An injectable, self-healing hydrogel (≈1.5 kPa) is developed for healing nerve-system deficits. Neurosphere-like progenitors proliferate in the hydrogel and differentiate into neuron-like cells. In the zebrafish injury model, the central nervous system function is partially rescued by injection of the hydrogel and significantly rescued by injection of the neurosphere-laden hydrogel. The self-healing hydrogel may thus potentially repair the central nervous system.

No abstract

A major challenge in tissue engineering is to generate a functional microvasculature that ensures proper blood perfusion and connection with surrounding tissues. Strategies such as the incorporation of growth factors have been proposed to induce the growth of new blood vessels into engineered tissue, but limitations remain. Herein a novel chitosan-fibrin (CF)-based self-healing hydrogel with a modulus of~1.2 kPa was developed. The self-healing hydrogel was found to be injectable and to degradẽ 70% in 2 weeks. Vascular endothelial cells seeded in the CF hydrogel were able to form capillary-like structures. Moreover, the injection of the CF hydrogel alone promoted angiogenesis in the perivitelline space of zebrafish and rescued the blood circulation in ischemic hindlimbs of mice. The excellent self-healing and angiogenic capacities of the hydrogel may be associated with the formation of an interpenetrating polymer network structure between chitosan and fibrin. This unique self-healing hydrogel offers new possibilities for future applications to vascular repair.

Thermo-responsive hydrogels of a polyurethane–soy protein hybrid provide unique rheological properties for 3D bioprinting and a biomimetic environment for neural repair.