Pathologic changes due to joint replacement in patients suffering from osteoporosis affect the bone microstructure and the implant stability. In order to assess changes in bone density as an improvement index of the trabecular microarchitecture, Ti6Al4V screws were biofunctionalized by electrospray (Electrostatic Spray Deposition) with TiO2 nanoparticles (TiO2np) or nanoparticles of TiO2 and raloxifene (TiO2np+R).
These treated screws were implanted into adult female Wistar rats at the proximal femur right and left, respectively. Untreated titanium screws were used in the distal portion of each femur as a negative control. Radiographic examinations of each femur were made 50 and 80 days post screw implantation and the regions of interest in the neighborhood of the bolts were extracted to compare the bone density of the distal (untreated) vs. proximal (treated) bolts and the proximal left (TiO2np) vs. proximal right (TiO2np+R) regions. Subsequently, the specimens were euthanized so as to correlate the images with both the microscopic and macroscopic changes from bone to implant.
The results of this preliminary study showed that the biofunctionalization with TiO2np+R improves the response to the implant, increasing the osseous density from the radiological perspective and favoring the osseointegration from both a microscopic and macroscopic perspective.