Supported Lipid Bilayers for the Generation of Dynamic Cell-Material Interfaces.

Supported lipid bilayers (SLB) offer unique possibilities for studying cellular membranes and have been used as a synthetic architecture to interact with cells. Here, the state-of-the-art in SLB-based technology is presented. The fabrication, analysis, characteristics and modification of SLBs are described in great detail.

Photoresponsive Cucurbit[8]uril-Mediated Adhesion of Bacteria on Supported Lipid Bilayers.

In this work, the development of a photoresponsive platform for the presentation of bioactive ligands to study receptor-ligand interactions has been described. For this purpose, supramolecular host-guest chemistry and supported lipid bilayers (SLBs) have been combined in a microfluidic device. Quartz crystal microbalance with dissipation monitoring (QCM-D) studies on methyl viologen (MV)-functionalized oligo ethylene glycol-based self-assembled monolayers, gel and liquid-state SLBs have been compared for their nonfouling properties in the case of ConA and bacteria.

A supramolecular host-guest carrier system for growth factors employing V(H)H fragments.

A supramolecular strategy is presented for the assembly of growth factors employing His6-tagged single-domain antibodies (VHH). A combination of orthogonal supramolecular interactions of β-cyclodextrin (βCD)-adamantyl (Ad) host-guest and N-nitrilotriacetic acid (NTA)-histidine (His) interactions was employed to generate reversible and homogeneous layers of growth factors. A single-domain antibody V(H)H fragment was identified to bind to the human bone morphogenetic protein-6 (hBMP6) growth factor and could be recombinantly expressed in E.

Locked-in biomimetic surface gradients that are tunable in size, density and functionalization.

Tuneable and stable surface-chemical gradients in supported lipid bilayers (SLBs) hold great promise for a range of applications in biological sensing and screening. Yet, until now, no method has been reported that provides temporal control of SLB gradients. Herein we report on the development of locked-in SLB gradients that can be tuned in space, time and density by applying a process to control lipid phase behaviour, electric field and temperature.

About supramolecular systems for dynamically probing cells.

This article reviews the state of the art in the development of strategies for generating supramolecular systems for dynamic cell studies. Dynamic systems are crucial to further our understanding of cell biology and are consequently at the heart of many medical applications. Increasing interest has therefore been focused recently on rendering systems bioactive and dynamic that can subsequently be employed to engage with cells.

On-chip electrophoresis in supported lipid bilayer membranes achieved using low potentials.

A micro supported lipid bilayer (SLB) electrophoresis method was developed, which functions at low potentials and appreciable operating times. To this end, (hydroxymethyl)-ferrocene (FcCH2OH) was employed to provide an electrochemical reaction at the anode and cathode at low applied potential to avoid electrolysis of water. The addition of FcCH2OH did not alter the SLB characteristics or affect biomolecule function, and pH and temperature variations and bubble formation were eliminated.

Dual-point dual-wavelength fluorescence monitoring of DNA separation in a lab on a chip.

We present a simple approach in electrophoretic DNA separation and fluorescent monitoring that allows to identify the insertion or deletion of base-pairs in DNA probe molecules from genetic samples, and to perform intrinsic calibration/referencing for highly accurate DNA analysis. The principle is based on dual-point, dual-wavelength laser-induced fluorescence excitation using one or two excitation windows at the intersection of integrated waveguides and microfluidic channels in an optofluidic chip and a single, color-blind photodetector, resulting in a limit of detection of ~200 pM for single-end-labeled DNA molecules. The approach using a single excitation window is demonstrated experimentally, while the option exploiting two excitation windows is proposed theoretically.

Modulation-frequency encoded multi-color fluorescent DNA analysis in an optofluidic chip.

We introduce a principle of parallel optical processing to an optofluidic lab-on-a-chip. During electrophoretic separation, the ultra-low limit of detection achieved with our set-up allows us to record fluorescence from covalently end-labeled DNA molecules. Different sets of exclusively color-labeled DNA fragments-otherwise rendered indistinguishable by spatio-temporal coincidence-are traced back to their origin by modulation-frequency-encoded multi-wavelength laser excitation, fluorescence detection with a single ultrasensitive, albeit color-blind photomultiplier, and Fourier analysis decoding.

High-resolution electrophoretic separation and integrated-waveguide excitation of fluorescent DNA molecules in a lab on a chip.

By applying integrated-waveguide laser excitation to an optofluidic chip, fluorescently labeled DNA molecules of 12 or 17 different sizes are separated by CE with high operating speed and low sample consumption of approximately 600 pL. When detecting the fluorescence signals of migrating DNA molecules with a PMT, the LOD is as low as 2.1 pM.