Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2024.12.23.630148

Wide-field optical redox imaging with leading-edge detection for assessment of patient-derived cancer organoids

Gillette, A. A.·Udgata, S.·Schmitz, A. E.·Stoecker, J. E.·Deming, D. A.·Skala, M. C.
View original source ↗Export metadata ↓

Abstract

Patient-derived cancer organoids (PDCOs) are a valuable model to recapitulate human disease in culture with important implications for drug development. However, current methods for assessing PDCOs are limited. Label-free imaging methods are a promising tool to measure organoid level heterogeneity and rapidly screen drug response in PDCOs. The aim of this study was to assess and predict PDCO response to treatments based on mutational profiles using label-free wide-field optical redox imaging (WF ORI). WF ORI provides organoid-level measurements of treatment response without labels or additional reagents by measuring the autofluorescence intensity of the metabolic co-enzymes NAD(P)H and FAD. The optical redox ratio is defined as the fluorescence intensity of [NAD(P)H / NAD(P)H +FAD] which measures the oxidation-reduction state of PDCOs. We have implemented WF ORI and developed novel leading-edge analysis tools to maximize the sensitivity and reproducibility of treatment response measurements in colorectal PDCOs. Leading-edge analysis improves sensitivity to redox changes in treated PDCOs (G{Delta} = 1.462 vs G{Delta} = 1.233). Additionally, WF ORI resolves FOLFOX treatment effects across all PDCOs better than two-photon ORI, with [~]7X increase in effect size (G{Delta} = 1.462 vs G{Delta} = 0.189). WF ORI distinguishes metabolic differences based on driver mutations in CRC PDCOs identifying KRAS+PIK3CA double mutant PDCOs vs wildtype PDCOs with 80% accuracy and can identify treatment resistant mutations in mixed PDCO cultures (G{Delta} = 1.39). Overall, WF ORI enables rapid, sensitive, and reproducible measurements of treatment response and heterogeneity in colorectal PDCOs that will impact patient management, clinical trials, and preclinical drug development. Statement of SignificanceLabel-free wide-field optical redox imaging of patient-derived cancer organoids enables rapid, sensitive, and reproducible measurements of treatment response and heterogeneity that will impact patient management, clinical trials, and preclinical drug development.

Explore related subjects

bioengineeringPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Gillette, A. A., Udgata, S., Schmitz, A. E., Stoecker, J. E., Deming, D. A., Skala, M. C.. 2024-12-23. Wide-field optical redox imaging with leading-edge detection for assessment of patient-derived cancer organoids. https://doi.org/10.1101/2024.12.23.630148

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Ferrybots: Programmable Hydrogel Microbots for Rapid Magnetic Navigation and Modular Function

Untethered microrobots could enable localized delivery, sensing, and intervention in confined biological and engineered environments. Magnetic actuation is especially attractive for such systems because it provides remote, fuel-free control, but practical magnetic microrobots remain difficult to manufacture and functionalize. High magnetic loading can interfere with polymerization and structural integrity, while integrating application-specific payloads directly into the robot body often requires the entire material formulation to be redesigned. Here, we introduce Ferrybots, programmable hydrogel microrobots that physically separate magnetic navigation from functional cargo. An automated droplet-on-demand microfluidic flow-lithography process confines high-concentration ferrofluid cores within photopolymerized poly (ethylene glycol) diacrylate (PEGDA) structures, enabling magnetic loading to be programmed through core number and spacing without uniformly dispersing magnetic particles throughout the hydrogel. The process achieved a minimum fabrication cycle time of 15 s. Ferrybots exhibited magnetic-dose-dependent translation and rotation, branched-channel steering, out-of-plane obstacle traversal, and rapid translation, with two-core robots following an external magnet at speeds up to the 9000 mm/min limit of the actuation system. Differences in magnetic loading also enabled sequential selective navigation of distinct Ferrybot populations. Using PEGDA 575 as a common interface material, independently formulated hydrogel cargo modules could subsequently be fused to preformed Ferrybots while preserving navigation. Separately, cargo modules enabled composition-dependent molecular release and oxygen-responsive sensing through 1-mm-thick skin-mimicking optical phantoms representing a broad range of skin types. By decoupling locomotion from function, Ferrybots provide a common magnetic vehicle that can be combined with interchangeable delivery, sensing, or responsive-material modules, offering a general strategy for rapidly adapting microrobots to different applications.

bioengineering↗
bioRxiv2026

Circular-Arc Modal Migration for Ultrasound Imaging--Part I: Finite-Arc Spectral Theory and Stolt-Pullback Factorization

Circular-arc ultrasound imaging requires a spectral construction that accommodates radius-dependent propagation and the spatially varying phase of offset-source transmission. This first of two articles develops Circular-Arc Modal Migration (CAMM), a direct Stolt-type imaging framework in angular modal coordinates. Starting from a first-Born acoustic model, angular decomposition and local radial Stolt mappings convert channel spectra into fields for coherent image synthesis. The offset transmit phase is represented by a phase-screen factorization through reusable spectral factors and spatially weighted fields. A scalar-pullback approximation simplifies this correction to reading one reference image at a geometrically fitted radial coordinate. Both realizations share the same modal construction. Error controls address local radial synthesis, transmit-path expansion, scalar approximation, and phase-screen truncation, with direct integration verifying the separated numerical evaluation. Same-RF point-target comparisons show that scalar pullback closely preserves the principal peak positions and widths of phase-screen imaging in the compact semicircular configuration, while phase screens better control surrounding responses in the shallow convex examples. The retained modal spectrum, frequency band, image radius, and source displacement guide this accuracy--computation choice. CAMM thereby extends direct spectral image formation to circular arcs and supplies the theoretical and numerical basis for the image-quality and performance studies in Part~II.

bioengineering↗
bioRxiv2026

Identification and isolation of migratory subpopulations of cancer cells using microfluidics with fluid walls

Microfluidic assays have great potential for investigating cancer cell migration, a key process underlying metastasis which remains a major clinical challenge. However, adoption by biologists is limited due to complex fabrication and operation methods combined with difficulty in retrieving cells of interest. We jet-print dumbbell-shaped microfluidic environments with fluid walls in standard Petri dishes in seconds using standard growth media and immiscible oil. Prostate cancer cells and chemoattractant (bovine serum) are introduced into each end using local transient differences in Laplace pressure to enable spatial confinement. Automated live-cell imaging monitors chemotaxis towards serum using standard microscopes, as the confining fluid walls are optically transparent. Distinct subpopulations of migratory cells exhibit different morphologies and motilities, assessed using a custom machine-learning segmentation model. Then, we leverage the reconfigurability of fluid walls to isolate and retrieve rapidly-migrating single cells. This demonstrates that fluid-walled microfluidics is a versatile and accessible approach for investigating cancer cell migration at single-cell resolution, offering new opportunities to examine cellular heterogeneity in metastasis.

bioengineering↗