Functional and cell surface characteristics of periodontal ligament cells (PDLCs) on RGD‐synthetic polypeptide conjugate coatings

Background and Objective Periodontal ligament cells (PDLCs) are an important source for periodontal tissue healing and regeneration. Proper cell adhesion is a key for survival of anchorage‐dependent cells and also initiates further intracellular signals for essential cellular functions. We aimed to test 3 different synthetic conjugates with integrin‐binding RGD sequence (SAK‐c[RGDfC], AK‐c[RGDfC], and SAK‐opn on the adhesion of human PDLCs and subsequent events including proliferation, migration, behavior of cell surface molecules, and osteogenic differentiation. Materials and Methods Synthetic peptides were synthesized by solid‐phase technique and attached to branched chain polymeric polypeptides via thioether linkage. Simple adsorption method was used to coat tissue culture plastic or electric arrays. PDLCs were isolated from 24 surgically extracted human third molars. Cell adhesion and proliferation were measured with real‐time impedimetric xCELLigence SP system. Cell migration assay was performed with Ibidi® Culture inserts. Cell surface antigens were detected using flow cytometry analysis. Osteogenic differentiation was assessed with alkaline phosphatase (ALP) assay and Alizarin Red S staining, and real‐time qPCR was performed to analyze the osteoblast‐related gene expression. Osteogenic differentiation and adipogenic differentiation of PDLCs were monitored by real‐time Electrical Cell‐Substrate Impedance Spectroscopy (ECIS). Results Primary outcome of this study relies on that all three synthetic RGD peptides improved PDLC adhesion (P