Immobilization of type I collagen/hyaluronic acid multilayer coating on enoxacin loaded titania nanotubes for improved osteogenesis and osseointegration in ovariectomized rats

Titania nanotubes (Ti-NTs) have been proven to be good drug carriers and can release drugs efficiently around implants. Enoxacin (EN) is a broad-spectrum antibiotic that has the ability of anti-osteoclastogenesis. Immobilization of extracellular matrix components on the surface of the material can greatly enhance the biological activity of the implant and slow down the release rate of the drug in Ti-NTs. In the present study, a material system that provided uniform drug release, promoted osteogenesis, and inhibited osteoclast was designed and developed. Scanning electron microscopy, X-ray photoelectron spectroscopy, and water contact angle measurements were used for material surface characterization. Enoxacin release was detected by high performance liquid chromatography. Alkaline phosphatase and Alizarin Red staining were used to evaluate the osteogenic differentiation of rat bone marrow mesenchymal stem cells. Tartrate-resistant acid phosphatase staining and bone absorption assay were applied to osteoclastogenesis experiments. A drug delivery system based on Ti-NTs and type I collagen /hyaluronic acid multilayer coating (Ti-NT + EN +Col/HyA) with predominant biocompatibility, osteogenic property, and anti-osteoclastogenesis ability was successfully constructed. These excellent biological properties were further validated in an ovariectomized rat model. The results of the study indicate that Ti-NT + EN + Col/HyA is a potential material for future orthopedic implants.