We’ve written here before about the plan to put iron nanoparticles in the ocean as a way to increase growth of plankton, thereby absorbing carbon dioxide. Previously this was to be done by a company called Planktos; now a new company called Climos is making similar plans. There was controversy about Planktos, and no doubt there will be about the new plan as well. Excerpts from the San Jose Mercury News:

Climos, a San Francisco company, says it can mitigate climate change by putting small amounts of iron in the ocean to spur the growth of carbon-dioxide-absorbing plankton, an idea that has left some environmentalists wary.

On Wednesday, the seven-person start-up went from a concept that sounds like the plot of a ’50s sci-fi movie to an innovative (and controversial) going concern with the news that it has raised $3.5 million.

Climos seeks to answer whether what it calls “ocean iron fertilization” could be “a meaningful mitigation tool” to fight climate change, said Dan Whaley its chief executive officer. It will make money by entering the growing carbon-offset market, in which companies like Climos sell credits to companies that produce pollution to make up for their greenhouse-gas emissions…

[Investor Elon] Musk, in an e-mail, wrote that “oceans have tremendous potential for affordable carbon sequestration.” Ocean microorganisms, such as phytoplankton, are very good at absorbing carbon. Plus, “the real estate is free, plankton are super easy to grow and they bury themselves by sinking to the ocean bottom.”

One point to notice here is that this is not about nanotech or nanoparticles per se. The same basic questions would arise if the particles were not nanoscale. The questions to ask here are (1) do we have confidence in how carbon credit offset techniques are approved, and (2) do we have confidence in the rules on what can be put into the oceans? These are some higher-level questions to focus on when trying to evaluate either carbon offsets or ocean health.

For those of us unable to evaluate the science of climate change on our own (certainly including me), it may be useful to check out the company’s Chief Science Officer and Scientific Advisory Board. Some heavy hitters there — more prestigious than I had been expecting. We can look forward to some intense debate as the company proceeds. —Christine

As a follow-up to Monday’s post on optimizing nanoparticle design for nanotech drug delivery, the same research group has also demonstrated the advantages of a multistage approach in which micrometer-sized mesoporous particles are used to deliver two different nanoparticles in a way that circumvents some of the biological barriers that bedevil attempts to precisely deliver drugs where they are needed. From the University of Texas Health Science Center at Houston, via AAAS EurekAlert “Nanomedicine system engineered to enhance therapeutic effects of injectable drugs“:

Mauro Ferrari, Ph.D., of The University of Texas Health Science Center at Houston presented a proof-of-concept study on a new multistage delivery system (MDS) for imaging and therapeutic applications. This discovery could go a long way toward making injectable drugs more effective…

“This is next generation nanomedicine,” said Ferrari, the senior author. “Now, we’re engineering sophisticated nanostructures to elude the body’s natural defenses, locate tumors and other diseased cells, and release a payload of therapeutics, contrasting agents, or both over a controlled period. It’s the difference between riding a bicycle and a motorcycle.”

Nanotechnology offers new and powerful tools to design and to engineer novel drug delivery systems and to predict how they will work once inside the body. “The field of therapeutic nanoparticles began with tiny drug-encapsulated fat bubbles called liposomes, now commonly used in cancer clinics worldwide. Targeting molecules were later added to liposomes and other nanovectors to assist in directing them to diseased cells,” Ferrari said.

Getting intravenous agents to their intended targets is no easy task. It’s estimated that approximately one of every 100,000 molecules of agent reaches its desired destination. Physicians are faced with the quandary of increasing the dosage, which can lead to side effects or reducing the dosage, which can limit the therapeutic benefits.

The multistage approach, according to Ferrari, is needed to circumvent the body’s natural defenses or biobarriers, which act as obstacles to foreign objects injected in the blood stream. “To overcome this problem, we hypothesized and developed a multifunctional MDS comprising stage 1 mesoporous particles loaded with one or more types of stage 2 nanoparticles, which can in turn carry either active agents or higher-stage particles. We have demonstrated the loading, controlled release and simultaneous in vitro delivery of quantum-dots and carbon nanotubes to human vascular cells,” the authors write.

The research was published in Nature Nanotechnology (abstract).
—Jim

Proponents of replacing gasoline with hydrogen for fueling cars have to find a practical way to store hydrogen. One potential nanotech-based solution is presented by the recent demonstration that hydrogen can form chemical bonds with most of the carbon atoms in single-walled carbon nanotubes of the appropriate diameter (2.0 nm). From “The March of the Carbon Nanotubes“:

Stanford Synchrotron Radiation Laboratory (SSRL) researchers have surpassed by a surprising margin the Department of Energy’s goal for storing hydrogen within a unique material called carbon nanotubes…

Hydrogen—the most abundant element in the universe—is an attractive carrier of renewable energy. It can be used in fuel cells to produce electricity, with the only byproduct being water. However, developing safe and efficient methods of storing hydrogen remains a challenge.

[Graduate student Anton Nikitin] and his colleagues were able to pack seven percent by weight hydrogen into carbon nanotubes through the formation of bonds with carbon atoms. The chemically grown nanotubes are made of pure carbon and have walls a single atom thick. Because single-walled nanotubes are essentially all surface area, they can theoretically store an enormous proportion of hydrogen, making it a promising storage medium.

The research was published in the American Chemical Society’s Nano Letters (abstract).

Another way in which nanotechnology could provide hydrogen-fueled cars is by making the electrolysis of water to produce hydrogen more efficient. For the latest on this approach, see “Nanotechnology-based clean hydrogen for cars” on Roland Piquepaille’s blog.
—Jim