In a new study published by the prestigious Nature Materials review, Harvard University researchers announced the creation of the first 3D-printed heart-on-a-chip, capable of collecting data about how reliably a heart is beating. Made from a synthetic material designed to mimic the structure and function of native tissue, the printed organ presents a promising alternative to traditional methods of animal testing.
Referred to in the scientific community as microphysiological systems (MPS), the microfluidic cell culture chips simulate the activities, mechanics, and physiological responses of entire organs. Constructed from a flexible, translucent polymer, they contain multiple wells – each with separate tissues and integrated sensors. Using multi-material 3D printing in a single automated procedure, an enormous part of this breakthrough was the development of six different printable inks capable of integrating these sensors into the tissue being printed. These sensors provide non-invasive, electronic readouts on structures within the body and allow researchers to study multiple engineered cardiac tissues at once.
Conducted by Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering at Harvard, the researchers demonstrated the device’s efficacy by performing drug studies and longer-term studies of measured changes in the contractile stress of the engineered tissue.
"The data we get from the sensors is the most critical information pertaining to cardiac tissue: the strength of the 'heart beat' and the beat rate," Johan Ulrik Lind, first author of the paper and a postdoctoral fellow at the SEAS, told Computerworld. "This enables us to study how the tissue responds to toxic compounds. Because pharmaceutical research can involve [tests of] thousands of compounds, this is an important improvement over previous work."
For now, these chips are only able to replicate the architecture and function of lungs, hearts, tongues and intestines – with the heart being the most advanced organ-on-a-chip yet. These synthetic organs have the potential to replace animal testing with a customisable and humane alternative that could even gauge a more accurate result. Unfortunately, the cost of manufacture for these organs-on-a-chip is still quite high, and the process is also time-consuming. Researchers are pushing forward to improve their methods, though, in the hopes of making this a viable alternative toward the cruel practice of animal testing.