内容简介：

The intervertebral disc (IVD) is the largest avascular structure in the human body and its main function is to support load and to provide flexibility for the spine system. Disc degeneration is related to low back pain which affects more than 600 million people worldwide. Understanding degenerative processes in human IVDs is challenging, due to nonlinear interactions among biological, chemical, electrical, and mechanical signals. Characterizing these signals is crucial for developing effective treatment strategies for degenerated discs. A 3D finite element model for human IVDs has been developed recently. This model was used to simulate degenerative progression of the IVDs caused by reduced nutrition supply at the disc boundaries. The disc repairing processes due to biological therapies (e.g., cell therapy) were also investigated. The changes in cell density, oxygen concentration, glucose concentration, swelling pressure, proteoglycan (PG) content, water content, mechanical stress and strain, and disc height during tissue degeneration (up to 55 years) and repairing processes (up to 10 years) were investigated. The model was validated by comparing its predictions on PG and water distributions in the disc with experimental results from the literature. The effect of dynamic compression on cell viability in the discs was also investigated. The simulations of MRI images for the degenerated discs were conducted and compared with those in the literature. The findings from this study provide new knowledge on nonlinear interactions among biological, chemical, electrical, and mechanical events in the disc over an entire period of degeneration or repairing processes. This study also provides guidance on developing new diagnostic methods for detecting early disc degeneration, design clinical trials for biological therapies for disc repair, and evaluate long-term efficacy of clinical trials.

报告人简介：

Dr. Gu is currently a professor in the Department of Mechanical and Aerospace Engineering and professor in Biomedical Engineering at the University of Miami. He received his PhD in Mechanical Engineering at Columbia University in 1994. After completing his postdoctoral training and serving as an Associate Research Scientist in the Orthopaedic Research Lab, Department of Orthopaedic Surgery at Columbia University, Dr. Gu joined the University of Miami College of Engineering faculty in the Department of Biomedical Engineering in 1998. Over the past 25 years, Dr. Gu has been continuously developing new theory and constitutive relations for transport and mechanical properties in soft tissues, new computational methods for quantitatively investigating biological, chemical, electrical, and mechanical signals within cartilaginous tissue under mechanical loading, and new, innovative experimental techniques for characterizing mechanical and transport properties in cartilaginous tissues.  He has published more than 170 papers and abstracts in the area of tissue mechanics, transport phenomena, computational biomechanics, disc cell metabolism and disc degeneration.