Strong bacterial cellulose/poly(vinyl alcohol)/glycerol tubes with bioactive poly(vinyl alcohol)/silk microfibers hydrogel sheaths for esophageal grafts

Tubular esophageal grafts have been widely studied for their potential in replacing tissue damaged by esophageal cancer. However, developing readily available grafts for clinical use remains challenging due to high rates of esophageal leakage and limited biocompatibility. Herein, bilayer bacterial cellulose (BC)/poly(vinyl alcohol) (PVA)/glycerol (Gly)-PVA/silk microfiber (SMF) tubes were developed, featuring an inner BC/PVA/Gly layer and an outer PVA/SMF hydrogel sheath. The tubes were fabricated through a combination of rolling and freeze-thawing, creating a strong inner BC/PVA/Gly layer and a bioactive outer PVA/SMF hydrogel layer. The effects of the inner layer’s thickness and SMF content on the morphology, microstructure, thermal stability, mechanical properties, suture retention strength, and burst pressure strength of the bilayer tubes were examined. The inner BC/PVA/Gly tubes exhibited a compact structure, while the outer PVA/SMF sheaths had a porous architecture. The mechanical properties, suture retention strength, and burst pressure strength of the bilayer tubes were much greater than that of the native esophagus. Hemocompatibility and cytocompatibility testing confirmed the excellent blood compatibility and strong biocompatibility of these new bilayer tubes, largely attributed to the SMF content. These characteristics highlight the potential of bilayer BC/PVA/Gly-PVA/SMF tubes as promising candidates for esophageal graft applications.

Graphic abstract