Mosquito saliva is the key to a potential malaria vaccine and Tenzer, a postdoctoral research fellow at Harvard University’s Biorobotics Laboratory, has spent the last two years designing a machine that can very precisely behead an infected mosquito and gently squeeze its body to extract and collect its parasite-filled spit.
He’s come up with a machine that uses a very small blade to cut off the head of a mosquito in a petri dish, then applies gentle pressure to the thorax to force out the salivary glands, which are captured in a special fluid and purified later to make the vaccine.
This week, the Maryland company that asked the Harvard lab to build the machine launched a fund-raising campaign on Indiegogo to finance a working prototype.
Killing a mosquito is easy, but doing it without turning the bug into a little brown smear is no easy task.
“We needed to find a way to restrain the mosquito,” Tenzer said. “A mosquito is very soft. It’s very delicate. If you’ve ever killed a mosquito, you know how easy it is to damage anything on the small creature.”
Though still in clinical trials, the vaccine by Sanaria Inc., of Rockville, Md., is widely considered one of the most promising weapons against a disease that kills more than 600,000 people every year. In a small-scale trial last year, six people who received high doses of the vaccine did not contract malaria when bitten by infected mosquitoes.
Beyond the regulatory hurdles Sanaria must clear before taking the vaccine to market, there is another major obstacle — the painstaking process of collecting mosquito saliva. For now, the beheading and extracting is performed by hand. Even a fast worker can do only two per minute.
Collecting saliva is critical because Sanaria needs malaria sporozoites — the infective form of the parasite that is injected during a mosquito bite — to produce its vaccine. Five mosquitoes are required for a single dose.
The goal of the Harvard Biorobotics Lab is to develop a machine — which it calls the Sporobot — that can automate mosquito dissection and harvest sporozoites up to 30 times faster than a human. Added speed will help make the vaccine more affordable and available in large quantities.
The lab has built and tested components of the Sporobot but does not have a working prototype. The Indiegogo fund-raising campaign hopes to raise $250,000 in 30 days for the prototype.
Even if Sanaria meets its goal, there is no guarantee that the company will succeed in bringing the vaccine to market. But Tenzer said the fun of engineering the Sporobot makes up for any uncertainty.
“This is where our fascination as researchers comes in,” he said. “We’re always trying to solve problems that no one has solved before. We’re excited about the vaccine, but from our perspective, the challenge of dissecting mosquitoes to extract saliva and building a robot to do it is exciting enough to jump on the opportunity, no matter what happens.”
Source: The Boston Globe