Coaxial Electrospinning of Multicomponent Fiber Membranes for Sustained Oxygen Supply in Hypoxic Environment.

A major challenge for cell and tissue transplantation is providing a sustaining environment for newly transplanted cells and tissues. They require a temporary oxygen source since newly transplanted cells and tissues are not yet connected to the recipient's vascular system. Here we report on core-sheath fiber membranes formed using the coaxial electrospinning process that contain calcium peroxide (CPO) embedded in the fiber core to provide a source of oxygen by diffusion from the fibers over a period of multiple days. Embedding the enzyme catalase in the fiber sheath as a catalyst is found to significantly reduce the production of cytotoxic hydrogen peroxide (H2O2) by ~59% and to increase the overall amount of oxygen released up to ~28% after 4 days of release. CPO-containing PCL/PVP-PEO core-sheath fiber membranes produced enhanced cell viability of > 90% at Day 5 for metabolically active pancreatic beta cell spheroids in a hypoxic environment, while non-CPO control cases resulted in no surviving cells at Day 5. Preliminary investigations with the incorporation of lysozyme as a model protein in the fiber core for eventual growth factor incorporation have yielded promising sustained release of lysozyme up to 10 days.