Dependence of Filopodia Morphology and the Separation Efficiency of Primary CD4⁺ T-Lymphocytes on Nanopillars

Abstract

Despite significant improvement in separation efficiency using nanostructure-based platforms, the mechanism underlying the high efficiency of rare cell capture remains elusive. Here we report on the first mechanistic study by developing highly controlled nanostructures to investigate cell surface nanomorphology to better understand the cellular response of CD4(+) T-lymphocytes in contact with nanostructured surfaces and to elucidate key mechanisms for enhancing separation efficiency. Our results showed that actin-rich filopodia protruded from T-cells in the early stage of cell capture (<20 min), demonstrate the different morphologies in response to various quartz nanopillar (QNP) arrays functionalized with streptavidin and the generation of sufficient adhesion sites for rendering more stable binding through three-dimensional local nanotopographic interactions between filopodia-QNPs and cell-substrate, leading to synergistic effects for enhancing cell-capture efficiency. This responsive mechanism of T-cells on nanotopographic templates provides new insights to understand the enhanced cell-capture efficiency and specificity from the primary cell suspension on nanostructured substrates.

Effect of graphene oxide ratio on the cell adhesion and growth behavior on a graphene oxide-coated silicon substrate

“…Nanostructures such as nanowires, nanopillars, and nanoholes are known to improve cell-capture efficiency by ~20% as reported previously 5 6 7 . This improvement is mainly due to enhanced cell adhesion to nanostructures with higher cell adhesion forces on the surface 6 8 9 10 11 . In addition, cell morphology on nanostructured surfaces can be characterized by the number of filopodia and their morphology 6 9 .…”

Microfabricated Systems and Assays for Studying the Cytoskeletal Organization, Micromechanics, and Motility Patterns of Cancerous Cells

“…Filopodia are thin (0.1 to 0.3 µm), [109] linear, actin-rich protrusive structures [110] which function as directional sensors and have been shown to be prominent in highly metastatic cells. [111] Although filopodia can emerge from the lamellipodial actin network, these finger-like protrusions are thought to be initiated by the actin nucleating for mins rather than Arp 2/3.…”

“…[105–106] To date, substrates displaying micro- and nano-topographical features have been used to study filopodia structures formed by fibroblasts, [105,107] neurons, [106] microglia, [108] and leading endothelial cells during angiogenic sprouting of vessels, [109] and for capturing low-abundance cells from the bloodstream. [110] Some key examples are discussed in Section 6.3.2.…”

“…[106] The “topographical preference” of nanofibrillar substrates (displaying nanopillars, nanowires or nanotexture) may be a possible mechanism accounting for the successful use of such substrates in capturing of low abundance circulating tumor cells (CTC) from cancer patients’ blood. [110] …”

Electrochemiluminescence of a Vinyl‐Functionalized Ruthenium Complex and Its Monolayer Formed through the Photoinduced Thiol‐Ene Click Reaction

“…So they have been widely used as detectors in flow injection analysis (FIA), liquid chromatography (LC) and capillary electrophoresis (CE). [4] A variety of methods have been developed for immobilization of ECL probes, such as Langmuir-Blodgett technique, [5] self-assembly method, [6] electrodeposition, [7] elec-trostatic interaction [8] and physical adsorption. [9] However, leakage of ECL probes from sensor surface has remained to be a technical issue of concern.…”