On the Destruction of Cancer Cells Using Laser-Induced Shock-Waves: A Review on Experiments and Multiscale Computer Simulations

Abstract

In the clinical treatment of solid tumors, besides traditional surgery and chemotherapy, the use of High Intensity Focused Ultrasound (HIFU) has been established as a minimally non-inva-sive technique for tumor treatment, which is based on coagulative necrosis of cells, induced by conversion of mechanical energy into heat. Another, less developed technique for the destruction or damage of tumor cells, is based on the pure mechanical effects of strong shock waves on cells, which are generated by using laser ablation, thus avoiding the heat-related unwanted side-effect when using HIFU (cutaneous burns of healthy tissue). Despite the general therapeutic success of extracorporeal shock wave therapy in medicine, e.g. for disintegrating con-grements, the mechanical effects of shock waves on the cytoskeleton of cells, on the transient permeability and rupture of cell membranes, or on tissue damage remain widely unknown. The mechanical behavior of bio-macromolecules however, is of particular importance on the cellular level as several basic and yet unanswered questions are raised: How are cell stresses and energy transmitted through cells and in what way are the forces and interactions that determine the stability of cell plasma membranes affected by a shock wave and give rise to cell deformation , structural damage or rupture of the membrane with subsequent apoptosis? Here, we intend to review research on the shock wave destruction of tumor cells and discuss the use of laser-ablation as a new potential technique for tumor treatment. We also discuss here recent progress in computational modeling strategies and techniques for understanding the basic physical mechanisms that occur in the interaction of shock waves with cellular structures and show how computer modeling and numerical simulation can contribute to a fundamental understanding in this emerging multidisciplinary field, where physics, chemistry, biology and medicine meet.