Crosstalk between PC12 cells and endothelial cells in an artificial neurovascular niche constructed by a dual-functionalized self- assembling peptide nanofiber hydrogel

The coordination between neurogenesis and angiogenesis plays an important role in nerve tissue development and regeneration. Recently, using bioactive materials to drive neurogenic and angiogenic responses has gained increasing attention. Understanding the neurovascular link between regulatory cues offers valuable insight into the mechanisms underlying nerve regeneration and the design of new bioactive materials. In this study, we utilized a dual-functionalized peptide nanofiber hydrogel presenting the brain- derived neurotrophic factor and vascular endothelial growth factor mimetic peptides RGIDKRHWNSQ (RGI) and KLTWQELYQLKYKGI (KLT) to construct an artificial neurovascular microenvironment. The dual-functionalized peptide nanofiber hydrogel enhanced the neurite outgrowth of pheochromocytoma (PC12) cells and tube-like structures formation of human umbilical vein endothelial cells (HUVECs) in vitro, and promoted rapid lesion infiltration of neural and vascular cells in a rat brain injury model. Using indirect co-culture models, we found that the dual-functionalized peptide hydrogel effectively mediated neurovascular crosstalk by regulating secretion of paracrine factors from PC12 cells and HUVECs. When the two cells types were directly co-cultured on the dual-functionalized peptide hydrogel, the efficiency of cell–cell communication was enhanced, which further accelerated the differentiation and maturation of PC12 cells with an increased number of pseudopodia and spread morphology, and HUVECs tube-like structure formation. In summary, the dual-functionalized peptide nanofiber hydrogel successfully formed an artificial neurovascular niche to directly regulate the behaviors of neural and vascular cells and promote their neurovascular crosstalk through paracrine signaling and direct cell–cell contact.