Biodegradable electrospun patch containing cell adhesion or antimicrobial compounds for trachea repair in vivo

Difficulty breathing due to tracheal stenosis (i.e. narrowed airway) diminishes the quality of life and can potentially be life-threatening. Tracheal stenosis can be caused by congenital anomalies, external trauma, infection, intubation-related injury, and tumors. Common treatment methods for tracheal stenosis requiring surgical intervention include end-to-end anastomosis, slide tracheoplasty and/or laryngotracheal reconstruction. Although the current methods have demonstrated promise for treatment of tracheal stenosis, a clear need exists for the development of new biomaterials that can hold the trachea open after the stenosed region has been surgically opened, and that can support healing without the need to harvest autologous tissue from the patient. The current study therefore evaluated the use of electrospun nanofiber scaffolds encapsulating 3D-printed PCL rings to patch induced defects in rabbit tracheas. The nanofibers were a blend of polycaprolactone (PCL) and polylactide-co-caprolactone (PLCL), and encapsulated either the cell adhesion peptide, RGD, or antimicrobial compound, ceragenin-131 (CSA). Blank PCL/PLCL and PCL were employed as control groups. Electrospun patches were evaluated in a rabbit tracheal defect model for 12 weeks, which demonstrated re-epithelialization of the luminal side of the defect. No significant difference in lumen volume was observed for the PCL/PLCL patches compared to the uninjured positive control. Only the RGD group did not lead to a significant decrease in the minimum cross-sectional area compared to the uninjured positive control. CSA reduced bacteria growth in vitro, but did not add clear value in vivo. Adequate tissue in-growth into the patches and minimal tissue overgrowth was observed inside the patch material. Areas of future investigation include tuning the material degradation time to balance cell adhesion and structural integrity.