IBM Creates Nanoparticles That Burst Superbugs Like Popped Balloons

By Patrick Morgan | April 6, 2011 11:17 am

What’s the News: Scientists are using nanoparticles to develop ways to fight bacteria that are resistant to conventional antibiotics. These tiny drugs physically punch holes through bacteria instead of killing them chemically, which means that they could be especially effective on antibiotic-resistant bacteria strains like the dangerous methicillin-resistant Staphylococcus aureus (MRSA). “The applications are going to be very diverse, whether we’re talking about wound healing or dressing, skin infection, and quite possibly injections into the bloodstream,” James Hedrick, master inventor at IBM Almaden Research Center in San Jose, California, told Popular Science.

How the Heck:

  • Developed by IBM (yes, that IBM), but tested at the Singapore Institute of Bioengineering and Nanotechnology, the nanoparticles are made of bits of polycarbonate plastic that are amphilic: with one part that’s attracted to water (hydrophilic), and another that’s attracted to fats (hydrophobic). This means when you inject these particles into blood, for example, the hydrophilic parts of the polycarbonates hide within the hydrophobic parts, forming self-assembled clots about 200 nanometers wide.
  • These nanoparticles then glom onto certain kinds of bacteria, including drug-resistant staph, because of electrical attraction: The outer side of the particles is positively charged, whereas the microbes are negatively charged.
  • By attaching to the surface of the bacteria’s cell wall, the nanoparticles disrupt the wall and burst it open.
  • Hedrick told Popular Science that scientists aren’t sure why the particles are so good at killing bacteria. His experiments showed that the particles killed some bacteria and even fungi.

What’s the Context:

Not So Fast:

  • Will this technique be used for healing wounds and injecting into the bloodstream to fight bacteria? Hedrick says “this is way early in the discovery process to be going there.”
  • The technique only killed some kinds of bacteria: the ones whose charges attracted the nanoparticles. This means that other kinds of harmful bacteria were unaffected. The researchers say that they can tweak the nanoparticles by changing their charge, shape, and solubility to target other kinds in the future.

Next Up: Now the scientists are marking larger batches of nanoparticles so that they’ll have enough for tests in humans. In the years to come, IBM hopes to partner with healthcare companies to make the drug available for medical use.

Reference: Nederberg, F. et al. “Biodegradable nanostructures with selective lysis of microbial membranes.” Nature Chemistry. doi:10.1038/nchem.1012.

Image: The left-hand images show an intact Enterococcus faecalis bacteria cell; the right-hand images shows the bacteria with its cell wall broken by nanoparticles. IBM.

CATEGORIZED UNDER: Health & Medicine, Technology
  • Richard

    Several antibiotics work by punching holes in the bacteria. So this is a pretty nice idea. My worry is the polycarbonate substrate that is used – as some of these use Bisphenol-A, an endocrine disruptor chemical (EDC).

    Nature Reviews Endocrinology just published a review on this .

    They end their abstract with:

    “Although more experimental work is necessary, evidence already exists to consider exposure to EDCs as a risk factor in the etiology of type 2 diabetes mellitus and other diseases related to insulin resistance.”

    I’m leery right now of the long term effects of directly adding particles based on such plastics. I wish I did not have to pay $32 to read the article itself and see if any work has examined the plastic they use to determine if it could disrupt the endocrine systems of the patients.

  • Idlewilde

    How will they keep the nanoparticles from attacking friendly bacteria or even cells?

  • M.Semones

    Normal antibiotics attack both friendly and unfriendly bacteria, so that’s something you deal with when using current antibiotics.

    What happens when the nanoparticles pass through the body and out into the environment? Are they inactivated, or will they continue to do their job on natural assemblages of microbes in ecosystems and possibly wreak havoc?

    amphilic=amphiphilic or amphipathic

  • C. Wade

    I think the article is incorrect in saying that the hydrophilic part would fold inward. It would be exposed to the polar sera in the blood with the hydrophobic part folded inward. Polycarbonate would be degraded through hydrolysis eventually so it wouldn’t be around forever in the body much less after excretion. I think this is an interesting phenomenon, but they don’t seem to understand the mechanism very well.

  • amphiox

    The immune complement system also works by punching holes into bacterial cell membranes.

    Also, how easy or difficult would it be, theoretically, for bacteria to evolve resistance to these nanoparticles? (For example, by changing the charge of their outer membrane.)

  • ChuckB

    As with any drug, this one seems to have unforseen side effects and results, and it must be thoroughly tested, and used with caution, but it is definitely a new and promising idea.


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