Bioengineering Seminars

Join us for our first Bioengineering Department Seminar of the spring semester:

“Macromolecular Material Systems as Synthetic Cellular Transducers”

Dr. Herdeline (Digs) Ardoña
Assistant Professor of Chemical and Biomolecular Engineering
with joint appointments in the Department of Biomedical Engineering and the Department of Chemistry
UC Irvine

Wednesday, March 11
12noon – 1:00pm
Stanley Hall, Room 177

Abstract:
Signaling in physiological environments relies on ion currents, biomolecular exchange, and other physical cues, all of which are processed by cellular machinery to elicit a specific response. This presentation will focus on the development of macromolecular organic materials as ‘transducer biomaterials’—materials capable of converting external or cell-mediated biophysical cues to stimulatory, regenerative cues or as sensory output signals—for electroactive living systems. Specifically, molecular engineering and fabrication approaches for endowing these systems with the order-dependent ability to convert exogenous optical, electronic, mechanical or chemical cues at the interface with excitable cells will be discussed. Soft lithography, nanoimprinting, surface templating, and light-based micropatterning techniques are leveraged to introduce topographical confinement effects on the self-assembly of optoelectronic peptide units on inorganic lattices or polymeric surfaces, consequently leading to tissue anisotropy. We elucidated the dependence of specificity of these surface-based assembly cues on the molecular design and size of the assembly units, as well as supramolecular distance to surface lattice matching. The peptide-polymer or organic-inorganic hybrid surfaces resulting from the templating process are capable of generating photocurrents upon excitation of the functionalized peptides. Additionally, stabilization of these assemblies on conductive polymer film substrates or as hydrogels can be achieved via surface conjugation chemistries. Through these efforts, we have unraveled new insights on macromolecular assembly on surfaces, as well as how cardiomyocytes perceive the sub-micron dimensionality, local molecular order, and other surface cues from their immediate environment. Lastly, this presentation will cover biohybrid platforms of cardiac and brain models where the sequence-/chemical design-tunable polymeric or supramolecular assembly interface can transduce light to stimulate tissue function or drive spatial heterogeneity of model tissues. Overall, we envision these design-programmable and ordered transducer macromolecular systems towards promoting stem cell-derived cardiomyocyte maturation, facilitating regenerative processes, and advancing the capabilities of engineered tissue constructs for in vitro modeling applications.

Bioengineering Seminar: Exploring light and life: Nanophotonics and AI for molecular sequencing and single-cell phenotyping

Noon – 1 p.m.
Stanley Hall, Room 177

Jennifer ​(Jen) Dionne, PhD, Stanford University

Abstract:
The earth’s biosphere is incredibly information-rich, with estimated information transmission rates exceeding those of the technosphere by 9 orders of magnitude. Here, we present nanophotonic methods that may enable unprecedented data about biochemical systems, at rates previously unattainable. First, we describe our lab’s Si-photonic “Very-large-scale Integrated high-Q Nanophotonic Pixels” (VINPix). These photonic resonators achieve high-Q factors, subwavelength mode volumes, and controlled dipole-like radiation, with Q-factors from the thousands to millions, and resonator densities exceeding 10M/cm2. By combining VINPix arrays with acoustic bioprinting for local chemical functionalization, we develop Si-chip microsystems and the associated AI framework to detect multi-omic signatures on the same platform. As a first application, we describe integration of these sensors with autonomous underwater robots from Monterey Bay Aquarium Research Institute for targeted gene, protein, and metabolite detection. Then, we describe how these chips can be used for peptide and glycoconjugate sequencing. We tether peptides from major histocompatibility complex to each resonator, and use dynamic Raman spectroscopy to monitor the cleavage of each amino acid from the distal terminus. We also show how these resonators, combined with computational metadynamics, can be used to identify previously unseen molecular species. Finally, we show how these resonators enable subcellular differentiation and functional state characterization of cells in the tumor immune microenvironment (TIME), including the ability to predict drug resistance, macrophage polarization, and T-cell activation state. Collectively, we anticipate that these nanophotonic platforms can provide completely new data on the biosphere – from improved understanding of molecular communication systems, to optimization of novel biochemical sensing platforms for health and sustainability.