Janus Composite Hydrogels with Directional Exudate Management and Microenvironmental Homeostasis Regulation Effects for Peristomal Skin Protection

Peristomal skin post-intestinal stoma surgery is chronically exposed to a complex microenvironment (intestinal fluid erosion, bacterial overgrowth, chronic inflammation), leading to peristomal skin complications (PSCs). Herein, this study first constructed a Janus composite hydrogel as an ostomy bag wafer for peristomal skin protection. This material integrates wet adhesion, directional exudate management, broad-spectrum antibacterial activity, antioxidant capacity, and anti-inflammatory properties to improve the peristomal skin microenvironment and reduce PSCs. Its core structure is a tannic acid (TA)-polyvinyl alcohol (PVA)-polyacrylic acid (PAA) double-network hydrogel embedded with a Janus film (asymmetric wettability on the skin side). TA's phenolic hydroxyl groups endow long-lasting, moist adhesion and sustained bacteriostasis. The Janus film enables directional migration and retention of leaked intestinal fluid, preventing prolonged skin erosion. Overall, this TPPP hydrogel provides a new strategy for peristomal skin protection with clinical prospects, enhancing patient quality of life.