Antibacterial and osteogenic activity on titania nanotubes modified with electrosprayed tetracycline PLGA nanoparticles

Abstract

The successful restoration using implants depends on secure bonding between the biomaterial and bone tissue. The titania nanotube surface (TNT) for implant is known to accelerate cell proliferation and differentiation, but is also vulnerable to failure because of induced bacterial attachment. To minimize the risk of infections, many researches were focused on producing TNT with antibacterial polymer layer coatings. However, these often have resulted in loss of the original advantageous structure.

In this experiment, TNT by electrochemical anodization were deposited on titanium, which were coated tetracycline in poly(lactic-co-glycolic acid) solution using electrospray deposition (TC/PLGA). The characteristics of the deposited TC/PLGA nanoparticles were adjusted by varying the coating time from 0 to 60 minutes on machined (M0, M4, M8, M16, M30 and M60) and TNT substrate (T0, T4, T8, T16, T30 and T60).

The surface characteristics were analyzed by X-ray diffraction and field-emission scanning electron microscopy. Transmission electron microscopy and dynamic light scattering were used to analyze the characteristics of nanoparticles. The antibacterial effect was confirmed with immunofluorescence bacteria staining and colony count of unit method. Biocompatibility and the osteogenesis activity of the surface was evaluated by immunofluorescence cell staining, real-time polymerase chain reaction and Alizarin Red S staining using MC3T3-E1 cells on both TNT and conventional simple machined surface.

In conclusion, M8 and T8 had decent antibacterial activity against Staphylococcus aureus and biocompatibility with MC3T3-E1 pre-osteoblast. The osteogenic activity of the TNT structure was preserved in T8. Hence, the study concluded that the electrosprayed TC/PLGA nanoparticles coating of TNT is a simple method and has potential to be applied for bactericidal implant.