Showing 131 results for Author: John Katsaras
Apr, 2026
Journal
Melatonin, a hormone primarily produced by the brain’s pineal gland, not only regulates circadian rhythms, but also influences the structural and biophysical properties of neuronal membranes. Its amphiphilic nature enables direct incorporation into lipid bilayers and preferential interactions with cholesterol-rich lipid rafts, critical hubs for cellular signaling and membr…
Apr, 2026
Journal
A rotaxane consisting of a macrocycle ring with two azobenzene units mechanically interlocked onto a bolaamphiphilic axle was incorporated into droplet interface bilayers (DIBs). The azobenzene groups on the ring underwent quasi-reversible, photoisomerization-induced cycling between 1-E and 1-Z configurations when irradiated with 370 and 467 nm light, respectively, enablin…
Apr, 2026
Journal
Human neural networks of interconnected neurons have evolved to be remarkably efficient and are capable of learning and memory through the brain’s synaptic plasticity, including short-term plasticity (STP), and long-term potentiation (LTP) and depression (LTD). These activity-dependent mechanisms induce changes in synaptic efficiency over both transient and extended timesc…
Aug, 2025
Journal
Cholesterol and lipid unsaturation underlie a balance of opposing forces that features prominently in adaptive cell responses to diet and environmental cues. These competing factors have resulted in contradictory observations of membrane elasticity across different measurement scales, requiring chemical specificity to explain incompatible structural and elastic effects. He…
Aug, 2025
Journal
Solvent toxicity limits n-butanol fermentation titer, increasing the cost and energy consumption for subsequent separation processes and making biobased production more expensive and energy-intensive than petrochemical approaches. Amphiphilic solvents such as n-butanol partition into the cell membrane of fermenting microorganisms, thinning the transverse structure, and eve…
Jun, 2025
Book Chapter
The structure of the plasma membrane (PM) has been undergoing continuous evolution for the greater part of 100 years. It is also well understood that the underlying organizing structure of the PM is the lipid bilayer. Recently, it was shown that the lipid bilayer can behave as a memory capacitor, or memcapacitor, exhibiting pinched hysteresis loops when plotting charge vs…
Apr, 2025
Journal
Amphiphilic charged oligomers (oligodimethylsiloxane – methylimidazolium cation, ODMS-MIM (+)), assemble into bilayers using the droplet interface bilayer (DIB) platform, possess similar size and functionality as phospholipid bilayers, but exhibit increased stability. The oligomer ionic headgroups (MIM(+)) are covalently bound to monodisperse, short-chain (n = 13) hydropho…
Feb, 2025
Journal
Biological memory is the ability to develop, retain, and retrieve information over time. Currently, it is widely accepted that memories are stored in synapses (i.e., connections between brain cells throughout the brain) through a process known as synaptic plasticity, which leads to either long-term potentiation (LTP) or long-term depression (LTD). However, the strengthenin…
Jan, 2025
Journal
We demonstrate, using non-equilibrium molecular dynamics simulations, that lipid membrane capacitance varies with surface charge accumulation linked to membrane shape and curvature changes. Specifically, we show that lipid membranes exhibit a hysteretic response when exposed to oscillatory electric fields. The electromechanical coupling in these membranes leads to hysteret…
Sep, 2024
Journal
Synaptic plasticity refers to activity-dependent synaptic strengthening or weakening between neurons. It is usually associated with homosynaptic plasticity, which refers to a synaptic junction controlled by interactions between specific neurons. Heterosynaptic plasticity, on the other hand, lacks this specificity. It involves much larger populations of synapses and neurons…
Jun, 2024
Journal
Cell membranes are responsible for a range of biological processes that require interactions between lipids and proteins. While the effects of lipids on proteins are becoming better understood, our knowledge of how protein conformational changes influence membrane dynamics remains rudimentary. Here, we performed experiments and computer simulations to study the dynamic res…
Jun, 2024
Journal
Hypothesis: Understanding the rules that control the assembly of nanostructured soft materials at interfaces is central to many applications. We hypothesize that electrolytes can be used to alter the hydration shell of amphiphilic oligomers at the air-aqueous interface of Langmuir films, thereby providing a means to control the formation of emergent nanostructures. Experim…