Nerve Cells Decide to Orient inside an Injectable Hydrogel with Minimal Structural Guidance

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Injectable biomaterials offer minimally invasive application but often lack structural complexity for aligned tissue regeneration.
• Current methods struggle to create the necessary anisotropic matrices for complex tissue repair.

Purpose of the Study:

• To develop a novel class of injectable, tissue-regenerative materials capable of forming anisotropic matrices with controlled dimensions.
• To utilize magnetoceptive microgel objects for guided self-assembly within a biocompatible hydrogel precursor.

Main Methods:

• Rod-shaped, magnetoceptive microgel objects doped with superparamagnetic iron oxide nanoparticles were synthesized.
• Microgels were dispersed in a biocompatible gel precursor and aligned using external magnetic fields (millitesla order).
• Aligned microgels were fixed within the matrix hydrogel post-injection and orientation.

Main Results:

• A macroscopic, unidirectional orientation of microgels was achieved even at low volume concentrations (<3%).
• The oriented microgel matrix significantly influenced cellular behavior, promoting parallel nerve extension.
• This demonstrates that controlled microgel alignment can guide cellular alignment and tissue formation.

Conclusions:

• A new class of injectable, magnetically alignable biomaterials was successfully developed.
• These materials enable the creation of anisotropic matrices for guided tissue regeneration.
• This approach presents a promising, minimally invasive strategy for therapies, particularly for spinal cord injury repair.