Down-Regulating Scar Formation by Microneedles Directly via a Mechanical Communication Pathway

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Dermatology

Background:

• Excessive extracellular matrix deposition causes fibroblast mechanical stress, leading to pathological fibrosis and hypertrophic scars.
• Current treatments for hypertrophic scars often involve invasive procedures with limited efficacy.

Purpose of the Study:

• To investigate the efficacy of silk fibroin microneedle patches (SF MNs) for scarless tissue regeneration.
• To elucidate the underlying mechanisms of SF MNs in modulating fibroblast behavior and reducing scar formation.

Main Methods:

• Development and characterization of silk fibroin microneedle patches (SF MNs) with tunable size and density.
• In vivo evaluation of SF MNs in a rabbit ear hypertrophic scar model.
• In vitro study using a fibroblast-populated collagen lattice and finite element modeling to analyze MN-mediated cellular responses.

Main Results:

• SF MNs significantly reduced the scar elevation index and increased ultimate tensile strength in hypertrophic scar models.
• SF MNs decreased fibroblast-generated contraction and mechanical stress, evidenced by reduced ANKRD1 gene expression.
• SF MNs attenuated integrin-FAK signaling, leading to down-regulation of TGF-β1, α-SMA, collagen I, and fibronectin.

Conclusions:

• Silk fibroin microneedle patches provide a minimally invasive approach for scarless wound healing.
• The mechanotherapeutic strategy of SF MNs creates a low-stress microenvironment, effectively reducing scar formation and improving tissue function.