Osteoblast cellular activity on low elastic modulus Ti-24Nb-4Zr-8Sn alloy

Low modulus β-titanium alloys with non-toxic alloying elements are envisaged to provide good biocompatibility and alleviate the undesired stress shielding effect. The objective of this study is to fundamentally elucidate the biological response of novel high strength-low elastic modulus Ti2448 alloy through the study of bioactivity and osteoblast cell functions.

Characterization techniques such as SEM, EDX, XRD, and fluorescence microscopy were utilized to analyze the microstructure, morphology, chemical composition, and cell adhesion. The cellular activity was explored in terms of cell-to-cell communication involving proliferation, spreading, synthesis of extracellular and intracellular proteins, differentiation, and mineralization.

The formation of fine apatite-like crystals on the surface during immersion test in simulated body fluid confirmed the bioactivity of the surface, which provided the favorable osteogenic microenvironment for cell-material interaction. The proliferation and differentiation of pre-osteoblasts and their ability to form a well mineralized bone-like extracellular matrix (ECM) by secreting bone markers (ALP, calcium, etc.) over the surface point toward the determining role of unique surface chemistry and surface properties of the Ti-24Nb-4Zr-8Sn (Ti2448) alloy in modulating osteoblasts functions.

These results demonstrated that the low modulus (∼49GPa) Ti2448 alloy with non-toxic alloying elements can be used as a potential dental or orthopedic load-bearing implant material.