Paper Number
BL8 My Program
Session
Biomaterials, Bio-fluid Dynamics and Biorheology
Title
Spatiotemporal mapping of dynamics and viscoelasticity in ligase-fueled DNA fluids
Presentation Date and Time
October 20, 2025 (Monday) 1:50
Track / Room
Track 6 / Sweeney Ballroom C
Authors
- McGovern, Ashlee D. (University of San Diego)
- Riggle, Emma (University of San Diego)
- Protopapas, Dimitra (University of San Diego)
- Chang, Kaden (University of San Diego)
- Razzaghi, Aysan (University of San Diego, Physics and Biophysics)
- McGorty, Ryan J. (University of San Diego, Physics and Biophysics)
- Robertson-Anderson, Rae M. (University of San Diego, Physics and Biophysics)
Author and Affiliation Lines
Ashlee D. McGovern, Emma Riggle, Dimitra Protopapas, Kaden Chang, Aysan Razzaghi, Ryan J. McGorty and Rae M. Robertson-Anderson
Physics and Biophysics, University of San Diego, San Diego, CA 92110
Speaker / Presenter
McGovern, Ashlee D.
Keywords
bio-fluid dynamics; biomaterials; biorheology; microscopy; polymer solutions
Text of Abstract
Naturally occurring ligase enzymes catalyze the formation of phosphodiester bonds between strands of deoxyribonucleic acid (DNA), playing a critical role in cellular replication and repair to maintain genomic integrity. In this work, we harness ligase activity to drive linear DNA solutions out of equilibrium. By leveraging real-time ligation of DNA, we dynamically alter chain length distributions within the solution, increasing both polydispersity and entanglement density. These molecular-level changes give rise to time-varying viscoelastic behavior and macromolecular diffusivity, which we characterize using epifluorescence microscopy, differential dynamic microscopy (DDM), and holographic optical tweezers (HOT) microrheology. This approach allows us to spatiotemporally resolve transport and rheological properties across decades of length and timescales during ligase activity. We investigate the role of DNA length and topology, as well as ligase concentration, on the time-varying rheological properties, focusing on the poorly understood crossover regime between semidilute unentangled to entangled polymer dynamics. Our findings demonstrate that in situ ligation can be used to precisely and tunably modulate the rheology of DNA-based materials in real-time. Incorporating photoresponsive ATP and photopatterning further equips this platform with responsiveness and switchability. Establishing spatiotemporally resolved composition-rheology relationships of ligase-fueled DNA fluids paves the way for the design of programmable active biofluids that can reconfigure, respond and self-heal for applications from wound-healing and tissue engineering to self-repairing infrastructure and mineral sequestration.