Optimized consolidation process at a near-room temperature of nano-hydroxyapatite and sodium silicate glass composites for bone healing applications

ABSTRACT

Hydroxyapatite nanoparticles (nHap) with chemical and structural characteristics similar to the bone mineral are widely used for orthopaedic applications. However, conventional sintering methods applied to consolidate nHap alter significantly their properties. Recently, a near-room temperature process was developed to consolidate nHap using a sodium silicate solution (SS) as a mineral binder to produce highly reactive composites. In this work, a central composite design is employed to determine the best parameters to elaborate nHap/SSG with optimized mechanical properties. The studied factors were the molar ratio of SS (n), liquid-to-solid ratio (Ls) and drying temperature (T°C). A maximum compressive strength of 24.01 MPa was achieved when composites were formulated using SS with a ratio of 1, Ls of 0.4 cm3/g and drying temperatures below 50 °C. In vitro biocompatibility of bone cells (MG-63) revealed that the optimized composite enhanced cellular proliferation and differentiation which make them a promising candidate for bone regeneration.   

KEYWORDS:

• Hydroxyapatite
• central composite design
• sodium silicate solutions
• bone tissue engineering
• low-temperature consolidation

Acknowledgments

The authors would like to thank Fundação para a Ciência e Tecnologia (FCT) for the financial support through Centro de Química Estrutural project UIDB/00100/2020 and LAQV – Laboratório Associado para a Química Verde project UIDB/50006/2020.

The authors would also like to mention that the ATR-FTIR, XRD, and compressive strength analysis were carried out in the department of chemistry, Faculty of Sciences, University of Mohamed first Oujda, Morocco, under the supervision of Professor Abdelmonaem TALHAOUI.

Disclosure statement

No potential conflict of interest was reported by the author(s).