Injectable drug-eluting elastomeric polymer: A novel submucosal injection material

Background: Biodegradable hydrogels can deliver therapeutic payloads with great potentials in EMR and endoscopic submucosal dissection (ESD) to yield improvements in efficacy and foster mucosal regeneration. Objective: To assess the efficacy of an injectable drug-eluting elastomeric polymer (iDEEP) as a submucosal injection material. Design: Comparative study of 3 different solutions by using material characterization tests and ex vivo and in vivo porcine models. Setting: Academic hospital. Interventions: Thirty gastric submucosal cushions were achieved with saline solution (0.9%), sodium hyaluronate (0.4%), and iDEEP (n = 10) in ex vivo porcine stomachs. Four porcine gastric submucosal cushions were then created in vivo by using iDEEP. Main Outcome Measurements: Maximum injection pressure, rebamipide release rate, submucosal elevation duration, and assessment of in vivo efficacy by en bloc resection. Results: No significant difference in injection pressures between iDEEP (28.9 ± 0.3 psi) and sodium hyaluronate (29.5 ± 0.4 psi, P >.05) was observed. iDEEP gels displayed a controlled release of rebamipide up to 2 weeks in vitro. The elevation height of iDEEP (5.7 ± 0.5 mm) was higher than that of saline solution (2.8 ± 0.2 mm, P <.01) and sodium hyaluronate (4.2 ± 0.2 mm, P <.05). All EMR procedures were successfully performed after injection of iDEEP, and a large gel cushion was noted after the resection procedure. Limitations: Benchtop, ex vivo, and nonsurvival pig study. Conclusions: A novel injection solution was evaluated for endoscopic resection. These results suggest that iDEEP may provide a significant step toward the realization of an ideal EMR and endoscopic submucosal dissection injection material.