Multifuctional Nanofilm for Stimulating Bone Cell Attachment, Proliferation and Preventing Bacterial Colonization

Osseointegration and infection prevention are of great importance for the long-term success of bone-in-contact implants. In this study, we developed multi-drug loaded polypeptide nanofilms on orthopedic implant models for potential enhanced osseointegration and improved infection prevention. RGD, a cell-adhesive ligand, transforming growth factor beta 1 (TGF-β1), a growth factor, and gentamicin, a common antibiotic, were successfully incorporated into one single polypeptide nanofilm. On one hand, the incorporation of Arg-Gly-Asp (RGD) within polypeptide nanofilms significantly improved osteoblast cell adhesion, proliferation, and viability. The incorporation of TGF-β1 led to enhanced osteoblast cell proliferation at day 5 and improved cell viability as well. However, polypeptide nanofilms with RGD or a combination of RGD and TGF also promoted bacterial growth after 2 days. On the other hand, the incorporation of gentamicin resulted in anticipated antimicrobial properties against Staphylococcus aureus (S. aureus). However, the incorporation of gentamicin alone had reduced cell adhesion and proliferation. By combining RGD and TGF with gentamicin within a single nanofilm, an ideal surface with overall improved osteoblast adhesion, proliferation, viability, and antibacterial properties was able to be achieved. The developed multi-drug loaded polypeptide nanofilms may provide a promising means for not only enhancing tissue integration but also simultaneously reducing bacterial infection.