Articles by Shirley Mao in JoVE
Cell Squeezing as a Robust, Microfluidic Intracellular Delivery Platform Armon Sharei1, Nahyun Cho1, Shirley Mao1, Emily Jackson1, Roberta Poceviciute1, Andrea Adamo1, Janet Zoldan2, Robert Langer1,2, Klavs F Jensen1 1Department of Chemical Engineering, Massachusetts Institute of Technology, 2David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology Rapid mechanical deformation of cells has emerged as a promising, vector-free method for intracellular delivery of macromolecules and nanomaterials. This protocol provides detailed steps on how to use the system for a broad range of applications.
Other articles by Shirley Mao on PubMed
Microfluidics-based Assessment of Cell Deformability Analytical Chemistry. Aug, 2012 | Pubmed ID: 22746217 Mechanical properties of cells have been shown to have a significant role in disease, as in many instances cell stiffness changes when a cell is no longer healthy. We present a high-throughput microfluidics-based approach that exploits the connection between travel time of a cell through a narrow passage and cell stiffness. The system resolves both cell travel time and relative cell diameter while retaining information on the cell level. We show that stiffer cells have longer transit times than less stiff ones and that cell size significantly influences travel times. Experiments with untreated HeLa cells and cells made compliant with latrunculin A and cytochalasin B further demonstrate that travel time is influenced by cell stiffness, with the compliant cells having faster transit time.
A Vector-free Microfluidic Platform for Intracellular Delivery Proceedings of the National Academy of Sciences of the United States of America. Feb, 2013 | Pubmed ID: 23341631 Intracellular delivery of macromolecules is a challenge in research and therapeutic applications. Existing vector-based and physical methods have limitations, including their reliance on exogenous materials or electrical fields, which can lead to toxicity or off-target effects. We describe a microfluidic approach to delivery in which cells are mechanically deformed as they pass through a constriction 30-80% smaller than the cell diameter. The resulting controlled application of compression and shear forces results in the formation of transient holes that enable the diffusion of material from the surrounding buffer into the cytosol. The method has demonstrated the ability to deliver a range of material, such as carbon nanotubes, proteins, and siRNA, to 11 cell types, including embryonic stem cells and immune cells. When used for the delivery of transcription factors, the microfluidic devices produced a 10-fold improvement in colony formation relative to electroporation and cell-penetrating peptides. Indeed, its ability to deliver structurally diverse materials and its applicability to difficult-to-transfect primary cells indicate that this method could potentially enable many research and clinical applications.