In vitro evaluation of novel low-pressure spark plasma sintered HA-BG composite scaffolds for bone tissue engineering

Muhammad Rizwan; Krishnamurithy Genasan; Malliga Raman Murali; Hanumantha Rao Balaji Raghavendran; Rodianah Alias; Yi Ying Cheok; Won Fen Wong; Azura Mansor; M Hamdi; Wan Jeffrey Basirun; Tunku Kamarul

doi:10.1039/d0ra04227g

In vitro evaluation of novel low-pressure spark plasma sintered HA-BG composite scaffolds for bone tissue engineering

RSC Adv. 2020 Jun 23;10(40):23813-23828. doi: 10.1039/d0ra04227g. eCollection 2020 Jun 19.

Authors

Affiliations

¹ Department of Metallurgical Engineering, Faculty of Chemical and Process Engineering, NED University of Engineering and Technology 75270 Karachi Pakistan materialist.riz@gmail.com.
² Centre of Advanced Manufacturing and Material Processing, University of Malaya 50603 Kuala Lumpur Malaysia hamdi@um.edu.my.
³ National Orthopaedic Centre of Excellence for Research & Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya 50603 Kuala Lumpur Malaysia hbr_bala@yahoo.com mrmurali08@gmail.com azuramansor@ummc.edu.my tkzrea@ummc.edu.my.
⁴ Department of Manufacturing Technology, Faculty of Innovative Design & Technology, University Sultan Zainal Abidin 21030 Kuala Terengganu Malaysia rodianahalias2112@gmail.com.
⁵ Department of Medical Microbiology, Faculty of Medicine, University of Malaya 50603 Kuala Lumpur Malaysia heathercheok@gmail.com wonfen@um.edu.my.
⁶ Chancellery Office, The National University of Malaysia 43600 Bangi Selangor Malaysia.
⁷ Department of Chemistry, Faculty of Science, University of Malaya 50603 Kuala Lumpur Malaysia jeff@um.edu.my.

Abstract

The low-pressure spark plasma sintering (SPS) technique is adopted to fabricate hydroxyapatite-bioglass (HA-BG) scaffolds while maintaining the physical properties of both components, including their bulk and relative density and hardness. However, prior to their orthopaedic and dental applications, these scaffolds must be validated via pre-clinical assessments. In the present study, scaffolds with different ratios of HA : BG, namely, 100 : 0 (HB 0 S), 90 : 10 (HB 10 S), 80 : 20 (HB 20 S) and 70 : 30 (HB 30 S) were fabricated. These scaffolds were characterized by investigating their physicochemical properties (X-ray diffraction (XRD) and surface wettability), bioactivity in a simulated body fluid (SBF) (field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR) and calcium dissolution), antimicrobial properties, biocompatibility and osteoinduction of human bone marrow-derived mesenchymal stromal cells (hBMSCs) and human monocyte immune cell response. The XRD and surface wettability results confirmed no formation of undesirable phases and the enhanced surface hydrophilicity of the scaffolds, respectively. The bioactivity in SBF indicated the formation of bone-like apatite on the surface of the scaffolds, corresponding to an increase in BG%, which was confirmed through FTIR spectra and the increasing trend of calcium release in SBF. The scaffolds showed inhibition properties against Staphylococcus aureus and Staphylococcus epidermidis. The scanning electron microscopy (SEM) micrographs and Alamar Blue proliferation assay indicated the good attachment and significant proliferation, respectively, of hBMSCs on the scaffolds. Alizarin Red S staining confirmed that the scaffolds supported the mineralisation of hBMSCs. The osteogenic protein secretion (bone morphogenetic protein-2 (BMP2), type-I collagen (COL1) and osterix (OSX)) was significant on the HB 30 S-seeded hBMSCs when compared with that of HB 0 S. The monocyte migration was significantly halted in response to HA-BG-conditioned media when compared with the positive control (monocyte chemoattractant protein-1: MCP-1). In conclusion, the HB 30 S composite scaffold has a greater potential to substitute bone grafts in orthopaedic and dental applications.