A Novel In Vitro Wound Healing Assay Using Free-Standing, Ultra-Thin PDMS Membranes.

Advances in polymer science have significantly increased polymer applications in life sciences. We report the use of free-standing, ultra-thin polydimethylsiloxane (PDMS) membranes, called CellDrum, as cell culture substrates for an in vitro wound model. Dermal fibroblast monolayers from 28- and 88-year-old donors were cultured on CellDrums.

Bio-Functionalized Ultra-Thin, Large-Area and Waterproof Silicone Membranes for Biomechanical Cellular Loading and Compliance Experiments.

Biocompatibility, flexibility and durability make polydimethylsiloxane (PDMS) membranes top candidates in biomedical applications. CellDrum technology uses large area, <10 µm thin membranes as mechanical stress sensors of thin cell layers. For this to be successful, the properties (thickness, temperature, dust, wrinkles, etc.

Recombinant Activated Protein C (rhAPC) Affects Lipopolysaccharide-Induced Mechanical Compliance Changes and Beat Frequency of mESC-Derived Cardiomyocyte Monolayers.

Background: Septic cardiomyopathy increases mortality by 70% to 90% and results in mechanical dysfunction of cells.

Methods: Here, we created a LPS-induced in-vitro sepsis model with mouse embryonic stem cell-derived cardiomyocytes (mESC-CM) using the CellDrum technology which simultaneously measures mechanical compliance and beat frequency of mESCs. Visualization of reactive oxygen species (ROS), actin stress fibers, and mRNA quantification of endothelial protein C receptor (EPCR) and protease-activated receptor 1 (PAR1) before/after LPS incubation were used for method validation.

Sample-specific adaption of an improved electro-mechanical model of in vitro cardiac tissue.

We present an electromechanically coupled computational model for the investigation of a thin cardiac tissue construct consisting of human-induced pluripotent stem cell-derived atrial, ventricular and sinoatrial cardiomyocytes. The mechanical and electrophysiological parts of the finite element model, as well as their coupling are explained in detail. The model is implemented in the open source finite element code Code_Aster and is employed for the simulation of a thin circular membrane deflected by a monolayer of autonomously beating, circular, thin cardiac tissue.

Development of a Bioreactor to Culture Tissue Engineered Ureters Based on the Application of Tubular OPTIMAIX 3D Scaffolds.

Regenerative medicine, tissue engineering and biomedical research give hope to many patients who need bio-implants. Tissue engineering applications have already been developed based on bioreactors. Physiological ureter implants, however, do not still function sufficiently, as they represent tubular hollow structures with very specific cellular structures and alignments consisting of several cell types.

Effects of spermine NONOate and ATP on the thermal stability of hemoglobin.

Background: Minor changes in protein structure induced by small organic and inorganic molecules can result in significant metabolic effects. The effects can be even more profound if the molecular players are chemically active and present in the cell in considerable amounts. The aim of our study was to investigate effects of a nitric oxide donor (spermine NONOate), ATP and sodium/potassium environment on the dynamics of thermal unfolding of human hemoglobin (Hb).

Contractile tension and beating rates of self-exciting monolayers and 3D-tissue constructs of neonatal rat cardiomyocytes.

The CellDrum technology (The term 'CellDrum technology' includes a couple of slightly different technological setups for measuring lateral mechanical tension in various types of cell monolayers or 3D-tissue constructs) was designed to quantify the contraction rate and mechanical tension of self-exciting cardiac myocytes. Cells were grown either within flexible, circular collagen gels or as monolayer on top of respective 1-mum thin silicone membranes. Membrane and cells were bulged outwards by air pressure.

Hemoglobin senses body temperature.

Unlabelled: When aspirating human red blood cells (RBCs) into 1.3 mum pipettes (DeltaP = -2.3 kPa), a transition from blocking the pipette below a critical temperature T(c) = 36.

Structural transition temperature of hemoglobins correlates with species' body temperature.

Human red blood cells (RBCs) exhibit sudden changes in their biophysical properties at body temperature (T (B)). RBCs were seen to undergo a spontaneous transition from blockage to passage at T (C) = 36.4 +/- 0.

Body temperature-related structural transitions of monotremal and human hemoglobin.

In this study, temperature-related structural changes were investigated in human, duck-billed platypus (Ornithorhynchus anatinus, body temperature T(b) = 31-33 degrees C), and echidna (Tachyglossus aculeatus, body temperature T(b) = 32-33 degrees C) hemoglobin using circular dichroism spectroscopy and dynamic light scattering. The average hydrodynamic radius (R(h)) and fractional (normalized) change in the ellipticity (F(obs)) at 222 +/- 2 nm of hemoglobin were measured. The temperature was varied stepwise from 25 degrees C to 45 degrees C.

Bactericidal effects of plasma-generated cluster ions.

Air purification by plasma-generated cluster ions (PCIs) relies on a novel technology producing hydrated positive and negative ions. Phenomenological tests have shown strong evidence of lethal effects of the PCIs on various micro-organisms. However, the mechanisms of PCI action are still widely unknown.

Adhesion of erythrocytes to endothelial cells after acute exercise: differences in red blood cells from juvenile and adult rats.

Erythrocytes (RBC) from untrained male Wistar rats and rat glomerular endothelial cells (EC) were used to investigate the effects of acute exercise (speed: 20 m/min, slope: 0, duration: 1 hour) on RBC membrane protein oxidation and adhesion to cultured EC. Experimental animals were divided into juvenile (age 10 weeks) and adult (age 30 weeks) groups for these studies. Immediately following exercise, juvenile rat RBC membrane protein oxidation was significantly enhanced.

Does antioxidant supplementation alter the effects of acute exercise on erythrocyte aggregation, deformability and endothelium adhesion in untrained rats?

This study aimed to determine whether high-dose antioxidant supplementation had an impact on the acute exercise effects related to erythrocyte membrane mechanics. Experimental animals (n=32) were divided into four groups as control, exercised, supplemented, and supplemented + exercise. Four-week antioxidant supplementation (vitamin C, vitamin E, and zinc) was applied to experimental animals.

NMR in vitro effects on proliferation, apoptosis, and viability of human chondrocytes and osteoblasts.

This study presents findings on the proliferation rate, cellular apoptosis, and viability of human chondrocyte and osteoblast cultures before and after treatment with NMR pulse sequences. A commercially available nuclear magnetic resonance machine (MBST(R)-Nuclear Magnetic Resonance Therapy) was used for treatment. The study was carried out for 19 days, including 9 days of NMR exposure in a controlled, double-blind, randomized manner, using commercially available human cell lines.

In vitro effects of high glucose concentrations on membrane protein oxidation, G-actin and deformability of human erythrocytes.

The object of this study was to examine the effect of elevated in vitro glucose concentrations on protein modification and functional changes in human erythrocytes. Groups were exposed to 5-45 mM glucose concentrations. The time effect of any changes was also evaluated.

Circular dichroism spectra of human hemoglobin reveal a reversible structural transition at body temperature.

Previously we have shown that human red blood cells (RBCs) undergo a sudden change from blocking to passing through a 1.3+/-0.2-microm micropipette when applying an aspiration pressure of 2.