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Spring 2014 Seminar Schedule

*All seminars are held in Grote 411 at 3 p.m., unless otherwise indicated.

Following the seminar, the speaker will be available for comments and questions.

Date

Speaker

Title

 January 24, 2014

Andrew Lyon - Georgia Tech 

 Dynamic Microgel/Fibrin Composites

February 14, 2014 

Jeff Johnston - Vanderbilt University

 Reagent and Reaction Development in the Service of Complex Target Synthesis: Chiral Proton Catalysis, Umpolung Amide Synthesis, and Case Studies in Therapeutic Development

February 21, 2014 

Chris Scarborough - Emory University 

 Selective Oxidation with Earth-Abundant Elements

March 28, 2014

Andrew Tennyson - Clemson University

 

April 4, 2014 

Shawn Campagna - UTK 

 

 

Abstracts

Andrew Lyon, Georgia Tech, "Dynamic Microgel/Fibrin Composites"

Disease occurs at the molecular, cellular, and tissue levels. However, current biomaterials designed to treat those diseases do not interact at all of those scales. To that end, we have undertaken studies of “colloid-modulated biological architectures”, which dramatically alter our approach to biomaterials design by interfacing with biology over the entire physiologic range of length, energy, and time-scales.

This talk will focus on illustrations of this concept using hydrogel microparticles (microgels) as the colloidal component, which are then embedded within a biological matrix (fibrin). From this simple construct have emerged complex phenomena such as the platelet-like clot contraction enabled by fibrin binding (H6) microgels (Figure 1). These and other advantageous properties of our “synthetic platelets” offer a potential route to the next generation of hemostatic agents for applications in trauma medicine.

Figure 1

Figure 1

(Left) Fibrin clots after exposure to platelet poor plasma (PPP), H6 (fibrin-binding) microgels, or S11 (non-binding) microgels. (Right) Confocal microscopy images of (top) fibrin clot and (bottom) fibrin formed in the presence of H6-microgels.

We will also discuss the development of microgel-fibrin composites wherein the microgel component provides a means to dramatically alter the cell-level viscoelastic properties of the matrix, thereby guiding cell movement and proliferation. Such architectures are potentially important in wound healing and tissue scaffold applications.

 

Jeff Johnson, Vanderbilt University, "Reagent and Reaction Development in the Service of Complex Target Synthesis: Chiral Proton Catalysis, Umpolung Amide Synthesis, and Case Studies in Therapeutic Development"

Our discovery that chiral nonracemic Bis(AMidine) – ‘BAM’ – ligands can be effective modifiers of achiral Brønsted acids such as triflic acid became the basis for a general approach to fully stereocontrolled aza‐Henry reactions. These reagents are bifunctional catalysts that rely on the basic principles of Brønsted acid (hydrogen bond) and base activation much like biological catalysts. Our latest findings in bifunctional Brønsted acid/Brønsted base catalyst design and development, reaction exploration, and target acquisition using these tools will be described. Our work to leverage chiral proton catalysis against the goal of fully enantioselective and efficient peptide synthesis via Umpolung Amide Synthesis (UmAS) will be introduced.

 

Chris Scarborough, Emory University, "Selective Oxidation with Earth-Abundant Elements"

The manufacture of commodity chemicals from hydrocarbon feedstocks is often wasteful and expensive. Such wasteful, multi-step synthetic routes are adopted because direct hydrocarbon oxidation protocols generally suffer from over-oxidation of the desired product, because the functionalized product is more kinetically susceptible to oxidation than its parent hydrocarbon. The development of highly selective catalysts for hydrocarbon oxidation could transform the chemical industry, but product susceptibility to oxidation remains a difficult challenge to address. To further complicate things, the elements that often show the most promise for selective oxidation catalysis (e.g. palladium and platinum) are among the scarcest in the earth’s upper crust. Research in the Scarborough lab that focuses on the development of selective oxidation catalysts derived from earth-abundant metals for C–H oxidation reactions will be described, with an emphasis on the design, synthesis, and application of new catalysts from our laboratory.

 

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