Fast-Curing Injectable Microporous Hydrogel for In Situ Cell Encapsulation

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Injectable hydrogels are promising for tissue regeneration and cell/drug delivery.
• Current systems often lack microporosity, hindering cell infiltration and proliferation.
• This limits their efficacy in regenerative medicine applications.

Purpose of the Study:

• To develop an injectable, microporous hydrogel with enhanced properties for cell delivery.
• To overcome limitations of existing hydrogel scaffolds regarding cell migration and proliferation.
• To investigate the potential of this hydrogel in enhancing cell behavior for regenerative medicine.

Main Methods:

• Fabrication of injectable microporous hydrogels from gelatin/gelatin methacryloyl (GelMA) composite microgels via water-in-oil emulsion.
• Dual-crosslinking using UV photopolymerization and microbial transglutaminase (mTG) for rapid curing and tissue adhesion.
• In situ cell encapsulation of human dermal fibroblasts and human mesenchymal stem cells (hMSCs).

Main Results:

• The composite microgels exhibited improved thermal stability compared to GelMA-only microgels.
• Dual-crosslinking enabled fast hydrogel formation, reduced photoinitiator concentration, and minimized cytotoxicity.
• Encapsulated hMSCs and fibroblasts demonstrated rapid spreading and proliferation within the hydrogel's pore space.
• Encapsulated cells secreted prostaglandin E2 (PGE2) and interleukin-6 (IL-6), indicating enhanced anti-inflammatory behavior.

Conclusions:

• The developed injectable microporous hydrogel offers a promising scaffold for tissue regeneration.
• The dual-crosslinking strategy enhances hydrogel properties and biocompatibility.
• This formulation supports cell viability, proliferation, and functional behavior, positioning it as a valuable cell delivery vehicle for regenerative medicine.