Biological and physicochemical characterization of carbonated hydroxyapatite-honeycomb-polyethylene oxide bone scaffold fabricated using the freeze-drying method

Abstract

In this work, a carbonated hydroxyapatite/honeycomb/polyethylene oxide (CHA/HCB/PEO) scaffold was fabricated using the freeze-drying method. The CHA bioceramic component was synthesized from oyster shells using the precipitation method. HCB and PEO act as reinforcing materials that influence the physicochemical properties of the scaffold and as antibacterial agents on the scaffold. The CHA produced was B-type, confirmed by Fourier transform infrared (FTIR) and x-ray diffractometer (XRD) spectra of the CHA. FTIR analysis of the scaffold demonstrated the presence of functional group vibrations originating from PEO and HCB, affirming the successful application of the freeze-drying method, which preserved the polymer content within the scaffold during the evaporation process, thus facilitating pore formation. The XRD results show that a lower CHA concentration is associated with a smaller size of the scaffold crystallites, potentially inducing dislocations favorable for cellular proliferation. The porosity of the formed scaffold is in the ideal range of >60% with CHA concentration of 5 and 10 wt%. The size of the pores that formed on the scaffold was 3–69 μm, classifying them within the micropore category. The in vitro test results in the form of an antibacterial test revealed that the scaffold could inhibit S. aureus and E. coli bacteria. Notably, a scaffold consisting of 10 wt% of CHA had a larger zone of inhibition diameter, 10.083 ± 0.104 for S. aureus and 10.517 ± 0.247 mm for E. coli. The MTT assay and cell morphology MC3T3E1 results in the scaffold show that the CHA/HCB/PEO scaffold is non-cytotoxic and can facilitate cells to attach and proliferate. The cell viability of the scaffold was 96.23% at the concentration of 31.25 μg ml⁻¹, and the IC₅₀ value was at 16144 μg ml⁻¹. Therefore, CHA/HCB/PEO composites can be an alternative material in scaffold fabrication for bone tissue engineering.