Tissue engineered intervertebral disc repair in the pig using injectable polymers

J Mater Sci Mater Med. 2007 Feb;18(2):303-8. doi: 10.1007/s10856-006-0693-6.

Abstract

The intervertebral disc (IVD) has a central nucleus pulposus (NP) able to resist compressive loads and an outer annulus fibrosus which withstands tension and gives mechanical strength. The tissue engineering of a disc substitute represents a challenge from mechanical and biological (nutrition and transport) points of view. Two hyaluronan-derived polymeric substitute materials, HYAFF 120, an ester and HYADD 3, an amide were injected into the NP of the lumbar spine of female pigs (11.1 +/- 1.0 Kg) in which a nucleotomy had also been performed. Homologous bone marrow stem cells, obtained from the bone marrow three weeks before spinal surgery, were included in the HYADD 3 material (1x 10(6) cells/ml). Two lumbar discs were operated in each animal. Control discs received a nucleotomy only. The animals were killed after 6 weeks and the lumbar spines recovered for histopathological study. Nucleotomy resulted in loss of normal IVD structure with narrowing, fibrous tissue replacement and disruption of the bony end-plates (4/4). By contrast, both HYAFF 120 (4/4) and HYADD 3 (4/4) treatment prevented this change. The injected discs had a central NP-like region which had a close similarity to the normal biconvex structure and contained viable chondrocytes forming matrix like that of normal disc.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / administration & dosage
  • Cell Culture Techniques / methods
  • Female
  • Hematopoietic Stem Cell Transplantation / methods*
  • Hyaluronic Acid / administration & dosage
  • Hyaluronic Acid / analogs & derivatives*
  • Injections
  • Intervertebral Disc / drug effects
  • Intervertebral Disc / pathology*
  • Intervertebral Disc / surgery
  • Intervertebral Disc Displacement / pathology*
  • Intervertebral Disc Displacement / therapy*
  • Materials Testing
  • Polymers / administration & dosage
  • Swine
  • Tissue Engineering / methods*
  • Treatment Outcome

Substances

  • Biocompatible Materials
  • HYADD 3
  • Polymers
  • hyaluronic acid ethyl ester
  • Hyaluronic Acid