Month: September 2017

New technology from Prof. Thanh Nguyen published in Science

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The latest issue of Science features a new technology invented and developed by our very own assistant professor Dr. Thanh D. Nguyen. Prof. Nguyen’s brainchild, developed during his postdoc with Prof. Robert Langer at MIT, offers the latest advance in 3D manufacturing for microstructures of biomaterials: StampEd Assembly of polymer Layers, or SEAL for short. The reliance of current 3D printing techniques on potentially toxic impurities (e.g. UV-curing agents) for formulating printable inks poses clear problems for bio and medical applications. SEAL, on the other hand, can create nearly any 3D micro-objects of pure biopolymers (e.g. polymers used for surgical sutures) with complex geometries and at high resolution. Such enhanced biocompatibility of fabricated 3D microstructures for medical applications enables a broad scope of exciting new possibilities. For example, Prof. Nguyen along with other researchers at MIT used SEAL to create 3D core-shell micro-particles containing biological cargos (e.g. vaccines), which can be programed to sequentially release at different times or even at specific locations within the body. The compelling implications of this technique include the potential for a new set of single-injection vaccines/drugs, which could avoid the repetitive, painful, expensive, and inconvenient injections often required to administer vaccines and drug therapies like insulin or growth hormone. To view the article, click here. 

 

Microengineering Approaches for Tissue Engineering and Developmental Biology

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Abstract: Early stages of human neural development include neural induction, shaping, folding, and closure of neural tubes. Current understanding of early neural development relies on animal studies. However, insights in human neural development mechanism are very limited, largely due to the inaccessibility of human embryo, lack of in vitro models, and ethical concerns. In this talk, I will first discuss our recent experimental and computational works using a series of microengineered tools to model the neural induction, polarization, and bending of neural tubes. Our results demonstrate that biomechanical cues, in addition to morphogen gradient, also play functional roles during multiple stages of neurulation. Direct measurement of cell shape and contractile forces depicted their important roles in regulating the cell fate decision during neural induction. By dynamically changing the shape of cells using an expandable membrane, we further confirm the possibility to tune the cell fate by solely modulating cell shape. In the second part of the talk, I will discuss how mechanical cues regulate the differentiation of human pluripotent stem cells, including their neural differentiation and anterior-posterior patterning. Together, we provide a novel mechano-chemical model of neural development, which provides novel insights in the biomechanics of embryogenesis and morphogenesis.

Biographical Sketch: Yubing Sun is an assistant professor for the Department of Mechanical and Industrial Engineering at the University of Massachusetts, Amherst. He is also a faculty member of Molecular & Cellular Biology Graduate Program and Institute for Applied Life Sciences at UMass. He received his Ph.D. degree from the Department of Mechanical Engineering at the University of Michigan, Ann Arbor in 2015, and his B.S. degree in Materials Science and Engineering from the University of Science and Technology of China. His Ph.D. work with Professor Jianping Fu established the Hippo/YAP-dependent mechanosensitivity of human pluripotent stem cells. His current research interests include mechanotransduction, stem cell biology, microfabrication, developmental biomechanics, lab-on-chip, biosensing, and ultrasound technologies.

 

 

New Device for Testing Heart Health

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George LykotrafitisDr. George Lykotrafitis and his student Kostyantyn Partola have been featured for their development of a device that tests blood viscosity – an important indicator of heart health.  Kostyantyn has had support from the Accelerate UConn program as well as the Connecticut Center for Entrepreneurship and Innovation Fellowship program to support the commercialization of the technology.  More information on their work can be found at UConn Today: http://today.uconn.edu/2017/09/new-device-testing-heart-health/

 

Atomistic Modeling at Experimental Strain Rates and Time Scales

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Abstract: I will present a new computational approach that couples a recently  developed potential energy surface exploration technique with applied mechanical loading to study the deformation of atomistic systems at strain rates that are much slower, i.e. experimentally-relevant, as compared to classical molecular dynamics simulations, and at time scales on the order of seconds or longer.  I will highlight the capabilities of the new approach via multiple examples, including:  (1) Providing new insights into the plasticity of amorphous solids, with a particular emphasis on how the shear transformation zone characteristics, which are the amorphous analog to dislocations in crystalline solids, undergo a transition that is strain-rate and temperature-dependent; (2) Demonstrating new, strain-rate-dependent yield mechanisms and phenomena in bicrystalline metal nanowires; (3) Demonstrating new mechanical force-induced unfolding pathways for the protein ubiquitin.

Biographical Sketch: Harold Park is a Professor of Mechanical Engineering at Boston University. He received his BS, MS and PhD in Mechanical Engineering from Northwestern University in 1999, 2001 and 2004, respectively.  He was a postdoctoral researcher at Sandia Labs (California) from 2004-2005.  He held tenure-track positions at Vanderbilt University (2005-2007) and the University of Colorado (2007-2009) before moving to Boston University in 2010.  His research has generally focused on the mechanics of nanostructures, coupled physics phenomena at nano and continuum length scales, and the mechanics of soft, active materials.