Tissue engineering and regenerative medicine are the foundation of cultivating human organs. Photo: HKU
Tissue engineering and regenerative medicine are the foundation of cultivating human organs. Photo: HKU

Researchers at the University of Hong Kong’s Department of Mechanical Engineering, in collaboration with their US peers with the University of Pennsylvania, University of Virginia and Stanford University, have made a breakthrough in cell mechanics that may help scientists understand better how cells perform their biological duties in vivo.

Their research outcome may also help bring the lab cultivation of human tissues and organs closer to reality.

Dr Lin Yuan and his international collaborators are the first team worldwide to reveal the mechanism by which surrounding viscoelasticity affects cell response across a wide range of material parameters.

The findings were published in the prestigious international academic journal Proceedings of the National Academy of Sciences of the United States of America.

Dr. Lin Yuan, with the University of Hong Kong’s Department of Mechanical Engineering. Photo: HKU

Lin’s area of expertise, regenerative medicine, or “tissue engineering”, is about using living cells to grow adult tissues such as skin, blood vessels, joints, or major organs such as a healthy heart, for transplantation.

A key to cultivating living cells is to provide them with a proper extracellular matrix close to the natural body environment for optimal growth and functioning, according to Lin.

Most existing studies on this front focus on chemical composition, surface coating, porosity or stiffness of the extracellular matrix as they affect the cell behavior. But the role of material viscosity in regulating the behavior of cells remains largely unknown to scientists.

Lin’s research provides a novel insight into the dissipation in proper extracellular matrices, which can be as important as elasticity in directing cell response.

Specifically, the research team developed a stochastic model to examine the dynamics of motor clutches formed between the cell and a viscoelastic substrate as well as its implications in the spreading of cells.

The model was tested and validated on three different material systems – hydrogel, polyacrylamide- and hyaluronic acid-based systems.

Dr. Lin’s team is among the world’s most active groups in cell mechanics research, particularly in elucidating the physical mechanisms behind important cellular processes such as cell adhesion, cell migration and mechanotransduction, as well as exploring their possible applications in disease detection and tissue engineering.