Nano-Structure Designing Promotion Osseointegration of Hydroxyapatite Coated Ti–6Al–4V Alloy Implants in Diabetic Model

Mammalian diabetes mellitus which contains altered microenvironment always impairs diverse cellular processes such as osteogenesis, angiogenesis and tissue regeneration via different mechanisms. For researches in materials science, modifying the ability of osteogenesis and angiogenesis in dental implants shows its significant importance. Nano-structure designing is considered as a facile strategy to improve the surface bioactivity of the implants. In this study, the nanorod-structured hydroxyapatite (HA) coatings on Ti-6Al-4V implants were facilely designed by the combination of plasma-spraying and hydrothermal treatment via varying reaction media. Intriguingly, hydrothermal treatment eliminated the glassy phase and impurity phases of HA coatings, and nanorod-structured surface was successfully constructed under hydrothermal treatment in Na₃PO₄ solution. Additionally, the HA coatings with nanorod-structured surface effectively promoted the adhesion and proliferation and further enhanced osteogenic differentiation of DM-rBMSCs in vitro. Moreover, the osseointegration of Ti-6Al-4V implants with nanorod-structured HA coating was also enhanced in diabetes mellitus rabbit model in vivo. Therefore, the nano-structured surface modification of HA coating on Ti-6Al-4V implants could target pathological bone loss via strengthening osteogenesis and angiogenesis and further potentially used as a therapeutic coating to promote diabetic osteointegration.