Ph.D Thesis

Ph.D StudentPeer Elad
SubjectNano-Injectors for Cells
DepartmentDepartment of Nanoscience and Nanotechnology
Supervisors PROF. Uri Sivan
PROF. Lior Gepstein
Full Thesis textFull thesis text - English Version


We present a novel hollow nano-needle array (NNA) device capable of delivering diverse cargo into specific cells in a culture over prolonged periods. A new high throughput method enabling the fabrication of hollow nanostructures is employed to produce large arrays of high-aspect-ratio silica nanoneedles fed by a common reservoir. The content of the reservoir can be replenished and modified in real time while maintaining contact with the same cells.The NNA, albeit its sub-micrometer features, is fabricated in a silicon-on-insulator wafer using conventional, large scale, silicon technology.

3T3-NIH Fibroblast cells and HEK293 human embryonic kidney cells are shown to grow and proliferate successfully on theNNAs.Cargo delivery from the reservoir through the needles to specific cells in the culture is demonstrated by repeated administration of fluorescently labeled dextran to the same cells and transfection with DNA coding for Red Fluorescent Protein.  This is achieved by combining the mechanical effects of these nanoneedles on the cells' membrane with localized concentrations of the reagent saponin.

The capabilities demonstrated by the NNA device open the door to large scale studies of the effect of individual cells on their environment as encountered, for instance, in the study of cell-fate decisions, the role of cell-autonomous versus non-autonomous mechanisms in developmental biology, and in the study of excitable cell-networks.