Recent topics in biomechanics and mechanobiology

Biomechanics may be seen as an independent discipline of research with its own methods, approaches, and a very long history—questions related to the functioning of living matter have preoccupied philosophers and scientists for millennia, in fact. Notwithstanding, it was continuously advanced by the theories and techniques established for classical engineering materials. Both the specific developments and those adopted and adapted from other mechanical disciplines render biomechanics a continuously evolving field until today. The progress in biomechanical research also profits from the advances in other fields, including instrumentation and techniques for experimental analyses and, in the recent decades, particularly computational science. The new insights gained from experiments serve to continuously refine models and to reconsider problems. The available computational power allows the inclusion of the increasing amount and detail of information in models of ever-growing complexity. In about the last two decades mechanobiology has emerged as an independent discipline, yet complementary to biomechanics in many aspects. Unravelling the relations between mechanical loads and the cells' biological response requires a deep understanding of cell and tissue biology, and thus represents a multidisciplinary task. Accordingly, the corresponding model formulations need to couple the mechanical field quantities with those of other physical disciplines and with the kinetics of biochemical reactions to integrate mechanics in the complex pathways of biological systems. Evidently, such deep understanding of the mechanobiological processes may help shedding light on dysfunctions and pathological situations, and also biomechanical research has incessantly been driven by medical questions from its infancy until today. Both biomechanics and mechanobiology, but in particular the joint disciplines can therefore be considered as life sciences able to face more and more detailed research problems. Concomitant with the emerging complex questions are changes in the research strategies from general to specific aspects, from singleto multiscale approaches, from monoto multiphysics problems, and from isolated problem considerations to systems approaches. With the issues 3 and 4 of this volume of the GAMM-Mitteilungen, we are very glad to present seven contributions that reflect these recent trends and their advances in biomechanics and mechanobiology. Issue 3 contains three overview-oriented articles: the article by S. Brandstaeter, S. L. Fuchs, R. C. Aydin, and C. J. Cyron presents stomach biomechanics as an emerging topic and highlights challenges. The work by M. K. Rausch, M. Mathur, and W. D. Meador gives deep insight into the biomechanics of the tricuspid annulus under healthy, diseased and repaired conditions. S. Schmitt, M. Günther, and D. F. B. Häufle in their article provide a new view on muscle models as biophysical systems. Issue 4 is dedicated to specific modeling approaches for cells, tissues, and organs. M. Hillgärtner, K. Linka, and M. Itskov present a scale-spanning modeling concept for inelastic tissue behavior, and a biphasic approach is combined with strain-gradient plasticity in the article by A. Grillo, S. Di Stefano, A. Ramírez-Torres, and M. Loverre to address tissue growth and remodeling. Modeling and simulation of the electromechanically coupled behavior of in vitro cultures of human induced pluripotent stem cell-derived cardiomyocytes are dealt with by A. Jung and M. Staat, and an extended porous media theory to simulate the perfusion of liver lobules is presented and compared to alternative approaches in the contribution by T. Ricken and L. Lambers. The guest editors would like to express their gratitude to all authors who contributed to this collection of papers, and thank the editor for the opportunity to compile these contributions in two issues of the GAMM-Mitteilungen.