Fabrication and in vitro evaluation of Sulphonated Polyether Ether Ketone/nano Hydroxyapatite composites as bone graft materials

Sulphonated Polyether Ether Ketone/nano Hydroxyapatite (SPEEK/nHA) composites were fabricated using two different techniques - phase inversion and electrospinning. The surface morphology of the composites examined using SEM revealed that the SPEEK/nHA membranes (obtained through phase inversion technique) was highly porous and the SPEEK/nHA nanofibre mats (obtained through electrospinning) showed increased tendency for bead formation with increase in the nHA concentration. The drug release studies performed using 5-Fluorouracil (5-FU) showed that the nanofibre mats had a better drug loading and release profile than the membranes. In addition, it was also noted that the nHA filler concentration influenced the drug release property. The in vitro bioactivity studies revealed that the propensity for mineralization of hydroxycarbonate apatite increased with increasing concentration of nHA in all the composites. The generation of triboelectricity was also observed to be influenced by the concentration of nHA which also translated into better in vitro bioactivity results. The wear properties analysed using pin-on-disc tribometer showed a decrease in μ as well as wear rates with increase in nHA content which was attributed to the preferential wearing out of the SPEEK matrix as much as due to the resistance to wear offered by the nHA particles. The in vitro cytotoxicity studies performed using MG-63 cells by MTT method revealed that all the composites possessed excellent cytocompatibilities which only increased marginally with increase in the nHA content. The studies showed that SPEEK/nHA composites could be considered as potential synthetic non-degradable bone graft materials which could find applications in both stress - bearing (membranes) and areas subject to minimal wear (nanofibre mats).