Scientists create "bone marrow on a chip"
The trend of growing organs and tissues in a lab is picking up speed. The newest lab-grown breakthrough is Harvard's “bone-marrow-on-a-chip.” The Wyss Institute for Biologically Inspired Engineering at Harvard recently published their experiment news in the journal Nature Methods.
The researchers said the invention will enable scientists to analyze the effects of drugs and certain agents on whole bone marrow without animal testing. It also allows scientists to determine how radiation hurts bone marrow and other alternatives that could help. Initial testing showed bone marrow withers under radiation unless a drug that specifically fights off radiation poisoning is involved. The chip could also serve as a temporary “home” for a cancer patient’s bone marrow while they undergo radiation treatment. Bone marrow produces all blood cell types, and the Harvard chips allow the bone marrow to perform these essential functions while “in vitro.”
This chip is one of many that the Wyss Institute team has developed, alongside lung, heart, kidney, and gut chips. To build it, the team put dried bone powder into an open circular mold the size of a coin battery. This mold was then implanted under the skin on the back of a mouse. Eight weeks later, scientists removed the mold and examined it under a microscope to find a honeycomb structure filled in the middle of the mold, looking just like natural trabecular bone. The marrow of this looked identical to normal marrow as well. It was filled with red blood cells, mimicking the marrow of the mouse. When sorting and organizing the different bone marrow blood cells, the team found the types and numbers were the same as that in a mouse thighbone. The engineered bone marrow was then placed in a microfluidic device and received a steady supply of nutrients and waste removal to imitate circulation the tissue would normally be exposed to in the body. The marrow-on-a-chip lasted in the lab for one week, long enough to test it with radiation.
Researchers are hoping this will eventually lead to growing human bone marrow in mice, as well as using the blood cells produced on these chips to help other organs grown on chips in the lab.