Microwave assisted calcium phosphate coatings on carbon fiber reinforced polyether-etherketone composite scaffolds for implant applications

Abstract

Carbon fiber reinforced polyetheretherketone(CF-PEEK) is a prime synthetic biomaterial with good strength, stiffness, X-ray translucence, wear properties and also a future candidate for replacing the metallic implants such as Ti and its alloys. On the contrary,bioinertness and poor osteointegration hinders its clinical application as an orthopaedic implant. In the present work, a porous CFPEEK scaffold with varying porosities (50–70%) was prepared by a compression moulding and particle leaching method to remove the porogen. In order to make the sc affolds bioactive, the CF-PEEK samples were surface activated and microwave irradiated at 900 W in a simulated biomimetic fluid (SBF) for 3.5 min. The coated and uncoated scaffolds were then characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and the volume density of the scaffolds was measured by liquid displacement method. Mechanical and in-vitro biological properties such as water absorption, protein adsorption, hemolysis studies, in vitro bioactivity and cell viability studies were evaluated. The FESEM micrographs showed a good porous architecture and deposition of calcium phosphate (Ca-P) on CF-PEEK scaffolds, confirmed by energy dispersive spectra (EDS) analysis and XRD. The volume porosity of the scaffolds was in close to the amount of NaCl porogen used and the in vitro biological properties (water absorption, protein adsorption, hemolysis, bioactivity) of the Ca-P coated CF-PEEK scaffolds showed promising results than the uncoated CF-PEEK scaffolds. Compressive strength of the scaffold increased with decreasing porosity with P50C scaffold exhibiting a maximum compressive strength of 310.18 MPa and an elastic modulus of 0.33 GPa meeting the requirements for implant applications. Cell viability and proliferation studies of the sample with MG-63 osteoblast cell line demonstrated that P70C scaffold displayed the highest cell viability due to the presence of Ca-P coating on the highly porous structure.
Thus, the developed Ca-P coated CF-PEEK scaffold(P50C) with improved surface, in vitro biological and mechanical properties can act as a potential candidate for orthopaedic applications.