Publications

Hiroaki Ito, Navina Kuss, Bastian E. Rapp, Masatoshi Ichikawa, Thomas Gutsmann, Klaus Brandenburg, Johannes M. B. Pöschl, and *Motomu Tanaka,
Quantification of the Influence of Endotoxins on the Mechanics of Adult and Neonatal Red Blood Cells,
Journal of Physical Chemistry B 119, 7837−7845 (2015).

[Summary] In this study, we physically modeled the influence of endotoxin-induced sepsis symptoms on human red blood cells (RBCs) by quantifying the impact of endotoxins on the cell mechanics by the analysis of Fourier-transformed mean square amplitude of shape fluctuation, called flicker spectroscopy. With the aid of a microfluidic diffusion chamber, we noninvasively determined principal mechanical parameters of human RBCs in the absence and presence of endotoxins for individual RBCs for the first time. Because of the elongation of saccharide chain length of endotoxins, we found an increase in the morphological transition from discocytes to echinocytes, and monotonic changes in the mechanical parameters. Since septic shocks often cause lethal risks of neonates, we measured the mechanical parameters of neonatal RBCs, and compared them to those of adult RBCs. The quantitative comparison reveals that neonatal RBCs are more susceptible to the effect of endotoxins than adult RBCs. Furthermore, coincubation with the antiseptic peptide P19-2.5 (Aspidasept) with endotoxin results in a slight suppression of the impact of the endotoxin. The strategy proposed in our study can potentially be applied for the quantitative diagnosis of RBCs based on mechanical readouts.

Alexandra S. Burk, Cornelia Monzel, Hiroshi Y. Yoshikawa, Patrick Wuchter, Rainer Saffrich, Volker Eckstein, *Motomu Tanaka and *Anthony D. Ho,
Quantifying Adhesion Mechanisms and Dynamics of Human Hematopoietic Stem and Progenitor Cells.,
Scientific Reports 5, 9370 (2015).

[Summary] Using planar lipid membranes with precisely defined concentrations of specific ligands, we have determined the binding strength between human hematopoietic stem cells (HSC) and the bone marrow niche. The relative significance of HSC adhesion to the surrogate niche models via SDF1a-CXCR4 or N-cadherin axes was quantified by (a) the fraction of adherent cells, (b) the area of tight adhesion, and (c) the critical pressure for cell detachment. We have demonstrated that the binding of HSC to the niche model is a cooperative process, and the adhesion mediated by the CXCR4- SDF1a axis is stronger than that by homophilic N-cadherin binding. The statistical image analysis of stochastic morphological dynamics unraveled that HSC dissipated energy by undergoing oscillatory deformation. The combination of an in vitro niche model and novel physical tools has enabled us to quantitatively determine the relative significance of binding mechanisms between normal HSC versus leukemia blasts to the bone marrow niche.

Nataliya Frenkel, Ali Makky, Ikhwan Resmala Sudji, *Michael Wink, and *Motomu Tanaka,
Mechanistic Investigation of Interactions between Steroidal Saponin Digitonin and Cell Membrane Models,
The Journal of Physical Chemistry B 118, 14632−14639 (2014).

Harden Rieger, Hiroshi Y. Yoshikawa, Katharina Quadt, Morten A. Nielsen, Cecilia P. Sanchez, Ali Salanti, *Motomu Tanaka and Michael Lanzer,
Cytoadhesion of Plasmodium falciparum–infected erythrocytes to chondroitin-4-sulfate is cooperative and shear enhanced,
Blood 125, 383-391 (2014).

Phuc Nghia Nguyen, Mariam Veschgini, Motomu Tanaka, Gilles Waton, Thierry Vandammec and *Marie Pierre Krafft,
Counteracting the inhibitory effect of proteins towards lung surfactant substitutes: a fluorocarbon gas helps displace albumin at the air/water interfac,
Chemical Communications 50, 11576-11579 (2014).

Nataliya Frenkel, Jens Wallys, Sara Lippert, Jörg Teubert, Stefan Kaufmann, Aparna Das, Eva Monroy, Martin Eickhoff and *Motomu Tanaka,
High Precision, Electrochemical Detection of Reversible Binding of Recombinant Proteins on Wide Bandgap GaN Electrodes Functionalized with Biomembrane Models,
Advanced Functional Materials 24, 4927–4934 (2014).