Novel Biodegradable PTX-PLGA-Coated Magnesium Stent for Benign Esophageal Stricture: An Experimental Study

Metal or plastic stent implantation is the most common treatment for benign esophageal stricture. Biodegradable stents, with unsatisfied radial force, can degrade step by step and thereby avoiding secondary surgical removal compared with metal stents. Herein, a novel biodegradable composite stent, with poly(lactic-co-glycolic acid) (PLGA) containing paclitaxel (PTX) coated the surface of the magnesium (Mg)-based braided stent, was designed and tested. By adding this drug-loaded polymer coating, the radial force of the stent increased from 32.56 Newton (N) to 82.64 N. PTX continuously released as the stent degraded, and the in vitro cumulative drug release in phosphate buffer saline for 28 days were 114.52 ± 13.47 μg/mL (pH = 7.4) and 176.10 ± 11.95 μg/mL (pH = 4.0). There was no statistically significant difference in the viability of fibroblasts of stent extracts with different concentration gradients (P > 0.05), while the PTX-loaded stents effectively promoted fibroblast apoptosis. In animal experiment, the stents were able to maintain the esophageal patency during the 3-week follow-up and to reduce infiltration of the inflammatory cells and the amount of fibrous tissue. These results showed that the PTX-PLGA-coated Mg stent has the potential to be a safe and effective approach for benign esophageal stricture.