Predicting Nonlinear Behavior of Adipose Tissue Extracellular Matrix Based on Structural Model

Adipose tissue is a loose connective tissue distributed in two main anatomic depots including subcutaneous and visceral. Since in many pathological condition and diseases associated with adipose tissue alteration, the micro-components of adipose tissue undergoes considerable changes from mechanical characteristics point of view, it is quite vital to present an accurate structural technique for modelling tissue microstructure. Accordingly, this paper presents a structural model based on adipose tissue main components and interaction between them. Adipocytes was considered as a fluidic spheres and extracellular matrix modeled as solid media. The interaction between these two different phases simulated by solving well-known fluid-structure interaction (FSI) problem. In order to obtain the constitutive parameters for ECM, finite element simulation results fitted to experimental uniaxial compression test data. To make a comparison between the performances of different constitutive models, three conventional hyperelastic models were used for describing the mechanical behavior of ECM. The agreement between experimental data and simulation results confirm that the presented technique has a high potential for modeling adipose tissue microstructure both in normal and pathological condition. Considering the accuracy and mathematical complexity, results show that Yeoh hyperelastic model has a better performance than two others. In all three model, results reveals that the stiffness of adipose tissue ECM is ~ (2-3) times higher than that of the adipose tissue.