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Updated: Feb 5, 2026

Preparation of Chitosan-based Injectable Hydrogels and Its Application in 3D Cell Culture
Published on: September 29, 2017
The green and stable dissolving system based on KOH/urea for homogeneous chemical modification of chitosan
Shichao Bi1, Shihao Hu1, Zhongzheng Zhou1
1College of Marine Life Science, Ocean University of China, 5# Yushan Road, Qingdao 266003, Shandong Province, PR China.
Abstract:
The novel solvent (0.25 M KOH/0.01 M urea alkaline solution) was used to successfully dissolve chitosan without freezing-thawing cycles, for the first time. The results from XRD, FTIR, and 13CNRM proved that KOH/urea solution could destroy the hydrogen bonds between chitosan chains more efficiently than NaOH/urea solution. The dynamic light scattering, rheology, viscosity and elemental analysis confirmed that the KOH/urea hydrogen-bonded chitosan complex had a better thermal stability at 40 °C, and no obvious deacetylation and degradation appeared in dissolution process. Subsequently, the homogeneous chemical modification of chitosan based on KOH/urea dissolution system solution was conducted at 25 °C. The FTIR and microscopic observation indicated that the carboxymethyl chitosan, N,N,N-trimethyl chitosan and hydroxyl butyl chitosan were synthetized successfully. This work provided a green and stable solvent for homogeneous chemical modification of chitosan.
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