Methocel

A hydrogel composed of 1.5% SeaPrep (Lonza) agarose and 7.0% Methocel (Dow Chemical) methylcellulose was created in a manner similar to that of Martin et al.²⁸ (link) Electrospun fibers as produced in the preceding sections were dispersed into the hydrogel matrix by first removing the PVA film with fibers from the coverglass substrate, cutting the samples perpendicular to fiber alignment into 1.0 mm wide strips, and dissolving the PVA substrate overnight in water. The solution was passed through 22 gauge and then 26 gauge needles by a 1mL syringe to disrupt the fiber strips. A 0.45 μm microcentrifuge filter was used to isolate the fibers from the PVA solution. The fibers were washed with deionized water to remove the residual PVA and then sterilized by 80% ethanol for 15 minutes before subsequent centrifugation. The dry, sterilized fibers were then removed from the filter membrane, placed onto 500 μL of hydrogel in a 2.0 mL microcentrifuge tube (10 coverslips of fibers for high density and 5 for low density), drawn into a 1 mL slip-tip syringe with the needle removed, and forcefully dispensed back into the microcentrifuge tube multiple times to disperse the fibers throughout the gel. Each sample was then passed through a 26 g needle to ensure full dispersion. All samples were kept on ice until the point of application.