Research to Address the Limitations of Electrospun Coated Stents: Double-Sided Coating of Stents and Enhancement of Membrane Properties.

Electrospinning is a technology for producing a variety of functional polymer membranes, offering easy incorporation of particles and customizable membrane shapes. Therefore, it is actively studied across diverse fields, from cosmetics to advanced industries such as semiconductors and aerospace. In particular, it is attracting attention for application in the medical field, and research is being conducted for application in various implant fields such as artificial eardrums and artificial blood vessels in the field of tissue regeneration. However, the low mechanical properties and adhesiveness unique to electrospun fibers are obstacles to applying electrospinning technology to artificial conduits or stent coating membranes. Addressing this problem, it is necessary to solve the unique shortcomings of electrospun fibers mentioned above. In this study, a multilayer membrane was manufactured using electrospinning technology and one of the layers was converted into a film to improve the weak physical properties unique to electrospun fibers. In addition, while coating is usually performed only on the outer layer of the stent, in this study, both the inner and outer surfaces of the stent were coated to minimize movement of the stent wire when external stimuli were applied. The electrospun multilayer membrane was heat-treated, converting one layer into a film. This process enhanced interlayer adhesion and significantly improved mechanical properties compared to a membrane composed solely of fibers. In addition, we confirmed that the manufactured covered stent could significantly improve the hoop strength when both the inner and outer surfaces of the stent were coated compared to when only the outer surface of the stent was coated, confirming that the sandwich structure in which the stent wire is positioned between the electrospun film and the fiber can prevent the movement of the stent wire and improve the strength. The multilayer membrane composed of film/fiber developed in this study is expected to be sufficiently utilized in the fields of tissue regeneration and implants in the future because it showed sufficient properties to be used as a stent coating material while improving the shortcomings of existing electrospun fibers.