A uniform-unsaturated crosslinking strategy to construct injectable alginate hydrogel.

Area of Science:

• Materials Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Injectable hydrogels require controlled crosslinking for a uniform 3D network.
• Traditional methods like dropping or soaking can lead to uneven crosslinking and loss of injectability.

Purpose of the Study:

• To develop a facile and universal strategy for creating injectable sodium alginate (SA) hydrogels.
• To establish a controllable crosslinking method for enhanced hydrogel properties and broader applications.

Main Methods:

• A uniform-unsaturated crosslinking strategy using metal ions and vigorous stirring.
• Coordination of moderate metal ion concentrations with SA guluronate moieties.
• Optimization of CaCl2 concentration (0.2% w/v) for SA-Ca hydrogel preparation.

Main Results:

• Achieved uniform crosslinking, preventing local excess and maintaining injectability.
• Demonstrated tunable injectability by adjusting metal ion concentration.
• Successfully prepared injectable SA hydrogels using multiple metal ions.
• Showcased SA hydrogels as a versatile platform for drug delivery, tissue repair, and wound treatment.
• Validated the efficacy of injectable SA-0.2%Cu hydrogel in promoting full-thickness skin wound healing.

Conclusions:

• The developed strategy provides a low-cost, universal method for preparing injectable SA hydrogels.
• These hydrogels exhibit significant potential for diverse biomedical applications and clinical translation.
• The uniform crosslinking approach enhances hydrogel performance and expands functional possibilities.