Effects of surface charges of graphene oxide on neuronal outgrowth and branching

Abstract

Graphene oxides with different surface charges were fabricated from carboxylated graphene oxide by chemical modification with amino- (-NH2), poly-m-aminobenzene sulfonic acid- (-NH2/-SO3H), or methoxyl- (-OCH3) terminated functional groups. The chemically functionalized graphene oxides and the carboxylated graphene oxide were characterized by infrared spectroscopy, X-ray photoelectron spectroscopy, UV-Vis spectrometry, ζ potential measurements, field emission scanning electron microscopy, and contact angle analyses. Subsequently, the resulting graphene oxides were used as substrates for culturing primary rat hippocampal neurons to investigate neurite outgrowth and branching. The morphological features of neurons that directly reflect their potential capability in synaptic transmission were characterized. The results demonstrate that the chemical properties of graphene oxide can be systematically modified by attaching different functional groups that confer known characteristics to the substrate. By manipulating the charge carried by the functionalized graphene oxides, the outgrowth and branching of neuronal processes can be controlled. Compared with neutral, zwitterionic, or negatively charged graphene oxides, positively charged graphene oxide was found to be more beneficial for neurite outgrowth and branching. The ability to chemically modify graphene oxide to control neurite outgrowth could be implemented clinically, especially in cases wherein long-term presence of outgrowth modulation is necessary.

Autophagic flux induced by graphene oxide has a neuroprotective effect against human prion protein fragments

“…25 Some studies suggest that GO promotes differentiation of neural stem cells and neural outgrowth. 26,27 Moreover, injection of GO stimulates the immune response and antitumor effects via upregulation of autophagic flux. [13][14][15] However, the effect of GO-mediated autophagy has not yet been defined in neurodegenerative disorders.…”

Influence of polyethylene glycol coating on biodistribution and toxicity of nanoscale graphene oxide in mice after intravenous injection

“…[1][2][3][4][5] As a nascent nanomaterial, NGO exhibits unique size, shape, and physicochemical properties that make it a promising biomaterial for biomedical applications. [6][7][8][9][10] Recently, NGO has been demonstrated to be an effective nanocarrier of anticancer drugs. [11][12][13][14] However, the in vivo distribution and toxicity of NGO, which would provide important supporting information to help determine its feasibility for potential biomedical applications, have rarely been evaluated.…”

Biomaterials control of pluripotent stem cell fate for regenerative therapy

“…On the other hand, CNT is also electrically conductive and nanotubular in morphology which can provide nanotopography as well as electrical conductivity to the substrate. For these reasons, some types of cells that need electrical signals like neural cells have been shown to be stimulated upon the carbon nanomaterials, primarily CNTs and rGO, in their neurite outgrowth (for primary neurons) and neuronal differentiation (for NSCs) [216][217][218][219][220]. On the other hand, GO, even though its low electrical conductivity, has been shown to stimulate the differentiation of other types of progenitor/stem cells, such as the differentiation of MSCs into osteoblasts, MSCs into chondrocytes, and muscle precursor cells into myoblasts [221][222][223][224][225].…”