Microbivores

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One of many novel therapeutic technology concepts in Nanomedicine, Microbivores are nanorobots designed to detect and destroy microbiological pathogens in the human bloodstream. Approximately 3.4 microns (1 micron=1000nm) in diameter, Microbivores are being designed to maneuver through the smallest capillaries in the body (<4 microns), and subsequently attach to and digest harmful bacteria, fungi, and viruses in a process similar to that of human phagocytes. By using a power supply of glucose and compressed oxygen, Microbivores are predicted to be 80-times more efficient than regular or even antibiotic-enhanced phagocytes in terms of pathogen digested per second[2].

These nanorobots would consist of 4 main components: reversible binding site, telescoping grapples, morcellation chamber, and digestion chamber. The bacterial membrane of all microbial pathogens contains at least one species-specific identifying characteristic, whether it is a carbohydrate chain, surface protein, or amino acid. A reversible binding site (reversibility being for a Microbivore to attach to pathogens more than once) on the outside of the Microbivore allows the nanorobot to identify and attach to pathogens. This form of targeted delivery of nanomedicine prevents the destruction of helpful bacteria, and can be highly customized, depending on the number of ligand receptors at the reversible binding site. Telescoping grapples, attached to the outside of the Microbivore, would also be equipped with binding sites, and help to maneuver the pathogen towards the ingestion port and into the morcellation chamber. Inside the morcellation chamber, the pathogen is morcellated (minced into small pieces), using diamondoid (resembling the dense, crystalline structure of diamond or sapphire, usually consisting of C-H bonds supplemented with atoms of N,O,Si, and S) blades powered by a nanomotor[bib]10.1088/0957-4484/11/2/309[/bib]. The morcellate would then be transferred into the digestion chamber, a mixture of peptidases and other enzymes break down the pathogen into amino acids, simple sugars, and mononucleotides to be harmlessly released back into the bloodstream[1]. After treatment, Microbivores would be removed though nanapheresis, a process whereby blood is cycled through an apparatus to separate nanorobots and return blood back into the body[bib]617[/bib]. 

References

  1. Freitas RA 2. IMM Report Number 25: Nanomedicine. 2001 .
  2. Citekey <a href="http://dx.doi.org/10.1088/0957-4484/11/2/309">10.1088/0957-4484/11/2/309</a> not found

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Designed to treat septicemia (blood poisoning), Microbivores would be a class of medical nanorobots, made of a diamondoid arrangement of atoms, that target harmful pathogens within the bloodstream. These nanorobots are hypothesized to be 1000 times faster and 80 times more effective than the body’s natural phagocytes, and can be applied to a variety of medical practices. The Microbivores would consist of 4 main functional groups: a reversible binding site, telescoping grapples, morcellation chamber, and digestion chamber. The reversible binding sites use ligand receptors on the nanorobot to identify a bacteria based on the content of its cellular membrane, or other characteristic materials. Once identified, telescoping grapples would maneuver the bacteria or virus into the morcellation chamber where the pathogen could be cut into digestible pieces for enzymatic digestion. Harmless waste materials would be released into the bloodstream and the Microbivores cycled out of the blood through nanapheresis. 

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Not only would Microbivores offer faster, more effective treatment to septicemia, they could also be applied as sterilization agents or as a valuable tool in molecular biopsy[1]. Nanorobots can be used in biopsy to detect and capture a potential pathogen intact, then be retrieved for analysis and treatment evaluation, decreasing the need for broad spectrum antibiotics like ampicillin, which can indiscriminately destroy helpful, naturally occurring bacteria in the body[2]. The design for Microbivores could potentially be applied to create artificial red blood cells and platelets as well. 

References

  1. Citekey <span>618 not found
  2. Citekey </span><span>619 not found

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The most significant risk posed by Microbivores is the potential for the long flagellar tails of bacteria to become severed during insertion into the ingestion port, releasing the immunogenic tail into the bloodstream. This biocompatibility issue could be addressed by incorporating a rotating mechanism within the morcellation chamber into the current design.  Additional risks and limitations of the nanorobots include their inability to traverse certain cavities in the spleen 1-2 microns in length, potentially blocking the flow of blood in the splenic tissue. Microbiovres are also at risk of being attacked by the body’s natural phagocytes, decreasing their effectiveness and producing an unnecessary immune response from the body[1]

References

  1. Citekey <span>616 not found

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