Fabrication and characterization of 3D printed PCL/ZrO2/FA scaffolds for bone tissue engineering

Abstract

Design of bone tissue engineering composites consisting of biodegradable polymers and biocompatible ceramics as bioscaffolds has attracted many attentions in recent years. In the present study, polycaprolacton (PCL) scaffolds and its composites with zirconia (PCL/ZrO₂), and zirconia and fluorapatite (PCL/ZrO₂/FA) were fabricated by a 3D printing technique. Various analyses such as X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy and Fourier transform infrared spectroscopy were used to characterize the scaffolds. Furtheremore, compressive strength, degradability, and cytotoxicity were also assessed. The results showed that by adding ZrO₂ and FA to polycaprolactone, the filament (strut) diameter increased from about 464.2 to 643.8 and 766.3 μm, respectively; thus, the pore size decreased (from 735.5 to 436.5 and 426.2 μm), accordingly. The EDS and FTIR results showed that in PCL/ZrO₂ and PCL/ZrO₂/FA scaffolds, the contributing elements including zirconium, calcium, and phosphorus were uniformly dispersed in polymer matrix. In addition, it was found that the compressive strength of the composite scaffolds was higher due to the presence of ZrO₂ (1.807 MPa) and ZrO₂/FA (2.252 MPa). Meanwhile, biodegradability test in simulated body fluid showed that PCL scaffolds had a slower degradation rate than the two composite scaffolds. Furthermore, the biocompatibility of scaffolds was confirmed by MTT assay on osteoblastic cells (MC3T3-E1). From the results obtained, it can be concluded that PCL/ZrO₂/FA composite scaffolds with 3 wt% of ZrO₂ and 2 wt % of FA can be considered as an optimal scaffold, which can be a suitable candidate for bone regeneration and orthopedic applications.