Testing the effects of chemicals, drugs, cosmetics, etc. on living organisms has always been a cause of ire from the animal rights advocates. Due to the obvious cruelty of the practice and the wretched idea that animals are dispensable items, several advances have been made to create neurophysiological systems or organs-on-chips. These aim to reduce the usage of animals for testing and allow the scientists to study these effects without harming any living beings.
This seemed to have solved the problem, but manufacturing and data retrieval from the chip using contemporary technology is both costly and time-consuming process. Thus to make it more affordable and practical, researchers at Harvard have successfully developed new materials which allow them to 3D print the devices along with all its intricacies and integrated sensors that can make the device incredibly cheap besides enabling easy data collection.
The device measures around the size of a USB stick and uses living human cells to test the effects of drugs and diseases on organs such as the lungs, intestines, placenta and heart.
But the creation of the chip is still a very delicate and complicated process, involving microscopes and high-speed cameras to make the concept practical. Travis Busbee, co-author of the paper and part of the team, said on the technology,
“Our approach was to address these two challenges simultaneously via digital manufacturing. By developing new printable inks for multi-material 3D printing, we were able to automate the fabrication process while increasing the complexity of the devices.”
The chip created by the Harvard team is special because it uses six custom 3D-printable materials capable of replicating the structure of human heart tissue and soft strain sensors embedded inside. The chip is printable in one continuous and autonomous process, which makes it easy to fabricate along with being incredibly powerful as it can host different tissues in separate wells located on the chip.
Jennifer Lewis, another of the paper’s co-authors said,
“We are pushing the boundaries of three-dimensional printing by developing and integrating multiple functional materials within printed devices. This study is a powerful demonstration of how our platform can be used to create fully functional, instrumented chips for drug screening and disease modeling.”
The state of the art miniature sensors enable the researchers to study and collect data from the tissue over time, and by measuring the contractile stress changes and effects of long-term exposure to drugs and toxins on the organs, they can make reasonable conclusions and suggestions. The research was published in the journal, Nature Materials.
Time-lapse of the 3D printing is visible in the video below.
Johan Ulrik Lind, first author of the study and postdoctoral fellow at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), commented on the amazing achievement,
“Researchers are often left working in the dark when it comes to gradual changes that occur during cardiac tissue development and maturation because there has been a lack of easy, non-invasive ways to measure the tissue functional performance. These integrated sensors allow researchers to continuously collect data while tissues mature and improve their contractility. Similarly, they will enable studies of gradual effects of chronic exposure to toxins.”