快猫短视频

快猫短视频s have created the world鈥檚 most complex biological computer 鈥� a group of engineered cells that could one day be implanted into the body to detect diseases and deliver treatments.

In 2012,聽聽at ETH Zurich, in Switzerland, and his colleagues engineered two kidney cells to become a biological circuit capable of simple mathematics. One of the cells was able to do a form of addition: the presence or absence of each of two chemicals would switch on a reaction inside the cell that would make it glow different colours. The other cell worked in the same way but could subtract.

This kind of biological circuit is reminiscent of a simple logic circuit in a computer, and could in theory be used to make a skin patch to glow in the presence of an infectious agent, for example.

Most biological reactions in the body aren鈥檛 that simple, though, says Fussenegger. They rarely rely on 鈥渙ne input and one output鈥� 鈥� instead, multiple inputs lead to different outputs. For instance, a high level of calcium in the body in the聽presence聽of a specific hormone might suggest one disease, whereas a high level of calcium in the presence of another hormone might be a completely different condition.

To be more practical, biological computers would need to be able to perform more complex mathematics. That鈥檚 difficult, though, because it is hard to pack multiple computations into a single cell. To get around this, Fussenegger and his team have engineered a multicellular system, in which different cells each perform a separate computation, and pass the results to one another.

Automated diagnosis

The system has nine cells, each containing a chemical cascade that responds to three chemical inputs 鈥� reminiscent of an AND, NOT and OR system in a traditional electronic circuit. These cells can coordinate their activities by releasing chemicals like histamine that pass from one cell to the other. Together, they form a fully programmable, multicellular circuit that can respond to multiple inputs.

鈥淎lthough it is not at a stage yet where we can test in animals, we believe it is the most complex biological computer ever assembled,鈥� says Fussenegger.

鈥淭his work addresses one of the most pressing limitations in synthetic biology 鈥� a lack of programmable devices,鈥� says , a synthetic biologist at Newcastle University, UK. He says that traditionally a synthetic circuit inside a cell will always perform the same function, but Fussenegger鈥檚 multicellular approach enables you to programme the circuit and achieve different computations just by connecting the nine cells in different configurations. 鈥淚t is very powerful,鈥� he says.

In the future, a biological computer like this could be used to monitor more complex medical conditions. For example, it could respond to a rise in calcium, a drop in a hormone, and an increase in a cancer biomarker, that together would signal the presence of a specific type of cancer, says Fussenegger. The team wants to develop a single implant that continuously monitors all the chemical reactions in the body, and either treats any problems, or helps diagnose them.