Encapsulating cells within microfibers allows for immobilization with a high degree of spatial-temporal control. Furthermore, microfluidic encapsulation allows for the continuous creation of tunable fibers using mild, cell-friendly gelation conditions, making it advantageous over other fabrication methods. Mouse astrocyte cells (MACs) encapsulated within microfluidically produced alginate fibers had a 24 h survival rate of up to 89%, with up to 60% of cells surviving 11 days of encapsulation. The Young’s modulus values of both dry and wet fibers were found to be within the range of 400 and 17 000 MPa for dry fibers and 20 and 90 MPa for wet fibers and wet cell-encapsulated fibers. Porosities between 12% and 92% were achieved.

Microfluidically manufacturing graphene-alginate microfibers create possibilities for encapsulating rat neural cells within conductive 3D tissue scaffolding to enable the creation of real-time 3D sensing arrays with high physiological relavancy. Cells are encapsulated using the biopolymer alginate, which is combined with graphene to create a cell-containing hydrogel with increased electrical conductivity. Resulting novel alginate-graphene microfibers showed a 2.5-fold increase over pure alginate microfibers, but did not show significant differences in size and porosity. Cells encapsulated within the microfibers survive for up to 8 days, and maintain ∼20% live cells over that duration. The biocompatible aqueous graphene suspension used in this investigation was obtained via liquid phase exfoliation of pristine graphite, to create a graphene-alginate pre-hydrogel solution.