Special Joint BioE/ChBE Seminar: Jeanne Stachowiak
Thursday, February 24, 2011
11:00 a.m.-12:00 p.m.
1105 Jeong H Kim Engineering Building
301 405 9673
Reverse Engineering Biological Membranes
Sandia National Laboratories
My research employs micro- and nanotechnology to build biological membranes component-by-component from the bottom up. By reconstructing membranes from known components under controlled conditions, we can simultaneously model the biophysical mechanisms that underlie membrane function in cells and employ cell-like synthetic membranes for practical applications in medicine, materials science, and energy.
The first part of the talk will discuss development of a microfluidic method for direct encapsulation of biomolecular solutions in lipid vesicles. Construction of vesicle-encapsulated systems has been limited by the difficulty of forming vesicles with controlled size and composition. We have recently developed a method for forming and loading lipid vesicles using a pulsed microfluidic jet. Akin to blowing a bubble, the microfluidic jet deforms a planar lipid bilayer into a vesicle that is filled with solution from the jet and separates from the planar bilayer. In contrast to existing techniques, this method rapidly generates multiple monodisperse vesicles with controlled membrane composition and virtually unrestricted internal contents, creating broad opportunities for the construction of biomimetic devices.
The second part of the talk will discuss the use of synthetic membrane systems to explore a new mechanism of membrane curvature induction that can define membrane architecture at the nano-scale. While critical to cellular function, deformation of lipid membranes into highly curved structures remains poorly understood. Using lipid vesicles that contain phase-separated lipid regions with engineered affinity for proteins, we observed that protein crowding on membrane surfaces created a protein layer that buckled outward, spontaneously bending the membrane to form stable buds and tubules. These observations may help explain how lipids and proteins collaborate to create the highly curved structures observed in cellular membranes, and could be used to build synthetic nano-scale containers and dynamic membrane networks.
The talk will conclude with a brief discussion of research opportunities at the intersection of micro/nano technology, membrane biophysics, and biomedical applications of membrane-encapsulated systems.
About the Speaker
Dr. Jeanne Stachowiak completed her undergraduate education in Mechanical Engineering at the University of Texas at Austin in 2002. She received a Masters degree in Mechanical Engineering from the University of California, Berkeley in 2004. Her Masters work, under the supervision of Professor Arun Majumdar, involved fabrication and characterization of micro-scale sensor arrays for detection of biomolecular interactions relevant to biosecurity and disease diagnostics. Following completion of her Masters degree, Dr. Stachowiak joined Sandia National Laboratories in Livermore, California, where she developed microfluidic systems for detection of aerosolized spores. She received a Doctorate in Mechanical Engineering from the University of California, Berkeley in 2008. Her doctoral work, under the supervision of Professor Daniel Fletcher, involved development of microfluidic systems for transdermal drug delivery and encapsulation of biomolecules inside lipid membrane vesicles. Since completing her Doctorate, Dr. Stachowiak has worked as a Senior Member of the Technical Staff at Sandia National Laboratories, where her research program explores basic biophysical questions and practical applications of lipid membrane materials and systems.