Freeze-Dried Molecules Whip Up Medicines On-Site

Just add water. That’s the appeal of a new freeze-dry method that turns DNA and other molecules into small reaction pellets needed to make a wide range of pharmaceuticals. Portable enough to tote around in a suitcase, researchers want to use freeze-dried molecular machinery to mix up drugs in remote places like developing countries, military outposts, and even outer space.

In a paper published Thursday in the journal Cell, investigators from Harvard and MIT show that this technique can be used to manufacture antimicrobial compounds, vaccines and antibodies that are just as effective as traditionally-made drugs.

Drug manufacturers have been freeze-drying some vaccines and other compounds for decades to preserve their biological properties so they can be transported to regions where reliable power for refrigeration is hard to come by. What’s different about this method is that instead of freeze-drying the whole drug or compound, researchers have figured out a way to freeze dry the individual molecular components. And at just $0.03 per microliter, the approach could be as much as 10 times cheaper than previous techniques.

“When rehydrated with water and when mixed with engineered DNA constructs that are designed to make the molecules of interest, these elements together rapidly and within minutes begin to produce a therapeutic molecule,” says lead author James Collins, who runs a lab at Harvard’s Wyss Institute for Biologically Inspired Engineering.

Collins’s lab tested the ability of the pellets to synthesize a diphtheria vaccine, which is difficult to store and distribute because of its sensitivity to both heating and freezing. So being able to quickly make the vaccine on-site would be an important advance. The scientists found that the pellet-made vaccine elicited a protective response in mice that was comparable to a traditional diphtheria vaccine.

The researchers also used their system to create a small, modular toolbox for making designer antibodies for a variety of diseases. Antibodies, which are being studied for a wide range of uses from microbial infections to cancer, work by harnessing the natural immune system to neutralize pathogens and tumor cells. Collins and his team made one such antibody drug that could neutralize Clostridium difficile bacteria, which causes serious intestinal infections in people, and another that was effective at killing breast cancer cells.

Collins envisions these pellets being used in the future for long-term medical treatment during space travel—and more immediately, for treatment in disease outbreaks.

David Shoultz, program leader for drug development and devices and tools for PATH, a global health organization that delivers vaccines to developing countries, says while Collins’s idea is interesting, he doesn’t think it’s quite as simple as it seems.

“What it would allow you to do is to ship to a remote site for less money, but you still need sterility and you’d still need a trained health worker on the other end,” Shoultz says. While he doesn’t think these kits would be used in the field anytime soon, he could see an organization like Doctors Without Borders eventually using them to quickly delivery vaccines and drugs for disaster relief.

Collins is now working with the Wyss Institute to explore how his team might be able to spin out the idea into a start-up company or nonprofit.