Effect of a synthetic link N peptide nanofiber scaffold on the matrix deposition of aggrecan and type II collagen in rabbit notochordal cells

Self-assembling peptide nanofiber scaffolds have been studied extensively as biological materials for 3-dimensional cell culture and repairing tissue defects in animals. However, few studies have applied peptide nanofiber scaffolds in the tissue engineering of intervertebral discs (IVDs). In this study, a novel functionalized peptide scaffold was specifically designed for IVD tissue engineering, and notochordal cells (NCs) as an alternative cell source for IVD degeneration were selected to investigate the bioactive scaffold material. The novel RADA16-Link N self-assembling peptide scaffold material was designed by direct coupling to a bioactive motif link N. The link N nanofiber scaffold (LN-NS) material was obtained by mixing pure RADA16-I and RADA16-Link N (1:1) designer peptide solutions. Although live/dead cell assays showed that LN-NS and RADA16-I scaffold materials were both biocompatible with NCs, the LN-NS material significantly promoted NC adhesion compared with that of the pure RADA16-I SAP scaffold material. The depositions of aggrecan and type II collagen, which are significant markers for IVD cells, were remarkably increased. Furthermore, the results indicated that the link N motif, the matrix analog of the nucleus pulposus, significantly promoted the accumulation of other extracellular matrices in vitro. We conclude that the novel LN-NS material is a promising biological scaffold material, and may have a broad range of applications in IVD tissue engineering.