Cellulose acetate core–shell structured electrospun fiber: fabrication and characterization

This study explored the effect of type of core fluids on the fabrication of hollow and core–sheath cellulose acetate (CA) fiber. Tailoring the CA fiber with desirable features such as reinforced core, porous and hollow structure provides unique features for use in various applications. Fibers with such characteristics can be used for better controlled release drug delivery system or to promote cell adhesion in tissue engineering. Type of core material, tensile strength, and rheological properties were evaluated. DSC and FTIR analysis were performed to confirm the presence of core and sheath components. CA hollow structures were successfully obtained after selectively extracting the mineral oil. CA hollow fibers were twice the size of solid fiber despite similar solution and process conditions. Fiber morphologies indicated incomplete encapsulation by the CA when 80 kDa PCL molecular weight was used. This problem was not observed with 43 and 10 kDa PCL. DSC and FTIR analyses showed presence of both PCL and CA components. The rheology results suggest that the fibers could be formed when the viscosity of the core is less than that of sheath. Hydrated CA–43 kDa PCL fibers showed nearly ten-fold improvement in break point and stiffness. Human umbilical vein endothelial cells showed increased attachment and viability in both hollow CA and CA–PCL fibers relative to tissue culture plastic.