Nonswellable Curdlan/Linseed Gum Biogel with Water Retention Modulation: A Therapeutic Platform for Post-Traumatic Urethral Stricture Reconstruction.

Despite the potential of hydrogels in urethral tissue engineering, their efficacy in urethral repair is hindered by swelling caused by urine and the escape of water under urethral pressure. This study presents a biogel specifically designed for the urinary microenvironment, featuring nonswellable properties and water retention regulation, making it suitable for urethral tissue engineering. A robust primary gel network was constructed through a temperature-controlled multilevel assembly of Curdlan (Cur), transitioning from random coils to triple helices, ensuring structural stability and nonswellable characteristics in urine. During this period, linseed gum (LG) was integrated into the gel network to achieve water retention regulation, thereby preventing dehydration during urethral compression. Finally, cuttlefish ink nanoparticles (CINPs) with inherent immunomodulatory properties were added to regulate the inflammatory microenvironment in the area of urethral injury. The resulting biogel (Cur/LG/CINPs) exhibits excellent nonswellable characteristics along with water retention modulation and immunomodulatory properties, effectively preventing the occurrence of urethral stricture by adapting to the urinary microenvironment and enhancing urethral repair. This specially designed biogel tailored for the urinary microenvironment represents a promising strategy to address the limitations of traditional hydrogels in the treatment of urethral strictures.