Intestinal stent with polydopamine-enhanced sodium alginate/polyacrylamide hydrogel coating: Design, fabrication and...

Endoscopic stent placement is an established effective intervention for relieving acute malignant obstruction secondary to colorectal tumors. However, clinically used stents are frequently associated with complications such as tumor ingrowth and stent migration, which limit their long-term efficacy. In this study, we developed a novel 3D-printed flexible tubular intestinal stent coated with polydopamine-enhanced sodium alginate/polyacrylamide (SA/PAM) hydrogel (hereafter referred to as PSP hydrogel). The stent itself acts as a physical barrier to inhibit tumor ingrowth, whereas the PSP coated hydrogel markedly improves tissue adhesion, thereby enhancing the overall performance of the stent system. The modified hydrogel demonstrates excellent compressive strength (>45 kPa) and superior tissue adhesiveness (>10 kPa), along with stable binding to the stent surface. The coated stent exhibits sufficient flexibility and can expand effectively to restore patency in constricted intestinal segments upon deployment. Compared with uncoated stents, the hydrogel-coated version shows a significantly higher anti-migration force (>7 N) and a markedly reduced migration distance (<1 mm). These findings indicate that the viscous PSP hydrogel-coated intestinal stent holds promising potential for clinical application in the management of acute colorectal obstructions.