CBE Seminar: Comb-Polyelectrolytes Stabilized Complex Coacervate Microemulsions

Abstract: Research in protocells has burgeoned in recent decades due to their fundamental importance in the origin of life and their latent technological potential. Complex coacervates formed by liquid-liquid phase separation of charged macromolecules can be simplistic protocellular models with a distinct interface, spontaneous biomolecular sequestration and chemical conversions within macromolecularly crowded environments. While the bulk material properties of such coacervates are well understood, this knowledge is yet to be applied towards tailoring protocell design. A major limitation was the long-term stabilization of the liquid-liquid interface, which we previously demonstrated using comb-polyelectrolytes (cPEs). In this talk, we demonstrate that this approach is generic and works with distinct polymer characteristics and salt identities, over a wide range of concentrations. We show improved salt resistance of droplets, tunable by cPE concentration and an expansion of the two-phase window. Furthermore, enzyme mediated reactions yielding bioluminescent molecules delineating reaction kinetics within coacervates will be shown. Finally, the effect of coencapsulation of enzymes on kinetics in cascading reactions within optimized protocellular characteristics will be presented.

Samanvaya Srivastava: Samanvaya is an assistant professor in chemical and biomolecular engineering at UCLA. He completed his undergraduate and master’s work from the Indian Institute of Technology Kanpur and his Ph.D. with Lynden Archer from Cornell University, all in chemical engineering. Before coming to UCLA, he was a postdoctoral scholar with Matthew Tirrell at the Pritzker School of Molecular Engineering at the University of Chicago. Samanvaya’s research interests are in understanding the influence of intermolecular interactions on material structure and properties with a broader aim to combine this fundamental understanding with molecular engineering and self-assembly processes to improve materials design. Samanvaya has received various awards, including the Austin Hooey Graduate Research Excellence Recognition Award at Cornell University (2013), the RSC Researcher Mobility Grant (2017), AIChE 35 under 35 (2020) and the NSF CAREER award (2020).

Eleni Papananou: Papananou earned her B.S. degree in physics from the University of Crete in 2005, her MSc in chemical engineering from Aristotle University of Thessaloniki in 2008 and her Ph.D. in chemistry from the University of Crete in 2017. For her graduate research she studied polymer structure and dynamics under confinement in polymer nanocomposites. During her postdoc, in the Segalman group at UC Santa Barbara, she focused on polymer functionalization to improve thin film adhesive properties as well as achieve selective deposition of films for the semiconductor industry. In her role as the BioPACIFIC MIP user coordinator, Papananou is responsible for the user program’s leadership, management and development. Papananou serves as the point of contact for users coming to BioPACIFIC MIP, helping to recruit new users, connecting users to the MIP resources and reporting and highlighting the products of their research at BioPACIFIC MIP to the NSF.

Host: Dr. Herdeline Ardoña