title: Near infrared laser stimulation of human neural stem cells into neurons on graphene nanomesh semiconductors.
abstract: Reduced graphene oxide nanomeshes (rGONMs), as p-type semiconductors with band-gap energy of ∼ 1 eV, were developed and applied in near infrared (NIR) laser stimulation of human neural stem cells (hNSCs) into neurons. The biocompatibility of the rGONMs in growth of hNSCs was found similar to that of the graphene oxide (GO) sheets. Proliferation of the hNSCs on the GONMs was assigned to the excess oxygen functional groups formed on edge defects of the GONMs, resulting in superhydrophilicity of the surface. Under NIR laser stimulation, the graphene layers (especially the rGONMs) exhibited significant cell differentiations, including more elongations of the cells and higher differentiation of neurons than glia. The higher hNSC differentiation on the rGONM than the reduced GO (rGO) was assigned to the stimulation effects of the low-energy photoexcited electrons injected from the rGONM semiconductors into the cells, while the high-energy photoelectrons of the rGO (as a zero band-gap semiconductor) could suppress the cell proliferation and/or even cause cell damages. Using conventional heating of the culture media up to ∼ 43 °C (the temperature typically reached under the laser irradiation), no significant differentiation was observed in dark. This further confirmed the role of photoelectrons in the hNSC differentiation.
authors.affiliation: Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran, Iran; Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 14588-89694, Tehran, Iran. Electronic address: oakhavan@sharif.edu.
authors.forename: Omid
authors.initials: O
authors.lastname: Akhavan
authors.affiliation: Nanobiotechnology Research Lab., Division of Advanced Materials, Azadi Ave., Tehran, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Ghaderi
authors.affiliation: Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran, Iran.
authors.forename: Soheil A
authors.initials: SA
authors.lastname: Shirazian
mesh_terms: D002478:Cells, Cultured; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007834:Lasers; D049329:Nanostructures / Q000737:chemistry*; D058953:Neural Stem Cells / Q000166:cytology* / Q000528:radiation effects*; D009474:Neurons / Q000166:cytology* / Q000528:radiation effects*; D010087:Oxides / Q000737:chemistry; D010316:Particle Size; D012666:Semiconductors; D013499:Surface Properties
chemical_list: D010087:Oxides; D006108:Graphite
keywords: Graphene nanomesh; NIR stimulation; Nanostructures; Neural differentiation; Stem cells; Tissue engineering