Transport phenomena research in biological systems may be at the dawn of a new age, with, for example, new opportunities to understand and control transport phenomena at the cellular level. By doing so, novel targeted therapies, including therapies based upon advances in nanotechnology, might be developed. Advances in pharmacology including drug discovery and screening, pharmaceutical manufacturing and drug delivery are widespread, and have already had a profound effect on the quality of life globally. Other areas such as tissue engineering are replete with transport phenomena of several types. In these and other emerging areas as well as in traditional areas of bioheat and mass transfer, the thermal sciences will significantly contribute to improved health and environment.
Heat and mass transfer in a single cell, tissue, and organ has been investigated. At the organ level, such as lung, liver, and kidney, their structure must allow rapid exchange of molecules between blood and tissues (Truskey et al., 2004). Although transport process occurs in all organs, the effect is very significant in some organs such as the cardiovascular and respiratory systems, the gastrointestinal tract, the liver and the kidneys. For example, the cardiovascular system consists of the heart, blood vessels and blood. The primary function of the cardiovascular system is to transport oxygen within red cells and remove carbon dioxide. In the respiratory system, oxygen is delivered to tissues when it is metabolized and carbon dioxide is removed. Digestion and absorption of nutrition are done in the gastrointestinal track. The liver performs metabolic functions such as carbohydrate storage and release, cholesterol metabolism, synthesis of plasma and transport proteins including removing toxic molecules from the blood. Kidneys are responsible for removal of urine and water products.
A cell is a membrane-bound soup of water, proteins, lipids and nucleic acids that grows, reproduces and interacts with its environment. Cells are regarded as the basic organizing unit of life and cell biology plays essential roles in human disease, such as bacterial infections and cancer. Depending on the complexity of a cell, it can be either a prokaryote or eukaryote. While the former can be found in bacteria and only has a cell membrane and cytoplasm and no other organelles, the latter exists in plants, animals, fungi, and protista and has a number of different cell organelles. The cells are usually in thermal equilibrium and the transport phenomena encountered in the cells are mainly momentum and mass transfer. While most existing models treat a cell as a well-mixed homogeneous system, cell heterogeneity is essential to capture many important phenomena at the cellular level. Due to barriers between biology and thermal sciences, the role and importance of mass transfer in information processing is not realized by biologists. To fully understand the role of transport phenomena at the cellular level, it is essential to develop more sophisticated models incorporating non-Newtonian mechanics, heterogeneities, time-dependence and stochastic fluctuations.
Faghri, A., and Zhang, Y., 2006, Transport Phenomena in Multiphase Systems, Elsevier, Burlington, MA.
Faghri, A., Zhang, Y., and Howell, J. R., 2010, Advanced Heat and Mass Transfer, Global Digital Press, Columbia, MO.
Truskey, G.A., Yuan, F., and Katz D.F., 2003, Transport Phenomena in Biological Systems, Prentice Hall, Upper Saddle River, NJ.