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Femtosecond Laser Shatters Viruses

Posted by kdawson on from the like-a-soprano-with-crystal dept.

wattrlz writes "In a development reminiscent of nineteenth century pseudo-science, the father-son team of Kong Thon and Shaw Wei Tsen recently demonstrated that the tobacco mosaic virus can be destroyed in vitro by nano-scale mechanical resonant vibrations induced by repeated ultra-short pulses from a laser. The total energy required is reportedly far below the threshold for human tissue damage and the technique should generalize to human pathogens. Cleaning stored blood is one obvious application."

9 of 154 comments (clear)

  1. How would that work? by Whatsisname · · Score: 2, Interesting

    Considering that viruses are essentially bundles of proteins, and this laser trashes the virus, how would the laser not trash proteins in cells potentially containing the viruses?

    1. Re:How would that work? by Anonymous Coward · · Score: 3, Interesting

      assuming that the virus was in a cell

      You've hit on one of the many problems with this approach.

      From listening to Dr. Tsen, it really does seem to work for free virions floating in solution - but once they unpackage themselves and infect a cell, it does nothing.

      You do make me wonder if this isn't doing more harm to cells than Dr. Tsen is aware of (which, given his utter lack of biology background would not surprise me). This could easily disrupt ribosomes, or possibly nucleosomes and similarly sized structures without causing cell death (but still doing significant harm).

      The alternative is to assume that they're actually tuning this to target particles of a certain size range - which would make it even more useless for general applications because there is so much diversity in terms of virion size.

  2. Cells may be safe, but what about their contents? by hcdejong · · Score: 3, Interesting

    DNA, for example, would be closer to the size of a virus. You could end up with an intact cell wall containing nothing but debris.

  3. I have a more important usage question.... by CodeShark · · Score: 4, Interesting

    Can this be tuned --or perhaps tuned with the assistance of another chemical marker-- to act as a "hunter killer" for auto-immune activated diseases such as multiple sclerosis, lupus, etc. where the resonant pulses would only kill the erroneously activated white blood cells and not the non-reactive white blood cells?

    Because if so this becomes in effect a computerized vaccine against a wide variety of ailments that have no other good medicinal choices. And because computing power is still rising exponentially faster than just about any other form of tech, this could be a whole lot quicker to market.

    --
    ...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
    1. Re:I have a more important usage question.... by theelectron · · Score: 2, Interesting

      Doubtful. They basically tune the pulse frequency to the resonant frequency of the virus's protein shell to break it. So it really needs to be tuned to a specific frequency to kill a specific thing. I would think white blood cells, activated or not, are too similar to be differentiated this way. Though I am no biologist, so correct if I am wrong - and I hope I am wrong because this would be an amazing breakthrough not just in autoimmune diseases but also cancer.

  4. Greatly exaggerated by Anonymous Coward · · Score: 5, Interesting

    This is (more or less) just some people who do a lot of Raman scattering deciding to try their technique to analyze virus particles and then noticing that some of them were damaged in the process. All of the other stuff (in particular the HIV) is largely BS - a few physicists who know almost nothing about biology going after NIH money by putting the magic "HIV" buzzword into their grant applications.

    The slightly cool thing about it is that you can target particles below a certain size (like viruses) without causing much damage to larger particles (like host cells).

    In terms of actually engineering this into a system for filtering blood (one of the main applications they envision), there are enough problems that it has no hope of succeeding in practice. Even if you could actually overcome all of those and build a system that could use this technique to destroy all of the virus particles in blood on a practical scale, many viruses that could contaminate whole blood (including HIV) will have uncoated and set up shop in the white cells, which would go on to release new virus after the treatment so this would offer no protection at all.

    For the same reason, you couldn't use this as a treatment even if you could somehow expose every cell in a patient to these pulses (which would be impossible unless you cut them into paper-thin slices).

    If the Tsens are actually unaware of this, then that alone should raise a huge red flag because anyone with the slightest bit of background in virology would know this.

    About the only thing this *might* be good for (other than generating press and bilking naive investors out of their money) is as a laboratory technique for killing all of the free virus in a very small sample without harming the cells.

    As a scientist, this kind of thing makes me sick, and it illustrates some of the harm caused by profit-motivated research in university settings (in particular, things Arizona State University's Biodesign Institute).

    It's great when science and discovery naturally leads to practical (and profitable) products, but this kind of thing is what happens when people put the goal of making money ahead of actually doing real science.

  5. Re:Danger of re-self-assembly and evolution? by digitalderbs · · Score: 4, Interesting

    A laser that disrupted covalent bonds in proteins would most certainly be detrimental to human cells too. There's nothing special about the covalent bonds of virus proteins over human proteins. What is special is the tertiary structure packing of coat proteins. I'm also not convinced that the process will be completely reversible as you suggest. Monomer coat protein could very easily dilute into very low concentrations once the virus is disassembled by destabilizing the complexed state (i.e. the intact virus). Nonetheless, I have concerns too. I would think that tissue penetration of the radiation would be quite poor. Tissue is more invisible to X-rays than lower frequency radiation. Presumably, this method uses lower frequency radiation -- I couldn't see it mentioned in the story. These pulses may break viruses down in solution, but getting it to deep tissue is another matter entirely.

  6. Re:white blood cells, activated by CodeShark · · Score: 2, Interesting
    They are already working on an MS treatment where they basically take a person's own white blood cells and then modify them to go after the myelin-reactive white blood cells. Which means that they must have a way of identifying them -- so the question becomes, can a treatment be developed which basically attracts the myelin reactive cells only into the femtolaser scanning field where thay can be nuked, without killing off the rest of the immune system.

    But I'm not good enough at immunology to know if once killed, the MS causing cells would be gone or if the bone marrow would simply repopulate the count again later.

    --
    ...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
  7. Plasma donations, maybe by Rob+Simpson · · Score: 2, Interesting

    Since all the blood cells are removed from the donated plasma, it'd be much easier to make sure there was zero effect on what is left (normal blood proteins), and there wouldn't be any cells to make new virus.