymethyl chitosan to polymethyl vinyl ether is 1:0.25 ~1.5; the molar ratio of crosslinking agent glutaraldehyde and carboxymethyl chitosan is 1:10~30, and the balance is water. The preparation method of the hydrogel is as follows: under stirring, carboxymethyl chitosan and polymethyl vinyl ether are dissolved in deionized water at a molar ratio of 1:0.25 to 1.5, and fully mixed, while controlling the carboxymethyl chitosan and polymethyl vinyl ether. The concentration of methyl chitosan and polymethyl vinyl ether is in the range of 0.05 ~ 0.1M; then add pentamethylene glycol dropwise to the above mixed solution according to the molar ratio of carboxymethyl chitosan to 1:10 ~ 30 The aldehyde was stirred and reacted for 30 to 60 minutes, then poured into the mold after standing still, and dried at room temperature to a constant weight to obtain a semi-interpenetrating network pH-sensitive hydrogel. The hydrogel obtained by the invention not only has good pH sensitivity, but the addition of PVME improves the shortcoming of CMCS being hard and brittle, so that the obtained material has high adhesion and softness, and this hydrogel can be degraded under certain conditions , as a sustained-release drug carrier has potential application value.

Description

technical field [0001] The invention relates to a pH-sensitive hydrogel and a preparation method thereof, in particular to a pH-sensitive hydrogel with a semi-interpenetrating network structure and a preparation method thereof. Background technique [0002] Polymer gel refers to a macromolecular network filled with liquid, which is composed of polymers with a network structure and solvents. It is a three-dimensional network between liquid and solid, which has both liquid-like mobility and fluidity, and solid-like shape stability. When the macromolecular skeleton is hydrophilic, the liquid it fills can be water or an aqueous solution. This gel is called a hydrophilic gel, or hydrogel for short. [0003] Smart hydrogels are a class of hydrogels that respond to subtle changes in the external environment (such as temperature, pH, ionic strength, light, and specific chemical substances, etc.). pH-sensitive hydrogel is a polymer hydrogel whose volume changes with the pH value of...

AI Technical Summary

Problems solved by technology

However, the cross-linked PNIPAAm hydrogel itself cannot be degraded in vivo, which greatly limits its application.

Currently, there is no report on the preparation of pH-sensitive biodegradable PVME / CMCS hydrogels using semi-IPN technology.