PhD (M/F) INTERACTION OF ULTRASOUND WITH THE 3D MICROENVIRONMENT OF BONE CELLS: EXPERIMENTAL AND NUMERICAL STUDIES

Lab: The thesis will be carried out within the Biomechanics team of the IRPHé (UMR CNRS/Aix-Marseille Université/ Centrale Méditerranée) located in Marseille (France). Funding: ANR INVICT-US project. Thesis supervisors: Cécile Baron, CR CNRS (HDR), and Carine Guivier-Curien, MCF AMU (HDR) Contact: cecile.baron@univ-amu.fr; carine.guivier@univ-amu.fr

Bone tissue is a complex biological tissue, capable of adapting to its mechanical environment by optimising its structure, a process known as bone remodelling. Ultrasound stimulation of bone regeneration (UStim) was discovered in the 1950s and has been widely studied ever since. However, the underlying mechanotransduction mechanisms (translation of mechanical stimuli into a biological response) remain poorly identified and this lack of knowledge is fuelling controversy, preventing the development of effective and optimised therapeutic tools. Characterising and quantifying the mechanical stresses induced by ultrasound stimulation on bone cells (osteocytes) is essential to understanding these mechanisms. As part of the ANR INVICT-US project, an experimental device for stimulating bone remodelling in vitro incorporating a biomimetic 3D culture medium is being developed. The aim of the thesis will be to design a multiscale, multiphysics 'digital twin' in order to identify and quantify the hydrodynamic phenomena (acoustic streaming) within this three-dimensional microenvironment that are likely to be involved in the mechanotransduction of bone cells induced by ultrasound waves.