Conducting PEEK Nanocomposites with Electrophoretically Deposited Bioactive Coating for Bone Tissue Regeneration and Multi-Modal Therapeutic Applications

The use of polyetheretherketone (PEEK) has grown exponentially in the biomedical field in recent decades due to its outstanding biomechanical properties. However, its lack of bioactivity/osteointegration remains an unresolved issue towards its wide use in orthopedic applications. In this work, graphene nanosheets have been incorporated into PEEK to obtain multifunctional nanocomposites. Due to the formation of electrical percolation network and the π-π* conjugation between graphene and PEEK, the resulting composites have achieved twelve order of magnitude enhancement in its electrical conductivity, and have enabled electrophoretic deposition of bioactive/anti-bacterial coating consisting of stearyltrimethylammonium chloride (STAC) modified hydroxyapatite (HA). The coated composite implant showed significant boosting of BMSC cell proliferation in vitro. In addition, the strong photothermal conversion effect of the graphene nanofillers have enabled laser induced heating of our nanocomposite implants, where the temperature of the implant can reach 45 oC in 150 s. The unique multi-functionality of our composite implant has also been demonstrated for photothermal applications such as enhancing bacterial (E. coli and S. aureus) eradication and tumor cell (MG63) inhibition, as well as bone tissue regeneration in vivo. The results suggest the strong potential of our multi-functional implant in bone repair applications as well as multi-modal therapy of challenging bone diseases such as osteosarcoma and osteomyelitis