Electrospun Tubular Scaffold for Stenting Application: A Proof of Concept

Abstract

Bioresorbable Stents (BRS) offer enormous potential, however they must accomplish some specific requirements such as: (I) their manufacturing process must be precise; (II) degradation should have minimal toxicity; (III) their degradation rate should match the recovery rate of vascular tissue; (IV) ideally, they should induce rapid endothelialization to restore the functions of vascular tissue, but at the same time reduce the risk of restenosis; and (V) their mechanical behavior should comply with the medical requirements. With the recent inclusion of polymeric materials and additive manufacturing technologies, a new idea makes its way, Electrospun Tubular Scaffolds (ETS) for stenting process. Unlike current stents, ETS can present some advances (I) Longitudinal flexibility to help the placement of the stent, (II) Material matrix that mimic body tissue to help the rapid endothelization. The present work aims to study the feasibility of this new idea by analyzing how the electrospinning (ES) parameters affect the ETS properties. ETS were fabricated with a Rotational Electrospinning Machine. Poly (ε-caprolactone) (PCL) and Acetone were chosen as biopolymer and non-toxic solvent respectively. Electrospinning Voltage (Ev), Flow Rate (Fr), Polymer Concentration (PCL%), and Target Volume (Tv) were analyzed on the final ETS properties, namely, ETS Thickness (TK), ETS Maxim Radial Expansion (Mø), ETS Recoil Ratio (Rø). ETS thickness were measured by micrometer. Finally ETS radial behavior was studied by Radial Tests. Target Volume proved to be one of the most important parameter to obtain different ETS thickness, while Flow Rate and PCL Concentration has been the most important parameters to obtain a uniform ETS both longitudinally as radially. Regarding the radial behavior, ETS has proved their dependence of the fiber diameter obtained during the ES process. ETS have been able to expand radially a maximum of 67% with an average recoil ratio of 20% which left the ETS expand at 47%. These results allow us to conclude that ETS for stenting applications could be a possible solution for the current BRS problems.