Ex vivo methods of screening for, and characterizing, cardiac therapeutics using preloaded cardiac tissues

A method for assaying a response of a cardiac organoid to a compound comprising:

• (a) preloading a cardiac organoid in at least one organoid module by adjusting a hydrostatic pressure inside an organoid chamber to induce a change in stroke work of between 1-50% normalized to an untreated baseline to expand the cardiac organoid prior to administering a compound, wherein the cardiac organoid is housed in at least one organoid module, each organoid module comprising:
• (i) a media inlet, a media outlet, and at least one wall compatible with an external detection device, wherein the cardiac organoid comprises at least one human cell, wherein the one human cell is a human embryonic stem cell, a human adult stem cell, a human induced pluripotent stem cell, a cell derived from a human tissue, or a progenitor cell of a human tissue, and wherein the cardiac organoid is in fluid communication with a fluid pump or a fluid reservoir comprising an adjustable volume of fluid, wherein the fluid pump or fluid reservoir modulates the pressure within the organoid;
• (ii) a mirror arrangement for simultaneous monitoring of any biological development of the cardiac organoid in each of at least two organoid chambers;
• and
• (iii) a detection device for observing the monitored biological development of the cardiac organoid in each of at least two organoid chambers;
• (b) administering the compound to the cardiac organoid;
• and
• (c) detecting a response of the cardiac organoid to the compound.