Differential patterning of neuronal, glial and neural progenitor cells on phosphorus-doped and UV irradiated diamond-like carbon

Diamond-like carbon (DLC) is an attractive biomaterial for coating human implantable devices. Our particular research interest is in developing DLC as a coating material for implants and electrical devices for the nervous system. We previously reported that DLC is not toxic to N2a neuroblastoma cells or primary cortical neurons and showed that phosphorus-doped DLC (P:DLC) could be used to produce patterned neuron networks. In the present study we complement and extend these findings by exploring patterning of dorsal root ganglion (DRG) explants, human neural progenitor cells (hNPC) and U-87 astroglioma cells on P:DLC. Further P:DLC data is provided to highlight that P:DLC can be used as an effective coating material for in vitro multi-electrode arrays (MEAs) with potential for patterning groups of neurons on selected electrodes. We also introduce ultraviolet (UV) irradiation as a simple treatment to render DLC neurocompatible. We show that UV:DLC can be used to support patterned and unpatterned cortical neuron growth. These findings strongly support the use of DLC as tailorable and tuneable substrate to study neural cell biology in vitro and in vivo. We conclude that DLC is a well-suited candidate material for coating implantable devices in the human nervous system.