Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter at the nanoscale. We do this by exploring ways to shape light and its environment. It's what we call active and passive control. Our current focus is on the interaction of light with biomolecules and nanostructures. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.
We participate in the EU-COST actions MP1102: Coherent Raman microscopy (MicroCor) and CM1202: Supramolecular photocatalytic water splitting (PERSPECT-H2O)


An atomic force microscope operating at hypergravity for in situ measurement of cellular mechano-response

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J.J.W.A. Van Loon, M.C. van Laar, J.P. Korterik, F.B. Segerink, R. J . Wubbels, H.A.A. de Jong & N. F . Van Hulst
Journal of Microscopy
vol. 233 issue 2 p234-243 feb 2009

We present a novel atomic force microscope (AFM) system, operational in liquid at variable gravity, dedicated to image cell shape changes of cells in vitro under hypergravity conditions.
The hypergravity AFM is realized by mounting a standalone AFM into a large-diameter centrifuge. The balance between mechanical forces, both intra- and extracellular,
determines both cell shape and integrity. Gravity seems to be an insignificant force at the level of a single cell, in contrast to the effect of gravity on a complete (multicellular) organism, where for instance bones and muscles are highly unloaded under near weightless (microgravity) conditions. However, past space flights and ground based cell biological studies, under both hypogravity and hypergravity conditions have shown changes in cell behaviour (signal transduction), cell architecture (cytoskeleton) and proliferation. Thus the role of direct or indirect gravity effectsat thelevelof cellshasremained unclear. Here we aim to address the role of gravity on cell shape. We concentrate on the validation of the novel AFM for use under hypergravity conditions. We find indications that a single cell exposed to 2 to 3×g reduces some 30–50% in average height, as monitored with AFM. Indeed, in situ measurements of the effects of changing gravitational load on cell shape are well feasible by means of AFM in liquid.
The combination provides a promising technique to measure, online, the temporal characteristics of the cellular mechanoresponse during exposure to inertial forces.
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