Lipids, membranes, colloids and cells: A long view

Critical analysis of explanations for cellular homeostasis and electrophysiology from murburn perspective

“…The contention seemed to subside after Cope's untimely demise in 1982. In recent times, the debate has been rekindled with some dedicated physicists collecting more arguments and evidence to support their perspective (Bagatolli et al, 2021; Bagatolli & Stock, 2021; Fillafer et al, 2021; Olsen et al, 2020).…”

Surface Characterization of Lipid Biomimetic Systems

“…It has been described how dipole potential and zeta potential are correlated which, in essence is due to water reorganization. Considering that in a cell the interphase region the membrane extends to the cell interior or overlaps with the interphase region of another supramolecular structure, as proposed in complex systems, the correlation of dipole and electrostatic forces can contribute to the propagation of perturbations between membrane and cytoplasm and vice versa [3]. Thus, this picture gives the membrane a responsive character in addition to its selective permeability barrier.…”

“…The hydration of the lipids is determinant for the thermodynamic stability and structural dynamics and are a clue to understand the response of the membrane to environmental changes and biologically relevant bio-effectors (hydric and oxidative stress, hydrolytic enzymes, signal peptides, antioxidants). A recent model of lipid membranes includes explicitly the lipid-water interaction considering the membrane as composed by a bidimensional solution of hydrated polar head groups of phosphatidylcholines, named the interphase [1][2][3][4][5][6][7] (Figure 1). This model can be sustained in terms of the formalism of Thermodynamics of Irreversible Processes, in which the membrane is considered as an open system with respect to water exchange.…”

“…The distribution of charged groups, dipoles from the lipid residues and water dipoles determines, approximately within the limits of the interphase in Figure 1, an electric double layer (EDL) that stablishes an electrical barrier for interacting compounds and is susceptible to conformational changes by the action of physical and chemical variables which would explain the responsive properties of the membrane to changes in its adjacencies. This is not a trivial matter, since models of membranes should be considered in the context of the cells as a complex system, i.e., the link between chemical processes in cytoplasm and membrane phenomena [3].…”

Hydration Dynamics in Biological Membranes: Emerging Applications of Terahertz Spectroscopy

“…However, spatially resolved insights into these water subpopulations (e.g., spatial coordinates defined with respect to proximity to a nonaqueous hydrogen-bonding partner) remain scarce. Hydration sheaths associated with biomimetic and biological membranes are expected to be particularly amenable to THz-based studies investigating spatial heterogeneity in the water hydrogen-bond network because of the rich tapestry of existing knowledge regarding membrane organization and dynamics. ,,− ,,− Hydration sheaths associated with biomimetic and biological membranes are expected to be particularly amenable to THz-based studies investigating spatial heterogeneity in the water hydrogen-bond network because of the rich tapestry of existing knowledge regarding membrane organization and dynamics.…”