Electrospinning for cell fiber fabrication: effects of process parameters on fiber quality

Abstract

There is growing interest in cell-encapsulated fibers (“cell fibers”) for regenerative biology and medicine. In tissue engineering, cell fibers can be used to fabricate biomimetic cell-scaffold constructs for enhancing human body tissue regeneration. Continuous generation of cell-laden hydrogel fibers is shown recently. In this study, coaxial electrospinning (coaxial-ES) was investigated for continuously fabricating structurally stable hydrogel cell fibers. Using coaxial-ES, fibroblasts (1×105~1×106 cells/mL in final fibers) were encapsulated in crosslinked alginate hydrogel fibers. In coaxial-ES, inner capillary of coaxial spinneret was fed with a blended liquid made by mixing a fibroblast suspension (in PBS; at different cell densities) and a sodium alginate (Na-alginate) aqueous solution and outer capillary was fed with a CaCl2 aqueous solution for crosslinking Na-alginate to Ca-alginate hydrogel during coaxial-ES. The applied voltage in coaxial-ES was kept low (1~3 kV) to achieve high cell viability and properties. At 1, 2 and 3 kV voltages, cell fibers had diameters of 500, 400 and 350 nm and exhibited smooth fiber structure. Cells were generally evenly distributed in cell fibers. Using parameters outside optimal conditions, either cell fibers could not be continuously produced or cell fibers did not possess desired properties. In vitro tests revealed high cell viability in fibers.