Microstructural and biological characterization of 3D printed PEEK scaffolds coated with alginate/CNT for bone regeneration applications

The main aim of bone tissue engineering is to develop novel scaffold structures that integrate biological functionality with sufficient mechanical strength and properties. In this study, bone scaffolds were fabricated using polyether ether ketone (PEEK) via 3D printing, resulting in three different porous designs. To enhance their biological attributes, these scaffolds were coated with an alginate and carbon nanotube (CNT) composite using a freeze-drying technique. The biological characteristics of fabricated samples, such as biocompatibility and bioactivity, were evaluated in simulated body fluid (SBF). Field emission scanning electron microscopy (FE-SEM) analysis showed that the 3D-printed PEEK scaffolds had a porous, uniform, and interconnected architecture with pore sizes between 321–378 µm. Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) confirmed the formation of hydroxyapatite (HA) and bioactive calcium phosphate (Ca-P) on the scaffold surfaces, indicating their bioactivity. Cell biocompatibility was assessed using the MTT assay, which revealed a high cell viability rate of approximately 97% and no significant toxicity. Consequently, the 3D-printed PEEK scaffold coated with Alginate/0.3%wt CNT demonstrated promising microstructure, bioactivity, and biocompatibility, making it suitable for bone tissue regeneration.