CMCSMA-Citric Acid Hydrogel-Coated Pancreatic Duct Stent Used for Pancreatic Calculi

Pancreatic calculi, a common complication of chronic pancreatitis, significantly contribute to ductal obstruction, increased intraductal pressure, and debilitating abdominal pain. Although endoscopic pancreatic duct stenting alleviates ductal stenosis, conventional stents lack litholytic functionality, limiting their therapeutic efficacy. To address this challenge, we developed a drug-eluting pancreatic duct stent coated with a carboxymethyl chitosan methacrylate (CMCSMA)-based hydrogel utilizing 50% w/v citric acid (CA) as a litholytic agent. Polydopamine (PDA) interlayer was employed to enhance interfacial adhesion between the hydrogel and the stent surface. The CMCSMA hydrogel exhibited favorable physicochemical properties, including rapid gelation, excellent compressive strength (229.2 ± 14.8 kPa), hemocompatibility, and cytocompatibility. In vitro release studies revealed sustained CA release, achieving 66.3% cumulative release within 72 h. The hydrogel-coated stent demonstrated superior litholytic activity, dissolving over 90% of pancreatic calculi within 24 h. These results underscore the potential of CMCSMA-CA hydrogel-coated stents as a biocompatible and effective local drug delivery platform for targeted pancreatic duct litholysis.