Influence of different pressure regimes on the properties of an engineered small-diameter vascular scaffold tested in a custom-made bioreactor.

Abstract

Vascular tissue engineering endeavors to design, fabricate, and validate biodegradable and bioabsorbable small-diameter vascular scaffolds engineered with bioactive molecules, capable of meeting the challenges posed by commercial vascular prostheses. A comprehensive investigation of these engineered scaffolds in a bioreactor (BR) is deemed essential as a prerequisite before anyin vivoexperimentation in order to gather information regarding their behavior under physiological conditions and predict the biological activities they may exhibit. This study focuses on an innovative electrospun scaffold made of poly(caprolactone) and poly(glycerol sebacate), integrating quercetin (Q), which is able to modulate inflammation, and gelatin (G), which is necessary to reduce permeability. A custom-made BR was used to assess the performance of the scaffolds maintained under different pressure regimes, covering the human physiological pressure range. As a result, the 3D microfibrous architecture of the scaffolds was notably influenced by the release of bioactive molecules, while retaining the properties required forin vivoregeneration. Furthermore, the scaffolds exhibited mechanical properties comparable to those of native human arteries. The release of Q was effective in counteracting post-surgical inflammation, whereas the amount of released G was adequate to avoid blood leakage and useful to make the material porous during the testing period. This study showcases the successful validation of an engineered scaffold in a BR, supporting its potential as a promising candidate for vascular substitutes inin vivoapplications. Our approach represents a significant leap forward in the field of vascular tissue engineering, offering a multifaceted solution to the complex challenges associated with small-diameter vascular prostheses.