Electrospun PCL-Based Vascular Grafts: In Vitro Tests.

BACKGROUND: Electrospun fibers have attracted a lot of attention from researchers due to their several characteristics, such as a very thin diameter, three-dimensional topography, large surface area, flexible surface, good mechanical characteristics, suitable for widespread applications. Indeed, electro-spinning offers many benefits, such as great surface-to-volume ratio, adjustable porosity, and the ability of imitating the tissue extra-cellular matrix. METHODS: we processed Poly ε-caprolactone (PCL) via electrospinning for the production of bilayered tubular scaffolds for vascular tissue engineering application. Endothelial cells and fibroblasts were seeded into the two side of the scaffolds: endothelial cells onto the inner side composed of PCL/Gelatin fibers able to mimic the inner surface of the vessels, and fibroblasts onto the outer side only exposing PCL fibers. Extracellular matrix production and organization has been performed by means of classical immunofluorescence against collagen type I fibers, Scanning Electron-Microscopy (SEM) has been performed in order to evaluated ultrastructural morphology, gene expression by means gene expression has been performed to evaluate the phenotype of endothelial cells and fibroblasts. RESULTS AND CONCLUSION: results confirmed that both cells population are able to conserve their phenotype colonizing the surface supporting the hypothesis that PCL scaffolds based on electrospun fibers should be a good candidate for vascular surgery.

Highly polydisperse keratin rich nanofibers: Scaffold design and in vitro characterization.

The use of bioactive proteins such as keratin has been successfully explored to improve the biological interface of scaffolds with cells during the tissue regeneration. In this work, it is optimized the fabrication of nanofibers combining wool keratin extracted by sulfitolysis, with polycaprolactone (PCL) in order to design bicomponent fibrous matrices able to exert a self-adapting pattern of signals-morphological, chemical, or physical-confined at the single fiber level, to influence cell and bacteria interactions. It is demonstrated that the blending of highly polydisperse keratin with PCL (50:50) improves the stability of the electrospinning process, promoting the formation of nanofibers-144.1 ± 43.9 nm-without the formation of defects (i.e., beads, ribbons) typically recognized in the fabrication of keratin ones. Moreover, keratin drastically increases the fiber hydrophilicity-compared with PCL fiber alone-thus improving the hMSC adhesion and in vitro proliferation until 14 days. Moreover, the growth of bacterial strains (i.e., Escherichia coli and Staphylococcus aureus) seems to be not specifically inhibited by the contribution of keratin, so that the integration of further selected compounds (i.e., metal ions) is suggested to more efficiently fight against bacteria resistance, to make them suitable for the regeneration of different interfaces and soft tissues (i.e., skin and cornea). © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1803-1813, 2019.