Electrospun Fiber Surface Roughness Modulates Human Monocyte-Derived Macrophage Phenotype

Area of Science:

• Biomaterials Science
• Immunology
• Tissue Engineering

Background:

• Fibrous connective tissues have limited self-renewal and poor healing capacity post-injury.
• Macrophage phenotypic shifts are crucial for mediating tissue healing responses.
• Immunomodulatory biomaterials offer a strategy to control macrophage polarization and promote regeneration.

Purpose of the Study:

• To investigate the impact of surface roughness (SR) on macrophage phenotype.
• To assess if biomaterial surface roughness can modulate macrophage polarization for improved healing.
• To explore the potential of surface roughness as a design feature in immunomodulatory biomaterials.

Main Methods:

• Electrospun poly(-caprolactone) fibers with controlled surface roughness were fabricated.
• Macrophage phenotype was assessed *in vitro* using human monocyte-derived macrophages.
• Macrophage responses were evaluated *in vivo* in MacGreen mice following subcutaneous implantation of biomaterials.

Main Results:

• Increasing surface roughness decreased pro- and anti-inflammatory cytokine release from macrophages *in vitro*.
• Higher surface roughness correlated with increased expression of the pro-regenerative marker CD206 relative to the pro-inflammatory marker CD80.
• Implanted biomaterials with increased surface roughness showed a higher CD206 to CD80 ratio in macrophages *in vivo*.

Conclusions:

• Biomaterial surface roughness is sufficient to drive macrophage polarization.
• Surface roughness can be a simple yet effective feature in biomaterial design to control innate immunity.
• This approach holds promise for developing advanced biomaterials that promote tissue regeneration.