Max von Pettenkofer drank cholera to demonstrate the bacterias’ spread in ground water, Bengt Lundqvist performed the first injection of lidocaine (the first local anaesthetic) on himself and Edward Jenner injected the son of his gardener with the first smallpox vaccine. Thankfully, modern medical research is somewhat more thorough than this. New pharmaceuticals typically going through 5-10 years of basic research before the first patients even see them.
When Elizabeth Loboa found out her mosquito bite had been infected with the superbug MRSA, she was less patient and decided to self administer a completely new type of treatment. Elizabeth is a materials engineer from North Carolina State University in Raleigh, who has been developing a degradable “super-bandage” type material.
the extracellular matrix
At the heart of Loboa’s super-plaster is a material, based on the bodies own extracellular matrix (ECM), that degrades until nothing is left but your own, newly regenerated cells. According to Loboa, this same material could one day be used to heal everything from shredded muscle and destroyed digestive tract to shattered bone.
The ECM was once regarded as a simple inert scaffold for cells to grow around, however, it is becoming increasingly obvious that the ECM is no mute biological bystander. While it consists of mainly inanimate structural proteins such as collagen and elastin, it also contains proteins which coax the right cells to be in the right place at the right time. For example, hook like molecules called fibronectins and integrins provide tailored molecular velcro for specific cells.
Once these molecules have summoned the rights cells, the matrix has another trick up its sleeves, it can coax cells to turn into muscle, bone or fat cells depending on the specific mix of biological, chemical and mechanical signals at that specific location.
For Loboa, the big breakthrough came when her friend went into hospital for an ankle replacement, the wound became infected with MRSA. “They ended up having to amputate the leg below the knee,” she says. It was a wake-up call. “We’re learning so much about how to regenerate so many different types of tissues,” she says, “but how do you keep infection out in the age of drug-resistant superbugs?”
Loboa began working on a new synthetic matrix that could be placed over the patients skin to aid tissue repair without ever exposing the wound to bacteria. The idea is that the matrix will slowly degrade, acting like a bandage that never needs to be changed. Whats more, the matrix can be made from any shape the researchers want. You could, for example, make a porous fibre structure containing small amounts of anti-inflammatory drugs or substances such as Silvadur, a silver containing drug lethal to most drug-resistant bacteria.
The structure of the bandage itself dictates how these drugs are released, Loboa opted for a waved release designed to first overwhelm all existing bacteria then slowly release small amounts of anti-microbials to stop new infections developing. The matrix structure also ensures proper healing of the would, directing cells to differentiate into muscle, bone and fat as required. This means no excess collagen formation, and hence no scarring.
After seeing the bandage work several times in animal models, it was with this type of bandage that Loboa decided to treat her own wound. And thats where the true implications took hold. “I put my scaffold on, and the sores were gone in three days,” she says. Soon the bandage itself vanished, leaving a dark scar that was quick to disappear.
Loboa is currently in the process of publishing her findings, but it may be a long time before off the shelf super-bandages become a reality. Loboa is confident we will see this sort of treatment in the near-future however. Today, even simple skin wounds are becoming increasingly dangerous as antibiotic-resistant bacteria thrive in and out of hospitals. And thats where Loboa’s change-free bandage could come into its own. “Right now, hospitals are scary places,” Loboa says.
original article: New Scientist