title: Mechanistic micro-structural theory of soft tissues growth and remodeling: tissues with unidirectional fibers.
abstract: A new mechanistic theory was developed for soft tissues growth and remodeling (G&R). The theory considers tissues with unidirectional fibers. It is based on the loading-dependent local turnover events of each constituent and on the resulting evolution of the tissue micro-structure, the tissue dimensions and its mechanical properties. The theory incorporates the specific mechanical properties and turnover kinetics of each constituent, thereby establishing a general framework which can serve for future integration of additional mechanisms involved in G&R. The feasibility of the theory was examined by considering a specific realization of tissues with one fibrous constituent (collagen fibers), assuming a specific loading-dependent first-order fiber's turnover kinetics and the fiber's deposition characteristics. The tissue was subjected to a continuous constant rate growth. Model parameters were adopted from available data. The resulting predictions show qualitative agreement with a number of well-known features of tissues including the fibers' non-uniform recruitment density distribution, the associated tissue convex nonlinear stress-stretch relationship, and the development of tissue pre-stretch and pre-stress states. These results show that mechanistic micro-structural modeling of soft tissue G&R based on first principles can successfully capture the evolution of observed tissues' structure and size, and of their associated mechanical properties.
authors.affiliation: Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel, yoram@bm.technion.ac.il.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Lanir
mesh_terms: D001696:Biomechanical Phenomena; D003198:Computer Simulation; D008954:Models, Biological; D038081:Organogenesis; D013314:Stress, Mechanical; D013997:Time Factors