Production and Multi-Parameter Live Cell Fluorescence Lifetime Imaging Microscopy (FLIM) of Multicellular Spheroids
August 9th, 2024
Here, we describe different multicellular spheroid formation methods to perform follow-up multi-parameter live cell microscopy. Using fluorescence lifetime imaging microscopy (FLIM), cellular autofluorescence, staining dyes, and nanoparticles, the approach for analysis of cell metabolism, hypoxia, and cell death in live three-dimensional (3D) cancer and stem cell-derived spheroids is demonstrated.
In this work, we present and compare spheroid formation methods that can be used for analysis of cell metabolism and oxygen distribution using live cell microscopy. In recent years, fluorescence lifetime imaging microscopy has been extensively used to investigate metabolic biomarkers like NADPH and FAD in live cells, and several fluorescent nanoparticles have been developed to multiplex such measurements with imaging of cell and tissue oxygenation. Multicellular spheroids, organoids, and organ-on-a-chip can replicate a complex, in-vivo-like microenvironment, minimizing the need in animal research.
For spheroid production, we show different formation methods, can span from low to high throughput. They also highlight their optical accessibility, compatibility with fluorescence lifetime imaging microscope, and the possibility of including extracellular matrix components. So, even though 3D in vitro models provide better context in comparison to 2D cultures, their high variability, low reproducibility, and incomplete experimental reporting remain a problem.
Parameters such as the spheroid size, the nutrient composition, the extracellular viscosity, and even spheroid formation methods can all lead to increased cellular heterogeneity. With this protocol, we aim to harmonize and standardize the spheroid production methods, highlighting key aspects important for life-continuous and multiparametric analysis of spheroids using FLIM microscopy.
Overview
This article presents various methods for forming multicellular spheroids to analyze cell metabolism and oxygen distribution using live cell microscopy. The study highlights the use of fluorescence lifetime imaging microscopy (FLIM) to investigate metabolic biomarkers in live cells.
Key Study Components
Area of Science
- Neuroscience
- Cell Biology
- Live Cell Imaging
Background
- Multicellular spheroids and organoids replicate in-vivo-like microenvironments.
- Fluorescence lifetime imaging microscopy is used to study metabolic biomarkers.
- High variability and low reproducibility are challenges in 3D in vitro models.
- Different spheroid formation methods can be employed for various applications.
Purpose of Study
- To compare spheroid formation methods for live cell microscopy.
- To analyze cell metabolism, hypoxia, and cell death in 3D models.
- To improve the understanding of oxygen distribution in multicellular systems.
Methods Used
- Fluorescence lifetime imaging microscopy (FLIM)
- Cellular autofluorescence analysis
- Use of staining dyes and fluorescent nanoparticles
- Different spheroid formation techniques
Main Results
- Demonstrated methods for analyzing cell metabolism in 3D spheroids.
- Showed compatibility of spheroids with FLIM for metabolic studies.
- Highlighted the importance of extracellular matrix components in spheroid formation.
- Addressed challenges in reproducibility and variability of 3D cultures.
Conclusions
- Different spheroid formation methods can enhance live cell analysis.
- FLIM provides valuable insights into metabolic processes in 3D models.
- Continued development of these methods can reduce reliance on animal models.
Frequently Asked Questions
Executive Industry Relevance
Standardized production and multi-parameter FLIM analysis of multicellular spheroids address critical challenges in modeling tumor microenvironments for drug discovery. Harmonizing spheroid formation and live-cell imaging workflows enhances predictive confidence in metabolic and hypoxia-related readouts, supporting robust early-stage decision-making. This approach strengthens translational continuity and reduces biological risk across oncology and stem cell R&D portfolios.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables interrogation of metabolic pathways and oxygen gradients in physiologically relevant 3D models.
- Supports functional target validation by quantifying NADPH and FAD biomarkers in live spheroids.
- Facilitates biological de-risking through multiplexed metabolic and hypoxia measurements.
- Improves predictive confidence for target engagement and pathway modulation in complex systems.
Screening & Assay Development
- Prepares reproducible 3D spheroid models compatible with widefield, confocal, and two-photon FLIM platforms.
- Standardizes assay conditions to reduce variability and enhance quantitative output reliability.
- Enables scalable, high-throughput screening of compound effects on cell metabolism and viability.
- Supports robust evaluation of bio- and nanosensor integration for multiplexed readouts.
Translational & Preclinical Research
- Aligns in vitro metabolic and hypoxia profiles with disease-relevant tumor microenvironments.
- Provides continuity from discovery through preclinical validation by minimizing animal model reliance.
- Enables risk-adjusted advancement decisions based on quantitative, multiparametric data.
- Facilitates translational biomarker development using live-cell FLIM outputs.
Pipeline & Workflow Integration
This harmonized workflow integrates from early discovery through lead identification and preclinical validation, leveraging standardized spheroid production and FLIM analytics.
- Discovery Biology: Supports hypothesis testing and pathway clarification in 3D, in vivo-like contexts.
- Screening: Delivers reproducible, quantitative metabolic and hypoxia readouts for compound triage.
- Analytics: Provides multiplexed fluorescence lifetime measurements for robust condition comparison.
- Translational Research: Bridges in vitro findings to preclinical models by recapitulating tumor microenvironment features.
- Enterprise Reuse: Establishes a reusable platform for diverse oncology and stem cell R&D programs.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in 3D model systems.
- Operational Value: Enhances standardization, reproducibility, and scalability of live-cell imaging workflows.
- Strategic Value: Improves go/no-go decisions and capital efficiency by providing robust, quantitative data.
- Portfolio Impact: Enables risk-adjusted prioritization and advancement of candidates with validated biological relevance.
Implementation Considerations
- Requires expertise in 3D cell culture, live-cell microscopy, and FLIM analytics.
- Demands access to widefield, confocal, or two-photon FLIM instrumentation and compatible analysis software.
- Necessitates cross-team standardization of spheroid production and imaging protocols.
- May require adaptation for different cell types, extracellular matrices, or sensor integration.
- Variability in spheroid size and composition can impact reproducibility and data interpretation.
Biopharma FAQs
Chapters in this video
0:00
Introduction
1:51
High‐Throughput Generation of Multicellular Spheroids from Human Cancer Cell Line for Live 3D Imaging
4:15
Assessing the Impact of Spheroid Formation Methods in 3D Cell Culture Systems Using Live Cell Fluorescence Lifetime Imaging Microscopy (FLIM)
