Spontaneous Differentiation of Human Neural Stem Cells on Nanodiamonds

The potential use of stem cells in regenerative medicine requires the ability to be able to control stem cell fate as cellular networks are developed. Here, nanodiamonds (≈10 nm) are supported on glass and shown to be an excellent host for the attachment and proliferation of human neural stem cells. Moreover, it is shown that spontaneous differentiation into neurons occurs on nanodiamonds. The use of variously oxygen terminated and hydrogen terminated nanodiamonds has been explored. It is shown that O-ND monolayers promote the differentiation of human neural stem cells into neurons with increased total neurite length, degree of branching, and density of neurites when compared with H-NDs or the glass control. The total number of neurites and total neurite length expressing MAP2, a protein enriched in dendrites, is over five times higher for spontaneously differentiated neurones on the O-NDs compared to the control. The fact that inexpensive nanodiamonds can be attached through simple sonication from water on 2D and 3D shapes indicates significant promise for their potential as biomaterials in which neuro-regenerative diseases can be studied.