Fabrication of 3D Cardiac Microtissue Arrays using Human iPSC-Derived Cardiomyocytes, Cardiac Fibroblasts, and Endothelial Cells
March 14th, 2021
6.9K views
Here, we describe an easy-to-use methodology to generate 3D self-assembled cardiac microtissue arrays composed of pre-differentiated human-induced pluripotent stem cell-derived cardiomyocytes, cardiac fibroblasts, and endothelial cells. This user-friendly and low cell requiring technique to generate cardiac microtissues can be implemented for disease modeling and early stages of drug development.
Overview
This article presents a methodology for generating 3D self-assembled cardiac microtissue arrays using human-induced pluripotent stem cell-derived cardiomyocytes, cardiac fibroblasts, and endothelial cells. The technique is user-friendly and requires a low number of cells, making it suitable for disease modeling and early drug development.
Key Study Components
Area of Science
- Cardiovascular biology
- Stem cell research
- Drug development
Background
- Induced pluripotent stem cells can generate various human cardiovascular cell types.
- Cardiac spheroids can be produced rapidly, within 72 hours.
- This technique allows for the generation of a high number of beating cardiac spheroids.
- Each spheroid can be assessed for contractile function using imaging techniques.
Purpose of Study
- To develop a simple method for creating cardiac microtissues.
- To facilitate disease modeling and drug testing.
- To enable functional assays of cardiac spheroids.
Methods Used
- Generation of cardiac spheroids from stem cells.
- Use of agarose in silicone micromolds to form microtissue arrays.
- Imaging techniques for assessing contractile function.
- Implementation of a 12-well plate format for scalability.
Main Results
- Nearly 1000 beating cardiac spheroids can be generated in a standard 12-well plate.
- Each spheroid exhibits contractile function that can be measured.
- The methodology is efficient and reproducible.
- Cardiac microtissues can be used for various applications in research.
Conclusions
- This methodology provides a robust platform for cardiac research.
- It can significantly aid in drug development and disease modeling.
- The technique is accessible and requires minimal resources.
Frequently Asked Questions
What are cardiac microtissues?
Cardiac microtissues are 3D structures composed of cardiac cells that mimic the function of heart tissue.
How long does it take to generate cardiac spheroids?
Cardiac spheroids can be generated in less than 72 hours.
What is the advantage of using induced pluripotent stem cells?
Induced pluripotent stem cells can differentiate into various cardiovascular cell types, providing a versatile tool for research.
Can the contractile function of cardiac spheroids be measured?
Yes, each cardiac spheroid can be assayed for its contractile function using imaging techniques.
What applications can these cardiac microtissues be used for?
They can be used for disease modeling and drug testing.
Is this technique scalable?
Yes, the technique allows for the generation of a large number of spheroids in a standard laboratory format.
Executive Industry Relevance
This protocol enables rapid generation of vascularized, fibroblast-containing cardiac microtissues from iPSCs, addressing a key gap in physiologically relevant in vitro heart models. The ability to produce nearly 1000 contractile spheroids in a standard 12-well plate within 72 hours supports scalable preclinical screening. The platform facilitates mechanistic de-risking by allowing contractility assessment and single-cell analysis post-digestion, improving target validation confidence in cardiovascular drug discovery.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of multicellular cardiac interactions to clarify pathogenic mechanisms and validate therapeutic targets in a human-relevant system.
- Operational Value: Provides a reproducible, vascularized microtissue model that reduces biological ambiguity in early target hypothesis testing.
Screening & Assay Development
- Scientific Value: Generates contractile microtissues with quantifiable functional readouts (beat rate, contraction/relaxation velocity) suitable for compound screening.
- Operational Value: Supports high-throughput preparation in standard multi-well plates with minimal hands-on time and rapid self-assembly.
Translational & Preclinical Research
- Scientific Value: Maintains cellular composition and structural organization over four weeks, enabling longitudinal disease modeling and chronic toxicity studies.
- Operational Value: Allows recovery of viable single cells post-digestion for flow cytometry and scRNA-seq, supporting biomarker discovery and mechanism of action studies.
Pipeline & Workflow Integration
The method fits within the discovery continuum from target validation through lead optimization, providing a functional, multicellular bridge between monolayer assays and in vivo models.
- Discovery Biology: Supports hypothesis testing via controlled co-culture of iPSC-derived cardiomyocytes, fibroblasts, and endothelial cells to model tissue-level responses.
- Screening: Enables assay-ready microtissue formation with measurable contractility, facilitating compound effect evaluation in a 3D context.
- Analytics: Generates quantitative contractile parameters and post-digestion single-cell data for multidimensional phenotypic profiling.
- Translational Research: Models human cardiac tissue complexity, improving predictability for preclinical advancement decisions.
- Enterprise Reuse: Agarose mold replication allows standardized, reusable microtissue array production across projects and teams.
Operational & Enterprise Impact
- Scientific Value: Enhances predictive confidence by incorporating >60% nonmyocyte cell types critical for native heart function and drug response.
- Operational Value: Standardized fabrication in 12-well plates ensures reproducibility and scalability for large-scale screening campaigns.
- Strategic Value: Enables earlier identification of cardiotoxic compounds, reducing late-stage attrition and improving capital efficiency.
- Portfolio Impact: Supports risk-adjusted prioritization through functional, human-relevant efficacy and safety readouts.
Implementation Considerations
- Requires expertise in iPSC differentiation and sterile microtissue handling.
- Depends on access to silicone micromolds, agarose, and standard cell culture incubators.
- Necessitates standardized seeding protocols to ensure uniform microtissue formation across replicates.
- Adaptation to other cell types or ECM formulations may require optimization of digestion and maturation timelines.
- Practical limitation: Long-term functional stability beyond four weeks requires validation for chronic study applications.
Biopharma FAQs
Why does measuring contractile velocity matter for target validation in cardiac microtissues?
Contractile velocity provides a quantitative, functional readout of cardiomyocyte health and multicellular coordination, enabling objective assessment of compound effects on heart muscle performance. This metric supports target validation by linking molecular mechanisms to tissue-level physiology in a human-relevant model.
How does isolating endothelial cells and cardiac fibroblasts in the microtissue model improve discovery pipeline efficiency?
Including endothelial cells and cardiac fibroblasts replicates the native cellular composition (>60% nonmyocytes), which influences cardiomyocyte function and drug response, thereby increasing physiological relevance. This reduces the risk of false positives/negatives in early screening by modeling intercellular signaling critical to disease mechanisms.
What quantitative dependent variable measurements enable compound screening in this cardiac microtissue platform?
The platform measures beat rate, contraction velocity, and relaxation velocity as key functional endpoints derived from pseudo heat maps of microtissue motion. These parameters allow dose-response analysis and comparison across treatment conditions to identify bioactive compounds.
Why do replication requirements across microtissue arrays matter for cross-functional collaboration in drug discovery?
The ability to generate nearly 1000 uniform spheroids in a 12-well plate ensures high reproducibility, enabling consistent data sharing between biology, screening, and toxicology teams. Standardized microtissue size and contractility reduce variability, supporting reliable interdepartmental decision-making.
What statistical analysis capabilities are required before implementing this microtissue model in a screening workflow?
Implementation requires the ability to analyze contractile parameters (beat rate, velocity) across replicates using appropriate statistical tests to detect significant changes from baseline. Additionally, post-digestion single-cell data from flow cytometry or scRNA-seq necessitates bioinformatics support for differential expression and cell state analysis.
Chapters in this video
0:04
Introduction
0:47
Casting of the Cardiac Microtissue Molds and Cell Seeding
3:32
Fixation and Permeabilization of the Cells and the Cardiac Microtissues for Immunostaining
5:45
Digestion of the Cardiac Microtissues and Cell Preparation for the Flow Cytometry
7:34
Results: Estimation of the Purity, Morphology, the Contraction Profile of the Cells in the Cardiac Microtissues
9:47
Conclusion
