Research ArticleBIOMOLECULES

Enzymatically active biomimetic micropropellers for the penetration of mucin gels

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Science Advances  11 Dec 2015:
Vol. 1, no. 11, e1500501
DOI: 10.1126/sciadv.1500501


In the body, mucus provides an important defense mechanism by limiting the penetration of pathogens. It is therefore also a major obstacle for the efficient delivery of particle-based drug carriers. The acidic stomach lining in particular is difficult to overcome because mucin glycoproteins form viscoelastic gels under acidic conditions. The bacterium Helicobacter pylori has developed a strategy to overcome the mucus barrier by producing the enzyme urease, which locally raises the pH and consequently liquefies the mucus. This allows the bacteria to swim through mucus and to reach the epithelial surface. We present an artificial system of reactive magnetic micropropellers that mimic this strategy to move through gastric mucin gels by making use of surface-immobilized urease. The results demonstrate the validity of this biomimetic approach to penetrate biological gels, and show that externally propelled microstructures can actively and reversibly manipulate the physical state of their surroundings, suggesting that such particles could potentially penetrate native mucus.

  • Micropropellers
  • gastric mucus barrier
  • gel-sol transition
  • propulsion in viscoelastic media
  • muco-adhesion
  • urease surface immobilization
  • helicobacter pylori swimming mechanism
  • biomimetic penetration of biological gels

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

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