An electroactive hybrid biointerface for enhancing neuronal differentiation and axonal outgrowth on bio-subretinal chip

Retinal prostheses offer viable vision restoration therapy for patients with blindness. However, a critical requirement for maintaining the stable performance of electrical stimulation and signal transmission is the biocompatibility of the electrode interface. Here, we demonstrated a functionalized electrode-neuron biointerface composed of an annealed graphene oxide-collagen (aGO-COL) composite and neuronal cells. The aGO-COL exhibited an electroactive 3D crumpled surface structure and enhanced the differentiation efficiency of PC-12 ​cells. It is integrated into a photovoltaic self-powered retinal chip to develop a biohybrid retinal implant that facilitates biocompatibility and tissue regeneration. Moreover, aGO-COL micropatterns fabricated via 3D bioprinting can be used to create neuronal cell microarrays, which supports the possibility of retaining the high spatial resolution achieved through electrical stimulation of the retinal chip. This study paves the way for the next generation of biohybrid retinal implants based on biointerfaces.