Distinctive glial and neuronal interfacing on nanocrystalline diamond

• Published in: PloS one Vol. 9; no. 3; p. e92562
• Main Authors: Bendali, Amel, Agnès, Charles, Meffert, Simone, Forster, Valérie, Bongrain, Alexandre, Arnault, Jean-Charles, Sahel, José-Alain, Offenhäusser, Andreas, Bergonzo, Philippe, Picaud, Serge
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 24-03-2014; Public Library of Science (PLoS)
• Subjects: Animal tissues; Animals; Applied physics; Axons; Biocompatibility; Biocompatible Materials - chemistry; Biocompatible Materials - pharmacology; Bioengineering; Biological products; Biology and Life Sciences; Biomaterials; Biomedical materials; Cell culture; Cell survival; Cell Survival - drug effects; Coatings; Diamond - chemistry; Diamond - pharmacology; Diamond films; Diamonds; Electric contacts; Electric Stimulation; Electrical stimuli; Electrodes; Engineering and Technology; Engineering Sciences; Firing pattern; Glial cells; Laboratories; Life Sciences; Materials Testing; Micro and nanotechnologies; Microelectronics; Nanocrystals; Nanoparticles; Neural networks; Neuroglia - cytology; Neuroglia - drug effects; Neuronal-glial interactions; Neurons; Physical Sciences; Prostheses; Prostheses and implants; Prosthetics; Proteins; Rats; Research and Analysis Methods; Retina; Retinal ganglion cells; Retinal Ganglion Cells - cytology; Retinal Ganglion Cells - drug effects; Sensors; Spectrum analysis; Stem cells; Stimulation; Survival; Transplants & implants; Visual stimuli; France; glial cells; diamond; Nanodiamond; visual prosthesis; biocompatibility; thin film; retinal ganglion cells; electrode-neuron interface; biomaterials; instrumentation; protein coating
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0092562

Direct electrode/neuron interfacing is a key challenge to achieve high resolution of neuronal stimulation required for visual prostheses. Neuronal interfacing on biomaterials commonly requires the presence of glial cells and/or protein coating. Nanocrystalline diamond is a highly mechanically stable biomaterial with a remarkably large potential window for the electrical stimulation of tissues. Using adult retinal cell cultures from rats, we found that glial cells and retinal neurons grew equally well on glass and nanocrystalline diamond. The use of a protein coating increased cell survival, particularly for glial cells. However, bipolar neurons appeared to grow even in direct contact with bare diamond. We investigated whether the presence of glial cells contributed to this direct neuron/diamond interface, by using purified adult retinal ganglion cells to seed diamond and glass surfaces with and without protein coatings. Surprisingly, these fully differentiated spiking neurons survived better on nanocrystalline diamond without any protein coating. This greater survival was indicated by larger cell numbers and the presence of longer neurites. When a protein pattern was drawn on diamond, neurons did not grow preferentially on the coated area, by contrast to their behavior on a patterned glass. This study highlights the interesting biocompatibility properties of nanocrystalline diamond, allowing direct neuronal interfacing, whereas a protein coating was required for glial cell growth.