Chiral tartaric acid improves fracture toughness of bioactive brushite-collagen bone cements

Abstract

Brushite cements are promising bone regeneration materials with limited biological and mechanical properties. Here, we engineer a mechanically improved brushite-collagen type I cement with enhanced biological properties by use of chiral chemistry; D- and L-tartaric acid were used to limit crystal growth and increase the mechanical properties of brushite-collagen cements. The impact of the chiral molecules on the cements was examined with FTIR, XRD and SEM. A 3-point bend test was utilised to study the fracture toughness and cell attachment and morphology studies to demonstrate biocompatibility. XRD and SEM analyses showed that L- but not D- tartaric acid, significantly restrained brushite crystal growth by binding to the {010} plane of the mineral, increased brushite crystal packing and the collagen-mineral interaction area. L-tartaric acid significantly improved fracture toughness compared to traditional brushite by 30 %. Collagen significantly enhanced cell morphology and focal adhesion expression on brushite cements.