Cell detachment and label-free cell sorting using modulated surface acoustic waves (SAW) in droplet-based microfluidics

We present a droplet-based surface acoustic wave (SAW) system designed to viably detach biological cells from a surface and sort cell types based on differences in adhesion strength (adhesion contrast), without the need to label cells with molecular markers. The system uses modulated SAW to generate pulsatile flows in the droplets and efficiently detach the cells, thereby minimizing SAW excitation power and exposure time. As a proof-of-principle, the system is shown to efficiently sort HEK 293 from A7r5 cells based on adhesion contrast. Results are obtained in minutes with sorting purity and efficiency reaching 97 % and 95 %, respectively.Comment: Accepted for publication in Lab on a Chi

MOL #93450 1. Title page Label-Free Monitoring of Mu Opioid Receptor-Mediated Signaling MOL #93450 2 2. Running title page a) Running title: Surface Plasmon Resonance to Assess Signaling Cascades b) Correspondence

Abstract: 231 word

Reactive Oxygen Species Alleviate Cell Death Induced by Thaxtomin A in Arabidopsis thaliana Cell Cultures

Thaxtomin A (TA) is a cellulose biosynthesis inhibitor synthesized by the soil actinobacterium Streptomyces scabies, which is the main causal agent of potato common scab. TA is essential for the induction of scab lesions on potato tubers. When added to Arabidopsis thaliana cell cultures, TA induces an atypical programmed cell death (PCD). Although production of reactive oxygen species (ROS) often correlates with the induction of PCD, we observed a decrease in ROS levels following TA treatment. We show that this decrease in ROS accumulation in TA-treated cells is not due to the activation of antioxidant enzymes. Moreover, Arabidopsis cell cultures treated with hydrogen peroxide (H2O2) prior to TA treatment had significantly fewer dead cells than cultures treated with TA alone. This suggests that H2O2 induces biochemical or molecular changes in cell cultures that alleviate the activation of PCD by TA. Investigation of the cell wall mechanics using atomic force microscopy showed that H2O2 treatment can prevent the decrease in cell wall rigidity observed after TA exposure. While we cannot exclude the possibility that H2O2 may promote cell survival by altering the cellular redox environment or signaling pathways, our results suggest that H2O2 may inhibit cell death, at least partially, by reinforcing the cell wall to prevent or compensate for damages induced by TA

Rod- and sphere-shaped cellulose nanocrystals (CNCs) type-II derived from Asclepias syriaca stem residues: composition, morphology, and thermal properties

Cellulose nanocrystals or nanoparticles (CNCs) have drawn a lot of attention due to their abundance, biocompatibility, renewability and their excellent mechanical properties paving the way to innovative and sustainable applications. In the present work, the stem residues of Asclepias syriaca L., better known as milkweed and generally regarded as a weed, was used for the first time to extract CNCs with a crystalline structure type-II (CNC-II). Structural, thermal, morphological, and mechanical properties of extracted CNC-II were characterized by means of Fourier transform infrared, X-ray diffraction, scanning electron microscopy, dynamic light scattering, thermogravimetric analysis, and atomic force microscopy (AFM). Asclepias syriaca stem fibers revealed quite similar cellulose content compared with other milkweed species, and stable suspensions made of nanosphere- and nanorod-shape CNC-II were successfully extracted from raw milkweed fibers. In addition, after conversion from cellulose-I to cellulose-II by mercerization, milkweed cellulose-II exhibited higher thermal resistance compared with cellulose-I with degradation temperatures at 328 °C and 310 °C, respectively. Finally, the transversal elastic modulus of individuals CNC-II, as measured by AFM, was found to be in the range of 3.5–27 GPa, which is consistent with reported values for CNC-I or -II in the literature.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Plasmonic biochips – from parallel acquisition to nano-enhanced sensitivity, specificity and actual structural imaging

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