Invited Seminar Series

The Invited Seminar series hosted by the Institute of Biomedical Engineering welcomes world class researchers to present and discuss their most recent research.

Review below for the upcoming seminars that is hosted in the 2020-2021 session.

Paul Weiss

Portrait of Paul Weiss

September 15th 2020 

12:00pm - 1:00pm

Nanotechnology Approaches to Biology and Medicine

Abstract: By controlling the exposed chemical functionality of materials from the submolecular through the centimeter scale, we have enabled new capabilities in biology, medicine, and other areas. I will discuss current and upcoming advances and will pose the challenges that lie ahead in creating, developing, and applying new tools using this capability. These advances include using biomolecular recognition in sensor arrays to probe dynamic chemistry in the brain and microbiome systems. In other areas, we introduce biomolecular payloads into cells for gene editing at high throughput for off-the-shelf solutions targeting hemoglobinopathies, immune diseases, and cancers. We circumvent the need for viral transfection and electroporation, both of which have significant disadvantages in safety, throughput, cell viability, and cost. Mechanical deformation can make cell membranes transiently porous and enable gene-editing payloads to enter cells. These methods use specific chemical functionalization and control of surface contact and adhesion in microfluidic channels. 

Jose Zariffa

Portrait of Jose Zariffa

October 13th 2020 

12:00pm - 1:00pm

Measuring Hand Function at Home Using Egocentric Video

Abstract: The recovery of upper limb function is often a central priority after neurological injuries. Developing therapies or technologies to improve upper limb function requires high-quality measures to quantify outcomes. Currently, options to directly and objectively measure hand function in real-world environments are lacking. Wearable systems based on egocentric cameras and computer vision present the opportunity to evaluate hand function in unconstrained environments with an unprecedented level of detail. This talk will describe our recent efforts using this strategy to measure the quantity and quality of hand use at home after spinal cord injury and stroke. 

Doug Lauffenburger

Portrait of Doug

November 10th 2020 

12:00pm - 1:00pm

Preclinical-to-Clinical Translation of Biological Information via Computational Systems Modeling Frameworks

Abstract: A vital challenge that the vast majority of biological research must address is how to translate observations from one physiological context to another—most commonly from experimental animals (e.g., rodents, primates) or technological constructs (e.g., organ-on-chip platforms) to human subjects.  This is typically required for understanding human biology because of the strong constraints on measurements and perturbations in human in vivo contexts.  Direct translation of observations from experimental animals to human subjects is generally unsatisfactory because of significant differences among organisms at all levels of molecular properties from genome to transcriptome to proteome and so forth.  Accordingly, addressing inter-species translation requires an integrated experimental/computational approach for mapping comparable but not identical molecule-to-phenotype relationships.  This presentation will describe methods we have developed for a variety of cross-species translation examples, demonstrated on applications in inflammatory pathologies and cancer. 

Adam Cohen

Portrait of Adam-Cohen

December 8th 2020 

12:00pm - 1:00pm

Electrophysiology in space

Abstract: We developed tools for all-optical electrophysiology: simultaneous optical perturbation and optical measurement of membrane voltage.  These tools enable spatially resolved measurements of bioelectrical dynamics.  I will give two examples of how we used these tools to study the roles of geometry and topology in excitable tissues.  First, I will talk about winner-takes-all attractor dynamics in Layer 1 of the mouse cortex.  Then I will talk about bioelectrical domain walls and topological action potentials in engineered cell lines.  Geometrical and topological effects can produce bioelectrical dynamics that are not apparent from point measurements alone.

Penney Gilbert

Portrait of Penney Gilbert

January 12th 2021

12:00pm - 1:00pm

Spatiotemporal control of skeletal muscle stem cell fate

Abstract: The native skeletal muscle stem cell niche is a three-dimensional entity. While conceptually it is accepted that dimensionality is a critical feature of tissues that defines the location and timing of cellular events, understanding how dimensionality exerts such a powerful influence on stem cell biology is less well understood. One area of focus in the Gilbert Lab is aimed at elucidating how the native three-dimensional tissue exerts spatiotemporal control over muscle stem cell fate by developing methods to quantify in vivo biomechanical stresses presiding over the quiescent and regenerating adult skeletal muscle niche, and by producing new three-dimensional models of skeletal muscle regeneration in a dish. In combining these approaches, we work to define interactions between muscle stem cells and the dynamic extracellular milieu that serve to orchestrate the elegant process by which a muscle stem cell switches from a state of quiescence, to activation, and then to specification, and how this process becomes derailed in disease states and in aging.

Eli Sone

Portrait of Eli Sone

February 9th 2021

12:00pm - 1:00pm

Biological and bioinspired collagen mineralization

Abstract: Collagen biomineralization is a complex process for which the controlling factors, at the molecular level, are still not well understood.  A particularly high level of spatial control over collagen mineralization is evident in the anchorage of teeth to the jawbone by the periodontal ligament. The close juxtaposition of mineralized and unmineralized tissues provides an excellent model in which to study the molecular factors that control collagen biomineralization. I will present recent progress from my lab in understanding the roles of matrix and solution macromolecules that mediate this process, along with applications to the design of collagen-based scaffolds for regeneration of hard-soft tissue interfaces.

Shyni Varghese

Portrait of Shyni Varghese

March 9th 2021 

12:00pm - 1:00pm

Biomaterials for mechanistic understandings and therapeutic interventions

Abstract: Regenerative medicine is an interdisciplinary field that has significant promise for treating compromised tissues and organs. In our laboratory, we use a number of bioengineering tools including biomaterials, organoids, quantitative modeling, and animal models to understand how the microenvironment regulates cell fate and to identify new therapeutic targets. In this talk, I will show several examples from our lab illustrating the use of such platforms to address key problems in tissue repair and disease progression. First, I will discuss our efforts in creating synthetic analogs of the extracellular matrix to direct stem cell commitment in vitro and in vivo and employing such platforms to understand molecular mechanisms underlying cell fate and identifying new therapeutic targets (Shih et al., PNAS 111: 990, 2014; 114: 5419 2017; Kang H et al., Biomacromolecules 16: 1050, 2015; Shih et al., Sci. Adv. 5: eaax1387, 2019). Next, I will discuss how these understandings can be leveraged to develop therapeutic interventions to promote tissue repair and mitigate pain (Zeng et al., Adv. Mater. 32, 2020). Finally, I will briefly discuss our efforts in creating materials with “living” functions such as self-healing along with their applications in soft robotics and tissue repair (Phadke at al., PNAS, 109: 4383, 2012, Kumar et al., BioRxiv/2020/067033).

Lena Ting

Portrait of Lena Ting

April 13th 2021 

12:00pm - 1:00pm

What does a muscle sense? Multiscale interactions governing muscle spindle sensory signals 

Abstract: Muscle spindles in vertebrate muscles provide rich sensory information about the body’s mechanical interactions with the environment necessary for neural control of movement. But, muscle spindle afferent signals during behavior are not simple readouts of biomechanical variables of the parent muscle. Rather, muscle spindles are active sensors whose firing patterns can be altered by efferent drive from the central nervous system. Multiscale biophysical interactions provide a mechanistic framework for interpreting muscle spindle signals during behavior. We hypothesize that complex muscle spindle firing patterns are explained by the force and yank of intrafusal muscle fibers within muscle spindles.  I will present a biophysical model of a muscle spindle that  demonstrates how well-known firing characteristics of muscle spindle Ia afferents – including a dependence on prior movement history, and nonlinear scaling with muscle stretch velocity – emerge from first principles of muscle contractile mechanics. The model provides a computational framework that address tension between the common understanding of muscle spindles as providing readouts of muscle kinematics, i.e. length and velocity (primarily obtained in passive muscle stretch conditions) with a variety of evidence from more naturalistic and behavioral conditions that defy this classic description of muscle spindle function.  Concurrent efferent drive to the parent muscle and muscle spindles (efference copy) dissociates contractile force generated by the parent muscle, from external forces. As such, muscle spindles act as physical predictors of muscle force, encoding muscle exafference during movement. Efferent drive to muscle spindles (g-drive) also selectively tune and amplify information encoded by muscle spindle firing patterns during expected and purposeful interactions between the body and environment. A multiscale muscle spindle model provides an extendable, multiscale, biophysical framework for understanding and predicting movement-related sensory signals in health and disease.

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