Effects of Interface Conditions and Volume Fraction on the Apparent Stiffness of Surrogate Multicellular Constructs

A common theme in tissue engineering and cell and tissue biomechanics is how the mechanical properties of individual tissue components or embedded cellular structures influence the continuum mechanical behavior of a tissue or construct. Meshless methods provide a useful and convenient computational framework for answering these questions [1], allowing predictions of both the effective mechanical properties of constructs and the local stresses and strains at the level of the cell. Our research focuses on understanding the mechanics of angiogenic microvessels embedded in surrogate extracellular matrix (ECM) materials [1–4]. As a first step toward understanding the interface interactions between microvessels and the ECM, the objectives of this study were to use the material point method (MPM) to analyze models of surrogate microvessels embedded in collagen gel and investigate the effects of microvessel volume fraction and interface conditions between the surrogate vessels and the collagen gel.