Ph.D., National University of Singapore, Singapore.
M.Eng., Wuhan University, P.R. China.
B.Eng., Wuhan University of Hydraulic and Electric Engineering, P.R. China.
Cell mechanics and glaucoma
The leading cause of irreversible blindness in the world is glaucoma. In most cases of glaucoma, vision loss associates with partial blockage of normal fluid drainage from the eye resulting in abnormally high intraocular pressure. Unfortunately the underlying cause of these devastating mechanical changes in fluid drainage remains unknown. We have discovered that drug-induced changes in fluid drainage from the eye correlate with drug-induced mechanical changes in cells that line the wall of the eye’s main outflow conduit, called the canal of Schlemm. This study identifies these cells as a potential therapeutic target for future glaucoma treatment.
Soft condensed matter physics for animal cells
… , the cell can modulate its stiffness in two distinct ways. It may change the tension within its cytoskeleton, as is already well-known. But it may also change its water content and thereby its volume, as we demonstrate here. After all, the cell spends a large portion of its energy budget in regulating its volume; it must be doing so for a good reason.
Nanoparticles interact with cells in the lung
Human activities are producing large quantities of small particles. Compared to their micron-sized counterparts, nanoparticles stay longer in the air and reach deeper into the lung. There, a fraction of nanoparticles might penetrate through the epithelium and reach the airway smooth muscle (ASM), the contractility of which controls how easily we breathe. Are nanoparticles capable of interfering with the ASM contractility? Zhou, Berntsen and colleagues have brought the tools of bioengineering to address this environmental health question. Their findings suggest that direct exposure of the airway smooth muscle cells to particulates have the potential to initiate or aggravate respiratory diseases depending on the particle material, size, and dose.
** feel free to drop me an email if you want any of the papers below **
1. E.H. Zhou, R. Krishnan, W.D. Stamer, K.M. Perkumas, K. Rajendran, J.F. Nabhan, Q. Lu, J.J. Fredberg, and M. Johnson. 2011. Mechanical responsiveness of the endothelial cell of Schlemm’s canal: Scope, variability and its potential role in controlling aqueous humor outflow. Journal of the Royal Society, Interface: In Press. [Corresponding author]
2. E.H. Zhou, F. Xu, S.T. Quek and C.T. Lim. Power-law rheology based finite element model for cell deformation. 2012. Biomechanics and Modeling in Mechanobiology. In Press. [Corresponding author]
3. D.T. Tambe, C.C. Hardin, T.E. Angelini, K. Rajendran, C.Y. Park, X. Serra-Picamal, E.H. Zhou, M.H. Zaman, J.P. Butler, D.A. Weitz, J.J. Fredberg, and X. Trepat. 2011. Collective cell guidance by cooperative intercellular forces. Nature Materials 10:469-475.
4. N. Mizrahi, E.H. Zhou, R. Krishnan, G. Lenormand, D.A. Weitz, J.J. Fredberg, E. Kimmel. Therapeutic ultrasound and its biophysical mechanism of action. Soft Matter. In Press.
5. Berntsen P., Park C.Y., Rothen-Rutishauser B., Tsuda A., Sager T.M., Molina R.M., Donaghey T.C., Alencar A.M., Kasahara D.I., Ericsson T., Millet E.J., Tschumperlin D.J., Butler J.P., Brain J.D., Fredberg J.J., Gehr P., and Zhou E.H. 2010. Biomechanical effects of environmental and engineered particulates on human airway smooth muscle cells. J Royal Society Interface 7 (Suppl 3): S331-S340. [Corresponding author]
- To our knowledge the first application of cell mechanics to studying the physiological consequences of nanoparticle inhalation.
6. Zhou E.H., Lim C.T., and Quek S.T. 2010. Power-law rheology analysis of cells undergoing micropipette aspiration. Biomechanics and Modeling in Mechanobiology: In press. [Corresponding author]
7. Park C.Y., Tambe D., Alencar A.M., Trepat X., Zhou E.H., Millet E., Butler J.P., and Fredberg J.J. 2010. Mapping the cytoskeletal prestress. Am J Physiol Cell Physiol: Epub ahead of print.
8. Cheng Chen, Ramaswamy Krishnan, Enhua Zhou, Aruna Ramachandran, Dhananjay Tambe, Kavitha Rajendran, Rosalyn M. Adam, Linhong Deng, and Jeffrey J. Fredberg 2010. Fluidization and Resolidification of the Human Bladder Smooth Muscle Cell in Response to Transient Stretch. PLoS One 5(8): e12035.
9. Zhou E.H., Trepat X., Park C.Y., Lenormand G., Oliver M.N., Mijailovich S.M., Hardin C., Weitz D.A., Butler J.P., and Fredberg J.J. 2009. Universal behavior of the osmotically compressed cell and its analogy to the colloidal glass transition. Proceedings of the National Academy of Sciences of the United States of America 106:10632-10637.
- Cytoskeletal tension was long known as a primary determinant of cell mechanics. Our work reveals molecular crowding as another major, independent, determinant.
10. Lim C.T., Zhou E.H., and Quek S.T. 2006. Mechanical models for living cells – a review. Journal of Biomechanics 39:195-216.
11. Lim C.T., Zhou E.H., Li A., Vedula S.R.K., and Fu H.X. 2006. Experimental techniques for single cell and single molecule biomechanics. Materials Science & Engineering C-Biomimetic and Suppramolecular Systems 26:1278-1288.
12. Zhou E.H., Lim C.T., and Quek S.T. 2005. Finite element simulation of the micropipette aspiration of a living cell undergoing large viscoelastic deformation. Mechanics of Advanced Materials and Structures 12:501-512.