Oxygen plasma immersion ion implantation treatment enhances the human bone marrow mesenchymal stem cells responses to titanium surface for dental implant application

Objectives: The present investigation utilized a novel oxygen plasma immersion ion implantation (O-PIII) treatment to create a dense and thin oxide layer on a titanium (Ti) surface for dental implant application. Materials and methods: This study evaluated the behavior of human bone marrow mesenchymal stem cells (hMSCs) on O-PIII-treated Ti. The O-PIII treatments were performed using different oxygen ion doses (T_L: 1 × 10¹⁶; T_M: 4 × 10¹⁶; T_H: 1 × 10¹⁷ ions/cm²). Results: Analysis using an X-ray photoelectron spectrometer (XPS) and high resolution X-ray diffractometer (HR-XRD) indicated that the O-PIII-treated specimen T_M had the highest proportion of rutile phase TiO₂ component. The O-PIII-treated specimen T_M had the greatest protein adsorption capability of the test Ti surfaces using XPS analysis and bicinchoninic acid (BCA) protein assay. Immunofluorescent staining revealed that hMSCs had the best cell adhesion on the O-PIII-treated specimen T_M, whereas green fluorescent protein (GFP)-labeled hMSCs experienced the fastest cell migration based on a wound healing assay. Other assays, including MTT assay, Alizarin red S staining and Western blot analysis, demonstrated that the adhered hMSCs exhibited the greatest cell proliferation, mineralization, and differentiation capabilities on the T_M specimen. Conclusions: Oxidated Ti (primarily rutile TiO₂) was produced using a facile and rapid O-PIII treatment procedure, which enhances the biocompatibility of the Ti surface with potential implications for further dental implant application.