Using mechanobiological mimicry of red blood cells to extend circulation times of hydrogel microparticles

Proc Natl Acad Sci U S A. 2011 Jan 11;108(2):586-91. doi: 10.1073/pnas.1010013108. Epub 2011 Jan 10.


It has long been hypothesized that elastic modulus governs the biodistribution and circulation times of particles and cells in blood; however, this notion has never been rigorously tested. We synthesized hydrogel microparticles with tunable elasticity in the physiological range, which resemble red blood cells in size and shape, and tested their behavior in vivo. Decreasing the modulus of these particles altered their biodistribution properties, allowing them to bypass several organs, such as the lung, that entrapped their more rigid counterparts, resulting in increasingly longer circulation times well past those of conventional microparticles. An 8-fold decrease in hydrogel modulus correlated to a greater than 30-fold increase in the elimination phase half-life for these particles. These results demonstrate a critical design parameter for hydrogel microparticles.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry
  • Biomimetics
  • Drug Carriers / chemistry
  • Equipment Design
  • Erythrocytes / cytology*
  • Female
  • Hydrogel, Polyethylene Glycol Dimethacrylate / chemistry*
  • Kinetics
  • Materials Testing
  • Mice
  • Mice, Inbred BALB C
  • Microscopy, Fluorescence / methods
  • Particle Size
  • Polymers / chemistry
  • Time Factors
  • Tissue Distribution


  • Biocompatible Materials
  • Drug Carriers
  • Polymers
  • Hydrogel, Polyethylene Glycol Dimethacrylate