Spleen-on-a-chip uses magnetic nanobeads to rid blood of pathogens

We live in a world where we can't quite replace our internal organs without having another internal organ on standby. Every so often, there is a breakthrough in prosthetic, bionic limb technology, but humans can't quite replace their entire hearts or brains with a machine counterpart as of yet. The only thing we can do is add a machine supplement. Now, though, scientists at Harvard have built a machine spleen, which is able to remove pathogens from the bloodstream through the use of magnetic nanobeads.

Unfortunately, the spleen-on-a-chip, as Harvard is calling it, isn't exactly indicative of the images it probably invokes. It doesn't seem to be a tiny chip that gets connected to the rest of your guttyworks in place of a removed spleen, but rather seems to be a machine that sits outside of your body to which you're connected. Even though you can't be a spleen version of Jonny Mnemonic instead of having a 160GB storage chip in your head, the spleen-on-a-chip does work in a way that will make you feel like a science fiction character. Your blood is run through the machine, where it mixes with magnetic nanobeads(Opens in a new window). The nanobeads are covered with a genetically engineered protein found in human blood, opsonin, which in turn acts as something of a magnet for toxins, bacteria, and other things you don't traveling around your blood. Once the nanobeads collect the pathogens, the blood is run through some other areas of the device where a magnetic force pulls the nanobeads out of the blood, but leaves everything else intact. Once your blood is clean, it is sent back into you where it belongs, free of pathogens.

In order to prevent the blood from clotting as it flows through the machine, the Wyss team coated the channels through which the blood travels with a super-hydrophobic coating called SLIPS, which was developed in-house.

The Wyss Institute for Biologically Inspired Engineering was awarded $9.25 million from DARPA to help further its work on the blood-cleaning technology. The spleen-on-a-chip hasn't yet been tested on humans, but the Wyss Institute states that the continued funding from DARPA allows the device to be tested on larger animals, paving the way for human trials. The Institute isn't a stranger to things-on-chips, as they once developed a gut-on-a-chip, as well as a lung and heart.

So, while the spleen-on-a-chip isn't exactly a chip humans can put inside their bodies, the Institute is aiming for that goal. Thanks to DARPA, the team will have enough funding to eventually get the device up to human testing. The research certainly seems promising, and could be the de facto way to cleanse blood in the future.