From 1947 to 1948, Chien completed his medical preparatory study at Peking University Medical School. In 1949, Chien moved to Taiwan with his family. In 1953, Chien graduated from National Taiwan University. Chien went to study in the United States in 1954 and obtained his PhD in 1957 from Columbia University. Chien also received M.D. from the National Taiwan University.[3][4]
In 1967 Chien published three papers in Science that advanced the understanding of the physics behind the flow of red blood cells.[6][7] Chien and his colleagues were able to explore the flow properties of red blood cells through various experiments involved with filtering red blood cells through plastic porous sieves. One key finding was that the flow of red blood cells does not follow Newtonian behavior and this characteristic is fundamental in aiding red blood cells to squeeze through capillaries.
Chien and his colleagues further discovered the importance of the malleability of red blood cells to pass through tiny pores smaller than the cells' diameter. In other words, a healthy normal red blood cell is able to "squeeze" by deforming its shape and pass through small pores. In addition, this deformation helps lower the viscosity of blood and facilitate flow. Another important discovery that determines the viscosity of blood is the ability of red blood cells to aggregate to form rouleaux (like stacks of coins) due to their disc like shape. Chien and his colleagues discovered that this was a crucial factor in modulating viscosity and regulating blood flow and elucidated the mechanical, electrical and biochemical basis of this process. These discoveries show that the shape of red blood cells is not accidental, but rather a highly "engineered design" meant for efficient transportation.
Recent research
Chien has investigated the mechanisms by which mechanical forces such as pressure and flow regulate the behaviors of the cells in blood vessels, including the endothelial cells lining the vessel lumen and the smooth muscle cells in the vessel interior and their interactions. His work has led to the understanding how forces with a clear direction (as seen in the straight parts of the vascular tree) can protect the vessels from atherosclerosis and how forces without a clear direction (as seen in the branch points) make the vessels vulnerable to atherosclerosis. More recently, he has developed novel approaches to assess the optimum microenvironment for the growth and differentiation of stem cells.[citation needed]
