Polyelectrolyte multilayer-assisted fabrication of non-periodic silicon nanocolumn substrates for cellular interface applications

Abstract

Recent advances in nanostructure-based biotechnology have resulted in a growing demand for vertical nanostructure substrates with elaborate control over the nanoscale geometry and a high-throughput preparation. In this work, we report the fabrication of non-periodic vertical silicon nanocolumn substrates via polyelectrolyte multilayer-enabled randomized nanosphere lithography. Owing to layer-by-layer deposited polyelectrolyte adhesives, uniformly-separated polystyrene nanospheres were securely attached on large silicon substrates and utilized as masks for the subsequent metal-assisted silicon etching in solution. Consequently, non-periodic vertical silicon nanocolumn arrays were successfully fabricated on a wafer scale, while each nanocolumn geometric factor, such as the diameter, height, density, and spatial patterning, could be fully controlled in an independent manner. Finally, we demonstrate that our vertical silicon nanocolumn substrates support viable cell culture with minimal cell penetration and unhindered cell motility due to the blunt nanocolumn morphology. These results suggest that vertical silicon nanocolumn substrates may serve as a useful cellular interface platform for performing a statistically meaningful number of cellular experiments in the fields of biomolecular delivery, stem cell research, etc.

Interfacing Cells with Vertical Nanoscale Devices: Applications and Characterization

“…Diverse types of cells adhere and proliferate (C.-H. Choi et al 2007; Nomura et al 2005; Hu et al 2010) on pillar substrates and spread on high aspect ratio vertical nanostructures while maintaining their physiological activity (S. Lee et al2015).…”

Pattern-Dependent Mammalian Cell (Vero) Morphology on Tantalum/Silicon Oxide 3D Nanocomposites

“…Recent studies have used micro- and nanometer-scale engineered structures to mimic extracellular matrices and other biological structures, which have led to a groundbreaking understanding of the physical cues and molecular signal transduction pathways for integrin activated focal adhesion, protein adsorption, and pseudopodia formation [1,2,3,4,5,6,7,8,9]. Results have shown that cellular responses often depend on the mechanical properties, pattern structures, and surface chemistry of the microenvironment surrounding the cells [1,3,4,5,7,8,10,11,12,13,14,15,16,17,18,19,20]; however, work done thus far has been conducted with structures composed of monolithic materials having uniform surface chemical composition.…”

“…Results have shown that cellular responses often depend on the mechanical properties, pattern structures, and surface chemistry of the microenvironment surrounding the cells [1,3,4,5,7,8,10,11,12,13,14,15,16,17,18,19,20]; however, work done thus far has been conducted with structures composed of monolithic materials having uniform surface chemical composition. Studies of cell behavior on nanocomposite surfaces are limited [1,3,17,18,19,20].…”

What’s Happening on the Other Side? Revealing Nano-Meter Scale Features of Mammalian Cells on Engineered Textured Tantalum Surfaces

“…To understand the mechanisms that drive cell behavior on engineered surfaces, researchers often visually inspect cell surface morphology. However, it could be argued that some of the most important information in determining cell behavior is located on the underbelly of the cell, where the cell meets the substrate [10,18,19]. Are cells that have been observed to float on top of dense pillar patterns [10,18,19,20] or narrowly spaced line structures [21] truly floating?…”

“…However, it could be argued that some of the most important information in determining cell behavior is located on the underbelly of the cell, where the cell meets the substrate [10,18,19]. Are cells that have been observed to float on top of dense pillar patterns [10,18,19,20] or narrowly spaced line structures [21] truly floating? It is known that on widely spaced topographic features, cells wrap around the features [1,13,20,22] thus maximizing their contact.…”