A carboxymethyl chitosan and peptide decorated polyetheretherketone ternary biocomposite with enhanced antibacterial activity and osseointegration as orthopedic/dental implants.
Carbon fiber reinforced polyetheretherketone (CFRPEEK) possesses biomechanical properties such as elastic modulus similar to human bones and is becoming a dominant alternative to replace the traditional metallic implants. The defective osseointegration and bacterial infection risk of CFRPEEK, however, impede its clinical adoption. In the current study, a newly developed carbon fiber reinforced polyetheretherketone/nanohydroxyapatite (CFRPEEK/n HA) ternary biocomposite was functionalized by covalently grafting carboxymethyl chitosan (CMC) followed by the decoration of a bone forming peptide (BFP) assisted via the polydopamine tag strategy. Antibacterial test with Staphylococcus aureus (S. aureus) indicated that the CMC and peptide conjugated substrates (pep CMC CFRPEEK/n HA) significantly suppressed bacterial adhesion. In vitro cell attachment/growth, spreading assay, alkaline phosphatase activity, real time PCR analysis, osteogenesis related protein expression and calcium mineral deposition all disclosed greatly accelerated adhesion, proliferation and osteo differentiation of human mesenchymal stem cells (hMSCs) on the pep CMC CFRPEEK/n HA biocomposite due to the additive effect of the CMC polysaccharide and the small osteoinductive peptide. More importantly, in vivo evaluation of the beagle tibia model by means of micro CT, histological analysis, SEM observation and fluorescent labeling confirmed the remarkably boosted bioactivity and osteointegration. The CFRPEEK/n HA ternary composite with the dual functions of bacterial adhesion reduction and osteointegration promotion holds great potential as a bioactive implant material in orthopedic/dental applications based on this scheme.
Journal of materials chemistry. B