Synthesis, analytical characterization, and osteoblast adhesion properties on RGD-grafted polypyrrole coatings on titanium substrates

Abstract

The covalent attachment of an Arg-Gly-Asp (RGD) containing peptide to polypyrrole(PPy)-coated titanium substrates has been investigated in order to develop a bioactive material of potential use in orthopedic fields. Polypyrrole has been employed as the coating polymer because of its suitability to be electrochemically grown directly onto metallic substrates of different shapes, leading to remarkably adherent films. The synthetic peptide Cys-Gly-(Arg-Gly-Asp)-Ser-Pro-Lys, containing the cell-adhesive region of fibronectin (RGD), has been grafted to the polymer substrate via the cysteine residue using a procedure recently developed in the authors laboratory. The effectiveness of grafting was monitored by X-ray photoelectron spectroscopy (XPS), which assessed the presence of the peptide grafted onto the polymer surface exploiting the cysteine sulfur as target element. Neonatal rat calvarial osteoblasts were attached to RGD-modified PPy-coated Ti substrates at levels significantly greater than on unmodified PPy-coated Ti and glass coverslip substrates.

Gene Expression of MC3T3-E1 Cells on Fibronectin-immobilized Titanium Using Tresyl Chloride Activation Technique

“…There are several methods to bind cell-adhesive proteins to titanium, namely precoating with pyrrole or Au and cysteine, or pretreatment with silane coupling agents 10,11,16,30) . The prominent advantage of tresyl chloride activation technique is its simplicity.…”

Applications of conducting polymers and their issues in biomedical engineering

“…Modification of these materials with CP coatings has been suggested as an approach for improving the tissue -electrode interface and increasing the effective lifetime of the implants. PPy film has been used as a coating polymer for Ti alloy substrates to improve osteointegration performances (De Giglio et al 2001); such improvements, like its electropolymerization on the surface of metal alloys (De Giglio et al 2001), also with the covalent attachment of an RGD (Arg-Gly-Asp)-containing peptide (De Giglio et al 2000) or acrylic acid grafting (Cen et al 2003), will enable the development of bioactive materials for potential use in orthopaedic applications (e.g. Ti orthopaedic prostheses).…”

Bionic Ears: Their Development and Future Advances Using Neurotrophins and Inherently Conducting Polymers

“…This polypeptide (RGD) contains the cell adhesive region of Fn. Increase in osteoblast cell adhesion of the order of 200% compared with nonpolymercoated titanium was observed (De Giglio et al 2000).…”