Researchers at UCSF have developed a method called DNA Programmed Assembly of Cells (DPAC) that brings us one step closer to being able to print fully functional living organs. The new approach includes incubating cells with small single stranded snippets of DNA that have been modified to attach to the cells’ outer membranes. The resulting DNA-covered cells look similar to furry tennis balls. When a modified cell comes into contact with its counterpart, its complimentary DNA strands will bind to the other cell. Essentially, the DNA snippets not only serve as a cell recognition tool but also as a molecular Velcro to hold them together. In order to prove their concept, the group was able to print organoid arrays that mimicked human tissue such as mammary glands and branching vasculature.
In another test, the researchers printed an array of mammary epithelial cells and successfully did a small cancer gene study using this technique. The group was able to add a few modified cells with the RasG12V cancer gene in a printed organoid array and observed how the few mutated cells were able to induce a response from its surrounding tissue. Zev Gartner, PhD, the paper’s senior author, stated that he hopes to use this technology to study how changes in the structure of mammary glands can cause the destruction of tissue structure that is associated with tumors that metastasize. Furthermore, he and the group hope to use what they learn from this technique to be able to synthesize more complex human tissues such as the lungs, kidneys, or neural circuits using larger-scale techniques.
Here’s a video of the process. In step 1, cells attach to strand A. In step 2, cells attach to strand B. In step 3, cells assemble onto the cells from step 1. Playback is 8x real-time speed: