A Multiphysics Model of Capillary Growth and Remodeling

We report on an enhanced computational framework for simulating flow-tissue interactions that significantly expands the capabilities of our previous model [1]. We adhere to the basic structural concept of the so-called intussusceptive growth and remodeling which does not only generate capillaries and terminal vessels but also rebuilds them into a highly perfused system [2]. Present enhancements comprise calculation and visualization in three dimensions, refined tissue and fluid mechanics, and the transport of molecules that act as biochemical growth or signaling factors. Our present model explains formation of capillary meshes and bifurcations, and the emergence of feeding and draining microvessels in an interdigitating pattern that avoids arterio-venous shunts. In addition, it predicts detailed hydrodynamic properties and transport characteristics for oxygen, metabolites or signaling molecules. In comparison to the previous work, the complexity of our approach is dramatically increased by using a multiphysics modeling environment, where many independent computational components are combined and the data structure is unified.