Low-temperature 3D-printed collagen/chitosan scaffolds loaded with exosomes derived from neural stem cells pretreated with insulin growth factor-1 enhance neural regeneration after... oleh Xiao-Yin Liu, Yin-He Feng, Qing-Bo Feng, Jian-Yong Zhang, Lin Zhong, Peng Liu, Shan Wang, Yan-Ruo Huang, Xu-Yi Chen, Liang-Xue Zhou