Measurements of Cellular-scale Biophysical Signals within the Intervertebral Disc using Nanoscale DNA Origami sensors

This project addresses a current central question in musculoskeletal biology: how do physical forces inside the body influence the behavior of cells and the health of tissues? Everyday activities create forces on tissues, but scientists currently lack tools to measure exactly how these forces are sensed at the cellular level in real time. This impedes understanding of conditions like back pain, where damage to the intervertebral disc (IVD) - the tissue between spinal vertebrae—plays a major role. This project develops highly specialized sensors made from folded DNA, called DNA origami (DO). These nanoscale sensors can attach to tissues and detect changes in important signals such as changes in ion concentrations and forces from fluid flow. Placing these sensors directly in living tissue will allow scientists to observe how physical signals change over space and time down to the single cell level. The work focuses on the intervertebral disc, a tissue that experiences constant mechanical loading and is prone to degeneration. Understanding how cells in this tissue respond to physical signals could lead to improved treatments for back pain and other musculoskeletal conditions. The project advances emerging nanotechnology tools with applications in many fields of biology and engineering. The project also supports education and workforce development. Students at multiple levels - from high school to graduate school - gain hands-on experience at the intersection of engineering, nanotechnology, and biology. Outreach activities, including training programs and open educational materials, help prepare the next generation of biomedical scientists and engineers with unique training in nanotechnology and biomechanics, ultimately benefiting national health and innovation. This project elucidates how biophysical signals regulate cellular processes within the intervertebral disc (IVD) by developing DNA origami (DO) nanosensors capable of measuring ion concentration gradients and fluid shear stresses in situ with micrometer spatial and second-scale temporal resolution. The hypothesis is that disease-related degeneration in the IVD alters the spatiotemporal dynamics of ionic and fluid shear signals, and that the pericellular matrix (PCM) modulates these signals at the cell surface. Objective 1 optimizes DO-based ion sensors with tunable sensitivity to resolve physiologically relevant gradients and quantify the role of the PCM in regulating the ionic microenvironment surrounding IVD cells. Objective 2 develops and calibrates DO-based fluid shear sensors to quantify shear stresses in the IVD microenvironment and evaluate PCM-mediated shielding effects. The multiscale experimental framework progresses from (A) sensor optimization in microfluidic systems, to (B) deployment in isolated cells with intact PCM, and (C) in situ measurements within mechanically loaded IVD tissue. This work advances nanoscale biosensing technologies that can facilitate new mechanistic insights into how biophysical signals contribute to tissue homeostasis and degeneration. The outcomes provide new understanding of the role of the PCM in modulating biophysical signals of IVD cells and how this role may change in disease, helping to inform future therapeutic strategies targeting mechanobiological pathways. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2611370 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Benjamin Walter | Institution: OHIO STATE UNIVERSITY, THE, COLUMBUS, OH | Award Amount: $550,000 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2611370 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2611370.html