SBES Distinguished Lecturer Series – March 6

March 6, 2014, 11-12, 310 Kelly (ICTAS)/WFU: 151 Biotech Bldg./VTCRI: R2139

Dr. Robin Queen

Assistant Professor, Department of Orthopaedic Surgery, Duke University Medical Center

Optimizing Life Long Function Following Surgical Intervention

Orthopaedic surgical intervention and post

 

operative return of function are vitally important to longterm health and function. Currently the postsurgical management of orthopaedic patients is not based on objective measures of function and ability; instead the clinical decisions that are made are based solely on surgeon experience and the time since surgery. Through this talk we will explore what is currently known about postoperative function following a variety of orthopaedic surgical interventions including joint replacements and anterior cruciate ligament (ACL) reconstruction, followed by a discussion of potential objective measures of function and ultimately how to improve longterm health and improve mobility in these patient populations.

In the first half of the talk, I will discuss previous work we have completed examining lower extremity function and loading patterns following these various surgical procedures. Recent work at the Michael W. Kzyzewski Human Performance Lab at Duke University has shown that following surgical intervention significant side-to-side asymmetries exist with regards to lower extremity gait mechanics independent of the surgical population that is being studied. This work has allowed us to begin asking questions about how to better quantify function in the clinical setting and how those measurements are related to threedimensional gait assessment. In addition through this work, we have begun to ask questions about how to improve function through additional, non-surgical interventions as well as identifying way to prevent secondary injuries following surgery. The goal of this work and this talk is to being to discuss method for improving longterm joint function and activity level following orthopaedic surgical interventions and to explore ways of keeping people healthy and active as they age.

Virginia Tech – Wake Forest University School of Biomedical Engineering and Sciences

317 ICTAS, Stanger St., (0298) Blacksburg, Virginia 24061 • 540-231-8191 • www.sbes.vt.edu

SBES Distinguished Lecturer Series, March 4

March 4, 2014, 11-12:15, 310 Kelly (ICTAS) /WFU: Biotech Bldg./VTCRI: R2139

Biological Laser Printing (BioLP) of Microvascular Cells onto Composite Hydrogel Biopapers

Dr. Bradley Ringeisen,

Dr. Bradley Ringeisen

Head, Bioengry and Biofabrication,

U.S. Naval Research Laboratory

Defense Threat Reduction Agency (DTRA)

Science & Technology Manager

Diagnostics and Disease Surveillance Division

 

Two major challenges in tissue engineering are mimicking the native cell cell arrangements of tissues and maintaining viability of threedimension (3D) tissues thicker than 200μm. Cell printing and prevascularization of engineered tissues are promising approaches to meeting these challenges. We suggest that both challenges could be addressed by printing 2D patterns of vascular cells onto biopaper substrates. Composite biopapers made of a mechanically supportive polymer scaffold and extracellular matrix-like hydrogel could sustain differentiation and network formation of printed vascular cells, while enabling transfer and stacking of individual biopapers to form thick 3D constructs. We have used several different polymer and hydrogel materials to make composite biopapers including polylactidecoglycolide (PLGA), polydimethylsiloxane (PDMS), MatrigelTM and collagen. Biological laser printing (BioLP) was then used to print patterns of vascular endothelial cells onto the biopapers. The vascular cells differentiated postprinting, stretching to form networks that retained the printed structure as well as forming smaller spontaneous outgrowths. After the onset of vascular differentiation, the biopapers were stacked, cultured and observed with confocal microscopy. Interlayer boundaries were defined with fluorescent beads so that cell migration and networking could be observed between layers. Additional experiments were performed to move towards a 3D brain model by printing vascular cells onto biopapers preseeded with astrocytes. These results demonstrate the feasibility of stackable biopapers as a way to build 3D vascularized tissues with a 2D cell printing technique.

Dr. Bradley Ringeisen is Head of the Bioenergy and Biofabrication Section at the U.S. Naval Research Laboratory (NRL). He is currently on loan to the Defense Threat Reduction Agency (DTRA) Joint Science and Technology Office (JSTO) as a science and technology manager in the Diagnostics and Disease Surveillance Division. He has been tasked as the Project Lead for DTRA/JSTO’s 24 month diagnostics challenge, which is a program that will demonstrate the linkage of point

 

ofcare/pointofneed diagnostic devices with an informaticsbased, biosurveillance ecosystem.

I will also discuss two projects that are beginning this year in my laboratory. We are engineering two 3D tissue models (lung and blood

 

-brain-barrier) for in vitro infection and diagnostic biomarker discovery experiments. Aerosolized Burkholderia pseudomallei will be exposed to the lung model while Venezuelan equine encephalitis virus (VEEV) will be exposed to the blood-brain-barrier model. Each model will utilize stacked biopaper and cell printing approaches. A second program will engineer an active acute care covering to stabilize wounds. This project will be developing autonomous materials with bioactive properties including antimicorbials, hemostasis agents and dynamic shape. We are searching for qualified postdoctoral candidates to work on these projects, and I will be available after the seminar to discuss potential opportunities.

During his postdoctoral position, Dr. Ringeisen performed the first successful laser induced forward transfer printing experiment on a living cell. He was hired as a research chemist at NRL in 2002 and currently maintains a six member research group. This group has a wide range of research interests that include the study of microbial extracellular electron transfer, biofuel production, the bio/nano interface, stem cell/material interactions as well as cell and tissue printing for medical and diagnostic applications.

Virginia Tech – Wake Forest University School of Biomedical Engineering and Sciences 317 ICTAS, Stanger St., (0298) Blacksburg, Virginia 24061 • 540-231-8191 • www.sbes.vt.edu

Hassan Aref Memorial Lecture & Fall Fluid Mechanics Symposium Invited Lecture*

Sap Flow and Sugar Transport in Plants

Thursday, November 21, 2013

11:00-12:00, Assembly Hall, The Inn

Dr. Tomas Bohr

Technical University of Denmark

 Plants have highly effective vascular systems, which can transport fluid over large distances. The xylem system carries water from the roots up to the leaves and the phloem system carries sugar solutions from sources (leaves) to sinks (roots, fruits etc.) and thus provides the necessary material for growth. There are many important fluid dynamical problems connected with these flows, and I shall discuss some of them. In the 1920’ies, Ernst Münch proposed that sugar transport in the phloem is driven by passive osmotic pressure gradients generated by loading and unloading sugar into the phloem tubes (sieve elements) of the leaves. It has been strongly debated whether this hypothesis can actually account for long distance translocation, e.g., from canopy to root of a large tree. In the lecture, I will argue that optimization of the efficiency of the sugar transport leads to a universal scaling of the width of the phloem tubes with the loading (leaf) length and the translocation (stem) length in plants. These predictions have been tested for plants ranging from 10 cm herbacious plants to 60 m trees – both hardwood and conifers – and provide the first quantitative test of Münch’s ideas. For both the xylem and the phloem, the leaves provide the driving force for the sap flow, and I shall discuss current ideas how this complex feat is accomplished.

The lecture is partly based on recent papers:

K. H. Jensen, J. Lee, T. Bohr, H. Bruus, N. M. Holbrook & M. A. Zwieniecki: Optimality of the Münch mechanism for translocation of sugars in plants, Journal of the Royal Society Interface 8, 1155–1165 (2011)

K. H. Jensen, T. Bohr & H. Bruus:  Osmotically driven flows in microchannels separated by a semipermeable membrane, Lab on a Chip 9, 2093-2099 (2009)

K. H. Jensen, J. Liesche , T. Bohr & A. S. Schulz: Universality of phloem transport in seed plants, Plant, Cell & Environment 35, 1065-1075 (2012)

K. H. Jensen, K. Berg-Sørensen, S. Friis & T. Bohr: Analytic solutions and universal properties of sugar loading models in Münch phloem flow, Journal of Theoretical Biology 304, 286-296 (2012)

K.H. Jensen, D.L. Mullendore, N.M. Holbrook, T. Bohr, M. Knoblauch & H. Bruus: Modeling the hydrodynamics of phloem sieve plates, Frontiers in Plant Science 3, article 151 (2012)

L. S. Haaning, K. H. Jensen, C. Hélix-Nielsen, K. Berg-Sørensen & T. Bohr: Efficiency of osmotic pipe flows, Physical Review E 87, 053019 (2013)

*This is a joint seminar co-sponsored by the Department of Engineering Science and Mechanics, the Department of Mechanical Engineering, and the MultiScale Transport in Environmental and Physiological Systems (MultiSTEPS) program.

BSE Seminar on earth systems modeling

Please join the BSE Department for the following seminar, presented by Dr. Matteo Convertino, candidate for a BSE assistant professor position in earth systems modeling.

Speaker:  Dr. Matteo Convertino
Research Faculty, Dept. of Agricultural and Biological Engineering
Affiliated Faculty, Climate Institute, & Water Institute
University of Florida, Gainesville, FL

Title:  “Models as Technology for Complex Natural-Human Systems’ Analysis and Design”
Date:
Monday, April 29, 2013
Time: 9:00 – 10:00 am
Location: 108 Seitz Hall

Seminar: Microfluidic Tools for Cellular Engineering and Analysis

Speaker: Dr. Chang Lu, Associate Professor of Chemical Engineering at Virginia Tech

Date: Wednesday, April 18, 2012
Time: 2:45-3:45 pm
Location: 310 ICTAS, 325 Stanger St.

Microfluidics provides a versatile platform for manipulating and analyzing cells down to single cell level. In this talk, I will discuss microfluidic devices we developed for genetic modification and cellular analysis. We developed a simple microfluidic flow-through technique that conducts electroporation under constant voltage for gene delivery. We showed that hydrodynamics such as Dean flows could be introduced to dramatically influence gene uptake and its distribution on the cell surface. We also developed a set of microfluidic cytometric tools for studying the subcellular localization of proteins and the cell surface events with high throughput and single cell resolution. Finally, I will briefly discuss our recent work on analyzing epigenetics of cells using chromatin immunoprecipitation assay. These tools may find applications to cell-based therapies, molecular biology studies, drug discovery, and clinical diagnosis/staging.

Seminar: Nanoscale electrokinetics for manipulation and measurement of biosystems

MultiSTEPS Seminar, Thursday, April 5, 10-11am, 310 ICTAS

Nanoscale electrokinetics for manipulation and measurement of biosystems
Dr. Nathan Swami, Dept. of Electrical Engineering, University of Virginia

Abstract: The ability to selectively manipulate bio-systems (cells, DNA and proteins) and nanostructures (nanofibers, nanotubes and nanowires) in fluids and at localized fluid/surface interfaces, within media of a wide range of conductivity, is fundamental to many applications in biomedicine and nanofabrication. Electrokinetic methodologies based on inherent dielectric properties of the manipulated nanostructures are uniquely poised for directing self-assembly since their scaling laws are highly compatible with micro- and nanofluidic systems, and their instrumentation are relatively simple. In our group, we focus on micro/nanofluidic device platforms for electrokinetic and magnetic trapping, alignment and patterning of nano- and biomaterials for applications within biosensing and tissue regeneration. This talk will present examples on the challenges and opportunities for the application of electrokinetics within biosensing for frequency-selective pre-concentration of target analytes to enhance detection sensitivity of biomarkers, within tissue regeneration for alignment of nanostructures for cell guidance, and within environmental remediation through dielectric characterization of infectious microbial cell viability.

Bio: Nathan Swami is an Associate Professor of Electrical Engineering at University of Virginia, where his research is centered on devices for the dielectric manipulation of bio- and nanostructures for biosensing and tissue regeneration applications. Previously he served as a Principal Scientist within the MEMS and Microfluidics group of Motorola Labs, and Senior Scientist at Clinical Microsensors, a Caltech start-up focused on electronically functional DNA micro-arrays.

Seminar: Synthetic Biological Systems for Environmental Deployment

The BSE Department invites us to join them for the seminar “Synthetic Biological Systems for Environmental Deployment” presented by Dr. Warren Ruder, candidate for a BSE assistant professor position.

Date: Tuesday, April 3, 2012
Time: 2:00 – 3:00 pm
Location: Fralin Auditorium

Dr. Warren Ruder is currently a postdoctoral research associate at Boston University, Harvard Wyss Institute, and Howard Hughes Medical Institute.  His current research focus is the construction of synthetic gene networks to enable bacteria to execute complex programmed behavior.  Dr. Ruder received his B.S. degree in Civil and Environmental Engineering from Massachusetts Institute of Technology in 2002 and his M.S. in Mechanical Engineering and Ph.D. in Biomedical Engineering from Carnegie Mellon University in 2008 and 2009, respectively.

Seminar: George Lauder on fish robotics

Fish robotics: understanding the diversity of fishes using mechanical devices

George V. Lauder,
Henry Bryant Bigelow Professor
Professor of Organismic and Evolutionary Biology
Harvard University
Tuesday, February 28, 10-11:30 am
ICTAS building on Stanger Street, Room 310

There are over 28,000 species of fishes, and a key feature of this remarkable evolutionary diversity is the variety of propulsive systems used by fishes for swimming in the aquatic environment. Fishes have numerous control surfaces which act to transfer momentum to the surrounding fluid. In this presentation I will discuss the results of recent experimental kinematic and hydrodynamic studies of fish locomotor function, and the implications for construction of robotic models of fishes.   Continue reading

Seminar: Multidisciplinary Collaboration – Making it Work

IDR Social and Seminar Series
Multidisciplinary Collaboration – Making it Work
Prof. Layne T. Watson
Monday, February 27th, 2012
12:00 pm – 1:00 pm
ICTAS (Building I), Room 310

Layne T. Watson received the B.A. degree (magna cum laude) in psychology and mathematics from the University of Evansville, Indiana, in 1969, and the Ph.D. degree in mathematics from the University of Michigan, Ann Arbor, in 1974. He is a professor of computer science and mathematics at Virginia Polytechnic Institute and State University. His research interests include fluid dynamics, solid mechanics, numerical analysis, optimization, parallel computation, mathematical software, image processing, and bioinformatics. He has worked for USNAD Crane, Sandia National Laboratories, and General Motors Research Laboratories and served on the faculties of the University of Michigan and Michigan State University, East Lansing, before coming to Virginia Tech. He has published well over 290 refereed journal articles and 200 refereed conference papers. He is a fellow of the IEEE, the National Institute of Aerospace, and the International Society of Intelligent Biological Medicine.