Enhanced Efficacy of Sandblasted, Large-Grit, Alkaline-Etched (SLA) Titanium Surfaces Combined with Plasma Treatment and Secretory Leukocyte Protease Inhibitor (SLPI) Coating in Promoting Osteoblast Activity and Reducing Bacterial Adhesion.

The clinical success rate of titanium (Ti) implants is significantly reduced in elderly patients and by implant-associated bacterial infections. Thus, Ti surfaces were modified using sandblasted large-grit alkaline etching (SLA), argon-nonthermal plasma treatment, and recombinant human secretory leukocyte protease inhibitor (rhSLPI) coating. This study evaluated surface characteristics, human fetal osteoblast (hFOB 1.19) activities, and antibacterial efficacy. The modified surfaces exhibited increased roughness and hydrophilicity compared to Ti. The SBPTi-rhSLPI enhanced 7-day protein retention on the surface. While Ti promoted higher cell proliferation, the modified groups demonstrated superior cell adhesion and mineralization. Specifically, SBPTi-rhSLPI showed the highest cytoplasmic spreading, adhesion-related gene expression (Itgα1, Itgα2, Itgα5, and Itgβ1), and mineralization. Additionally, rhSLPI-coated groups effectively reduced the adhesion of both S. aureus and E. coli. In conclusion, combining SLA modification, argon plasma treatment, and rhSLPI coating provides enhanced effects. This combined approach significantly enhances osteoblast adhesion and mineralization while possessing antibacterial potential, which could be a promising strategy to improve implant success rates.