Surface modification of polypyrrole/biopolymer composites for controlled protein and cellular adhesion

The ability to control the interaction between proteins and cells with biomaterials is critical for the effective application of materials for a variety of biomedical applications. Herein, the surface modification of the biological dopant dextran sulphate-doped polypyrrole (PPy-DS) with poly(ethylene glycol) to generate a biomaterial interface that is highly resistant to protein and cellular adhesion is described. Thiolated poly(ethylene glycol) (PEG-thiol) was covalently bound to PPy-DS backbone via a thiol-ene reaction. The surface resistance to an extracellular matrix protein fibronectin increased with increasing molecular weight and concentration of PEG-thiol, and was further optimised via increasing the reaction temperature and the pH of the reactant aqueous solution. Optimised surface modification conditions substantially reduced interfacial protein adsorption, with the complete inhibition of adhesion and colonisation by primary mouse myoblasts. PEG-thiol-modified inherently conducting polymers are highly protein resistant multifunctional materials that are promising compounds for a range of biomedical and aquatic applications.