Citrus Fruit-Based Calcium Titanate Anodization Coatings on Titanium Implants

With humans living longer and the median age of the population increasing, there is an ever-increasing demand for better biomedical implants. Titanium implants have a long history of successful use, but their naturally forming amorphous oxide surfaces are not ideal to promote bone growth. Therefore, titanium surfaces are often modified to improve bioactivity through electrochemical processes such as anodization which can crystallize the oxide into more bioactive titanium oxide phases, form hierarchical micro- and nano-scale roughness profiles, and incorporate beneficial bone chemistry into the oxide layer to improve interactions with bone cells. We have recently developed three innovative anodization electrolytes based on combinations of citrus fruit juices and commercially available calcium compounds. Anodization in these electrolytes produced citrus-based oxides exhibiting surface Ca/P ratios within the range of human bone, unique cauliflower-like hierarchical micro- and nano-scale surface roughness profiles, and the formation of titanate compounds which have been shown to be precursors for subsequent apatite formation. Thus, our titanate-containing citrus-based oxides show much promise for improving future osseointegration.