Putting aside beliefs about religion and the afterlife, most people agree that there are two stages of experience for living beings: life and death.
Obviously, a lot happens in between, but the general consensus is that death is the end point.
However, biologists have now studied how cells can be reused, and have suggested there may be another way – which could revolutionise the field of synthetic biology.
Scientists have observed how cells behave in a petri dish after the organism's death (Getty Stock Photo)
In an article published in The Conversation, biologists and co-authors Peter Noble and Alex Pozitkov explain how the emergence of new multicellular life-forms has allowed us to move beyond the 'traditional boundaries of life and death'.
Noble and Positkov study what happens inside organisms after they die, and while successful organ donation has proven that cells can continue to function after a person's death, they have looked further into the mechanisms that allow this to happen.
In their study, the researchers focused on biobots, which are generated from the cells of dead organisms, and their ability to transform into multicellular organisms with new functions after death.
Biobots are a sign of a 'third age' (Getty Stock Photo)
Previously, researchers had found that skin cells from dead frog embryos could transform into multicellular organisms called xenobots that showed new behaviours.
For example, they were able to move using hair-like protrusions called cilia, which are usually only capable of moving mucus, not the cells themselves.
And while studying human lung cells, researchers found that the cells can transform themselves into miniature multicellular organisms, capable of moving and behaving in new ways.
Taking both of these findings into consideration, the researchers found that cells have an 'inherent flexibility'.
With this in mind, researchers can use cells from living or dead organisms, and turn them into machines with entirely new functions.
Noble and Positkov said there are certain circumstances that determine whether cells and tissues can continue to survive after an organism dies, including environmental conditions, metabolic activity and preservation techniques, as well as factors such as age, health, sex and type of species.
The cells of frogs were able to develop into xenobots (Getty Stock Photo)
However, further research is needed to determine how these variables work together to allow some cells to continue to function even after an organism's death.
Although research is ongoing, Noble and Pozhitkov said the possibility of a “third state” not only offers new insights into how adaptable cells can be, but also offers the possibility of new treatments.
Giving an example of how this theory could be put into practice, the authors said: “Anthrobots could be derived from a person's living tissues, which could deliver drugs without triggering unwanted immune responses.”
“Engineered anthrobots injected into the body can dissolve arterial plaque in atherosclerosis patients and remove excess mucus in cystic fibrosis patients.”
The researchers found that if used, these biobots lasted no longer than 60 days, potentially preventing the growth of invasive cells.