Even amidst all the celebrated advances of modern medicine, basic life-saving interventions are still not reaching massive numbers of people who live in our planet’s most remote and non-industrialized locations. The World Health Organization states that one half of the global population lives in rural areas. And according to UNICEF, last year nearly 20 million infants globally did not receive what we would consider to be basic vaccinations required for a child’s health.
These daunting statistics are largely due to the logistical challenge of transporting vaccines and other biomolecules used in diagnostics and therapy, which conventionally require a "cold chain" of refrigeration from the time of synthesis to the time of administration. In remote areas lacking power or established transport routes, modern medicine often cannot reach those who may need it urgently.
A team of researchers at Harvard’s Wyss Institute for Biologically Inspired Engineering has been working toward a paradigm-shifting goal: a molecular manufacturing method that can produce a broad range of biomolecules, including vaccines, antimicrobial peptides and antibody conjugates, anywhere in the world, without power or refrigeration.
Now the team has unveiled what they set out to deliver, a "just add water" portable method that affordably, rapidly, and precisely generates compounds that could be administered as therapies or used in experiments and diagnostics.
"The ability to synthesize and administer biomolecular compounds, anywhere, could undoubtedly shift the reach of medicine and science across the world," said Wyss Core Faculty member James Collins, Ph.D., senior author on the study, who is also Professor of Medical Engineering & Science and Professor of Biological Engineering at the Massachusetts Institute of Technology (MIT)’s Department of Biological Engineering. "Our goal is make biomolecular manufacturing accessible wherever it could improve lives."
The approach, called "portable biomolecular manufacturing" by Collins’ team, which also included Neel Joshi, Ph.D., a Wyss Core Faculty member and Associate Professor of Chemical and Biological Engineering at Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS), hinges on the idea that freeze-dried pellets containing "molecular machinery" can be mixed and matched to achieve a wide variety of end-products. By simply adding water, this molecular machinery can be set in motion.
Compounds manufactured using the method could be administered in several ways to a patient, including injection, oral doses or topical applications. As described in the study, a vaccine against diphtheria was synthesized using the method and shown to successfully induce an antibody response against the pathogen in mice.
Subsequently, the team envisions that the method could be employed to create batches of tetanus or flu shots routinely manufactured in remote clinics. Vaccines against emerging infectious disease outbreaks could quickly be mobilized in the field to contain spiraling epidemics. Episodes of food poisoning could be dosed orally with the production of neutralizing antibodies produced on the spot. Flesh wounds susceptible to infection could be applied with topical antimicrobial peptides generated on demand. In these manners, the team’s approach could be leveraged to design a vast number of different lifesaving measures.
The approach is built upon work described in a seminal 2014 paper also published in Cell, when the team demonstrated that transcription and translation machinery could function in vitro, without being inside living cells, inside freeze-dried slips of ordinary paper embedded with synthetic gene networks.
Building off that work, the novel manufacturing method employs two types of freeze-dried pellets containing different kinds of components. The first kind of pellet contains the cell-free "machinery" that will synthesize the end product. The second kind contains DNA instructions that will tell the "machinery" what compound to manufacture. When the two types of pellets are combined and rehydrated with water, the biomolecular manufacturing process is triggered. The second type of pellet can be customized to produce a wide range of final products.
Since they are freeze-dried, the pellets are extremely stable and safe for long-term storage at room temperature for up to and potentially beyond one year.
"This approach could — with very little training — put therapeutics and diagnostic tools in the hands of clinicians working in remote areas without power," said Keith Pardee, Ph.D., a co-first author on the study who was a Wyss Research Scientist and is now an Assistant Professor in the Leslie Dan Faculty of Pharmacy at the University of Toronto. "Currently, distribution of life-saving doses of protein-based preventative and interventional medicines are often restricted by access to an uninterrupted chain of cold refrigeration, which many areas of the world lack."
The cost of the approach, at roughly three cents per microliter, could also give access to biomolecular manufacturing to researchers and educators who lack access to wet labs and other sophisticated equipment, impacting basic science beyond the immediately apparent promise in clinical applications.
"Synthetic biology has been harnessed to increase efficiency of manufacturing of biological products for medical and energy applications in the past, however, this new breakthrough utterly changes the application landscape," said Wyss Core Faculty member Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and the Vascular Biology Program at Boston Children’s Hospital, as well as Professor of Bioengineering at Harvard’s SEAS. "It’s really exciting because this new biomolecular manufacturing technology potentially offers a way to solve the cold chain problem that still restricts delivery of vaccines and other important medical treatments to patients in the most far-flung corners of the world who need them the most."