An experimental study of the regeneration of the intervertebral disc with an allograft of cultured annulus fibrosus cells using a tissue-engineering method.
METHODS
Cultured annulus fibrosus cells within an atelocollagen honeycomb-shaped scaffold with a membrane seal were allografted into the lacunas of intervertebral discs of which the nucleus pulposus had been vaporized using an indocyanine green dye-enhanced laser. Regeneration of the intervertebral disc was assessed based on the viability and histologic status of the allografted annulus fibrosus cells, as well as the prevention of narrowing disc space.


OBJECTIVE
To study the regeneration of intervertebral disc after laser discectomy using tissue-engineering methods.


BACKGROUND
Intervertebral disc is the most avascular tissue in the human body, and its ability to regenerate is as low as that of articular cartilage. When nucleotomy is carried out, little regeneration of the annulus fibrosus is observed; consequently, intervertebral disc degeneration is inevitable.


METHODS
Annulus fibrosus cells isolated from 20 Japanese white rabbits were labeled with a PKH-26 fluorescent dye and seeded within an atelocollagen honeycomb-shaped scaffold with a membrane seal. Annulus fibrosus cells cultured in atelocollagen honeycomb-shaped scaffold with a membrane seal for 1 week were allografted into the lacunas of intervertebral discs of recipient rabbit of which the nucleus pulposus had been vaporized using an ICG dye-enhanced laser. Soft radiograph photographs of the lumbar spine of these anesthetized rabbits were taken, the disc space measured, and the lumbar spine extracted 2, 4, 8, and 12 weeks after the operation. The proliferation of allografted annulus fibrosus cells with 5-bromo-2'-deoxyuridine/PKH-26 fluorescent labels was assessed using consecutive frozen sections, and safranin-O staining carried out for histologic evaluation.


RESULTS
The allografted annulus fibrosus cells were viable and showed proliferation activity with a hyaline-like cartilage being produced. The narrowing of the intervertebral disc space of the cell translation group was significantly prevented, as shown, up to 12 postoperative weeks.


CONCLUSIONS
The annulus fibrosus cells cultured in an ACHMS-scaffold were allografted into the lacunae of nucleus pulposus (obtained using laser vaporization), as well as the hole of annulus fibrosus (obtained by laser fiber insertion) of rabbit intervertebral discs. These cells were viable and showed cell proliferation in the disc tissues of recipients.
Sato
Masato
M
Department of Orthopaedic Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan. ma-sato@md-phd.com
Asazuma
Takashi
T
Ishihara
Masayuki
M
Ishihara
Miya
M
Kikuchi
Toshiyuki
T
Kikuchi
Makoto
M
Fujikawa
Kyosuke
K
D000818:Animals; D001973:Bromodeoxyuridine; D002455:Cell Division; D002470:Cell Survival; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D005456:Fluorescent Dyes; D006085:Graft Survival; D007403:Intervertebral Disc / Q000166:cytology / Q000601:surgery* / Q000637:transplantation*; D007405:Intervertebral Disc Displacement / Q000601:surgery / Q000628:therapy*; D053685:Laser Therapy; D009930:Organic Chemicals; D011817:Rabbits; D012038:Regeneration; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods*; D014184:Transplantation, Homologous; D016896:Treatment Outcome
D005456:Fluorescent Dyes; D009930:Organic Chemicals; C070080:PKH 26; D001973:Bromodeoxyuridine