Reinstating Niche Failure in Diabetic Cranial Defects via Chronotaxic Signal-Amplifying Fluidic Biomimetic Hydrogel

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Stem Cell Biology

Background:

• Cranial stem cell niches (SCNs) are scarce and hypoactive, especially in diabetes.
• Chronic inflammation in diabetes exacerbates niche failure and regenerative deficits.
• Restoring SCN function is crucial for healing cranial injuries.

Purpose of the Study:

• To develop a biomimetic niche that amplifies chronotaxic signals for SCNs.
• To enhance SCN abundance and activity to restore autonomous regeneration.
• To address regenerative deficits in diabetic cranial injuries.

Main Methods:

• Synthesized GelSSO hydrogel and PDA@SDF nanoparticles.
• Developed an in situ moldable fluidic biomimetic niche (GelSSO/PDA@SDF).
• Investigated chronotaxic signal amplification, progenitor recruitment, angiogenesis, immunomodulation, and osteogenesis in vitro and in vivo.

Main Results:

• GelSSO/PDA@SDF preferentially released nanoparticles, amplifying early-phase signals (SDF-1α/CXCR4).
• This promoted progenitor recruitment, AKT-dependent angiogenesis, and M1 macrophage suppression.
• Progressive degradation initiated secondary amplification, inducing MAPK/ERK-mediated osteogenesis.

Conclusions:

• The biomimetic niche restored autonomous regeneration in diabetic cranial defects.
• It established an immunologically favorable, progenitor-rich niche, activating vascular and osteogenic pathways.
• This strategy offers versatile regeneration for poorly healing tissues.