Fabrication of core-shell structured nanofibers of poly (lactic acid) and poly (vinyl alcohol) by coaxial electrospinning for tissue engineering

Poly Lactic Acid (PLA) nanofiber scaffold has enjoyed great interest as a candidate bioactive material for tissue regeneration. However, the hydrophobic nature of PLA and its weak mechanical properties with poor ductility and low strength hinder its practical applications. In this study, coaxial electrospinning was used to fabricate core-shell composite nanofibers with PLA in the core and PVA in the shell with significant enhancements in the surface wetting and mechanical properties. More specifically, the core/shell-structured PLA/PVA nanofiber mat exhibited excellent hydrophilic properties with a water contact angle of 27 ± 1.5° compared to 110° ± 2.5° for pristine PLA. Moreover, the fabricated composite nanofibers displayed nearly 254% and 175% increase in tensile strength and strain at failure, respectively, compared to pristine PLA (14.5 MPa vs. 4.1 MPa for tensile strength and 110% vs. 40% for ductility). The coaxial electrospun PLA(core)/PVA(shell) nanofibers also showed suitable properties for proliferation, and attachment of human embryonic kidney cells (HEK-293). These excellent combined mechanical, surface wetting, and cytocompatibility properties clearly demonstrate the potential applications of the synthetic core-shell PLA/PVA composite nanofibers in biomedical and tissue regeneration.