Iodine-supported titanium implants have good antimicrobial attachment effects.

BACKGROUND

We have developed iodine-supported titanium implants, which were shown to have good anti-bacterial effects for Methicillin-sensitive Staphylococcus aureus (MSSA) in our past basic research. However, PJI can be caused by various bacteria including MRSA, Pseudomonas aeruginosa, MSSE, and fungus. The purpose of this study was to investigate whether these implants also have good antibacterial attachment effects for MRSA, P. aeruginosa, MSSE, and fungus.

METHODS

Ti-6Al-4V titanium plates were either left untreated (Ti), treated with oxide film on the Ti surface by anodization (Ti-O), or treated with an iodine coating on oxidation film (Ti-I). The antibacterial activity of the TiI was measured by experimental methods according to Japanese Industrial Standard (JIS) protocols. Implants in this study were exposed to MRSA (ATCC43300), P. aeruginosa (ATCC27853), MSSE (ATCC35984), and Candida Albicans (ATCC10231). Colonies were counted immediately after the bacteria attached to the metal surface and again after 24 h incubation. The difference in the number of bacteria on each metal plate was statistically investigated and an antibacterial activity value was calculated. An effective antibacterial active value of more than 2.0 was judged to be effective according to JIS protocol.

RESULTS

No countable viable bacteria were observed on the Ti-I surface. For all bacteria there was a significant difference in the mean number of viable bacteria between Ti-I and Ti or Ti-O. Antibacterial activity value in Ti-I and Ti-O was more than 5.9 and 3.6 respectively for MRSA, more than 2.8 and zero for P. aeruginosa, more than 4.3 and zero for MSSE, and more than 4.7 and zero for C. Albicans.

CONCLUSIONS

This study showed that iodine-supported titanium implants have good antimicrobial attachment effects for MRSA, P. aeruginosa, MSSE, and C. Albicans. Iodine-supported titanium implants could have great potential as innovative antibacterial implants that can prevent early onset periprosthetic joint infection.