By Rivka Borochov
The close confines of space-station living demand that water in all its formats, including sewage, must be recycled and renewed. It can’t be dumped in space, and it’s not safe to keep contaminated water in an enclosed environment. America’s National Aeronautics and Space Administration (NASA) recognizes the importance of clean water in space, and invited an Israeli scientist to test his new nanotechnology solution for this problem aboard an Atlantis mission in the summer of 2011.
This wasn’t the first time Prof. Avraham Domb
from the Hebrew University of Jerusalem tested his science in outer space, but it is the first time he was able to get results.
His first experiment -- to see the effects of engineered cells in the space environment -- didn’t come back to Earth, but was lost aboard the space shuttle Columbia, which exploded in 2003. Onboard was Ilan Ramon, the first Israeli astronaut in space, who died along with the rest of the crew.
This time the return mission was a success and Domb, from the university’s School of Pharmacology, got the results he was hoping for: A new kind of anti-bacterial material he has manufactured in the lab worked in space. It’s a synthesized polymer with active sites that decontaminate bacteria.
From the space shuttle to the kitchen
Bacteria are some of the most difficult organisms to kill. Thanks to a hard outer surface, they can evade many attempts to subdue them. On board a space station, and especially in the closed environments of hospital wards, destroying bacteria is very much a sought-after goal for water purification researchers and companies.
Domb has developed a molecule based on an ammonium group. With one part of the molecule sticking out like a miniature sword, the molecule has the power to kill bacteria in their tracks. Loaded onto plastic surfaces, or added as a concentrate in liquid, the molecule and its sword-like arm rupture the hard bacteria surface on contact, causing the inside workings of the bacteria, the organelles, to spill out.
In conjunction with the Israeli company Strauss Water
(a subsidiary of the Strauss Group, Israel's second-largest food and beverage company), Domb’s new approach might provide answers that will help future space missions, hospitals and home consumers.
“The experiment was initiated by Strauss Water,” Domb says. “The intention is to develop a new and more effective filter for consumer-owned water purification systems.”
Several years ago, Strauss bought a company called Aquasound that Domb was involved in, and renamed it H2Q. Then, after acquiring Tana Industries
, maker of Tami 4 -- a popular home water filter company in Israel -- the company became Strauss Water about two years ago.
The Tami 4 filter owned and marketed by Strauss Water sits on countertops in homes and offices across Israel. Before delivering a hot or cold drink of water, the filter cleans the water using a carbon filter. Like a Brita water purifier, the Tami 4 also has some additives that remove chlorine and heavy metal ions from the water, Domb explains.
He is now working with Strauss on developing better technology for the home water filter so that contaminants like arsenic, lead, cadmium and mercury –– found occurring naturally in water wells –– are removed to levels below the recommended safety guidelines of the international Water Quality Association, and also to match regulations now being put into effect in China. Organic chemicals like herbicides and industrial contaminants, as well as bacterial and biological materials, are also targeted.
This is where the NASA part fits in, as the project has Domb developing a material that can deactivate or physically remove bacteria, viruses and other kinds of microbes from water.
Three days to liftoff
NASA gave Domb only three days’ notice to put the experiment together as a rudimentary test to see if it would work in the space environment under zero gravity, to determine if the idea is at all relevant for such conditions. Working quickly, Domb prepared two vials of water containing bacteria. In one vial, the surface was coated with his technology; the other was not.
On return to Earth, the experiment was deemed a success, he says. Now the Israeli laboratory is looking at the results more deeply, probing for DNA damage to the bacteria, for instance.
Interest from industry, the space industry especially, is good news for water drinkers everywhere, he says, because eventually it is industrial need that can take technologies one step farther.
If Domb’s material goes commercial, it can be impregnated into pipes and tubing, and could even be used in bacterial hotspots, such as public bathroom faucets.
“Yes, this is not only for water, but can be used on any kind of self-sterilizing surface,” says Domb, “like on a table where you eat so that the table is self-decontaminating.”
Another application is in dental work, he says. Imagine a plastic that can be added to dentures and restoration materials in dentistry to inhibit the growth of bacteria. Would that be bye-bye to halitosis and new cavities forever?
In fact, it was dentistry that prompted Domb’s work in outer space. A close friend of his, dentist Dan David, was a friend of the late Ilan Ramon. Through the dentist’s connection with the astronaut, Domb’s experiment on engineered cells was carried into space. He even spent an exciting day showing Ramon how it worked. Sadly, it didn’t come to fruition, but Domb was very surprised to get another invitation from NASA via his Israeli contacts.
Other good ideas from Domb
In his lab at the university, Domb focuses on targeted drug therapies, building better platforms for drug delivery to certain organs or tumors in the body.
“My main research at the Hebrew University is on biopolymers, and what we are doing is developing biodegradable materials for the controlled release of drugs,” says Domb.
One application is being explored through a company called Gliadel
, in order to provide a treatment for brain tumors based on research Domb carried out at the Massachusetts Institute of Technology. “We are also working on stents, and anything related to polymers for treating solid tumors, infections or ‘regional therapy’ so we can treat the tumor and not the entire body,” he explains.
Domb’s academic work looks at the delivery system, not the drug itself.
“Parasites can be removed by filtration, or be absorbed on a bio-filter. Common filters can remove these, but not to the level of 100 percent decontamination – like what we need in space. In these cases, we offer a solution that kills bacteria and viruses by contact.”
Focusing on a polymeric material, a nanotechnology, Domb’s objective was to develop a polymer that is anti-microbial, and when added to water can safely be consumed by people at low amounts. He also needed to develop a bio-filter made from these polymer particles so that the bacteria will be neutralized when it passes through the particles. And lastly, the experiment NASA brought on board, a plastic that could be loaded with the polymers so that bacteria will be killed on contact.
He is not sure if the technology will be used in space sewers of the future, but industry’s interest in it certainly fuels a whole range of ideas for home water filters and for use in the food industry and in hospitals. Just as it is hard to imagine life before penicillin, one day people might look back at history and say the same about Domb’s germ-vanquishing plastic –– a new world without bacterial contamination.