[P1-57] Shock Wave Induced Damage in Tumor Cells: Experiments and Simulations
ABSTRACT
Despite the therapeutic success of extracorporeal shock wave therapy in medicine, e.g. for disintegrating concrements, the effects of shock waves on the damage of biological cells and their membranes remain widely unknown. We present experimental results on the destruction of tumor cells using laser-induced shock waves. For the simulation of biological systems such as membranes under highly transient conditions such as external shock wave load, we propose a thermodynamically consistent and energy conserving coupling scheme between the atomistic and the continuum domain. The coupling scheme links the two domains using the DPDE (Dissipative Particle Dynamics at constant Energy) thermostat and is designed to handle strong temperature gradients across the atomistic/continuum domain interface. Using DPDE we investigate the effects of shock-wave impact on the damage of lipid bilayer membranes. A coarse-grained model for the phospholipid bilayer in aqueous environment is employed, which models single lipids as short chains consisting of a hydrophilic head and two hydrophobic tail beads. Water is modeled by mapping four water molecules to one water bead. Using the DPDE method enables us to faithfully simulate the non-equilibrium shock-wave process with a coarse-grained model as the correct heat capacity can be recovered. At equilibrium, we obtain self-stabilizing bilayer structures that exhibit bending stiffness and compression modulus comparable to experimental measurements under physiological conditions. We study in detail the damage behavior of the coarse-grained lipid bilayer upon high-speed shock-wave impact as a function of shock impact velocity and bilayer stability. A single damage parameter based on an orientation dependent correlation function is introduced.
REFERENCES
[1] Martin O. Steinhauser, Computational Multiscale Modeling of Fluids and Solids - Theory and Applications, Springer 2nd ed., Berlin, Heidelberg, New York 2017.
[2] Tanja Schindler, Dietmar Kröner, Martin O. Steinhauser, On the dynamics of molecular self-assembly and the structural analysis of bilayer membranes using coarse-grained molecular dynamics, Biochimica at Biophysica Acta, 1858, 1955-1963, 2016
Despite the therapeutic success of extracorporeal shock wave therapy in medicine, e.g. for disintegrating concrements, the effects of shock waves on the damage of biological cells and their membranes remain widely unknown. We present experimental results on the destruction of tumor cells using laser-induced shock waves. For the simulation of biological systems such as membranes under highly transient conditions such as external shock wave load, we propose a thermodynamically consistent and energy conserving coupling scheme between the atomistic and the continuum domain. The coupling scheme links the two domains using the DPDE (Dissipative Particle Dynamics at constant Energy) thermostat and is designed to handle strong temperature gradients across the atomistic/continuum domain interface. Using DPDE we investigate the effects of shock-wave impact on the damage of lipid bilayer membranes. A coarse-grained model for the phospholipid bilayer in aqueous environment is employed, which models single lipids as short chains consisting of a hydrophilic head and two hydrophobic tail beads. Water is modeled by mapping four water molecules to one water bead. Using the DPDE method enables us to faithfully simulate the non-equilibrium shock-wave process with a coarse-grained model as the correct heat capacity can be recovered. At equilibrium, we obtain self-stabilizing bilayer structures that exhibit bending stiffness and compression modulus comparable to experimental measurements under physiological conditions. We study in detail the damage behavior of the coarse-grained lipid bilayer upon high-speed shock-wave impact as a function of shock impact velocity and bilayer stability. A single damage parameter based on an orientation dependent correlation function is introduced.
REFERENCES
[1] Martin O. Steinhauser, Computational Multiscale Modeling of Fluids and Solids - Theory and Applications, Springer 2nd ed., Berlin, Heidelberg, New York 2017.
[2] Tanja Schindler, Dietmar Kröner, Martin O. Steinhauser, On the dynamics of molecular self-assembly and the structural analysis of bilayer membranes using coarse-grained molecular dynamics, Biochimica at Biophysica Acta, 1858, 1955-1963, 2016