Reprogramming cell shape with laser nano-patterning

Abstract

SummaryCell shape in vitro can be directed by geometrically defined micropatterned adhesion substrates. However conventional methods are limited by the fixed micropattern design, which cannot recapitulate the dynamic changes of the cell microenvironment. Here, we manipulate the shape of living cells in real time by using a tightly focused pulsed laser to introduce additional geometrically defined adhesion sites. The sub-micrometer resolution of the laser patterning allowed us to identify the critical distances between cell adhesion sites required for cell shape extension and contraction. This easy-to-handle method allows the precise control of specific actin-based structures that regulate cell architecture. Actin filament bundles or branched meshworks were induced, displaced or removed in response to specific dynamic modifications of the cell adhesion pattern. Isotropic branched actin meshworks could be forced to assemble new stress fibers locally and polarised in response to specific geometrical cues.

Bidirectional Interplay between Vimentin Intermediate Filaments and Contractile Actin Stress Fibers

“…To overcome this obstacle, we plated control and knockdown cells on crossbow-shaped fibronectin micropatterns, where they display regular morphology and organization of the actin stress fiber networks (Vignaud et al, 2012). By dividing the cells into four segments (from segment 1, the leading edge, to segment 4, the trailing end; see Figure 2B), we could quantify the intensity of vimentin at different cell regions.…”

How cells respond to environmental cues – insights from bio-functionalized substrates

“…Substrates with gradients of adhesive properties (Fig. 2D) or properties that vary in time, such as hydrogel with controlled aging rheological properties (DeForest and Tirrell, 2015;Young and Engler, 2011), or patterns with ondemand adhesion (Rolli et al, 2012;Vignaud et al, 2012) have also been designed (Fig. 2D).…”

“…Spatial gradients or properties that vary over time can also be built in to study directed cell migration (taxis). For instance, patterning with light-induced release of adhesive constraints (Rolli et al, 2012;Vignaud et al, 2012) has been used to study the transition from static to migratory behaviors. Our understanding of migration along gradients of soluble factors (chemotaxis) has benefited from microfluidics, where gradients of soluble factors that are transverse to the direction of microfluidic flow can be created (Chung and Choo, 2010;King et al, 2016;Li Jeon et al, 2002;Toh et al, 2014).…”

Ultraviolet laser patterning of porous silicon

“…Moreover, the optical behavior of nanoPS-based structures (1D, 2D, or 3D) is very sensitive to infiltration 12,13 or adsorption 6 of bio-species into the porous material. Furthermore, surface micro-and nano-patterning is becoming an important means for enhancing the performance of materials such as creating superhydrophobic surfaces with hierarchical meshporous structures, 14 reprogramming the cell shape, 15 or enlarging cell culture harvest. 16 For the particular case of nanoPS, patterns have been used to promote cell binding or growth [9][10][11]17,18 or to produce label-free biosensors, 3,19 the detection mechanism being based on changes either in the photoluminescence spectra or in the diffraction pattern.…”