Design of a MRI-Visible and Radiopaque Drug Delivery Coating for Bioresorbable Stents

Cardiovascular stents are currently being used for intraluminal stenting of the trachea for tracheomalacia treatment. These devices composed of permanent materials are controversial due to their limitations at internal reinforcement and biocompatibility, especially in pediatrics. We show in a pediatric tracheomalacia rabbit model, a poly-L-lactic acid (PLLA) Double Opposed Helical bioresorbable stent (DH) elicits a more mild inflammatory response in the malacic airway compared to a control metal stent. To further improve efficacy, a multi-drug delivery, bioresorbable coating was designed. The coating design controllably delivers ciprofloxacin (antibiotic) for one week and dexamethasone (anti-inflammatory agent) for three months. The bioresorbable polymeric components also demonstrate feasible visibility utilizing Magnetic Resonance Imaging (MRI). The local multi-drug delivery and imaging capabilities in this coating design in combination with the bioresorbable DH stent will result in a successful intervention specifically design for pediatric tracheomalacia. This design will eliminate long-term risks associated with current permanent devices and provide necessary theranostic agents to facilitate healing and monitor progress via non-invasive imaging techniques.