IMPACT OF BIOWASTE PORE-FORMERS ON THE PROPERTIES OF MULTI-DOPED CARBONATED HYDROXYAPATITE SCAFFOLDS

Nizar Hakim Muhammad Hilmi Lim; Yanny Marliana  Baba Ismail

Nizar Hakim Muhammad Hilmi Lim Pusat Pengajian Kejuruteraan Bahan dan Sumber Mineral, Kampus Kejuruteraan, Universiti Sains Malaysia, Nibong Tebal, 14300 Seberang Prai Selatan, Penang, Malaysia.
Yanny Marliana Baba Ismail Pusat Pengajian Kejuruteraan Bahan dan Sumber Mineral, Kampus Kejuruteraan, Universiti Sains Malaysia, Nibong Tebal, 14300 Seberang Prai Selatan, Penang, Malaysia. https://orcid.org/0000-0002-5635-3222

Keywords: Carbonated hydroxyapatite, biowaste, empty fruit bunch, soybean hull, bone scaffold

Abstract

Multi-doped carbonated hydroxyapatite, such as MgCoSr-CHA powders (md-CHA), has been developed as a potential alternative material for bone regeneration applications. This is due to their strong affinity for natural bone and good bioactivity, biocompatibility, and osteoconductivity properties. This study investigates the effect of incorporating biowaste as a pore-forming agent (BWPFA) on the structural and mechanical properties of md-CHA scaffolds. BWPFAs used in this study are (1) Empty fruit bunch (EFB) and (2) soybean hulls (SBH). Each BWPFA was milled for 3 hours, sieved to 150 μm, and mixed with md-CHA powders in a fixed ratio of 80:20. The scaffolds were then sintered at 800 °C to solidify the structure and ensure the complete removal of the BWPFA. Various techniques were employed, including X-Ray Diffraction (XRD) analysis, Fourier-Transform Infra-Red spectroscopy (FTIR), Field Emission Scanning Electron Microscopy with Energy-Dispersive X-ray spectroscopy (FESEM/EDX), density and porosity test, and diametral tensile strength (DTS) to characterize the scaffolds. Results confirmed that the scaffolds retained a single-phase CHA with a hexagonal crystal structure, and FTIR analysis verified the presence of B-type CHA. Adding BWPFA in the scaffold effectively creates scaffolds with an open pore structure with an optimal pore size of 200-300 μm, meeting the ideal bone scaffold’s requirements. Interestingly, different BWPFAs resulted in distinct pore shapes: elongated pores in EFB scaffolds and subrounded pores in SBH scaffolds, despite the initial particle size of EFB and SBH being similar. Scaffolds with SBH exhibited the highest porosity (15 %), followed by EFB (13 %), while the control had the lowest (5 %). As porosity increased, the DTS value decreased, with the control showing the highest strength (1.86 MPa), followed by EFB (1.09 MPa) and SBH (0.65 MPa).