RGD Peptide Grafting onto Micro-patterned PET: Peptide Distribution Impact on Cell Attachment

The aim of this study was to evaluate the impact of different RGD peptides densities and spatial distribution on Human Osteoblasts Progenitors (HOP) attachment onto Poly (ethylene terephthalate) (PET) film surfaces. Biomimetic modifications were performed by means of a four-step reaction procedure: surface hydrolyse, oxidation in order to create COOH functions, coupling agent grafting and finally immobilization of peptides. To validate modification steps we used physico-chemical techniques: XPS was used to prove covalent grafting at each step of the RGD grafting, toluidine blue and high-resolution -imager (using [ 3 H]-Lys) were used to evaluate densities and spatial molecules distribution , optical profilometer and Scanning Electron Microscopy were used to characterize ablated patterns. Moreover, -imager has exhibited the stability of peptides grafted onto the surface when treated in harsh conditions. The efficiency of this new route for biomimetic modification of PET surface was demonstrated by measuring the adhesion between 1 and 24 h of osteoprogenitor cells isolated from HBMSC. Benefits of the as-proposed method were related to the different concentrations and distribution of peptides grafted onto the surface as well as the capacity of RGD peptide to interact with integrin receptors.