Effect of polycaprolactone scaffold permeability on bone regeneration in vivo

Tissue Eng Part A. 2011 Jul;17(13-14):1831-9. doi: 10.1089/ten.TEA.2010.0560. Epub 2011 Apr 27.

Abstract

Successful bone tissue engineering depends on the scaffold's ability to allow nutrient diffusion to and waste removal from the regeneration site, as well as provide an appropriate mechanical environment. Since bone is highly vascularized, scaffolds that provide greater mass transport may support increased bone regeneration. Permeability encompasses the salient features of three-dimensional porous scaffold architecture effects on scaffold mass transport. We hypothesized that higher permeability scaffolds will enhance bone regeneration for a given cell seeding density. We manufactured poly-ɛ-caprolactone scaffolds, designed to have the same internal pore design and either a low permeability (0.688×10(-7)m(4)/N-s) or a high permeability (3.991×10(-7)m(4)/N-s), respectively. Scaffolds were seeded with bone morphogenic protein-7-transduced human gingival fibroblasts and implanted subcutaneously in immune-compromised mice for 4 and 8 weeks. Micro-CT evaluation showed better bone penetration into high permeability scaffolds, with blood vessel infiltration visible at 4 weeks. Compression testing showed that scaffold design had more influence on elastic modulus than time point did and that bone tissue infiltration increased the mechanical properties of the high permeability scaffolds at 8 weeks. These results suggest that for polycaprolactone, a more permeable scaffold with regular architecture is best for in vivo bone regeneration. This finding is an important step toward the end goal of optimizing a scaffold for bone tissue engineering.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bone Regeneration / drug effects*
  • Bone and Bones / cytology
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / drug effects
  • Elastic Modulus / drug effects
  • Humans
  • Mice
  • Minerals / metabolism
  • Organ Size / drug effects
  • Permeability / drug effects
  • Polyesters / pharmacology*
  • Tissue Scaffolds / chemistry*
  • Tomography, X-Ray Computed

Substances

  • Minerals
  • Polyesters
  • polycaprolactone