Biomechanics Training Grant

- Current Trainees

Ovid C. Amadi - Health Sciences and Technology

B.S., Mechanical Engineering, MIT

Thesis Advisor: Richard T. Lee, MD
Brigham and Women's Hospital Cardiovascular Research Laboratory

Thesis Project: The dominant cause of heart failure is loss of myocardium due to infarction and the limited regeneration potential of cardiomyocytes in mammals. Several different approaches have emerged as potential treatments to restore cardiac function, including tissue engineering, cell therapy, and protein therapy. The chemokine Stromal cell Derived Factor-1 (SDF-1) and its receptor CXCR4 are crucial for bone marrow retention of hematopoietic stem cells and participate in cardiogenesis and recruitment of endothelial-cell progenitor cells to ischemic tissue Recently, numerous laboratories have independently demonstrated that SDF-1 can attract stem cells to the myocardium and improve function. Most experiments to date have been performed with gene transfer, which can lead to variable delivery, while controlled delivery of chemokine proteins has potential for driving chemotaxis in vivo with more precise delivery. The precise effects of SDF-1 delivery and whether it promotes the recruitment of endogenous cardiac progenitor cells to regenerate the myocardium are unknown. My research investigates the recruitment of cardiac progenitor cells and identifies factors that contribute to their migration, proliferation and differentiation.

Philip Bransford - Biological Engineering

Bachelors of Biomedical Engineering, University of Minnesota

Thesis Advisor: ¹Roger Kamm, ²Mark Bathe
¹Mechanobiology Laboratory, ²Laboratory for Computational Biology and Biophysics

Thesis Project: Cadherin proteins mediate calcium-dependent cell-cell adhesion. From a few of premetazoan ancestor genes, a large and diverse superfamily evolved that is today is common to all vertebrates. Although typically considered homophilic, a few studies measured heterophilic interactions between select family members. My project uses statistical and structural modeling to ask if family members coevolved their binding sites, and which motifs confer specific or promiscuous binding interactions.

Andrew J. Koo - Biological Engineering

B.A., Biochemistry and Molecular Biology, Washington University in St. Louis

Thesis Advisor: ¹C. Forbes Dewey, Jr., ²Guillermo García-Cardeña
¹Hatsopolous Microfluids laboratory, ²Department of Pathology, Harvard Medical School

Thesis Project: The endothelial glycocalyx layer (EGL) is a thin gel-like layer (400-500 nm in thickness) located above the apical surface of endothelial cells. The glycocalyx has been shown to be a protective shield against arterial disease. I am interested in understanding the mechanotransduction event of how hemodynamic shear stress is transmitted through endothelial glycocalyx and initiate cellular responses such as nitric oxide production.

Paul Kopesky - Biological Engineering

S.B., Chemical Engineering, MIT
M.S., Chemical Engineering, MIT

Thesis Advisor: Alan Grodzinsky
Center for Biomedical Engineering

Thesis Project: Self-assembling peptide hydrogels promote in vitro chondrogenesis of bone marrow-derived stromal cells: Effects of peptide sequence, cell donor age, and method of growth factor delivery.

Ranjani Krishnan - Biological Engineering

BSE, Chemical Engineering, Princeton University

Thesis Advisor: Krystyn Van Vliet, Douglas Lauffenburger
Laboratory for Material Chemomechanics

Thesis Project: Interactions between cell surface integrin receptors and extracellular matrix (ECM) ligands are crucial to processes such as cell adhesion and migration. My thesis work is focused on understanding how integrin-ligand interactions are regulated by chemomechanical properties of the cell microenvironment, namely pH and ECM stiffness. These properties are significantly altered in contexts such as cancer and wound healing, and we hope to gain a molecular level understanding of how integrin-ligand interactions are affected by these conditions. The larger goal is to connect the receptor-ligand effects to cell adhesion and migration.

John Maloney - Materials Science and Engineering

B.S. and M.S., Mechanical Engineering, University of Maryland
M.Eng., Materials Science and Engineering, MIT

Thesis Advisor: Krystyn Van Vliet, Robert Langer
Laboratory for Material Chemomechanics

Thesis Project: Mesenchymal stem cells, or MSCs, (which live at low concentrations in our tissues) have the ability to self-renew and produce progeny such as muscle and bone cells when extracted and cultured in vitro. The therapeutic possibility of regenerating damaged tissue such as post-heart-attack cardiac muscle has motivated intense study of these cells' characteristics and behavior. I study the mechanics of MSCs: specifically, their deformability when exposed to a load. But the load is not mechanical but photonic; the optical pressure of a laser beam is enough to measurably stretch the cells. This technique, termed "optical stretching," allows us to quantify cell stiffness without ever physically touching the cell. Our goal is to identify unique mechanical markers of MSCs to enable them to be efficiently sorted ex vivo and isolated from their many non-stem-cell neighbors for therapeutic uses.

Eric Soller - Mechanical Engineering

S.B., Mechanical Engineering, Rose-Hulman Institute of Techology
S.M., Mechanical Engineering, MIT

Thesis Advisor: Ioannis V. Yannas
Fibers & Polymers Laboratory

Thesis Project: Cell-mediated mechanical forces play a critical role in the spontaneous healing of severe wounds in the adult mammal. When a peripheral nerve is transected a thick layer of contractile cells (myofibroblasts) surround and compress the nerve stumps (like a "pressure cuff"), preventing reconnection and resulting in a painful loss of function. There is considerable evidence, uncovered in the MIT Fibers & Polymers Laboratory, that some organs can be induced to regenerate if these forces are cancelled out in a local manner. The "pressure cuff" theory predicts that a transected nerve will heal by regeneration, rather than by contraction and scar formation, if the forces exerted by the myofibroblast capsule have been cancelled in a "local" manner. The goal of my current work is to evaluate this hypothetical mechanism for organ regeneration in vivo using various contraction-blocking strategies and a linear elastic model of the regenerating sciatic nerve.

Daniel Trahan - Chemical Engineering

B.S., Chemical Engineering, Rice University in Houston
M.S., Chemical Engineering Practice, MIT

Thesis Advisor: Patrick S. Doyle

Thesis Project: DNA is a fundamentally important biological molecule. Understanding the physics that govern the behavior of an individual DNA molecule is not only necessary to explain how it interacts with its native cellular environment, but is also important in engineering devices that manipulate DNA molecules in order to retrieve genetic information. I am interested in exploring and exploiting the physics related to DNA dynamics in microfluidic devices for diagnostic applications.