In vivo biocompatibility of porous and non-porous polypyrrole based trilayered actuators

  • Bill G. X. Zhang
  • Geoffrey M. Spinks
  • Robert GorkinIII
  • Danial Sangian
  • Claudia Di Bella
  • Anita F. Quigley
  • Robert M. I. Kapsa
  • Gordon G. Wallace
  • Peter F. M. ChoongEmail author
Biocompatibility Studies Original Research
Part of the following topical collections:
  1. Biocompatibility Studies


Trilayered polypyrrole (PPy) actuators have high stress density, low modulus and have wide potential biological applications including use in artificial muscles and in limb prosthesis after limb amputation. This article examines the in vivo biocompatibility of actuators in muscle using rabbit models. The actuators were specially designed with pores to encourage tissue in growth; this study also assessed the effect of such pores on the stability of the actuators in vivo. Trilayered PPy actuators were either laser cut with 150 µm pores or left pore-less and implanted into rabbit muscle for 3 days, 2 weeks, 4 weeks and 8 weeks and retrieved subsequently for histological analysis. In a second set of experiments, the cut edges of pores in porous actuator strips were further sealed by PPy after laser cutting to further improve its stability in vivo. Porous actuators with and without PPy sealing of pore edges were implanted intramuscularly for 4 and 8 weeks and assessed with histology. Pore-less actuators incited a mild inflammatory response, becoming progressively walled off by a thin layer of fibrous tissue. Porous actuators showed increased PPy fragmentation and delamination with associated greater foreign body response compared to pore-less actuators. The PPy fragmentation was minimized when the pore edges were sealed off by PPy after laser cutting showing less PPy debris. Laser cutting of the actuators with pores destabilizes the PPy. This can be overcome by sealing the cut edges of the pores with PPy after laser. The findings in this article have implications in future design and manufacturing of PPy actuator for use in vivo.

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This work was funded through the Australian Orthopaedic Association (AOA) research foundation grant. The authors would like to acknowledge the Australian National Fabrication Facility (ANFF) Materials Node at Wollongong for use of their facilities

Compliance with ethical standards

Conflict of interest

The authors declare that they have no competing interests.


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Copyright information

© Springer Science+Business Media, LLC 2017

Authors and Affiliations

  • Bill G. X. Zhang
    • 1
    • 2
  • Geoffrey M. Spinks
    • 3
  • Robert GorkinIII
    • 3
  • Danial Sangian
    • 3
  • Claudia Di Bella
    • 1
    • 2
  • Anita F. Quigley
    • 3
    • 4
  • Robert M. I. Kapsa
    • 3
  • Gordon G. Wallace
    • 3
  • Peter F. M. Choong
    • 1
    • 2
    Email author
  1. 1.Department of OrthopaedicsSt. Vincent’s Hospital Melbourne and the University of MelbourneFitzroyAustralia
  2. 2.Department of SurgerySt. Vincent’s Hospital Melbourne and the University of MelbourneFitzroyAustralia
  3. 3.ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research InstituteUniversity of WollongongWollongongAustralia
  4. 4.Department of MedicineSt Vincent’s Hospital Melbourne and the University of MelbourneFitzroyAustralia

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