Scientists from the Cluster of Excellence “3D Matter Made to Order” have developed a new molecular engineering technique that allows for precise control over the development of complex organoids. The technique uses microbeads made of specifically folded DNA to release growth factors or other signal molecules inside tissue structures.
Organoids are miniature, organ-like tissue structures derived from stem cells and are used in basic research to gain insights into human development or study disease development. Until now, it was not possible to control the growth of such tissue structures from their interior.
The researchers constructed microscopically small beads of DNA that can be “loaded” with proteins or other molecules. These microbeads were injected into organoids and released their cargo when exposed to UV light, allowing for the release of growth factors or other signal molecules at any given time and location within the developing tissue.
The team tested this process on retinal organoids of Japanese rice fish medaka by precisely inserting microbeads loaded with a Wnt signal molecule into the tissue. For the first time, they were able to induce retinal pigment epithelial cells— the outer layer of the retina—to form adjacent to neural retinal tissue.
Thanks to the localized release of signaling molecules, the researchers achieved a more realistic mix of cell types, mimicking the natural cell composition of the fish eye better than conventional cell cultures. The DNA microbeads can be flexibly adapted to transport many different signal molecules in various types of cultivated tissue, opening up new possibilities for engineering organoids with improved cellular complexity and organization.
This technique has potential applications in accelerating research on human development and disease, as well as potentially leading to better organoid-based drug research. The research was published in the journal Nature Nanotechnology.
Source: https://phys.org/news/2024-09-molecular-technique-complex-organoids.html