A 3D environment for anulus fibrosus regeneration.
OBJECTIVE
Biological repair strategies for the treatment of degenerated intervertebral discs are of growing interest. In addition to the development of nucleus pulposus implants to restore disc height and relieve pain, there is growing demand for an appropriate method for reconstructing the anulus fibrosus (AF). The aim of this pilot study was to evaluate the applicability of a resorbable 3D polymer of pure polyglycolic acid (PGA) combined with hyaluronan for the use in cell-free and cell-based regeneration and repair of the AF.


METHODS
Adult human AF cells were expanded in vitro using human serum and rearranged three dimensionally in hyaluronan-PGA scaffolds that were stabilized with fibrin for in vitro analyses. The capacity of dedifferentiated AF cells to redifferentiate was evaluated after 2 weeks of culture, using propidium iodide/fluorescein diacetate staining, gene expression analysis of typical marker genes, and histological staining of proteoglycans.


RESULTS
The propidium iodide/fluorescein diacetate staining demonstrated that vital human AF cells were evenly distributed within the construct. The induction of typical AF marker genes such as collagen Types I-III indicated the initiation of AF redifferentiation by 3D assembly in hyaluronan-PGA. Histological analysis of the constructs showed initial formation of an AF-like matrix comprising proteoglycans.


CONCLUSIONS
The results suggest that the 3D arrangement of human AF cells in resorbable hyaluronan-PGA scaffolds cultured in the presence of human serum is an excellent system for AF cell redifferentiation.
Department of Neurosurgery, Charité University Medicine, Berlin.
Mario
M
Cabraja
Michaela
M
Endres
Aldemar A
AA
Hegewald
Samuel
S
Vetterlein
Claudius
C
Thomé
Christian
C
Woiciechowsky
Christian
C
Kaps
D002357:Cartilage Diseases / Q000628:therapy*; D002358:Cartilage, Articular / Q000166:cytology*; D002478:Cells, Cultured / Q000166:cytology; D015870:Gene Expression / Q000235:genetics; D006801:Humans; D006820:Hyaluronic Acid / Q000494:pharmacology; D055959:Intervertebral Disc Degeneration / Q000628:therapy*; D010865:Pilot Projects; D011100:Polyglycolic Acid / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology; D012038:Regeneration / Q000502:physiology*; D023822:Tissue Engineering / Q000379:methods*
D011108:Polymers; D011100:Polyglycolic Acid; D006820:Hyaluronic Acid