Periodic Reporting for period 1 - LIGHTHEART (Surgical optogenetic bioprinting of engineered cardiac muscle)
Berichtszeitraum: 2023-03-01 bis 2025-08-31
Heart failure remains a leading cause of mortality worldwide taking an estimate of 16 million lives each year. Cardiac tissue engineering solutions that can improve the quality of life of those with advanced heart disease have proved challenging so far. Bioprinting is an exciting technology that holds promise to fabricate tissues and organs. Lab-grown engineered cardiac muscle requires at least four weeks to maturate in a bioreactor. In LIGHTHEART, an off-the-shelf solution will be developed for treating injured myocardium in vivo. An unconventional combination of bioprinting and optogenetics will be used to surgically fabricate engineered cardiac muscle directly at the patient’s heart. A surgical bioprinting tool will be constructed to achieve vascularization and cellular architectures as that observed in native cardiac muscle. Induced pluripotent stem cell-derived cardiac cells will be the basis of the bioinspired biomaterial-free ink that will be printed. Optogenetic expression of different light-sensitive proteins at the cell surfaces will be the sole trigger of cellular assembly, thus omitting the need to embed cells in hydrogels or printing in a supporting bath. Surgical optogenetic bioprinting will be first tested ex vivo using a silicone human phantom with a mimicking beating heart, and later in vivo in a large animal model in accordance with the 3R principles. LIGHTHEART opens up new horizons in the way heart failure can be clinically treated and brings hope to patients who are desperately waiting for a heart transplantation. The disruptive nature of LIGHTHEART will unite engineers, surgeons and scientists to change the future of transplantation medicine with modular bottom-up technologies that allow for in vivo tissue and organ restoration or replacement directly at the operating theatre.
During the course of the project, we achieved significant progress toward our goal of advancing cardiac tissue engineering through innovative biofabrication and biophysical manipulation strategies. We successfully created a realistic heart model replica that serves as a structural and functional reference for our experimental systems. A key technical achievement was the design and fabrication of a novel aspirator tool specifically developed for bioprinting cellular spheroids. Furthermore, we performed a series of experiments to fuse spheroids within custom-designed molds, enabling controlled tissue formation and maturation. In parallel, we developed an acoustic manipulation platform that allows patterning of spheroids, providing a versatile approach for scalable tissue assembly. Progress was also made in stem cell-based tissue engineering, with the differentiation of human induced pluripotent stem cells (iPSCs) toward cardiac lineages to generate functional cardiac tissue. Furthermore, we explored optogenetic strategies to control cardiac cell and spheroid aggregation using light. Complementing these efforts, we designed and fabricated advanced fluidic chips tailored for cardiac tissue culture with mechanical stimulation. Collectively, these achievements establish a comprehensive technological framework for engineering functional cardiac tissue and set the stage for future translational applications.
In this project, we have made a major breakthrough in cardiac tissue engineering by successfully developing vascularized heart tissue that can form and function without relying on microfluidic forces. This achievement overcomes one of the biggest challenges in the field, the traditional size limits of engineered heart tissues. Because our new tissue model is not confined by these constraints, we can now create larger, more realistic heart tissues to study how contractile forces, matrix stiffness, and extracellular matrix (ECM) composition influence heart function. Importantly, this approach also allows us to explore the role of blood vessels in heart development and disease, something that has been extremely difficult to achieve in laboratory models until now. Building on this innovation, we integrated acoustic manipulation technologies to guide the organization of cells within the tissue. These new vascularized tissues were evaluated beyond the current state of the art, allowing us to identify the key factors that determine tissue quality, alignment, and structure. We also conducted gene expression analysis on acoustically manipulated tissues, providing new molecular insights into how these structures form and mature. Moreover, we demonstrated the ability to generate hollow capillaries within complex co-cultures, a sign of self-organizing vascular networks that assemble naturally without external fluid pressure. Together, these advances represent a significant step forward toward employing these results to fabricate a living heart patch capable of mending human hearts, opening new possibilities for studying heart disease, testing therapies, and developing regenerative treatments for patients with heart failure.