The influence of silica on pore diameter and distribution in PLA scaffolds produced using supercritical CO2

  • N. J. Collins
  • G. A. Leeke
  • R. H. Bridson
  • F. Hassan
  • L. M. Grover


Macroporous polylactide (PLA) scaffolds were fabricated using a supercritical CO2 foaming process. The addition of silica particles to the polymer matrix resulted in a significant modification in the pore size distribution exhibited by the scaffold. In the absence of silica, the scaffolds contained pores between 88 μm and 980 μm in diameter as determined using X-ray computed microtomography. The addition of silica at only 2 wt% resulted in the elimination of pores of >620 μm, with no significant influence on the total porosity of the material. This effect was attributed to the silica nucleating the formation of gas bubbles in the polymeric material. Although the addition of further silica to the scaffold resulted in a further reduction in modal pore diameter, when more than 20 wt% was added to the matrix little additional effect was noted. In addition to enabling some control over pore diameter, mineral deposition was shown to occur considerably more rapidly on the silica-modified scaffolds than on those containing no silica.


Foam Pore Size Distribution Simulated Body Fluid Total Porosity Calcium Salt 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would like to acknowledge the BBSRC for the provision of studentship (NJ Collins) and Sue Fisher for her technical assistance.


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • N. J. Collins
    • 1
  • G. A. Leeke
    • 1
  • R. H. Bridson
    • 1
  • F. Hassan
    • 1
  • L. M. Grover
    • 1
  1. 1.Department of Chemical Engineering, Centre for Formulation EngineeringUniversity of BirminghamEdgbastonUK

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