Tissue engineered intervertebral disc repair in the pig using injectable polymers.
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.
Revell
P A
PA
Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, London WC1X 8LD, UK. parevell@btinternet.com
Damien
E
E
Di Silvio
L
L
Gurav
N
N
Longinotti
C
C
Ambrosio
L
L
D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage; D018929:Cell Culture Techniques / Q000379:methods; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives*; D007267:Injections; D007403:Intervertebral Disc / Q000187:drug effects / Q000473:pathology* / Q000601:surgery; D007405:Intervertebral Disc Displacement / Q000473:pathology* / Q000628:therapy*; D008422:Materials Testing; D011108:Polymers / Q000008:administration & dosage; D013552:Swine; D023822:Tissue Engineering / Q000379:methods*; D016896:Treatment Outcome
D001672:Biocompatible Materials; C520664:HYADD 3; D011108:Polymers; C086359:hyaluronic acid ethyl ester; D006820:Hyaluronic Acid