Papers and Work in Progress

The publication aspect of my career development is under construction. Please check back in regularly as I work to make this list grow exponentially. In the meantime, toggle the buttons on the left to read the abstract and access a quick link to my first few, exciting publications. 

MSCA-IF Proposal Abstract, Work in Progress: Organ architecture and performance are some of life’s most challenging self-assembling features to reduce into the minimal essential building blocks required for form and function. Organoid biology has gained scientific attention as an approach to study tissue formation and function using miniaturized versions of vital organs grown from stem cells in the laboratory. However, organoid methodology is in need of innovation to gain fundamental understanding and control over adhesion mediated interactions (e.g. cell/cell and cell/ECM) that influence stem cell programming. This action will combine organoid biology with bottom-up synthetic biology to design minimalist light-controlled and modular interactions between stem cells, synthetic cells, and ECM thereby leading to the innovation of programmable synthetic stem cell niches that will produce predictable and uniform organoid populations. I will develop this programmable hybrid organoid approach using human inducible pluripotent stem cells (hiPSCs), syncells with light-controllable cell/cell adhesion modules (optoSynCells), and droplet-based microenvironments comprising light-sensitive extracellular matrix (optoECM). I will use these new hybrid organoids to understand the impact of juxtacrine signalling on programming the differentiation and spatial organization of hiPSCs into hybrid organoids. The action is designed to produce bifunctional pancreatic organoids with the state-of-the-art implementation demonstrating exocrine and endocrine phenotypes, although the knowledge gained by the work packages will be far reaching and applicable to other organoid types. The new understanding of adhesion interactions that will be uncovered by my experiments will lay the foundation for applications in high-content drug screening and generation of patient-derived transplant materials. 

Submission In Progress: To better understand the dynamics of liquid-liquid phase separation (LLPS) that contribute to the formation of cellular compartments such as membraneless organelles (MLO) and deoxyribonucleoprotein (DNP) coacervates, we develop a minimal synthetic model system using an elastin-like polypeptide (ELP), “E3”, that is engineered to electrostatically interact with single-stranded DNA (ssDNA). We characterize and demonstrate control over LLPS using the lower critical solution temperature (LCST) behavior of E3 and show that the presence of ssDNA influences phase behavior. We validate the driving force behind E3-DNA complexation to be electrostatic interaction using charge shielding provided by NaCl counterions in a spectroscopic loss of fluorescence binding assay in bulk. We show this behavior to be conserved across six orders of magnitude within droplet-based microenvironments by fluorescence microscopy, demonstrating modulation of ssDNA capture by E3 as a function of NaCl. We present the first application of this type of minimal synthetic model system by demonstrating a two-step DNA purification assay. This strategy presents an important contribution to origins of life research as well as the fields of synthetic biology and DNA technologies.

The interplay between academics and society within the environment of the COVID-19 pandemic has impacted on scientists across the world, prompting reevaluation of how virtual toolboxes can be used to support responsible collaborative research practices. We provide awareness of virtual resources and activities that enable scientific discovery using safe and efficient practices. 

DOI: http://10.1016/j.tibs.2020.07.003

 

Quickly and easily producing uniform populations of microsphere-based 3D cell cultures using droplet-based templating methods has the potential to enable widespread use of such platforms in drug discovery or cancer research. Here, we advance the design of centrifuge-based droplet generation devices, describe the use of this platform for droplet generation with controlled cell occupancy, and demonstrate weeklong culture duration. Using simple-to-construct devices and easily implemented protocols, the initial concentration of encapsulated cells is adjustable up to hundreds of cells per microsphere. This work demonstrates the first instance of using centrifugal droplet-generating devices to produce large numbers of cell-encapsulating microspheres. Applications of this versatile methodology include the rapid formation of templated 3D cell culture populations suitable for suspension culture or large batch bioreactor studies that require uniform populations.

DOI: http://10.1177/2472630320915837

 

We present an easy-to-assemble microfluidic system for synthesizing cell-loaded dextran/alginate (DEX/ALG) hydrogel spheres using an aqueous two-phase system (ATPS) for templated fabrication of multicellular tumor spheroids (MTSs). An audio speaker driven by an amplified output of a waveform generator or smartphone provides acoustic modulation to drive the breakup of an ATPS into MTS template droplets within microcapillary fluidic devices. We apply extensions of Plateau–Rayleigh theory to help define the flow and frequency parameter space necessary for acoustofluidic ATPS droplet formation in these devices. This method provides a simple droplet microfluidic approach using off-the-shelf acoustic components for quickly initiating MTSs and subsequent 3D cell culture.

DOI: http://10.1021/acsabm.9b00617