A lithium-containing nanoporous coating on entangled titanium scaffold can enhance osseointegration through Wnt/β-catenin pathway

Abstract

An entangled titanium wire porous (ETP) scaffold shows similar mechanical properties of cancellous bone and is a promising bone repair material. However, the ETP scaffold's inert biocompatibility and poor osteogenic ability limit its clinical application. In this study, a Li-containing nanoporous coating was added on ETP by micro-arc oxidation (MAO). The SEM results indicated that a hierarchical and compact coating was formed on the Li-MAO-ETP scaffold. In vitro cell tests showed improved osteoblast morphology, adhesion, and viability in the Li-MAO-ETP group. Moreover, the Li-MAO-ETP scaffold exhibited improved osteogenic differentiation properties by activating the Wnt/β-catenin signal pathway based on the western blotting and RT-PCR results. The push-out test, sequential fluochrome labeling, and toluidine staining demonstrated that the Li-MAO-ETP scaffold contained improved osteogenic ability in vivo. The in vitro and in vivo experiments showed that the Li incorporated entangled porous titanium could be a suitable biomaterial for bone defect repair.

Keywords: Entangled porous titanium; Lithium(li); Micro-arc oxidation; Osteogenesis; Wnt/β-catenin.