All-Polysaccharide, Self-Healing Injectable Hydrogels Based on Chitosan and Oxidized Hydroxypropyl Polysaccharides
Junyi Chen1, Brittany L B Nichols1, Ann M Norris2,3
1Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.
Biomacromolecules
|August 19, 2020
Summary
This study presents a green method for creating polysaccharide hydrogels using dynamic imine bonds, avoiding toxic crosslinkers. These novel hydrogels offer tunable mechanical properties and rapid self-healing for various applications.
Area of Science:
- Materials Science
- Polymer Chemistry
- Biomedical Engineering
Background:
- Polysaccharide hydrogels are desirable for biomedical uses due to their biocompatibility and biodegradability.
- Existing polysaccharide hydrogels often rely on small-molecule crosslinkers, which can cause toxicity or unwanted chemical modifications.
- There is a need for safer, more efficient methods to produce functional polysaccharide hydrogels.
Purpose of the Study:
- To develop a green, simple, and efficient strategy for preparing in situ forming polysaccharide hydrogels.
- To create hydrogels using dynamic imine bonds formed between oxidized polysaccharides and chitosan, eliminating the need for small-molecule crosslinkers.
- To investigate the properties and potential applications of these novel all-polysaccharide hydrogels.
Main Methods:
- Chemoselective oxidation of oligo(hydroxypropyl)-substituted polysaccharides to introduce ketone groups.
- Condensation of ketone groups with amine-containing moieties (chitosan) to form dynamic imine crosslinks.
- Preparation of oxidized hydroxypropyl cellulose/chitosan (Ox-HPC-Chitosan) and oxidized hydroxypropyl dextran/chitosan (Ox-HPD-Chitosan) hydrogels.
- Characterization of mechanical properties, swelling rates, and self-healing capabilities using rheometry.
Main Results:
- Successfully prepared Ox-HPC-Chitosan and Ox-HPD-Chitosan hydrogels cross-linked via imine bonds.
- Hydrogel storage modulus was tunable from 300 Pa to 13 kPa by controlling the degree of substitution of ketone groups.
- Demonstrated rapid self-healing properties, high swelling rates, and facile injectability for the all-polysaccharide hydrogels.
- The imine linkage provided pH responsiveness and potential for self-healing and injectability.
Conclusions:
- A green and efficient strategy for constructing polysaccharide hydrogels without small-molecule crosslinkers was established.
- The developed hydrogels exhibit tunable mechanical properties, rapid self-healing, and injectability, making them attractive for biomedical applications.
- This approach offers a promising pathway for creating advanced hydrogels for biomedical, agricultural, and controlled release applications.
