Thursday, April 14, 2011

Smarter Nano-Materials Beat Bad Bugs

    Smarter Nano-Materials Beat Bad Bugs

  • Hospitals worldwide are suffering an increasing number of bacterial infections that have become resistant to antibiotics. New nanotech materials promise to eradicate bacteria in the body without affecting healthy human cells.
  • Hospitals worldwide are suffering an increasing number of bacterial infections that have become resistant to antibiotics. New nanotech materials promise to eradicate bacteria in the body without affecting healthy human cells.Using the same electrostatic principles used to control semiconductor microchips, researchers are targeting infectious bacteria with magic-bullet-like nano-particles.
    Every year, more than 100,000 infections and 20,000 hospital deaths are caused by antibiotic-resistant bacteria, but now IBM Research (San Jose, Calif.) working with the Institute of Bioengineering and Nanotechnology (Singapore) have demonstrated a self-assembling magic nano-bullet that can target harmful bacteria while ignoring healthy tissue.
    "We’ve been able to leverage decades of materials development traditionally used for semiconductor technologies to create an entirely new drug delivery mechanism," said Advanced Organic Materials Scientist at IBM Research (Almaden), James Hedrick.


    The cyclic carbonate organocatalysts used in this experiment exhibited ring-opening polymerization. (Source: IBM)
    Over many generations of selective breeding, many bacteria have developed resistance to the most common antibiotics, with increasingly high doses needed to kill bacteria being a threat to healthy cells. However, this fundamentally new mechanism, the electrostatic charge of the cell membrane, is claimed by the researchers to sidestep the normal ability of bacteria to build up resistance. And normal cells are safe, no matter the dose, because the electrostatic charge of normal cells cannot attract the polymer.
    The researchers hope to develop nano-materials that can be directly injected into the body--or even applied like a salve--to destroy harmful bacteria in all the places touched by deodorant, soap, hand sanitizers and table wipes as well as to help heal lung infections, wounds and perhaps even tuberculosis.
    How it works
    The magic nano-bullet works because the membranes of microbial agents--bacteria--are negatively charged. The magic nano-bullet was fabricated from polymers that can be injected into the blood stream, and which are biodegradable in that they flush through a healthy system in a short period. However, if one of the positively charged polymers become electro-statically attached to a negatively charged bacteria cell, then it acts like a spearhead, with other polymers chaining up behind to push through the cell membrane, killing the bacteria without harming surrounding cells.
    The magic nano-bullet synthesis method, which the researchers claimed could be scaled up for commercialization, used metal-free cyclic carbonate with an organo-catalytic ring-opening polymerization. The self-assembling nanoparticles were shown to disrupt only the cell walls of suspect bacteria and fungi, including one of the worst killers--methicillin-resistant staphylococcus aureus (MRSA).
    “Novel nano-structures can offer viable therapeutic solutions, effectively integrating our capabilities in biomedical sciences and materials research,"said Yiyan Yang, Group Leader at the Institute of Bioengineering and Nanotechnology.
    The antimicrobial polymers created by IBM Research and the Institute of Bioengineering and Nanotechnology and were tested against clinical microbial samples by the State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine and Zhejiang University (China).
      

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