Optimized Atmospheric Pressure Plasma Jet Amine Functionalization of Titanium Surfaces for Enhanced Osteogenic Differentiation

ABSTRACT Atmospheric pressure plasma jet (APPJ) treatment has emerged as an effective approach for surface functionalization of biomaterials due to its capability to introduce reactive chemical groups without altering bulk properties. In this study, an optimized APPJ process using cyclopropylamine precursor was developed to introduce amine-rich functional groups onto titanium surfaces. Plasma parameters were systematically adjusted to achieve stable amine polymerization and controllable surface chemistry. Surface characterization using X-ray photoelectron spectroscopy confirmed successful incorporation of nitrogen-containing functional groups and the formation of amine-functionalized surfaces. The plasma-treated titanium surfaces exhibited enhanced hydrophilicity and modified surface chemical composition. Biological evaluation demonstrated that the amine-functionalized titanium surfaces significantly promoted osteogenic differentiation of preosteoblast cells, resulting in approximately a 2.2-fold increase in ALP activity at day 14 compared with untreated titanium surfaces. These results indicate that APPJ-induced amine functionalization provides an effective strategy for controlling titanium surface chemistry and modulating cell–surface interactions. The study highlights the potential of plasma-based surface engineering as a versatile approach for tailoring the interfacial properties of biomaterials.