Antimicrobial performance of mesoporous titania thin films: role of pore size, hydrophobicity, and antibiotic release

Abstract

Implant-associated infections are undesirable complications that might arise after implant surgery. If the infection is not prevented, it can lead to tremendous cost, trauma, and even life threatening conditions for the patient. Development of an implant coating loaded with antimicrobial substances would be an effective way to improve the success rate of implants. In this study, the in vitro efficacy of mesoporous titania thin films used as a novel antimicrobial release coating was evaluated. Mesoporous titania thin films with pore diameters of 4, 6, and 7 nm were synthesized using the evaporation-induced self-assembly method. The films were characterized and loaded with antimicrobial agents, including vancomycin, gentamicin, and daptomycin. Staphylococcus aureus and Pseudomonas aeruginosa were used to evaluate their effectiveness toward inhibiting bacterial colonization. Drug loading and delivery were studied using a quartz crystal microbalance with dissipation monitoring, which showed successful loading and release of the antibiotics from the surfaces. Results from counting bacterial colony-forming units showed reduced bacterial adhesion on the drug-loaded films. Interestingly, the presence of the pores alone had a desired effect on bacterial colonization, which can be attributed to the documented nanotopographical effect. In summary, this study provides significant promise for the use of mesoporous titania thin films for reducing implant infections.

Keywords:

• mesoporous titania
• antibacterial
• drug delivery
• implant coating

Supplementary material

Figure S1 SEM micrographs of mesoporous titania coated onto glass substrates synthesized by different templates.

Notes: (A) CTAB, (B) P123, and (C) P123 + PPG (1:1).

Abbreviations: SEM, scanning electron microscopy; CTAB, cetyltrimethylammonium bromide; PPG, polypropylene glycol; EHT, extra high tension; WD, working distance.

Acknowledgments

The Wallenberg Foundation is acknowledged for financial support through their Wallenberg Academy Fellow Program (MA). Northeastern University is also acknowledged for financial support. Katherine Y Santizo is acknowledged for the AFM measurements.

Disclosure

The authors report no conflicts of interest in this work.