SCIENCE NEWS IN BRIEF
February BIOTECH
MEDICINE
Switching blood types - a step towards creating universal donor organs? Each individual has a particular blood type, which corresponds to the type of antigen presented on the surface of red blood cells. For example, type A blood contains A antigens (AAg) and anti-B antibodies, while type O lack antigens but has both anti-A and anti-B antibodies. Before patients undergo organ transplantation,
which removed nearly all A-Ag. Fluids were then supplied to the lungs in preparation for the transplantation via ex-vivo lung perfusion, where they tested the tolerance of the treated lungs. To simulate an incompatible transplant, type O blood containing high amounts of anti-A antibodies was added to the fluid. Minimal antibody
doctors must ensure the ABO blood groups of the donor and
response was recorded, suggesting a low chance of
patient are compatible. This is because our immune systems
antibody-mediated injuries if done in vivo. How long the lack
are not infallible - if the body detects foreign antigens from
of antigens will be maintained is not clear, and the team has
an incompatible blood type, hyperacute rejection could be launched, bearing deleterious consequences for the organ recipient. Given the lack of antigens in type O organs, an immune response will not be provoked, heralding type O as the “universal donor”. Dr Marcelo Cypel and his team at the University of Toronto, Canada performed a proof-ofconcept study into switching a type A organ into a type O, effectively making it a universal donor. They treated lungs with sugar-digesting-enzymes
plans to test the novel technique further in mice. With wait times for type O patients averaging twice as long as type A patients, “switching” blood types to create type O organs has massive implications for eliminating the “bloodmatching barrier” and allows doctors to “prioiritise patients by medical urgency, saving more lives and wasting less organs”, says Dr Cypel.
Vanessa Yip
Biohybrid fish powered by human cardiac muscle cells swims for 100 days
The first fully autonomous biohybrid fish from human stem-cell derived cardiac muscle cells. Credit: Michael Rosnach, Keel Yong Lee, Sung-Jin Park, Kevin Kit Parker
Harvard University researchers, in collaboration with colleagues from Emory University, have developed the first fully autonomous biohybrid fish from human cardiac muscle cells, in pursuit of building an artificial heart. The biohybrid fish is engineered with two cardiac muscle cells, one of each side of the tail fin. Whenever one of the muscles contracts, it opens a protein channel which can trigger the muscles on the opposite side to contract. The fish is also equipped with a pacemaker to coordinate the
frequency and rhythm of the contractions. As a result, this closed-loop system recreates the muscle contractions of a pumping heart, highlighting the role of feedback mechanisms in the heart muscular pump. The good news was that the fish could swim around for more than 100 days, which hinted that the researchers could build a long-lasting muscular pump from human stem-cell derived cardiac muscle cells, which was part of their aim to replace a child's malformed heart. Noelle Lee
ECOLOGY
A new method to eradicate invasive species
Over the recent centuries, invasive species have posed a threat to fragile ecosystems all over the world and people have come up with all sorts of methods to rid that areas of them. However, recently chefs and conservationists alike have agreed on a method to eradicate invasive species: by eating them. This new food movement is called invasivorism in which invasive species are incorporated into everyday and gourmet dishes. This method has 9
already been adapted in many places around the world, for example in the Caribbean Sea where restaurants serve the invasive lionfish, or in the where UK restaurants serve grey squirrel. However, though at face value it sounds amazing, there’s one important thing that everyone should keep in mind: eating invasive species should be to reduce or eradicate the species and it is not intended to create a market for that creature. Ludmila Neil
