Publications
Discover our work in our published papers ans posters!
Bocquet et al. – MPS World Summit 2025 (poster presentation)
The development of in-vitro 3D cardiac models with a physiological read-out, such as contraction force, is critical for advancing cardiac drug screening, as cardiovascular diseases remain the leading cause of death worldwide, killing over 20 million people annually. 3D cardiac models are made from cells compacting around flexible pillars, which bend under contraction, enabling analysis of contractile parameters. However, their need for high cell numbers per tissue translates to high cost and complex manufacturing, economically unfeasible for high-throughput drug screening. In this study, we miniaturize 3D cardiac strips by an order of magnitude, making them economically feasible for the first time.
Organ-on-Chips (OoCs) platforms are commonly made from polydimethylsiloxane (PDMS), which is not compatible with high throughput workflows. To overcome this, we replaced PDMS with a commercial thermoplastic elastomer (TPE), to culture our µ3D cardiac strips and fabricated them at scale using injection molding techniques. Our µ3D cardiac strips were composed of 90% hiPSC-CMs (human-induced Pluripotent Stem Cells-Cardiomyocytes) and 10% fibroblasts, which were seeded at 16.5M cells/mL resulting in 24000 cells/chamber. The chambers were sealed using biocompatible tape, and pipette tips were added as medium reservoirs in the in- and outlets. To confirm the biocompatibility of the material, we performed live/dead staining and immunostaining with alpha-actinin to detect sarcomeres. The spontaneous contraction force was measured after 10 days.
After 5 days we could already observe contractile movements and sarcomere structures, meaning that this material had no impact on cell viability. For preliminary results, we obtained a contraction force of 125 µN on average, which was similar to the µ3D cardiac strips in the PDMS platform.
To conclude, we demonstrated that we could miniaturize 3D cardiac strips to a level below 25000 cells. Furthermore, we showed that µ3D cardiac strips stay alive and beat in TPE chips, thereby achieving the first step towards a high throughput screening platform. As future plans, we will scale up the process in our in-house developed 3DCardiacHTS plate and perform drug screening.
Sambrotta et al. – MPS World Summit 2025 (poster presentation)
Cardiovascular disease is one of the leading causes of death worldwide. In the past decades cardiac drug discovery has been relatively unsuccessful. This is partially caused by lack of proper pre-clinical models, for example 2D assays lack complexity in readouts, while animal models have high differences with the physiology of the human heart and high costs. Human 3D cardiac strips are emerging as a gold standard for in vitro cardiac research and drug discovery. However, their scalability and cost-effectiveness remain significant challenges for high-throughput screening (HTS). This study addresses these limitations by miniaturizing the cardiac strips into µ3D Cardiac Strips and optimizing their composition to enhance contraction force while maintaining physiological relevance.
We were able to miniaturise our µ3D Cardiac Strips to approximately 16 000 cells per strip. After that, we systematically varied cardiomyocyte densities in the platform and cardiomyocyte-to-fibroblast ratios to evaluate their effects on sarcomere alignment and contraction force. We then incorporated endothelial cells and smooth muscle cells into the tissue composition to increase its physiological relevance. We were able to assess the optimal cell composition for our HTS platform by analysis of contraction force, contraction velocity, and relaxation velocity, while by immunostaining we showed differences in cell morphology and alignment. Finally, we showed the functionality of the tissue with the best performance and morphology by evaluation of its response to positive and negative inotropes.
This work showcases a scalable, cost-effective protocol for producing µ3D Cardiac Strips with optimized contraction force and physiological relevance. These advancements mark a significant step toward integrating miniaturized human cardiac tissue models into HTS assays, enabling more efficient drug discovery and cardiac research.
Cofiño Fabres, Boonen et al. – 2024
Advanced in vitro models that recapitulate the structural organization and function of the human heart are highly needed for accurate disease modeling, more predictable drug screening, and safety pharmacology. Conventional 3D Engineered Heart Tissues (EHTs) lack heterotypic cell complexity and culture under flow, whereas microfluidic Heart-on-Chip (HoC) models in general lack the 3D configuration and accurate contractile readouts. In this study, an innovative and user-friendly HoC model is developed to overcome these limitations, by culturing human pluripotent stem cell (hPSC)-derived cardiomyocytes (CMs), endothelial (ECs)- and smooth muscle cells (SMCs), together with human cardiac fibroblasts (FBs), underflow, leading to self-organized miniaturized micro-EHTs (μEHTs) with a CM-EC interface reminiscent of the physiological capillary lining. μEHTs cultured under flow display enhanced contractile performance and conduction velocity. In addition, the presence of the EC layer altered drug responses in μEHT contraction. This observation suggests a potential barrier-like function of ECs, which may affect the availability of drugs to the CMs. These cardiac models with increased physiological complexity, will pave the way to screen for therapeutic targets and predict drug efficacy.
