Biomimetic Dextran-Based Hydrogel Layers for Cell Micropatterning over Large Areas Using the FluidFM BOT Technology

Abstract

Micropatterning of living single cells and cell clusters over millimeter–centimeter scale areas is of high demand in the development of cell-based biosensors. Micropatterning methodologies require both a suitable biomimetic support and a printing technology. In this work, we present the micropatterning of living mammalian cells on carboxymethyl dextran (CMD) hydrogel layers using the FluidFM BOT technology. In contrast to the ultrathin (few nanometers thick in the dry state) CMD films generally used in label-free biosensor applications, we developed CMD layers with thicknesses of several tens of nanometers in order to provide support for the controlled adhesion of living cells. The fabrication method and detailed characterization of the CMD layers are also described. The antifouling ability of the CMD surfaces is demonstrated by in situ optical waveguide lightmode spectroscopy measurements using serum modeling proteins with different electrostatic properties and molecular weights. Cell micropatterning on the CMD surface was obtained by printing cell adhesion mediating cRGDfK peptide molecules (cyclo­(Arg-Gly-Asp-d-Phe-Lys)) directly from aqueous solution using microchanneled cantilevers with subsequent incubation of the printed surfaces in the living cell culture. Uniquely, we present cell patterns with different geometries (spot, line, and grid arrays) covering both micrometer and millimeter–centimeter scale areas. The adhered patterns were analyzed by phase contrast microscopy and the adhesion process on the patterns was real-time monitored by digital holographic microscopy, enabling to quantify the survival and migration of cells on the printed cRGDfK arrays.

Single-cell adhesion force kinetics of cell populations from combined label-free optical biosensor and robotic fluidic force microscopy

“…In order to reach the whole sensor surface, robotic fluidic force microscopy (FluidFM BOT), a novel AFM-based force spectroscopy tool was used. This technique allows for the positioning of the probe over large, mm-cm scale areas 65 . The force measurement is executed according to the AFM principle and a fluidic channel with a circular aperture incorporated into the cantilever is responsible for fixing the cell to the end of the cantilever 18,[66][67][68][69] .…”

A practical review on the measurement tools for cellular adhesion force

“…It can be used for printing of 2D surface patterns with various formations [186] or for precisely controlled template-free 3D micro-and nanoprinting [187], [188]. Micropatterning of living mammalian cells on carboxymethyl-dextran (CMD) hydrogel layers was presented using the FluidFM BOT technology [182].…”

“…This novel technique can both mechanically manipulate living cells and microinject biochemical reagents into them [181]. The whole FluidFM BOT system involved an inverted optical microscope [182].…”

Dissociation Constant of Integrin-RGD Binding in Live Cells from Automated Micropipette and Label-Free Optical Data

“…The principal binding target of integrins is the arginine-glycine-aspartic acid (RGD) tripeptide motif, which is present on numerous extracellular matrix (ECM) proteins, such as laminin and fibronectin. Artificial polymers containing the RGD motif have been employed with great success to precisely tailor the cell adhesion properties of surfaces [4][5][6]. The ability of cells to spread and actively adhere to a substrate depends on the two-dimensional RGD density [7] and patterning [8].…”