JHU biomedical engineering primary faculty
Aleksander S. Popel, PhD
Professor, Department of Biomedical Engineering, School of Medicine, Johns
Joint Appointment: Professor, Department of Chemical & Biomolecular Engineering, Department of Mechanical Engineering
Office: Traylor 611
Lab: Systems Biology Laboratory
M.S. and Ph.D. in Mechanics, Moscow University
Systems Biology of Angiogenesis
Angiogenesis (the growth of new blood vessels) is important in such diverse areas as cancer, cardiovascular disease, arthritis, diabetes, wound healing, and tissue engineering. We are interested in quantitative understanding of the mechanisms of microvascular network formation under different conditions. Using methods of computational and mathematical biology, we analyze the signaling pathways leading to angiogenesis, and the cellular mechanisms governing tubulogenesis and network formation. Our current focus is on Vascular Endothelial Growth Factor (VEGF) and its interactions with endothelial cell receptors, Matrix Metalloproteinases (MMPs) and their role in the extracellular matrix proteolysis and release of growth factors, and a transcription factor Hypoxia Inducible Factor HIF-1alpha; we are constructing multiscale models of angiogenesis spanning several levels of biological organization. In vitro experiments using endothelial cell assays are also conducted in our laboratory.
Blood Flow and Molecular Transport in the Microcirculation
We are formulating computational models of the microcirculation based on anatomical, biophysical, and physiological experimental data, spanning from the molecular to the tissue levels. These include detailed models of microcirculatory blood flow and molecular transport (e.g., oxygen and nitric oxide) and their regulation, and creation of databases of parameters necessary for models input and validation.
Electromechanical Transduction in the Cochlear Outer Hair Cell
Outer hair cell are among the most sensitive mechanosensory cells in the body and they are crucial for the amplification, sharp frequency selectivity, and nonlinearities of the mammalian cochlea. These cells perform exquisite electromechanical transduction at acoustic frequencies and exhibit a unique form of cell motility. The motility is attributed to membrane-based molecular motors driven by changes in the transmembrane potential. We develop biophysically-based computational models of cell mechanics, molecular transport, and cell electromotility at the microscopic and nanoscopic (molecular) scales.