Successful Regrowth of Retinal Neurons When Cultured Interfaced to Carbon Nanotube Platforms

A shared dream of ophthalmologists, neurologists and bioengineers is to recover sight ability in diseased eyes via coupling retinal cells with artificial devices. In the engineering of ophto-prosthetic devices the material directly exposed to the biological milieu is crucial, it has to guarantee tight contacts between retinal neurons and the interface, while assuring cell survival with physiological network development. Carbon nanotubes have been applied in several areas of nerve tissue engineering and are emerging as a promising material for neuro-interfacing applications, given their outstanding physical properties. In the current work we have tested carbon nanotube ability to interface cultured murine and human retinal neurons. We cultured rat retinal neurons on carbon nanotube substrates and described their morphology and synaptic functions via immunofluorescence microscopy and patch-clamp recordings. In a second set of experiments, we explored viability and morphology of human retinal ganglion cells (RGC) when grown on carbon nanotube substrates. We show here carbon nanotube ability to sustain the proper development of rat neurons and, more importantly, of human RGCs. In addition, patch-clamp recordings on rat retinal cells were functional to demonstrate that carbon nanotubes do not perturb the physiological synaptic activity when compared to controls. This result, strengthen by the shown biocompatibility with human cells and the nanotube well described high electrical conductivity, makes these nanomaterials promising candidates to interface, stimulate or record eye nerve cells.