Sodium Alginate-Based Submucosal Lifting Hydrogel for Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection.

Abstract

Submucosal lifting agents are crucial for enhancing the safety and efficacy of Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD) and other endoscopic interventions involving submucosal tunnelling. Frequently utilized lifting agents include saline, starch, ORISE Gel, Eleview, EverLift, BlueBoost and EndoClot SIS. In this context, we have formulated a sodium alginate-based lifting gel incorporating biocompatible methylene blue dye, which significantly enhances lesion visualization and delineation. Our Na alginate-derived lifting hydrogels displayed favorable shear-thinning characteristics, with an elevated viscosity (44-190 mPa∙s) at lower shear rates compared to commercially available lifting agents (1.7-44 mPa∙s). In lyophilized form, it exhibited short reconstitution time (60-90 s), near physiological pH (∼6.5), and osmolality (265-275 mOsm/kg). Ex vivo assessments validated the sustained lift height and cushion circumference for 60 min, while in vivo investigations in swine illustrated successful injectability, cushion retention for 45 min, and an absence of adverse tissue reactions. The goal was to investigate the relationship between rheological properties and mucosal lifting performance. By integrating prolonged elevation, improved visualization, biocompatibility, and optimal physicochemical characteristics, our alginate-based lifting gel effectively addresses the limitations inherent in previous agents, offers a more efficient, and versatile next-generation lifting agent for EMR and ESD.