Artikel
Engineering polymer-based nucleus pulposus grafts with human disc cells: a feasibility study
Konstruktion polymerbasierter Nucleus Pulposus Transplantate mit humanen Bandscheibenzellen: eine Durchführbarkeitsanalyse
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Veröffentlicht: | 30. Mai 2008 |
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Gliederung
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Objective: Spinal surgery procedures for disc herniation can be complicated by two major problems: re-herniation and painful degeneration of the spinal segment. Therefore, we examined biocompatible, absorbable poly-glycolic acid (PGA) scaffolds for their utility to support disc tissue regeneration. Here we present first in vitro results with engineering biocompatible nucleus pulposus grafts, intended for regeneration of intervertebral disc degeneration.
Methods: Microdiscectomy for lumbar disc herniation was performed in six patients. Disc cells were isolated from herniated disc tissue, as well as from disc tissue within the disc. In vitro cell expansion was accomplished using human serum and FGF2. In a fibrin-hyaluronan solution, disc cells were loaded on PGA scaffolds and cultured for one week. Formation of disc tissue was documented by histological staining of the extracellular matrix and gene expression analysis of typical marker genes.
Results: The use of human serum and FGF2 ensures efficient isolation and expansion of human disc cells. They demonstrated a linear growth kinetic over 3 passages resulting in a cell yield of approximately 5*107 cells after 24 days. During this phase, a marked dedifferentiation of the disc cells was observed, characterized by a 10 to 50-fold decrease of typical disc marker genes (aggrecan, collagene type II). Subsequent three-dimensional tissue culture of disc cells in PGA scaffolds, however, is accompanied by an up to 3-fold increase of typical disc marker genes after one week. Accordingly, histological detectable proteoglycans and collagens were found in the specimens. Propidium-iodide/fluorescein-diacetate (PI/FDA) staining documented that three-dimensional assembly of disc cells in PGA scaffolds allows prolonged culture and high viability of disc cells.
Conclusions: Disc cells from both, herniated disc tissue and tissue within the disc can be isolated and expanded in vitro. In combination with a fibrin-hyaluronan solution and loaded on a PGA scaffold, disc cells synthesize disc-like matrix. These results encourage further studies on the regenerative potential of polymer-based nucleus pulposus grafts.