title: Cellular uptake and dynamics of unlabeled freestanding silicon nanowires.
abstract: The ability to seamlessly merge electronic devices with biological systems at the cellular length scale is an exciting prospect for exploring new fundamental cell biology and in designing next-generation therapeutic devices. Semiconductor nanowires are well suited for achieving this goal because of their intrinsic size and wide range of possible configurations. However, current studies have focused primarily on delivering substrate-bound nanowire devices through mechanical abrasion or electroporation, with these bulkier substrates negating many of the inherent benefits of using nanoscale materials. To improve on this, an important next step is learning how to distribute these devices in a drug-like fashion, where cells can naturally uptake and incorporate these electronic components, allowing for truly noninvasive device integration. We show that silicon nanowires (SiNWs) can potentially be used as such a system, demonstrating that label-free SiNWs can be internalized in multiple cell lines (96% uptake rate), undergoing an active "burst-like" transport process. Our results show that, rather than through exogenous manipulation, SiNWs are internalized primarily through an endogenous phagocytosis pathway, allowing cellular integration of these materials. To study this behavior, we have developed a robust set of methodologies for quantitatively examining high-aspect ratio nanowire-cell interactions in a time-dependent manner on both single-cell and ensemble levels. This approach represents one of the first dynamic studies of semiconductor nanowire internalization and offers valuable insight into designing devices for biomolecule delivery, intracellular sensing, and photoresponsive therapies.
authors.affiliation: Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
authors.forename: John F
authors.identifier: 0000-0003-4099-8699
authors.initials: JF
authors.lastname: Zimmerman
authors.affiliation: Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Ramya
authors.initials: R
authors.lastname: Parameswaran
authors.affiliation: Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Graeme
authors.identifier: 0000-0002-6503-9294
authors.initials: G
authors.lastname: Murray
authors.affiliation: Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.; The CAS Key Laboratory of Innate Immunity and Chronic Diseases, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Yucai
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Michael
authors.identifier: 0000-0003-2472-7389
authors.initials: M
authors.lastname: Burke
authors.affiliation: Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Bozhi
authors.initials: B
authors.lastname: Tian
keywords: active transport; dynamics; intracellular; phagocytosis; silicon nanowires