M2-Macrophage-Derived Extracellular Vesicles-Functionalized Acellular Dermal Matrix as a New-Generation...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Immunology

Background:

• Extracellular vesicles (EVs) from M2 macrophages mediate tissue regeneration.
• Decellularized skin extracellular matrix (dSECM) provides a structural foundation for tissue repair.
• Integrating EVs into scaffolds enhances their therapeutic potential.

Purpose of the Study:

• To develop and evaluate a composite scaffold of M2 macrophage-derived EVs (M2-EVs) and dSECM.
• To assess the structural, biochemical, and regenerative properties of the dSECM/M2-EVs scaffold.
• To investigate the scaffold's efficacy in promoting vascularized tissue repair.

Main Methods:

• Bovine dermis was decellularized to create dSECM with preserved collagen and tunable stiffness.
• M2-EVs were isolated from IL-10-polarized macrophages and characterized via TEM, DLS, and Western blotting.
• The dSECM/M2-EVs scaffold was evaluated using in vitro cell assays and the chick CAM model.

Main Results:

• dSECM exhibited preserved collagen and tunable stiffness (15-40 kPa).
• M2-EVs (100 µg/mL) promoted >90% wound closure in vitro.
• The dSECM/M2-EVs scaffold significantly enhanced vascularization, collagen deposition, and anti-inflammatory gene expression (TGF-β, IL-10) in vivo.

Conclusions:

• M2-EVs are potent mediators for tissue regeneration when incorporated into ECM scaffolds.
• The dSECM/M2-EVs composite scaffold shows promise for vascularized tissue repair.
• This approach enhances immunomodulatory signaling and promotes angiogenesis for regenerative applications.