Photocurable liquid crystal hydrogels with different chargeability and tunable viscoelasticity based on chitin whiskers.

We develop a kind of photocurable liquid crystal hydrogels with bone extracellular matrix (ECM)-like liquid crystal state and viscoelasticity, as well as different chargeability. First, positively charged chitin whiskers (CHWs) and negatively charged maleic anhydride chitin whiskers (mCHWs) were prepared, which further self-assemble to form chiral nematic liquid crystals under ultrasonic treatment, respectively. Subsequently, poly (ethylene glycol) diacrylate (PEGDA) and photo initiator were added, and then two kinds of liquid crystal hydrogels with bone ECM-like viscoelasticity and different chargeability were prepared under ultraviolet (UV) irradiation. Benefiting from the bone ECM-like liquid crystal state and viscoelasticity, the prepared liquid crystal hydrogels exhibit remarkable cell affinity and osteogenic ability. Moreover, the liquid crystal hydrogel with negatively charged mCHWs is more favorable for cell adhesion, spreading and osteogenic differentiation than that with positively charged CHWs. This work provides a promising strategy to prepare the hydrogels with bone ECM-like liquid crystal properties and viscoelasticity for bone repair.