Coaxial electrospun Ag-NPs-loaded endograft membrane with long-term antibacterial function treating mycotic aortic aneurysm.

Abstract

Endovascular stent-graft has been widely used in the treatment of aortic pathologies. The stent-graft is consisted of two main parts: one is artificial vascular membrane which was used to exclude the lesions, and the other is the nitinol stent skeleton. But the current endograft membrane which was PET or ePTFE has a poor ability to inhibit bacterial colonization, it is not fit for endovascular treatment of mycotic aneurysms, as the infection is prone to progress after endograft implantation. And even after endovascular repair for non-mycotic aortic pathologies, endografts could become infected in short term or in long term, especially for patients with diabetes mellitus or in immune insufficiency conditions. In order to solve the problem that aneurysms cannot resist infection for a long time in clinic, in this study, a kind of silver nanoparticles (Ag-NPs) -loaded endograft membrane was prepared for coating the outer layer of the current stent-graft. The Ag-NPs-loaded membrane adopts coaxial electrospinning technique, with Polycaprolactone (PCL) as the shell, Chitosan (CS), Polyethylene oxide (PEO) and Ag-NPs with broad-spectrum antibacterial effect as the core, forming fibers with core-shell structure. A series of physical and chemical properties and biological properties of the Ag-NPs-loaded membrane were characterized: The formation of the core-shell structure was confirmed by TEM; The drug release experiment revealed that the membrane could effectively control the release rate of Ag-NPs; The bacteriostasis experiment proved that the membrane coating had an obvious inhibitory effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Animal experiments confirmed that the Ag-NPs-loaded membrane is basically non-toxic, has good biocompatibility, and can play an effective antibacterial role in the mycotic aortic aneurysm model in porcine. In conclusion, the Ag-NPs-loaded membrane prepared by coaxial electrospinning had optimal anti-infection function and it realized slow-releasing of Ag-NPs to achieve long-term bacteriostasis. Thus, the Ag-NPs-loaded membrane might have potential in preventing infection progression and treating mycotic aortic aneurysm in endovascular way.