Use of precisely sculptured thin film (STF) substrates with generalized ellipsometry to determine spatial distribution of adsorbed fibronectin to nanostructured columnar topographies and effect on cell adhesion

Abstract

Sculptured thin film (STF) substrates consist of nanocolumns with precise orientation, intercolumnar spacing, and optical anisotropy, which can be used as model biomaterial substrates to study the effect of homogenous nanotopogrophies on the three-dimensional distribution of adsorbed proteins. Generalized ellipsometry was used to discriminate between the distributions of adsorbed FN either on top of or within the intercolumnar void spaces of STFs, afforded by the optical properties of these precisely crafted substrates. Generalized ellipsometry indicated that STFs with vertical nanocolumns enhanced total FN adsorption two-fold relative to flat control substrates and the FN adsorption studies demonstrate different STF characteristics influence the degree of FN immobilization both on top and within intercolumnar spaces, with increasing spacing and surface area enhancing total protein adsorption. Mouse fibroblasts or mouse mesenchymal stem cells were subsequently cultured on STFs, to investigate the effect of highly ordered and defined nanotopographies on cell adhesion, spreading, and proliferation. All STF nanotopographies investigated in the absence of adsorbed FN were found to significantly enhance cell adhesion relative to flat substrates; and the addition of FN to STFs was found to have cell-dependent effects on enhancing cell-material interactions. Furthermore, the amount of FN adsorbed to the STFs did not correlate with comparative enhancements of cell-material interactions, suggesting that nanotopography predominantly contributes to the biocompatibility of homogenous nanocolumnar surfaces. This is the first study to correlate precisely defined nanostructured features with protein distribution and cell-nanomaterial interactions. STFs demonstrate immense potential as biomaterial surfaces for applications in tissue engineering, drug delivery, and biosensing.

A Full Vacuum Approach for the Fabrication of Hybrid White‐Light‐Emitting Thin Films and Wide‐Range In Situ Tunable Luminescent Microcavities

“…The white emission is obtained by incorporation of two photoluminescent small molecules, a blue (1,3,5‐triphenyl‐2‐pyrazoline TPP) and an orange (Rubrene) emitter (see chemical structure in Figure a) by physical vapor deposition (PVD) using as host a SiO 2 thin film fabricated by glancing angle vacuum deposition (GLAD). This type of films offers unique host possibilities for the incorporation of active molecules, metal nanoparticles, or quantum dots for the fabrication of photonic gas sensors, information encoding or biodetectors . In most of these applications the incorporation of the photonic or functional active component(s) requires the intervention of wet chemical processes .…”

“…SiO 2 GLAD thin films were prepared on fused silica and silicon substrates by electron evaporation at zenithal angles, α , of 70° and 80° . In the standard conditions, a typical distance of 80 cm separates the evaporation crucible and the substrate.…”

The retention of liquid by columnar nanostructured surfaces during quartz crystal microbalance measurements and the effects of adsorption thereon

“…5 for the smaller overtones. Future work may vary SCTF spacing, for example, via surface pre-patterning [64,65] or pre-roughening methods [28], to determine if there is a limit for nanostructure proximity to retain all liquid within the SCTF. Other nanostructure geometries, such as chevrons, staircases, helices, screws, and vertical posts, could also be evaluated.…”

“…SCTFs have many advantages over flat surfaces; SCTFs have increased surface area, have spatial dimensions that may be controlled by their fabrication process [23,24,29], may act as molecular filters or storage [27,28], have strongly anisotropic optical properties for sensor applications [26,30,31], provide improved biocompatibility with cells due to their topography [25,28], and may be fabricated from materials that result in films exhibiting the surface-enhanced Raman scattering (SERS) effect [32].…”

“…Three-dimensional (3D) spatially coherent nanostructured films, such as slanted columnar thin films (SCTFs) produced by glancing angle deposition (GLAD) [23,24], are emerging as scaffolding materials upon which adsorption processes may be evaluated [25][26][27][28]. SCTFs have many advantages over flat surfaces; SCTFs have increased surface area, have spatial dimensions that may be controlled by their fabrication process [23,24,29], may act as molecular filters or storage [27,28], have strongly anisotropic optical properties for sensor applications [26,30,31], provide improved biocompatibility with cells due to their topography [25,28], and may be fabricated from materials that result in films exhibiting the surface-enhanced Raman scattering (SERS) effect [32].…”