Ferrostatin-1 inhibits tracheal basal cell ferroptosis to facilitate the rapid epithelization of 3D-printed tissue-engineered tracheas.

Background: Tracheal replacement is a promising approach for treating tracheal defects that are caused by conditions such as stenosis, trauma, or tumors. However, slow postoperative epithelial regeneration often leads to complications, such as infection and granulation tissue formation. Ferroptosis, which is an iron-dependent form of regulated cell death, limits the proliferation of tracheal basal cells (TBCs), which are essential for the epithelialization of tissue-engineered tracheas (TETs). This study explored the potential of ferrostatin-1 (FER-1), which is a ferroptosis inhibitor, to increase TBC proliferation and accelerate the epithelialization of 3D-printed TETs.

Methods: TBCs were isolated from rabbit bronchial mucosal tissues and cultured in vitro. Ferroptosis was induced in TBCs at passage 2, as shown by increased reactive oxygen species (ROS) levels, Fe²⁺ accumulation, decreased ATP contents, and mitochondrial damage. TBCs were treated with FER-1 (1 μM) for 48 h to inhibit ferroptosis. The effects on ROS levels, Fe²⁺ levels, ATP contents, and mitochondrial morphology were measured. For in vivo experiments, FER-1-treated TBCs were seeded onto 3D-printed polycaprolactone (PCL) scaffolds, which were implanted into rabbits with tracheal injury. Epithelial regeneration and granulation tissue formation were evaluated 6 months after surgery.

Results: FER-1 treatment significantly reduced ferroptosis marker levels in vitro; that is, FER-1 treatment decreased ROS and Fe²⁺ accumulation, ameliorated mitochondrial structures, and increased ATP levels. TBC proliferation and viability were increased after ferroptosis inhibition. In vivo, the group that received 3D-printed scaffolds seeded with TBCs exhibited accelerated TET epithelialization and reduced granulation tissue formation compared with the control groups. These results suggest that inhibiting ferroptosis with FER-1 improves TBC function, leading to more efficient tracheal repair.

Conclusions: Ferrostatin-1 effectively inhibits ferroptosis in tracheal basal cells, promoting their viability and proliferation. This results in faster epithelialization of tissue-engineered tracheas, offering a promising strategy for improving tracheal reconstruction outcomes and reducing complications such as infection and granulation tissue formation. Future studies are needed to further investigate the molecular mechanisms underlying ferroptosis in TBCs and its potential clinical applications.