Biomedical Microdevices

, 11:1251 | Cite as

A monolithic polymeric microdevice for pH-responsive drug delivery

  • Jian Chen
  • Michael Chu
  • Khajag Koulajian
  • Xiao Yu Wu
  • Adria Giacca
  • Yu Sun


A drug-delivery microdevice integrating pH-responsive nano-hydrogel particles functioning as intelligent nano valves is described. The polymeric microdevices are monolithic without requiring peripheral control hardware or additional components for controlling drug-release rates. pH-responsive nanoparticles were synthesized and embedded into a composite membrane. The resulting pH-responsive composite membranes were integrated with PDMS micro reservoirs via a room-temperature transfer bonding technique to form the proof-of-concept microdevices. In vitro release characterization of the microdevices was conducted in which the release rate of Vitamin B12 (VB12) as a model drug increased dramatically when the local pH value was decreased from 7.4 to 4. This device concept can serve as a platform technology for intelligent drug delivery in response to various in vivo environmental signals.


Controlled drug delivery Microdevices pH-responsive hydrogel Nano hydrogel particles 


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Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Jian Chen
    • 1
  • Michael Chu
    • 2
  • Khajag Koulajian
    • 3
  • Xiao Yu Wu
    • 2
  • Adria Giacca
    • 3
  • Yu Sun
    • 1
  1. 1.Institute of Biomaterials and Biomedical EngineeringUniversity of TorontoTorontoCanada
  2. 2.Department of Pharmaceutical SciencesUniversity of TorontoTorontoCanada
  3. 3.Department of PhysiologyUniversity of TorontoTorontoCanada

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