Augmentation of bone defect healing using a new biocomposite scaffold: an in vivo study in sheep

Acta Biomater. 2010 Sep;6(9):3755-62. doi: 10.1016/j.actbio.2010.03.028. Epub 2010 Mar 24.

Abstract

Previous studies support resorbable biocomposites made of poly(L-lactic acid) (PLA) and beta-tricalcium phosphate (TCP) produced by supercritical gas foaming as a suitable scaffold for tissue engineering. The present study was undertaken to demonstrate the biocompatibility and osteoconductive properties of such a scaffold in a large animal cancellous bone model. The biocomposite (PLA/TCP) was compared with a currently used beta-TCP bone substitute (ChronOS, Dr. Robert Mathys Foundation), representing a positive control, and empty defects, representing a negative control. Ten defects were created in sheep cancellous bone, three in the distal femur and two in the proximal tibia of each hind limb, with diameters of 5 mm and depths of 15 mm. New bone in-growth (osteoconductivity) and biocompatibility were evaluated using microcomputed tomography and histology at 2, 4 and 12 months after surgery. The in vivo study was validated by the positive control (good bone formation with ChronOS) and the negative control (no healing with the empty defect). A major finding of this study was incorporation of the biocomposite in bone after 12 months. Bone in-growth was observed in the biocomposite scaffold, including its central part. Despite initial fibrous tissue formation observed at 2 and 4 months, but not at 12 months, this initial fibrous tissue does not preclude long-term application of the biocomposite, as demonstrated by its osteointegration after 12 months, as well as the absence of chronic or long-term inflammation at this time point.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / pharmacology*
  • Bone Substitutes
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / drug effects*
  • Bone and Bones / pathology*
  • Bone and Bones / surgery
  • Female
  • Femur / diagnostic imaging
  • Femur / drug effects
  • Femur / pathology
  • Femur / surgery
  • Organ Size / drug effects
  • Sheep / blood
  • Tissue Scaffolds / chemistry*
  • Wound Healing / drug effects*
  • X-Ray Microtomography

Substances

  • Biocompatible Materials
  • Bone Substitutes