Plasmas, membranes, and transport across the membranes

Physical agents, like cold plasma, may affect the cells at various levels, amongst which the cell membrane. Cell or “plasma” membrane is a vital “organ” for the cell. Indeed if cell membrane integrity is affected, transports from cell outside to cell inside and from cell inside to cell outside can no longer be regulated [1]. It is essential for the cell physiology and survival to keep fully regulated the transport across the cell membrane of ions (Na⁺, Ca⁺⁺, K⁺, Cl^-), of small molecules (sugars, ATP, aminoacids, drugs – amongst many other xenobiotics) and even of large molecules such as regulatory RNAs (e.g. siRNA) or even proteins, DNAs, …

The way in which physical agents can modify/perturb the cell membrane [2] to cause these changes in the molecules transport across the membrane are even less well known that the changes occurring in the molecules transport. The methods used to analyze cell membrane perturbations have to be very sophisticated due to the dimensions of this element of the cell (the phospholipid bilayer has a thickness of 5 nm). They include nonlinear optical methods such as Raman microspectroscopy [3, 4].

In the presentation, these issues (changes in membrane structure and changes in transport across the membrane) will be presented in spite of a still fragmentary knowledge. They will be discussed comparing the action of various physical agents (plasma, electromagnetic fields, ultrasounds) to the electric pulses effects for which a deeper knowledge has been accumulated. [1-4], and analyzing their potentialities to cause cell death and to develop in new cancer treatments.