Growth and Remodeling
Biological tissues have the unique and important ability to grow, to heal and to adapt to altered mechanical environment (remodeling). Growth and remodeling (G&R) are both driven by mechanical stimuli, and result in changes in the tissue mechanical properties, morphology and internal structure. Well known examples: the wall thickening of arteries under hypertension; the development of life threatening cerebral and aortic aneurism due to stress-modulated resorption and remodeling of the vessel wall elastin; and the rapid decrease in the mass, modulus and strength of bones, cartilage, tendons, ligaments and muscles under immobilization. Forces are also essential in the process of healing, and in engineering of constructs for load-bearing tissues.
Mathematical models can turn this research and clinical experience into precise knowledge about stress and growth, which should help physicians to better understand disease processes and to design healing and preventative measures. Such knowledge will establish reliable foundations for physical education, sports techniques, health care and rehabilitation and be of high importance in optimization of construct mechanical conditioning in tissue engineering.
Our research on the biomechanics of tissues’ G&R uses the tissue microstructure as its key and focus. This approach has two advantages. On one hand, tissue G&R results from biological turnover (degradation and synthesis) of its structural constituents (the fibers, the cells and the macromolecules in its fluid-like matrix) which are governed by specific stress-affected kinetic rates. On the other hand, tissue microstructure is the key to its mechanical properties.