A 3D-Printed nano-silver antibacterial membrane for local antibacterial protection of PTFE vascular grafts

Vascular graft infection remains a serious and potentially devastating complication after prosthetic vascular reconstruction, particularly in polytetrafluoroethylene (PTFE) grafts, which are prone to bacterial attachment, biofilm formation, and persistent colonization. Once infection occurs, the inert and relatively impermeable nature of PTFE limits local antibiotic penetration, often resulting in treatment failure, graft removal, and poor clinical outcomes. Therefore, developing an effective and biocompatible antibacterial strategy for PTFE vascular grafts is of considerable clinical importance. In this study, we developed a three-dimensional (3D)-printed nano-silver antibacterial membrane designed for physical wrapping of PTFE vascular grafts. Comprehensive physicochemical characterization confirmed the successful construction and structural stability of the membrane. The 3D-printed membrane was prepared using a 20 wt% polymer solution at a printing speed of 6 μL/s and could be shaped into ring-like structures compatible with PTFE graft segments. In vitro antibacterial assays, including quantitative inhibition-zone analysis and OD600 measurements, demonstrated concentration- and size- dependent antibacterial activity against both Escherichia coli and Staphylococcus aureus in solid and liquid culture systems. When combined with PTFE graft segments, the silver nanoparticle (AgNP)-containing membrane conferred clear antibacterial activity, whereas bare PTFE grafts and silver free supporting materials showed no obvious inhibitory effects. In a murine subcutaneous infection model, AgNP-containing membranes qualitatively reduced bacterial colonization on implanted PTFE grafts after 24 h. In vitro cytotoxicity and preliminary whole blood compatibility assessments further showed acceptable biosafety under low-dose conditions. A single animal porcine pilot implantation did not reveal obvious adverse findings based on postoperative ultrasound, serum biochemical assessment, and histopathological examination. Taken together, these findings suggest that the mechanically flexible 3D-printed nano-silver membrane represents a promising physically wrappable antibacterial platform for PTFE vascular grafts. Further studies are warranted to evaluate long term fixation stability, silver release kinetics, hemocompatibility, and efficacy in clinically relevant vascular graft infection models.