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

Abstract

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.

Figure 1

Photographic representation of the liquid to gel transformation of the iDEEP. Gel transformation only occurs after the A and B Components are combined.

Figure 2

A) Maximum injection pressures of the tested solutions, and B) in vitro Rebamipide release profiles from iDEEP gels.

Figure 2

A) Maximum injection pressures of the tested solutions, and B) in vitro Rebamipide release profiles from iDEEP gels.

Figure 3

Photographic images depicting the chronological changes in the submucosal elevation of A) saline (0.9%), B) sodium hyaluronate (0.4%), and C) iDEEP (30%) from top to bottom in turn 1, 5, 15, and 30 minutes after injection using porcine gastric samples ex vivo. D) Graphical representation of the chronological changes in the submucosal elevation.

Figure 4

Endoscopic views of A) Contained vertical submucosal elevation after injection of the iDEEP Part A and B solution, and B) Mucosal defect post-iDEEP EMR resection reveals a solidified soft biodegradable gel.

Figure 4

Endoscopic views of A) Contained vertical submucosal elevation after injection of the iDEEP Part A and B solution, and B) Mucosal defect post-iDEEP EMR resection reveals a solidified soft biodegradable gel.