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Pressure waves have the potential to cause injury to cells and tissue or enable novel therapeutic modalities, such as fragmentation of kidney stones and drug delivery. Research on the biological effects of pressure waves have shown that the biological response on depends the pressure-wave characteristics. One of the most prominent effects induced by pressure waves is the permeabilization of a number of barrier structures (cell plasma membrane, skin and microbial biofilms) and facilitate the delivery of macromolecules. The permeabilization of the barrier structure is transient and the barrier function recovers. Thus, pressure waves can induce delivery of molecular species that would not normally cross the barrier structure. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Cell permeabilization by shock waves may have application in gene therapy and anticancer drug delivery. In the present study we performed direct molecular dynamic (MD) simulation of the interaction of a single shock wave with a cell membrane to investigate the mechanism of the cell permeabilization. The shock wave was characterized by an impulse that was expressed with a velocity determined by the change in the momentum. The cell membrane was designed as a dipalmitoylphosphatidylcholine (DPPC) lipid bilayer placed between two layers of water molecules. The MD simulation determined the relationship between water penetration into the bilayer, the order parameter, the fluidity of each lipid molecule, and the intensity of impulse. These structural changes in the bilayer may be an important factor in the use of shock waves to produce transient membrane permeability. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]