LIGHTHEART · Surgical optogenetic bioprinting of engineered cardiac muscle

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.