Depending on who you ask, needles are either a minor inconvenience or a socially acceptable sadistic ritual. Still, vaccination remains one of the most effective safeguards against the spread of disease. Thanks to one Stony Brook scientist, a new type of needle-free vaccination may soon be possible.
Biomedical engineer and recent Stony Brook PhD graduate Katarzyna Sawicka won first place in the graduate division of the 2014 Collegiate Inventors Competition for her invention of Immuno-Matrix. Applied like a Band-Aid, Immuno-Matrix uses nanofibers to hold and deliver vaccine particles through skin in a non-invasive manner.
“The question for me was: how do you bring large molecules into the skin?” Sawicka said. “Most other technologies rely on some form of mechanical disruption of the skin. The patch that I helped develop does not require any abrasion or penetration of the skin, but instead works by exchanging moisture across the topmost layers of skin.”
Unlike conventional vaccines, Immuno-Matrix is painless, can be self-administered and does not produce biohazardous waste. Yet it still has all the advantages of a skin
“What’s great about skin is that it is the largest organ in the body,” Sawicka said. “One of skin’s main roles is to protect. Yet the way it does this involves more than just posing as a physical barrier. It is also an active process.”
“Scientists noticed that by delivering antigen into skin, you needed a lot less antigen,” she said. “It turns out that skin is equipped with an extensive lymphatic system. Skin is very immuno-competent, so that you don’t have to worry about trying to find an immune cell–they are all right there.”
Vaccines work by introducing an immunogenic particle (antigen), often part of a dead or weakened virus, to “teach” the immune system. The antigen serves as a kind of mock drill, so that if the particle is encountered again, say on the capsule of a live virus, the body can mount a rapid and effective immune response.
The challenge for researchers worldwide has been in finding new ways to engage the skin’s local environment in order to initiate a global immune response.
“When I first started, I was told that 500 daltons was the maximum size of particles that could be absorbed through skin,” Sawicka said. “With Immuno-matrix we have delivered particles 250 times that size, all without the use of microneedles or mechanical penetration.”
To reduce the volume that must be injected, Immuno-matrix delivers what is called a subunit vaccine, which contains only the most immunogenic part of the pathogen, typically a protein.
“What we’ve been seeing so far is that Immuno-Matrix seems to be as effective as intramuscular injections in conferring immunity,” Sawicka said.
To date, Sawicka and her colleagues have successfully tested the delivery of whooping cough antigen in vivo as well as influenza and anthrax in vitro. Over the next few months, Sawicka will continue to look at data for a variety of other antigens and macromolecules.
In the meantime, Sawicka, who was once a Stony Brook undergraduate studying engineering chemistry, reflected on the years of perseverance and interdisciplinary learning that led up to Immuno-Matrix.
“When I first started my PhD I realized I wanted to learn something new,” Sawicka said. “I don’t think I would know about both the immune response as well as the structure of skin had I not ventured into a more biologically relevant field.”
“When you sit on something for so long, you tend to only see from one perspective,” she said. “However, if you can somehow translate information from your field by working on something completely different, it’s very exciting. Whether by accident or not, it’s been the story of my career.”