<span class=strong>Reception and Poster Session</span><br><br/><br/><b>Poster submissions welcome from all participants</b><br><br/><br/><a<br/><br/>href=/visitor-folder/contents/workshop.html#poster><b>Instructions</b></a><br/><br/>

Monday, September 13, 2010 - 5:10pm - 6:30pm
Lind 400
  • Computational analysis of biofabrication in tissue engineering
    Xinfeng Liu (University of South Carolina)
    Bioprinting or organ printing can be operationally defined as computer-aided, layer-by-layer
    deposition of biologically relevant material with the purpose of engineering functional 3D
    tissues and organs. Printing or fabricating an organ requires computer-aided design of the
    organ, self-assembling cell aggregates or single cells, a bioprinter or dispenser of the
    bioink, scaffolds or processible biomimetric hydrogels. In this poster, we shall present
    computational tools using two computational technologies: phase-field model and front-tracking
    approach, to numerically study morphogenesis of cell aggregates during maturation and
    corase-grain internal mesoscale structures. The numerical results exhibit a great
    promise of our approach.
  • PROR - A novel transcriptional reporter system to study

    gene repression

    Edgardo Sanabria-Valentín (Harvard Medical School)
    Transcriptional reporters (genetic constructs in which the promoter of
    a gene of interest drives the expression of a reporter gene whose
    expression can be easily observed and/or measured) are valuable tools
    in molecular biology, and can aid in the search for small molecules
    affecting the expression of individual genes. Cells exposed to a
    condition that induces the expression of your gene of interest will
    have an output of reporter signal, which can be detected. This poses a
    problem when the gene of interest is constitutively turned on and are
    looking for treatments that selectively repress expression of your
    gene. Treatments that inhibit reporter output can be affecting a
    myriad of processes that are not specific to your gene (cell toxicity,
    generalized transcriptional repression, direct interference with your
    reporter output, etc.). We have designed a new transcriptional
    reporter system to study gene repression. That is, reporter output (in
    our case, fluorescence) is produced when your gene of interest is not
    being expressed or is being directly repressed. We have designated
    this system as PROR for Promoter-Repressor-Operator-Reporter. The
    system is composed of two modules; the first one contains the promoter
    of interest driving the expression of the λ phage transcriptional
    repressor cI (1), and the second contains a modified constitutive
    promoter with the operator sequences of λcI placed in front of the
    reporter gene yfp. Under conditions in which the gene of interest is
    being transcribed λcI is also transcribed, inhibiting expression of
    YFP. Under conditions in which the gene of interest is being
    repressed, λcI will not be transcribed and YFP is expressed. We have
    tested our system using expression of the genes coding for the protein
    component of the B. subtilis biofilm matrix (the yqxM operon), in
    growth conditions that promote or inhibit development of biofilms, and
    also with addition of the small molecule zaragozic acid, a potent
    inhibitor of matrix production in B. subtilis (2). We are currently
    using this tool to search for novel small molecules and natural
    products that selectively inhibit matrix production in B. subtilis.
  • Dormancy in planktonic and biofilm cultures

    Microbial populations, particularly those in biofilms, contain cells in varying phenotypic states. Here we consider one such phenotype, dormancy (possibly related to the phenomenon of persister cells) where, in response to an environ- mental stress, cells differentiate into a protected, slow- or non-growing state. We present modeling and computational tools designed to study dormancy within batch, chemostat, and biofilm population dynamics, in particular with respect to competitiveness.