Removed tissues and organs are classed as pathological waste, which has to be incinerated rather than binned normally. Treating hazardous healthcare waste this way costs up to ten times more than ordinary waste. So hospitals pay a premium to destroy the very thing Vasileios Trikalitis wants to save. He is a tissue engineer at the University of Twente's TechMed Centre.
How do you pick up a scrap you can barely see?
Vasileios has a very Dutch way of explaining the idea. A frikandel is made from the meat a machine scrapes off bones and carcasses, the bits too small to use any other way. Surgical scraps are just as small and awkward. Picture cutting a chicken breast at home: the shreds that cling to the knife are about the right size. No surgeon has the time or the dexterity to fish one of those out of a patient and mount it for research.
So Vasileios hands that job to a jar of microscopic beads, which he calls a Tissue Ark. Living tissue binds to the beads within minutes. A surgeon, or even an assistant, just wipes the scalpel across them, and the scrap sticks."Ideally it is a single wipe that an assistant can do during surgery," Vasileios says. The scrap stays sterile because it never leaves the operating theatre. The whole point is to add almost no work to an already intense operation.
Why the magnets matter
Picking the scrap up is only half the trick. Muscle lives under constant tension, and the moment you cut it, that tension is lost and the tissue starts to break down rapidly. If the muscle is under tension, like it is in a dead human body, it stays alive for roughly 12 hours, which is when rigor mortis occurs. "Keeping it gently stretched is probably the key to extend its lifetime," Vasileios says.
Vasileios makes the beads magnetic by adding a little iron, so a magnet can move them around. Pull on the beads and you pull, gently, on the tissue stuck to them. The scrap is kept on the stretch, and kept alive, without anyone touching it. The beads are not new. Vasileios helped develop them during his PhD in the Vascularization lab and his parallel work as a product developer, and they are now patented and sold by IamFluidics, a UT spin-off on campus. Making them magnetic is the fresh step that turns a lab tool into a way to rescue surgical scraps.
Why not just take a biopsy?
There is already a way to get living tissue from a patient: a biopsy. But a biopsy is a deliberate, separate procedure. The patient has to come to the hospital for it, and a surgeon cuts out healthy tissue on purpose, leaving a fresh wound and some lasting damage. Surgical scraps come free. They are removed anyway, during an operation the patient is already having, and nothing extra is taken. If you agree to it, the bits that were heading for the incinerator go to a lab instead. No second procedure, no second wound.
From the operating theatre to a chip
So what is a rescued scrap good for? Placed on a lab on a chip, a coin-sized device that mimics part of the body, it can show which drug works best for that specific patient. Because it carries your own DNA, your body would not reject it.
It could also be a head start for growing tissue. Vasileios says: “In the lab, building a single three-millimetre piece from scratch takes weeks of work and thousands of euros. Starting from a living scrap is like starting with dough instead of flour when you bake bread.” Small scraps can also survive without their own blood supply due to diffusion, which larger lab-grown tissues cannot. This has never been tried before. The tissue might simply refuse to stick to the beads. However artificial tissues and cells do stick in the first experiments. If this approach does not work, it gives us new information. Since the scraps are being burned anyway, there is little to lose by trying.
One person's waste, another's treasure
The near-term promise is not artificial organs. Human tissue models can replace some animal testing and make drug trials fit real people better, which is why the non-profit VitalTissue already rescues larger residual tissue for research. The longer-term dream is bigger, because far more people need a donor organ than ever receive one. For now, Vasileios just wants the scraps. “You get a personalised tissue model,” he says, “if you give permission to use your scraps.” Nothing extra is taken from you. The bins in the operating theatre suddenly look very different.
