Porous scaffold design for tissue engineering

  • An Erratum to this article was published on 01 July 2006


A paradigm shift is taking place in medicine from using synthetic implants and tissue grafts to a tissue engineering approach that uses degradable porous material scaffolds integrated with biological cells or molecules to regenerate tissues. This new paradigm requires scaffolds that balance temporary mechanical function with mass transport to aid biological delivery and tissue regeneration. Little is known quantitatively about this balance as early scaffolds were not fabricated with precise porous architecture. Recent advances in both computational topology design (CTD) and solid free-form fabrication (SFF) have made it possible to create scaffolds with controlled architecture. This paper reviews the integration of CTD with SFF to build designer tissue-engineering scaffolds. It also details the mechanical properties and tissue regeneration achieved using designer scaffolds. Finally, future directions are suggested for using designer scaffolds with in vivo experimentation to optimize tissue-engineering treatments, and coupling designer scaffolds with cell printing to create designer material/biofactor hybrids.

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Figure 1: Modulus versus porosity and permeability versus porosity for two designed spherical pore and cylindrical pore microstructures.
Figure 2: Example of designed microstructure optimized for maximum permeability with a constraint that effective modulus matches human mandibular condyle bone tissue and a porosity constraint of 54%.
Figure 3: Image-based procedure for integrating designed microstructure with anatomic shape.
Figure 4: Schematics of SFF systems categorized by the processing technique.
Figure 5: Examples of PCL scaffolds directly fabricated using SLS.
Figure 6: Cartilage regeneration by chondrocyte delivery on designed Bioplotter-fabricated PEG/PBT scaffolds is superior to PEG/PBT scaffolds made by porogen leaching.


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The author has been funded by the National Institutes of Health R01 DE 13608 (Bioengineering Research Partnership) and R01 DE 13416. He also acknowledges the contributions from his students, former students and laboratory staff including Alisha Diggs, Colleen Flanagan, Elly Liao, Cheng Yu Lin, Chia-Ying Lin, Sara Mantila, Eiji Saito, Rachel Schek, Juan Taboas, Jessica Williams and Darice Wong. Finally, he would like to thank his collaborators including Paul Krebsbach, Stephen Feinberg, Suman Das, Noboru Kikuchi, Michael Yaszemski and Antonios Mikos for many fruitful and stimulating research interactions.

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Hollister, S. Porous scaffold design for tissue engineering. Nature Mater 4, 518–524 (2005). https://doi.org/10.1038/nmat1421

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