Microfluidic GelMA/Bone-Derived Extracellular Matrix Microgels for Enhanced Stem Cell-Based Bone Regeneration.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Critical-sized bone defects present significant clinical challenges due to limited natural bone regeneration.
• Current tissue engineering strategies using hydrogels and mesenchymal stem cells (MSCs) show promise but often lack the necessary biomimetic architecture.
• Existing systems fail to replicate the hierarchical biochemical cues of native bone, hindering effective regeneration.

Purpose of the Study:

• To engineer modular, cell-laden microgels for enhanced bone defect regeneration.
• To create a biomimetic platform integrating bone-derived decellularized extracellular matrix (BdECM) within hydrogel networks.
• To evaluate the efficacy of these microgels in promoting osteogenic differentiation and bone repair in vivo.

Main Methods:

• Developed modular microgels (P-GE) by incorporating BdECM into gelatin methacrylate/polyethylene glycol diacrylate (GelMA/PEGDA) hydrogel networks.
• Utilized microfluidic encapsulation and UV-induced cross-linking for microgel fabrication.
• Assessed microgel structural integrity, injectability, and in vitro performance with rat bone marrow mesenchymal stem cells (BMSCs).
• Evaluated in vivo bone regeneration in critical-sized calvarial defects.

Main Results:

• Fabricated P-GE microgels demonstrated consistent structure, tunable injectability, and supported robust BMSC proliferation and osteogenic differentiation in vitro.
• In vivo implantation led to near-complete calvarial defect repair.
• Significant deposition of collagen and osteopontin was observed in the regenerated bone tissue.
• The microenvironment promoted sustained cell infiltration, proliferation, and osteogenic differentiation.

Conclusions:

• BdECM-based, cell-laden microgels represent an advanced biomimetic strategy for bone tissue engineering.
• The engineered P-GE microgels provide a structurally and biologically optimized platform for regenerating critical-sized bone defects.
• This approach facilitates efficient bone regeneration by mimicking native bone microenvironments.