时间：2023年5月16日（周二）上午9:00-10:30

Time：9:00-10:30 AM, Tuesday, May 16, 2023

地点：西湖大学云谷校区E10-222

Venue: E10-222, Yungu Campus

主持人：西湖大学工学院讲席教授 姜汉卿

Host: Chair Professor Hanqing Jiang, School of Engineering

主讲人/Speaker：

K. Jimmy Hsia

President’s Chair Professor of Mechanical Engineering

School of Mechanical & Aerospace Engineering

School of Chemistry, Chemical Engineering & Biotechnology

报告人简介/Biography：

K. Jimmy Hsia is President’s Chair Professor in the School of Mechanical & Aerospace Engineering and School of Chemistry, Chemical Engineering & Biotechnology at Nanyang Technological University (NTU) in Singapore. He received B.S. from Tsinghua University, China, M.S. from Beijing University of Aeronautics, and Ph.D. from MIT. His research interests include mechanics of soft materials, mechanics of plant organ morphogenesis and morphing metamaterials, mechanics of mammalian cells, micro- and nanotechnologies in mechanical devices and structures, smart adhesive systems, soft robotics. He is Fellow of American Association for the Advancement of Science (AAAS), Fellow of American Institute for Medical and Biological Engineers (AIMBE), Fellow of American Society of Mechanical Engineers (ASME), and recipient of NSF Research Initiation Award, Max-Planck Society Scholarship, and Japan Society for Promotion of Science Fellowship. He was Founding Dean of Graduate College and Vice President (Alumni & International Affairs) at NTU. Before joining NTU, Hsia was Professor of Mechanical Engineering and Biomedical Engineering and Vice Provost for International Programs at Carnegie Mellon University, and before then was W. Grafton and Lillian B. Wilkins Professor of Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign (UIUC). From 2005-2007, Hsia served as Founding Director of Nano and Bio Mechanics Program in the Directorate for Engineering at NSF. He is Founding co-Editor-in-Chief of an Elsevier journal, Extreme Mechanics Letters.

报告题目/Title:

Mechanobiological Effects of Geometry-mediated Wound Healing

讲座摘要/Abstract:

Wound healing through re-epithelialization of gaps is of profound importance to the medical community. One critical mechanism identified by researchers for closing non-cell-adhesive gaps is the accumulation of actin cables around concave edges and the resulting purse-string constriction. However, the studies to date have not separated the gap-edge curvature effect from the gap size effect. In this talk, I will present our recent work published in PNAS1. Our central question is how MDCK cells collectively respond to different curvatures and gap sizes during wound healing. Using micro-printing technology, we generated straight and wavy “wounds” whose size and curvature could be varied independently. Our results show that MDCK cell re-epithelization is closely regulated by the gap geometry and may occur through different pathways. Wavy wounds heal much faster than straight ones. In addition to purse-string contraction, we identify gap bridging either via cell protrusion or by lamellipodium extension as critical cellular and molecular mechanisms for wavy gap closure. Cell migration in the direction perpendicular to wound front, sufficiently small gap size to allow bridging, and sufficiently high negative curvature at cell bridges for actin cable constriction are necessary/sufficient conditions for gap closure. Our experiments demonstrate that straight stripes rarely induce cell migration perpendicular to wound front, but wavy stripes do; cell protrusion and lamellipodia extension can help establish bridges over gaps of about 5 times the cell size, but not significantly beyond; for the gap size that can be bridged, actin cables of sufficiently high negative curvatures can readily form to spread the bridges, leading to full gap closure. Such mechanobiological understanding of cell responses to wound curvature and size helps guide development of biophysical strategies for tissue repair, plastic surgery, and wound management.

讲座联系人/Contact:

科技合作部 sci-tech02@westlake.edu.cn