Development of a Sodium Alginate/Chitosan Nanocomposite Scaffold Incorporating Zircon Nanoparticles-Hydroxyapatite, and Alendronic Acid for Bone Tissue Engineering

Bone damage due to internal or external factors is one of the most common diseases of today's societies in the field of orthopedics, one of the common treatments to solve it is the use of artificial bone graft substitutes made by the usual methods of freeze drying. The method of making three-dimensional porous scaffolds, which has the potential to be used as an alternative to bone grafting using the freeze-drying method, is strongly felt by researchers. The use of new nanoparticles such as zirconium in the polymer network creates a porous scaffold. In this research, scaffolds were first prepared by freeze-drying with a structure and topology close to the bone, then the scaffold was placed in polymers with a weight percentage of 1% of different materials and placed in a freezedrying machine. The use of zirconium nanoparticles has been incorporated as an auxiliary element for the construction of bionanocomposite porous bone scaffolds. Scanning electron microscope (SEM) was used to examine the structure, X-Ray Diffraction (XRD) was used to examine the phasology, and mechanical and biological tests were used to describe the fabricated scaffolds. As a result of the construction of these scaffolds, it was found that these scaffolds show controlled and interconnected porous structures that the size of the pores and porosity of the scaffolds can be effectively adjusted by choosing appropriate amounts of polymer and nanoparticles. The results obtained from the measurement of mechanical properties showed that the scaffolds can basically maintain their strength in their dry state and are close to cancellous and even cortical bones in terms of mechanical properties. The swelling behavior of the scaffolds was also investigated in the body- simulating solution. The cytotoxicity of the scaffold was investigated by direct measurement for three days, and the result of the sample containing zirconium and drug (HA/SA/Cs/CaP/A/Zr) was significantly better than other samples. In the end, this research shows that bionanocomposite scaffolds are a suitable and desirable option for bone tissue engineering.