Hope Leng

All Publications

• Fluid-Squid: DIY Multiplexed Imaging of Cells and Tissues. bioRxiv : the preprint server for biology Hickey, J. W., Li, H., Caraccio, C., Yan, Y., Marx, K., Martin, P., Leng, H. T., Fayiah, J., Towalid, E., Dighero-Kemp, B., Nolan, G. P., Prakash, M., McIlwain, D. R. 2025

  Abstract

  Recent advances in multiplexed single-cell characterization have revolutionized our insight into cell biology, but many available technologies remain limited by high costs or a lack of customizability. To address these challenges, we developed Fluid-Squid, a cost-effective, quantitative imaging platform that integrates automated fluidics to support customizable, do-it-yourself multiplexed imaging workflows. Using Fluid-Squid, we successfully imaged fresh frozen human intestinal tissues with a 36-plex oligonucleotide-barcoded antibody panel and further demonstrated the feasibility of lyophilizing such multiplexed panels. We also adapted existing multiplexed imaging workflows to characterize individual cells to identify immune cell populations, phenotype, and antigen-specific cells from mouse splenocytes and human peripheral blood mononuclear cells (PBMCs) with a 39-antibody panel. To further expand its utility, we developed a barcoding strategy that allows for the pooling and simultaneous staining of multiple samples, reducing time, costs, and batch effects in single-cell experiments. This approach facilitated rapid titration to optimize antibody concentrations and assess the impact of various blood preparation methods on cell type retention. Overall, our work provides a new open-source framework for automated fluidics and microscopy in a flexible, cost-effective platform, empowering adaptable multiplexed characterization of both single cells and tissues.

  View details for DOI 10.1101/2025.10.09.680291

  View details for PubMedID 41279755

  View details for PubMedCentralID PMC12632534

• Ice gliding diatoms establish record-low temperature limits for motility in a eukaryotic cell. Proceedings of the National Academy of Sciences of the United States of America Zhang, Q., Leng, H. T., Li, H., Arrigo, K. R., Prakash, M. 2025; 122 (37): e2423725122

  Abstract

  Despite periods of permanent darkness and extensive ice coverage in polar environments, photosynthetic ice diatoms display a remarkable capability of living inside the ice matrix. How these organisms navigate such hostile conditions with limited light and extreme cold remains unknown. Using a custom subzero temperature microscope during an Arctic expedition, we present the finding of motility at record-low temperatures in a Eukaryotic cell. By characterizing the gliding motility of several ice diatom species, collected from ice cores in the Chukchi Sea, we record that they retain motility at temperatures as low as [Formula: see text]15 °C. Remarkably, ice diatoms can glide on ice substrates, a capability absent in temperate diatoms of the same genus. This unique ability arises from adaptations in extracellular mucilage that allow ice diatoms to adhere to ice, essential for gliding. Even on glass substrates where both cell types retain motility at freezing temperatures, ice diatoms move an order of magnitude faster, with their optimal motility shifting toward colder temperatures. Combining field and laboratory experiments with thermo-hydrodynamic modeling, we reveal adaptive strategies that enable gliding motility in cold environments. These strategies involve increasing internal energy efficiency with minimal changes in heat capacity and activation enthalpy, and reducing external dissipation by minimizing the temperature sensitivity of mucilage viscosity. The finding of diatoms' ice gliding motility opens new routes for understanding their survival within a harsh ecological niche and their migratory responses to environmental changes. Our work highlights the robust adaptability of ice diatoms in one of Earth's most extreme settings.

  View details for DOI 10.1073/pnas.2423725122

  View details for PubMedID 40924446

• Scalable Human IPSC-to-3D Bioprinting Pipeline: Successful Large-Scale Production Using Automated Bioreactor Systems Ladi, R., Ho, D., Lee, S., Du, J., Weiss, J., Tam, T., Sinha, S., Klinger, D., Devine, S., Hamfeldt, A., Leng, H., Herrmann, J., He, M., Fradkin, L., Tan, T., Standish, D., Tomasello, P., Traul, D., Dianat, N., Vicard, Q., Katikireddy, K., Skylar-Scott, M. CELL PRESS. 2024: 640

  View details for Web of Science ID 001332783402271

• Large-Scale Production of Wholly-Cellular Bioinks via the Optimization of Human Induced Pluripotent Stem Cell Aggregate Culture in Automated Bioreactors. Advanced healthcare materials Ho, D. L., Lee, S., Du, J., Weiss, J. D., Tam, T., Sinha, S., Klinger, D., Devine, S., Hamfeldt, A., Leng, H. T., Herrmann, J. E., He, M., Fradkin, L. G., Tan, T. K., Traul, D., Vicard, Q., Katikireddy, K., Skylar-Scott, M. A. 2022: e2201138

  Abstract

  Combining the sustainable culture of billions of human cells and the bioprinting of wholly-cellular bioinks offers a pathway towards organ-scale tissue engineering. Traditional 2D culture methods are not inherently scalable due to cost, space, and handling constraints. Here, we optimize the suspension culture of human induced pluripotent stem cell-derived aggregates using an automated 250 mL stirred tank bioreactor system. Cell yield, aggregate morphology, and pluripotency marker expression are maintained over three serial passages in two distinct cell lines. Furthermore, we demonstrate that the same optimized parameters can be scaled to an automated 1 L stirred tank bioreactor system. Our 4-day culture resulted in a 16.6- to 20.4-fold expansion of cells, we generate approximately 4 billion cells per vessel, while maintaining > 94% expression of pluripotency markers. The pluripotent aggregates can be subsequently differentiated into derivatives of the three germ layers, including cardiac aggregates, and vascular, cortical and intestinal organoids. Finally, the aggregates are compacted into a wholly-cellular bioink for rheological characterization and 3D bioprinting. The printed hAs are subsequently differentiated into neuronal and vascular tissue. This work demonstrates an optimized suspension culture-to-3D bioprinting pipeline that enables a sustainable approach to billion cell-scale organ engineering. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/adhm.202201138

  View details for PubMedID 36314397