Seminar Speakers
Upcoming Seminars
May 2, 2016
at 10:30AM in 322 ISE Lab [view/download flyer]
Larry Taber, Ph.D.
Dennis and Barbara Kessler Professor
Washington University in St. Louis
Seminar Title: “Mechanical Aspects of Early Heart and Eye Development”
Seminar Abstract: Although the molecular and genetic aspects of embryonic development are becoming clear, the physical mechanisms that create tissues and organs remain poorly understood. This talk focuses on two problems in the mechanics of organogenesis: (1) cardiac looping, which transforms the initially straight heart tube (HT) into a curved tube to lay out the basic plan of the mature heart; and (2) transformation of the optic vesicle (OV) into the optic cup (primitive retina).
Abnormal looping is thought to underlie many of the congenital heart defects that threaten the health of the developing embryo. Recently, we have proposed a new hypothesis for the first phase of looping (c-looping), as the HT bends and twists into a c-shaped tube. According to our hypothesis, differential hypertrophic growth causes the heart tube to bend, while a combination of growth, contraction, and external compression drives rightward torsion. The physical plausibility of this hypothesis was examined using a computational model based on realistic heart geometry. The behavior of the model is in reasonable agreement with experimental results from control and perturbed chick embryos, offering support for our hypothesis.
The eyes form initially as a pair of relatively spherical OVs that protrude from of the brain tube. Each OV grows until it contacts and adheres to the overlying surface ectoderm (SE) via an extracellular matrix (ECM). The OV and SE then thicken and bend inward (invaginate) to create the optic cup and lens vesicle, respectively. We speculate that invagination is driven by OV growth that is constrained by the ECM. By disrupting the ECM in chick embryos at various stages of development, we found that the matrix is required for the early stages but not the late stages of invagination. Finite-element model consisting of a growing spherical OV attached to a relatively stiff layer of ECM reproduced the observed behavior, as well as measured changes in OV curvature, wall thickness, and invagination depth reasonably well. These results support our hypothesis.
Our results provide new insights into the forces that drive early heart and eye development. Understanding the mechanics of morphogenesis could one day lead to new strategies for tissue engineering, tissue regeneration, and the prevention and treatment of congenital malformations.
Past Seminars
April 11, 2016
at 10:30AM in 322 ISE Lab [View/Download Seminar Flyer]
Rhonda Prisby, Ph.D.
Associate Professor of Kinesiology and Applied Physiology
University of Delaware
Seminar Title: “The coupled nature of the vascular and skeletal systems”
Abstract: Osteopathology can include conditions that impair the normal functioning of bone and bone marrow. For example, age-related declines in bone mass often coincide with increased fracture risk, reduced hematopoiesis, augmented bone marrow ischemia and adiposity, and immnosenescence. Even though normally ascribed to dysfunction of bone and bone marrow, osteopathology may derive a portion of its etiology from dysfunction of the bone vascular system. Declines in bone volume are associated with 1) diminished vasodilator capacity of bone arteries, 2) reduced bone blood flow, 3) impaired bone angiogenesis and blood vessel density, and 4) an increased distance between bone marrow blood vessels and bone surfaces. Thus, bone vascular dysfunction may rest internal to the skeleton (i.e., the bone marrow blood vessels) or external (i.e., nutrient arteries and veins that originate outside and penetrate the skeleton). We recently discovered severe calcification of bone marrow blood vessels, whereby this pathology extended beyond calcium deposition. In fact, the bone marrow blood vessels appeared ossified and bone-like in morphology, as evidence by the presence of osteocyte lacunae on their abluminal surfaces. The ossification of bone marrow blood vessels progressively worsened with advancing age in rats and was associated with reduced bone volume, augmented bone marrow adiposity and a reduced number of patent bone marrow blood vessels. Additionally, there may be a link between ossification and an increased inflammatory bone marrow microenvironment. This presentation will present quantitative and characteristic data on bone marrow blood vessel ossification as a function of advancing age in male Fischer-344 rats. Additionally, the influence of bone marrow, via enhanced inflammatory cytokine production, on bone vascular function will be highlighted. Lastly, data will bear out that ossification of bone marrow blood vessels translate to the human model.
March 28, 2016
at 10:30AM in 322 ISE Lab [view/download flyer]
Mark Pierce, Ph.D.
Assistant Professor
Rutgers University
Seminar Title: “Rare-earth doped nanocomposites for targeted short-wave infrared imaging of cancer”
Seminar Abstract: We are developing rare-earth doped nanocomposites as targeted contrast agents for clinical optical imaging of cancer. These materials undergo near infrared excitation and provide short-wave infrared emission, resulting in deeper imaging capability than visible or near infrared probes. Encapsulating rare-earth nanoparticles within an albumin shell and functionalizing with AMD3100 promotes targeting to CXCR4, a recognized marker for several highly metastatic cancers. This presentation will describe our team’s multi-disciplinary research in rare-earth spectroscopy, nanoparticle synthesis and biofunctionalization, alongside development of systems for macroscopic (whole-animal) and microscopic (sub-cellular) imaging. Results will be reported from an ongoing study using these technologies to detect and track early micrometastatic lesions in breast cancer.
March 7, 2016
at 10:30AM in 322 ISE Lab [view/download flyer]
Jason Burdick, Ph.D.
Professor
University of Pennsylvania
Seminar Title: “Engineering Hydrogels for Tissue Repair”
Seminar Abstract: Hydrogels represent a class of biomaterials that have great promise for the repair of tissues, particularly due to our ability to engineer their biophysical and biochemical properties. Hydrogels can provide instructive signals through material properties alone (e.g., mechanics, degradation, structure) or through the delivery of therapeutics that can influence tissue morphogenesis and repair. Importantly, hydrogel design should reflect both the clinical context and the natural healing cascades of the damaged tissue. Here, I will give examples of the design of hydrogels based on hyaluronic acid (HA) for the repair of two tissues (cardiac and cartilage) that have limited natural repair processes. Towards cardiac repair, my laboratory is interested in designing materials that can influence the left ventricular remodeling process that occurs after myocardial infarction. To permit percutaneous delivery of hydrogels (e.g., via catheters), we have developed a class of shear-thinning and self-assembling hydrogels that can be used for the delivery of mechanical signals, as well as cells and therapeutics (e.g., protease inhibitors). These hydrogels assemble based on guest-host interactions and can be designed to degrade via matrix metalloproteinases or to become more stable through secondary crosslinking. These iterations on material design are teaching us what important signals are needed in these hydrogels towards the next generation of translatable therapeutics for cardiac repair. Towards application in cartilage repair, we have developed multi-polymer fibrous hydrogels that permit control over scaffold porosity and therapeutic release via the engineering of specific fiber populations. Fibers are formed through an electrospinning and photocrosslinking process, where individual fiber degradation is controlled through macromer chemistry. We have investigated these scaffolds towards cartilage repair when combined with microfracture in a large animal (i.e., minipig) model with a focus on the influence of material choice and growth factor delivery on tissue repair.
February 29, 2016
at 10:30AM in 322 ISE Lab
Leaf Huang, Ph.D.
Fred Eshelman Distinguished Professor
University of North Carolina
Seminar Title: “Lipid stabilized nano precipitates for drug and gene delivery”
Seminar Abstract: TBA
February 26, 2016
at 1:00pm in 322 ISE Lab [view/download seminar flyer]
Julius Korley, Ph.D., MBA
President & CEO at Affinity Therapeutics
Associate Coulter Program Director
Case Western Reserve University
Seminar Title: “Translational Research to Address Unmet or Poorly Met Clinical Needs.”
Seminar Abstract: Biomedical translational research is aimed at meeting the unmet clinical needs that ultimately affect some measure of patient care and quality of life. Case Western Reserve University (CWRU) has engaged with the Wallace H. Coulter Foundation (WHCF) to change how biomedical translational research is conducted. In 2006, a partnership began between CWRU and WHCF and resulted in a joint $20 million endowment to run the program in perpetuity. This partnership has the Coulter Process at its core. This multi-step process fully integrated and executed has been proven to help mitigate risks and increase the odds of commercialization for the projects that go through the process. Additionally, projects subjected to the Coulter process have been very successful raising follow-on funding to include non-dilutive funding such as SBIR/STTR as well as equity funding such as Angel and VC. Affinity Therapeutics is one example of CWRU’s many success stories.
November 2, 2015
at 10:30AM in 322 ISE Lab [View/Download Seminar Flyer]
Clark Hung, Ph.D.
Professor
Biomedical Engineering
Columbia University
Seminar Title: “A Paradigm for Functional Tissue Engineering of Articular Cartilage”
Seminar Abstract: Articular cartilage is the specialized connective tissue that covers the ends of the bones that comprise our diarthrodial joints (e.g., knee and hip), and serves a critical load bearing and lubrication function. Absent of blood vessels, cartilage exhibits a poor intrinsic healing capacity after injury. The aim of our laboratory has been to engineer clinically-relevant articular cartilage grafts for repair of damaged and diseased joints. In this effort, several strategies have been employed to promote development of mechanically functional tissue including applied dynamic loading bioreactors and growth factor optimization. In addition to surviving the demanding physical environment, engineered cartilage grafts implanted in pathologic joints must often survive a harsh chemical environment. To address the latter, we have explored strategies to precondition developing cartilage constructs to proinflammatory cytokines, as well as for co-delivery of cells and dexamethasone-laden polymer carriers in engineered cartilage. While these complementary research thrusts were first developed using bovine cells, our team has made significant strides toward translation to cells of a large preclinical animal model (canine), and more recently to human cells.
October 5, 2015
at 10:30AM in 322 ISE Lab [View/Download Seminar Flyer]
Michelle Dawson, Ph.D.
Assistant Professor
Chemical & Biomolecular Engineering
Georgia Tech
Seminar Title: “Mechanics and Malignancy: Biophysical Approaches for Understanding Cancer”
Seminar Abstract: Despite huge advances in the molecular regulators of cancer growth and metastasis, patient survival rates have largely stagnated, with over 90% of cancer deaths due to metastasis. Recent studies have demonstrated that increased understanding of the forces generated by cancer cells and their influence on tumor growth, invasion, and metastasis are essential in finding new treatments for metastatic cancer. Bone marrow derived mesenchymal stem cells (MSCs) that accumulate in the primary tumor due to their natural tropism for inflammatory tissues may also enhance the metastatic potential of cancer cells through direct interactions or paracrine signaling. Quantitative analysis of actin cytoskeletal mechanics and surface traction forces allow us to probe the biomechanical properties of cells with an extraordinary level of detail. These biophysical techniques are used to systematically investigate the parameters in the tumor microenvironment that control MSC interactions with cancer cells and to identify specific conditions that induce tumor-promoting behavior in MSCs, along with strategies for inhibiting these conditions to limit force-dependent cancer progression. By systematically investigating the conditions in the tumor microenvironment that affect MSC interactions with cancer cells, we hope to gain a fundamental understanding of the role of MSCs in cancer progression, which is essential in developing new strategies for controlling the behavior and even manipulating the fate of MSCs in the tumor. This biophysical approach has also been used to classify cancer cells by their mechanical properties and to identify therapeutic targets for metastatic cancer based on the mechanical phenotypes of different types of cancer cells.
September 14, 2015
at 10:30am in 322 ISE Lab [Seminar Flyer]
Eleftherios Terry Papoutsakis, Ph.D.
Eugene DuPont Chaired Professor
Chemical & Biomolecular Engineering
University of Delaware
Seminar Title: “Microparticles as cellular communicators to empower therapies: the case of megakaryocyctic microparticles.”
Seminar Abstract: A long-standing goal in cell-culture technologies is the ability to produce human blood cells for transfusion medicine. Another important goal is to develop robust differentiation technologies of stem cells, technologies that could be transferred to the clinic but also used in in vitro investigational experimentation. Among blood cells, platelets, needed for blood coagulation and vascular repair, are an expensive “product” in limited supply. Production of platelets in a “blood factory” is recognized as a grand challenge that remains elusive. Platelets derive from polyploid megakaryocytes (Mks) in the bone marrow and lung vasculature, under the action of biomechanical forces. We will show how important these forces are for producing functional platelets and their precursors, as well as small, anuclear particles, Mk microparticles (MkMPs)*. MkMP generation was dramatically enhanced (up to 47 fold) by shear flow. Significantly, co-culture of MkMPs with hematopoietic stem and progenitor cells (HSPCs) promoted HSPC differentiation to Mks without exogenous thrombopoietin, thus identifying, for the first time, a novel and previously unexplored potential physiological role for MkMPs. This demonstrates the extraordinary ability of these MkMPs in programming HSPCs. I will discuss our efforts to understand the mechanisms by which MkMPs target and act upon cells. How general is the production and biological activity of MPs? Most cells release into the extracellular environment these very small MPs (typically less than 1 micron) under some stress or activation process. MPs result from direct budding off the the plasma membrane, and are increasingly recognized as important players in intercellular communication by transferring proteins, lipids, RNA, and perhaps DNA, between cells. They do so with good target specificity and thus, one can argue for producing and using them for regenerative-medicine applications, as well as in experimental investigations to deliver “cargo” to specific cell types.
* Jiang, J; Woulfe, DS; Papoutsakis, ET. Shear enhances thrombopoiesis and formation of microparticles that induce megakaryocytic differentiation of stem cells BLOOD 124: 2094-2103 (SEP 25 2014).
May 8, 2015
at 9:30am in 322 ISE Lab (Download Seminar Flyer)
Ting Lu, Ph.D.
Assistant Professor
Bioengineering & Institute for Genomic Biology
University of Illinois at Urbana-Champaign
Seminar Title: “Understanding and programming bacterial functionality via engineered gene networks.”
Seminar Abstract: Gene regulatory networks are one of the major cellular infrastructures that confer defined biological functions. My research focuses on synthetic biology—the analysis, construction, and exploitation of these networks for programming cellular functionalities, particularly those relating to probiotic bacteria and microbial community. Towards probiotic bacteria, I will report a recently developed pathway engineering platform for lactic acid bacteria, and will illustrate its applications such as bacteriocin overproduction. Due to the dominant presence of microbes in the form of complex community, we are equally interested in understanding and engineering bacterial collective behaviors implemented by natural and synthetic gene networks. Examples will be discussed to illustrate our efforts.
March 5, 2015
at 9:00am in 322 ISE Lab
Co-sponsored by the NIH-COBRE “Molecular Design of Advanced Biomaterials”
(Download Seminar Flyer)
Claudia Fischbach-Teschl, Ph.D.
Associate Professor
Biomedical Engineering
Cornell University
Seminar Title: “Cancer research from a tissue engineering and biomaterials perspective.”
Seminar Abstract: Perturbed microenvironmental conditions play important roles in tumor initiation, progression, and therapy response; however, the underlying molecular, cellular, and tissue-level mechanisms remain relatively poorly understood. By integrating biomaterials, tissue engineering, and microfabrication strategies our lab has developed a variety of in vitro and in vivo models to study tumorigenesis under pathologically relevant conditions. In particular, we are applying these model systems to evaluate the regulatory roles of extracellular matrix (ECM) physicochemical properties on tumor-stroma interactions with a focus on tumor angiogenesis and metastasis. This talk will summarize some of our efforts in this area and discuss tumor-mediated differences in mesenchymal stem cell fate, the effect of these changes on ECM physicochemical properties, and the resulting functional consequences on endothelial and tumor cell behavior.
September 18, 2014
at 11:00am in 311 Pearson Hall
(Download Seminar Flyer)
Susan Marguiles, Ph.D.
George H. Stephenson Term Professor
Bioengineering
University of Pennsylvania
Seminar Title: “Understanding why head rotation direction matters”
Seminar Abstract: Previously we reported that traumatic axonal injury and neurofunctional outcomes after rapid head rotations are influenced by head rotation direction. We hypothesized that injury is closely correlated with white matter tract deformation, and that these deformations vary with head rotation direction. We used our animal studies to identify relationships between rapid head rotation direction and velocity and regional axonal pathology, diffusion tensor images to define white matter tract orientation, and computational simulations validated with actual brain tissue displacement in physical model studies, and found that white matter tract-oriented strains and strain rates vary with head rotation direction, and are strongly correlated with traumatic axonal injury. Thresholds for the infant and pre-adolecent differ. These results have implications for traumatic brain injury risk in sports, automotive, and household environments.
October 16, 2014
at 11:00am in 322 ISE Lab
(Download Seminar Flyer)
Athanassios Sambanis , Ph.D.
Professor • School of Chemical & Biomolecular Engineering
Georgia Institute of Technology
Program Director • Biomedical Engineering Program
National Science Foundation
In this two part talk, Dr. Sambanis will first detail his lab’s research on cell and tissue-based therapies for diabetes, and will then describe the Biomedical Engineering Program at NSF.
Seminar Titles: “Cell and Tissue-based Therapies for Insulin-Dependent Diabetes” and “The Biomedical Engineering Program at the National Science Foundation”
Seminar Abstracts:
Part 1: His lab researches living biological substitutes for treating insulin-dependent diabetes that are less invasive and provide a more physiologic regulation of blood glucose levels than insulin injections. The critical technologies needed for such a substitute depend strongly on the type of cells used. The Sambanis lab focuses on encapsulated allo- and xenogeneic pancreatic cells and on non-pancreatic cells genetically engineered to secrete insulin in response to physiologic stimuli. With encapsulated cells, they are developing methods to improve immunoprotection by combining a semipermeable barrier that improves immune acceptance with the local presentation and delivery of pro-survival and insulinotropic factors. Furthermore, they are developing technologies for cryopreserving encapsulated cells and for monitoring grafts in minimally invasive or non-invasive ways. With non-pancreatic cells, they are genetically engineering hepatic and intestinal endocrine L cells for insulin secretion. The potential and challenges of developing clinical therapies based on these approaches will be discussed.
Part 2: The overall objectives of the Biomedical Engineering (BME) Program at NSF and various activities sponsored by the program will be presented. The program’s thrust areas are (i) cellular, molecular and tissue approaches for advanced biomanufacturing, and (ii) neural engineering and human brain mapping. These areas will be discussed in the context of their significance within the biomedical field and of funding opportunities offered to investigators by the BME program.
November 13, 2014
at 11:00am in 322 ISE Lab
(Download Seminar Flyer)
Jordan Green , Ph.D.
Associate Professor
Biomedical Engineering
Johns Hopkins School of Medicine
Seminar Title: “Polymeric Nanoparticles and Microparticles to Bioengineer Target Cells”
Seminar Abstract: The Green lab uses libraries of biodegradable polymers to construct microparticles and nanoparticles as enabling technology that can bioengineer target cells and treat cancer. In one branch of this research, bionanotechnology is constructed that is safe and effective for the intracellular delivery of nucleic acids such as DNA and siRNA. These gene delivery nanoparticles are designed to be specific to cancer cells over healthy cells. Biomaterial structure, and in particular polymer end-group, can determine this cell-type specificity. Examples will be shown for intracellular delivery to brain cancer, liver cancer, and lung cancer. A second branch of this research is on the design of micro and nanobiotechnology that mimics the surface presentation of biological cells. The role of particle size and shape in constructing artificial antigen presenting cells will be discussed. An example will be shown for how these biomimetic particles can be used for immunotherapy to treat melanoma.
December 4, 2014
at 11:00am in 322 ISE Lab
(Download Seminar Flyer)
Vincent Wang , Ph.D.
Associate Professor
Orthopedic Surgery
Rush University Medical Center
Seminar Title: “Mechano-biologic Approaches to Promote Tendon Healing”
Seminar Abstract: Functional impairment in tendons, such as those which control movement in the heel, elbow and shoulder, represent a major health care problem. The long-term goal of my laboratory is to determine whether the altered cell responses and extracellular matrix (ECM) disruption that are the hallmark of tendinopathies, can be modified towards healing using biologic and/or biomechanical therapies. In this seminar, a novel in vivo model of TGF-b1 induced murine Achilles tendinopathy will be described; the model produces biomechanical and biochemical alterations in the tendon which closely mimic those of the human pathologic condition. Specifically, tendinopathic tissues exhibited pronounced loss of mechanical properTies (relative to uninjured tendons) and accumulated chondroid deposits within the ECM. Consistent with clinical studies which describe beneficial effects of eccentric exercise, mechanical stimulation promoted restoration of mechanical properties and resolution of the chondroid deposits. Conversely, induction of tendinopathy in mice lacking ADAMTS5 (A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5) followed by mechanical stimulation resulted in enhanced chondrogenic responses and continued loss of mechanical properties. The latter findings are consistent with the generalized deficiency of fibrogenic repair responses in this knockout mouse, due to impairment of fibroblastic collagen synthesis and contraction. These results constitute key findings which will facilitate the development of therapeutic mechanobiologic strategies to treat human tendinopathies.
December 11, 2014
at 11:00am in 322 ISE Lab
(Download Seminar Flyer)
Jeff Jacot, Ph.D.
Assistant Professor
Biomedical Engineering
Rice University and Texas Children’s Hospital
Seminar Title: “Engineering Heart Tissue for Correction of Heart Defects”
Seminar Abstract: Congenital heart defects are the most common noninfectious cause of death in infants in the US. Repair of many heart defects includes the surgical placement of an acellular patch, and these non-conductive and non-contractile patches are associated with the development of arrhythmias and increased long-term risk of sudden cardiac death. Our laboratory is developing living, contractile heart tissue made from a child’s own stem cells for use in repair of heart defects. Because these functional patches enhance heart function, they can be used in areas critical to heart function, and could lead to the development of a total bioartificial heart. I will present the results of four projects in our lab: 1) The culture, characterization and differentiation of a population of human stem cells isolated from second trimester amniotic fluid, which are genetically matched to the fetus and have the potential to differentiate into endothelial cells and cardiac-like cells; 2) the effect of extracellular matrix elastic modulus and contractile strain on the electrophysiology of cardiac cells; 3) the design and characterization of multi-layered scaffolds combining natural and polymeric components for full-thickness ventricular replacement; and 4) the incorporation of single-walled carbon nanotubes or voltage-responsive liquid crystal elastomers to create electrically and mechanically active materials for cardiac tissue engineering.