The effect of the fibre orientation of electrospun scaffolds on the matrix production of rabbit annulus fibrosus-derived stem cells

Annulus fibrosus (AF) tissue engineering has recently received increasing attention as a treatment for intervertebral disc (IVD) degeneration; however, such engineering remains challenging because of the remarkable complexity of AF tissue. In order to engineer a functional AF replacement, the fabrication of cell-scaffold constructs that mimic the cellular, biochemical and structural features of native AF tissue is critical. In this study, we fabricated aligned fibrous polyurethane scaffolds using an electrospinning technique and used them for culturing AF-derived stem/progenitor cells (AFSCs). Random fibrous scaffolds, also prepared via electrospinning, were used as a control. We compared the morphology, proliferation, gene expression and matrix production of AFSCs on aligned scaffolds and random scaffolds. There was no apparent difference in the attachment or proliferation of cells cultured on aligned scaffolds and random scaffolds. However, compared to cells on random scaffolds, the AFSCs on aligned scaffolds were more elongated and better aligned, and they exhibited higher gene expression and matrix production of collagen-I and aggrecan. The gene expression and protein production of collagen-II did not appear to differ between the two groups. Together, these findings indicate that aligned fibrous scaffolds may provide a favourable microenvironment for the differentiation of AFSCs into cells similar to outer AF cells, which predominantly produce collagen-I matrix. Scientists have discovered a way of growing stem cells from discs in the spine that may have the potential to treat degenerative back pain. Intervertebral discs (IVDs) are cushions between the vertebrae and act as the spine's shock-absorbing system. Weakening of the annulus fibrosus (AF), the tough exterior that protects the soft material at the centre of the disc, is a common cause of chronic low back pain. Current treatments are limited and engineering AF tissue has received attention as a way of regenerating IVDs. Exploring this technique, a team led by Bin Li from Soochow University in Jiangsu, China, cultured AF-derived stem cells from rabbits. They discovered that an aligned fibrous scaffold provided a favorable environment for AF stem cells to grow into cells that produced disc-strengthening collagen.