PolyCore, a bimodal peritoneal dialysis solution based on xylitol, L-carnitine, and icodextrin: In vitro evidence of the peritoneal membrane protection, rationale, and design of the phase II pilot study EXCITE

Background Glucose exposure in peritoneal dialysis contributes to local peritoneal membrane injury and systemic metabolic complications. The osmo-metabolic approach seeks to reduce glucose burden by using alternative osmotic agents such as xylitol and L-carnitine. PolyCore is a novel glucose-free bimodal peritoneal dialysis solution combining icodextrin (4%), xylitol (1.5%), and L-carnitine (0.02%), designed to provide sustained ultrafiltration while improving biocompatibility. Methods Human peritoneal mesothelial cells were exposed to PolyCore, icodextrin 7.5% solution, or a control medium. Cell viability, transepithelial electrical resistance, fibrosis-related gene expression, and α-SMA (alpha-smooth muscle actin) protein expression were assessed. In parallel, the EXCITE study was designed as a phase II, single-arm, prospective pilot trial evaluating PolyCore in 28 adults with end-stage kidney disease receiving incremental peritoneal dialysis. Results PolyCore preserved mesothelial cell viability and barrier integrity, with transepithelial resistance values comparable to control and significantly higher than icodextrin 7.5%. Compared with icodextrin 7.5%, PolyCore showed a more favorable expression profile of mesothelial-to-mesenchymal transition markers, with lower α-SMA and vimentin and preserved E-cadherin. The EXCITE study will assess safety and preliminary efficacy, including dialysis adequacy, ultrafiltration, solute removal, metabolic parameters, and patient-reported outcomes. Conclusions PolyCore showed favorable in vitro biocompatibility compared with standard icodextrin 7.5% and may represent a glucose-free bimodal strategy for peritoneal dialysis. EXCITE will provide first clinical assessment on the safety and preliminary efficacy of PolyCore.