Dual crosslinking hydrogels with tunable injectability and stability for bone repair

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Injectable dual crosslinking hydrogels are promising for bone defect treatment.
• Current hydrogels face limitations in injectability, material loss, and non-physiological conditions.
• Ideal hydrogels require shear-thinning, rapid self-healing, and in vivo stability.

Purpose of the Study:

• To develop an injectable dual crosslinking hydrogel system for bone defect repair.
• To create a hydrogel with tunable injectability, rapid self-healing, and enhanced in vivo performance.
• To leverage ion coordination for secondary crosslinking in bone defect environments.

Main Methods:

• Fabrication of hydrogel precursors using poly(aspartic acid)-poly(ethylene glycol)-poly(aspartic acid) copolymers and tannic acid.
• Utilizing hydrogen bonds for initial gelation and Ca2+ ion coordination for secondary crosslinking.
• Evaluating injectability, self-healing properties, mechanical strength, and stability.

Main Results:

• The hydrogel precursors exhibited smooth injectability and rapid self-healing after injection.
• Ca2+ ion coordination significantly enhanced the mechanical properties and stability of the hydrogel network.
• The dual crosslinking strategy provides a robust platform for in vivo applications.

Conclusions:

• A novel injectable dual crosslinking hydrogel was successfully developed using hydrogen bonds and Ca2+ ion coordination.
• This biomaterial offers improved injectability, rapid self-healing, and enhanced mechanical properties for bone repair.
• The findings provide a design strategy for secondary crosslinking of injectable hydrogels in bone defect sites.