Robust Anisotropic Cellulose Hydrogels Fabricated via Strong Self-aggregation Forces for Cardiomyocytes Unidirectional Growth

The
development of a facile and fast method to construct anisotropic
hydrogels with the ability to induce unidirectional growth of cells
remains challenging. In this work, we demonstrated anisotropic cellulose
hydrogels (ACHs) that are composed of nanoscale aligned nanofibers
by dissolving cotton liner pulp in alkali/urea aqueous solution.
On the basis of directionally controlling the architecture of cellulose
chains with a facial prestretching strategy in chemical gel state
and locking the highly ordered nanostructure through the formation
of close physical networks via strong self-aggregation forces among
neighboring cellulose nanofibers, ACHs, combing with a long-range
aligned structure, entirely differential mechanical performances along
the parallel and perpendicular directions of the hydrogel orientation
and optical birefringence, were constructed. The aggregation of hydrogen
bonds in anisotropic and isotropic hydrogels are of significant difference,
confirmed by nuclear magnetic resonance technology. Importantly, ACHs
with microgroove-like structure promote the adhesion and orientation
of cardiomyocytes. Our work demonstrated the bottom-up fabrication
of polysaccharide-based hydrogels with anisotropic structure and properties,
paving the way to potentially apply them in cardiomyocytes in vitro
culture system.