title: Spontaneous Internalization of Cell Penetrating Peptide-Modified Nanowires into Primary Neurons.
abstract: Semiconductor nanowire (NW) devices that can address intracellular electrophysiological events with high sensitivity and spatial resolution are emerging as key tools in nanobioelectronics. Intracellular delivery of NWs without compromising cellular integrity and metabolic activity has, however, proven difficult without external mechanical forces or electrical pulses. Here, we introduce a biomimetic approach in which a cell penetrating peptide, the trans-activating transcriptional activator (TAT) from human immunodeficiency virus 1, is linked to the surface of Si NWs to facilitate spontaneous internalization of NWs into primary neuronal cells. Confocal microscopy imaging studies at fixed time points demonstrate that TAT-conjugated NWs (TAT-NWs) are fully internalized into mouse hippocampal neurons, and quantitative image analyses reveal an ca. 15% internalization efficiency. In addition, live cell dynamic imaging of NW internalization shows that NW penetration begins within 10-20 min after binding to the membrane and that NWs become fully internalized within 30-40 min. The generality of cell penetrating peptide modification method is further demonstrated by internalization of TAT-NWs into primary dorsal root ganglion (DRG) neurons.
authors.affiliation: Department of Chemistry and Chemical Biology and ‡John A. Paulson School of Engineering and Applied Science, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Jae-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Chemical Biology and ‡John A. Paulson School of Engineering and Applied Science, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Anqi
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Chemical Biology and ‡John A. Paulson School of Engineering and Applied Science, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Siheng Sean
authors.initials: SS
authors.lastname: You
authors.affiliation: Department of Chemistry and Chemical Biology and ‡John A. Paulson School of Engineering and Applied Science, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Lieber
mesh_terms: D000818:Animals; D057846:Cell-Penetrating Peptides / Q000008:administration & dosage* / Q000737:chemistry; D016503:Drug Delivery Systems; D006801:Humans; D051379:Mice; D018613:Microscopy, Confocal; D053770:Nanowires / Q000008:administration & dosage* / Q000737:chemistry; D009474:Neurons / Q000187:drug effects / Q000648:ultrastructure; D061251:Primary Cell Culture; D012666:Semiconductors; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D057846:Cell-Penetrating Peptides; D054322:tat Gene Products, Human Immunodeficiency Virus
keywords: Silicon nanowires; TAT peptide transfection; dorsal root ganglion cells; hippocampal neurons; live cell confocal imaging; membrane penetration; surface modification