title: Enhanced Neurite Outgrowth by Intracellular Stimulation.
abstract: Electrical stimulation through direct electrical activation has been widely used to recover the function of neurons, primarily through the extracellular application of thin film electrodes. However, studies using extracellular methods show limited ability to reveal correlations between the cells and the electrical stimulation due to interference from external sources such as membrane capacitance and culture medium. Here, we demonstrate long-term intracellular electrical stimulation of undamaged pheochromocytoma (PC-12) cells by utilizing a vertical nanowire electrode array (VNEA). The VNEA was prepared by synthesizing silicon nanowires on a Si substrate through a vapor-liquid-solid (VLS) mechanism and then fabricating them into electrodes with semiconductor nanodevice processing. PC-12 cells were cultured on the VNEA for 4 days with intracellular electrical stimulation and then a 2-day stabilization period. Periodic scanning via two-photon microscopy confirmed that the electrodes pierced the cells without inducing damage. Electrical stimulation through the VNEA enhances cellular differentiation and neurite outgrowth by about 50% relative to extracellular stimulation under the same conditions. VNEA-mediated stimulation also revealed that cellular differentiation and growth in the cultures were dependent on the potential used to stimulate them. Intracellular stimulation using nanowires could pave the way for controlled cellular differentiation and outgrowth studies in living cells.
authors.forename: Ilsoo
authors.initials: I
authors.lastname: Kim
authors.affiliation: ⊥Department of Neurosurgery, Spine, and Spinal Cord Institute, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea.
authors.forename: Hye Yeong
authors.initials: HY
authors.lastname: Lee
authors.forename: Hyungsuk
authors.initials: H
authors.lastname: Kim
authors.forename: Eungjang
authors.initials: E
authors.lastname: Lee
authors.affiliation: ¶Department of Physics, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Du-Won
authors.initials: DW
authors.lastname: Jeong
authors.affiliation: ¶Department of Physics, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Ju-Jin
authors.initials: JJ
authors.lastname: Kim
authors.forename: Seung-Han
authors.initials: SH
authors.lastname: Park
authors.affiliation: ⊥Department of Neurosurgery, Spine, and Spinal Cord Institute, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea.
authors.forename: Yoon
authors.initials: Y
authors.lastname: Ha
authors.forename: Jukwan
authors.initials: J
authors.lastname: Na
authors.forename: Youngcheol
authors.initials: Y
authors.lastname: Chae
authors.affiliation: ⊥Department of Neurosurgery, Spine, and Spinal Cord Institute, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea.
authors.forename: Seong
authors.initials: S
authors.lastname: Yi
authors.forename: Heon-Jin
authors.initials: HJ
authors.lastname: Choi
keywords: Nanowires electrode; cellular differentiation; enhanced neurite outgrowth; intracellular stimulation