Investigation of the Influence of Hydroxyapatite and Polysaccharide Concentration on the Mechanical Properties of Bone Scaffolds, Fabricated Using Freeze Drying Process

The overarching goal of this research work is to synthesize and fabricate mechanically robust, dimensionally accurate, and porous bone scaffolds for the clinical treatment of osseous fractures, defects, and diseases. In pursuit of this goal, the objective of the work is to investigate the influence of hydroxyapatite (HA) as well as polysaccharide concentration on the mechanical properties of bone scaffolds, fabricated using freeze drying process. Freeze drying or lyophilization has emerged as a robust method for the fabrication of a broad spectrum of tissue constructs. Freeze Drying allows for multi-material fabrication of structures with complex pore morphology for soft and hard tissue engineering applications. However, the process is intrinsically complex; the complexity of the process, to a great extent, stems from complex physical phenomena (such as sublimation) as well as material-process interactions, which may adversely affect the mechanical properties, the surface morphology, and ultimately the functional characteristics of fabricated bone scaffolds. Consequently, physics-based process and material characterization would be an inevitable need. In this study, the influence of HA and polysaccharide concentration was investigated using a central composite design (CCD). The concentration of both HA and polysaccharide was changed in the range of 5%–15% with the aim to obtain mechanically robust structures. The compression properties of the fabricated bone scaffolds were measured using a compression testing machine. The outcomes of this study pave the way for the fabrication of complex, mechanically strong, and porous bone-like scaffolds with tunable medical and functional properties.