Bioprinting of hydrogel-based bioinks can allow for the
fabrication
of elaborate, cell-laden 3D structures. In addition to providing an
adequate extracellular matrix mimetic environment and high cell viability,
the hydrogels must offer facile extrusion through the printing nozzle
and retain the shape of the printed structure. We demonstrate a strategy
to incorporate cellulose oxalate nanofibrils in hyaluronan-based hydrogels
to generate shear thinning bioinks that allowed for printing of free-standing
multilayer structures, covalently cross-linked after bioprinting,
yielding long-term stability. The storage modulus of the hydrogels
was tunable between 0.5 and 1.5 kPa. The nanocellulose containing
hydrogels showed good biocompatibility, with viability of primary
human dermal fibroblasts above 80% at day 7 after seeding. The cells
were also shown to tolerate the printing process well, with viability
above 80% 24 h after printing. We anticipate that this hydrogel system
can find broad use as a bioink to produce complex geometries that
can support cell growth.