Crosslinkable poloxamer in-situ gel as a submucosal cushion for endoscopic submucosal dissection

Abstract Hypertonic saline solution is used for endoscopic submucosal dissection (ESD) as a submucosal fluid cushion (SFC). However, short duration time and side effects like perforation and bleeding have limited the application of SFC. Here, an in-situ gel crosslinked acrylate/thiol Poloxamer 407 (PA-PSH) was used as an SFC for ESD to avoid perforation, and the feasibility and safety of the PA-PSH for ESD was evaluated in vitro and in vivo. PA-PSH thermal injection led to a longer-lasting elevation with clearer margins as compared with glycerol, with a high mucosal elevation induced by thiol-ene crosslinked acrylate Poloxamer 407 (PA) and thiol-capped Poloxamer 407 (PSH) in physiological conditions. ESD was achieved precisely without obvious adverse effects and tissue damage. The PA-PSH in-situ gel provides an excellent submucosal injection system, which has great potential to improve the ESD technique.