Super tough graphene oxide reinforced polyetheretherketone for potential hard tissue repair applications

Abstract

Biocompatible polyetheretherketone (PEEK) is a favorable material for hard tissue repair due to its similar elastic modulus to that of the human bone. In this work, graphene oxide (GO) reinforced PEEK nanocomposites with different GO loading have been prepared by injection molding. Mechanical testing reveals that the toughness of the reinforced composite varies with the GO loading, with 0.5% GO giving the greatest elongation at break (86.32% greater than pristine PEEK). The underlying toughening mechanism has been attributed to the well-dispersed GO forming π-π* conjugations at the GO / PEEK interface. These conjugations also acted as the nucleation sites for oriented crystallized region in PEEK. As the GO content increases further (e.g > 0.5%), the fillers tend to agglomerate and would disturb the crystallites of PEEK and serve as stress concentration sites, resulting in decreased toughness. The biocompatibility of the composites has been evaluated in vitro, and the results showed that the addition of GO into PEEK favors the adhesion and spreading of bone marrow stromal stem cells, demonstrating the strong potential of our GO reinforced PEEK composites in applications such as hard tissue repair and replacement.

Graphene Reinforced Polyether Ether Ketone Nanocomposites for Bone Repair Applications

“…The ultimate tensile strength of all samples are in the region of 100-110 MPa (see Figure 3e). The high stiffness is similar to that of the previously reported super tough graphene oxide reinforced PEEK nanocomposites [15] . According to Figure 3f, the ductility of the composites varies significantly with different G concentration, with 0.5% G-PEEK showing the greatest enhancement in strain at break (114.33 % increase) followed by 0.1% G-PEEK (88.29% increase) and 1% G-PEEK (82.04% increase).…”

Graphene Reinforced Polyether Ether Ketone Nanocomposites for Bone Repair Applications

“…For compressive testing, the stress-strain curves of all samples again have similar profile. The compressive moduli of all samples is in the range of 2,158 -2,649 MPa, similar to that of the natural cancellous bone (1, 500 -2, 500 M Pa) [15] . It is also noted that 5% G-PEEK showed 14 % decrease in compressive modulus in comparison to pure PEEK.…”

“…It can be seen that at low G concentration (e.g, 0.1% and 0.5% G-PEEK), the toughness of the composites has been enhanced substantially, with 0.5% G-PEEK having the greatest toughness (21.58 10 3 kJ/ m 3 ). This is 150% greater than the toughness of pure PEEK and is even greater than that of the previously reported super tough graphene oxide reinforced PEEK [15] . Further increasing G concentration has led to declined toughness.…”

“…Over the past few years, graphene (G) and its derivatives have been explored for diverse biological applications ranging from bioimaging, drug delivery [13] , biosensing [14] and tissue engineering [15] . Notably, G was found to promote adhesion, proliferation and osteogenic differentiation of human bone marrow stromal stem cells (BMSCs), showing their great potential in tissue regeneration [16,17] .…”

Novel PEEK Copolymer Synthesis and Biosafety—I: Cytotoxicity Evaluation for Clinical Application

“…Another carbon filler that can be used is graphene oxide (GO), a promising filler for both mechanical and biological applications due to its high surface area and hydrophilic oxygen-rich functional groups on the surface [21]. Several studies show that the mechanical properties of various polymers were enhanced by adding GO but decreased after adding 1 wt % of GO or more due to the aggregation of GO nanosheets [22][23][24]. According to recent studies, a low concentration of GO has been confirmed to be non-toxic and biocompatible because of the oxygen-rich functional groups which enhance cell adhesion and spreading [25][26][27].…”