Synergistic effects of citric acid - sodium alginate on physicochemical properties of α-tricalcium phosphate bone cement

Abstract

Calcium phosphate bone cement is one of the most widely used bone substitutes, but its clinical use is still critically limited by its poor physicochemical properties. In this work, calcium-binding agents, citric acid (CA) and sodium alginate (SA), were jointly introduced into α-tricalcium phosphate (α-TCP) cement to improve its physicochemical properties. Effects of CA and SA on the phase, morphology, deformation, handling and mechanical properties of the cement were further investigated. Co-existence of both agents significantly shortened the setting time whilst improved the anti-washout ability, injectability and mechanical strength of α-TCP cement in a CA-content-dependent manner. Rapid formation of SA-CA gel networks within the cement matrix enhanced the mobility of pastes with a strong cohesive action, which was beneficial for clinical injection. Herein, the conjunction of CA and SA was supposed to pave a way in developing injectable bone cement with good physicochemical properties for numerous clinical orthopedic applications.