A secretory leukocyte protease inhibitor-derived small peptide coating on a titanium surface enhances osteoblast adhesion, proliferation, and reduces bacterial adhesion

Establishing strong osseointegration and preventing infection are essential for the success of titanium implants. Previous studies demonstrate that the secretory Leukocyte Protease Inhibitor (SLPI) enhances osteoblast adhesion on titanium surfaces, highlighting its potential clinical applications in orthopedics or dental implantation. This study examined SLPI-derived small peptides (SDSPs) as innovative coatings aimed at improving the biological and antibacterial characteristics of titanium (Ti). SDSPs were generated via in silico digestion of human SLPI sequence and subsequently synthesised. In this study, evaluation using the human foetal osteoblasts (hFOB 1.19) revealed that SDSP fragments (P1, P7, P8) notably enhanced cell adhesion by more than 50% in addition to improving spreading and proliferation on Ti surfaces wthout cytotoxic effects. The coatings demonstrated a notable increase in calcium deposition when compared to uncoated Ti. Analysis using XPS and profilometry validated the presence of peptides, and the P7 coating notably enhanced surface hydrophilicity. The anti-bacterial adhesion assays revealed that P7 effectively decreased the presence of both Escherichia coli and Staphylococcus aureus on plastic surfaces. Interestingly, P7 fragments effectively prevented the adhesion of Gram-negative Escherichia coli on Ti, in a concentration-dependent manner. The findings indicate that SDSPs, especially P7, have the potential to enhance osteoblast activity while simultaneously decreasing bacterial adherence. This investigation presents initial findings indicating that SDSP-coated titanium may enhance the results of orthopaedic and dental implants.