Fabrication of palladium nanoparticles anchored polypyrrole functionalized reduced graphene oxide nanocomposite for antibiofilm associated orthopedic tissue engineering

Two-dimensional reduced graphene oxide (rGO) was used as a scaffold for bone tissue engineering application. To advance the biological properties including biocompatibility, osteoproliferation, and prevent bacterial infection, the rGO was non-covalently functionalized with polypyrrole (PPy) and palladium (Pd) nanoparticles (NPs). The results propose that PPy and Pd in the Pd/PPy/rGO nanocomposite (NC) create the surface functionalities and binding sites to enhance the physicochemical properties of rGO for biomedical applications. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis confirmed the highly dispersed 2-5 nm-sized Pd NPs distributed and anchored on the PPy/rGO surface. The Fourier-transform infrared (FTIR) spectrum shows a peak at 1672 cm(-1 )corresponds to Pd-nitrogen stretching band which is caused by the interaction between Pd and PPy matrix. Moreover, X-ray photoelectron spectroscopy (XPS) approves the zero oxidation state of Pd (Pd-0) NPs. It successfully prevents bacterial biofilms caused by E. coli, B. subtilis, P. aeruginosa, and K. pneumoniae. Therefore the NC may be used to build a bone implant material that ensures prevention from colonizing, adhering, and forming microbial biofilms on the substrates of such materials. In the future, Pd/PPy/rGO NC can be a promising material for pharmaceutical applications such as drug-delivery, anticancer and wound healing agents.