Graphene platform for neural regenerative medicine

Graphene is a material composed of a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice. The unique electrical, optical, thermal, and mechanical properties of graphene are extensively exploited for various applications in electronics, energy, and sensors. Studies also proposed the potential of graphene for biomedical applications. The intrinsic characteristics of graphene and its availability for chemical and physical modifications make graphene a promising vehicle for various biomedical applications including drug delivery, bioimaging, disease diagnostics, etc. The chemical structure of graphene and, in turn, its functionality, can be altered by attaching functional groups, which not only modify the properties of graphene but also allow its conjugation with antibodies, peptides, ligands, contrast agents, drugs, and genes for various biomedical applications (John et al., 2015). Graphene can also be used as a cell-contacting biomaterial for tissue engineering and regenerative medicine. Recent studies have shown that graphene substrates can support the adhesion, proliferation, and differentiation of mesenchymal stem cells (MSCs), induced pluripotent stem cells, and other mammalian cells. Specifically for neural regenerative medicine, graphene has demonstrated that it can perform as an effective culture platform compatible with neural cells and their precursors. Hippocampal cells and neural stem cells (NSCs) cultured on graphene substrates showed significantly enhanced neurogenesis, as assessed by neurite sprouting and neural network formation (Li et al., 2011; Tang et al., 2013). Human MSC growth and its neural differentiation were also supported by graphene culture (Kim et al., 2015). Further, the capability of graphene to electrically stimulate differentiated neuronal cells was demonstrated (Park et al., 2011). The current status of knowledge is that graphene can be conductive/inductive for cellular neurogenesis and may be a promising candidate scaffold material for neural tissue engineering. In this perspective, our group’s series of projects on neural regenerative medicine that exploit unconventional materials, including graphene, and mechanical stimuli will be introduced. Then, potential future directions in the study of graphenebased neural regenerative medicine will be discussed