Introduction: In order to address biomaterial associated infections caused by formation of adhesive biofilm on the surfaces of prosthetic materials, a practical strategy would be to apply an implant coating having the capability to release antimicrobial substances. This would result in a local antibiotic administration, which is believed to be an efficient treatment with low risks for systemic side effects. Additionally, reduction of bacteria adhesion to biomedical devices without the use of drugs only by manipulating surface properties is also an attractive method for hindering infections. Materials and Methods: In this study, the effectiveness of mesoporous titania films as an antimicrobial release coating was investigated. Mesoporous titania thin films were formed using evaporation induced self-assembly (EISA) method in combination with spin coating. Synthesis parameters, such as type and amount of template, swelling agent volume ratio and aging parameters were varied to form mesoporous titania with variable pore sizes.The surfaces were loaded with antimicrobial agents such as Vancomycin, Gentamicin and Daptomycin and applied to grow grow Staphylococcus aureus and Pseudomonas aeruginosa to evaluate the efficiency towards bacterial colonization. The drug delivery was studied using quartz crystal microbalance with dissipation monitoring (QCM-D) method. Results and Discussions: Transmission and scanning electron microscopy (TEM and SEM) showed that the materials had a well-defined porous structure with pore sizes ranging between 3 and 7.2 nm, depending on the used template. The antibiotic delivery was studied using QCM-D, showed a successful loading and release of the antibiotics. Results from counting the bacterial colony forming units showed a reduced bacterial adhesion for the drug-loaded films. Furthermore, also the presence of the pores showed to have a desired effect on the bacteria, an effect attributed to the nanoroughness. It was shown that applying a mesoporous thin coating on the substrates, apart from their function as an antibiotic delivery system can reduce the adhesion of bacteria just by creating nano level roughnesses. Mesoporous titania coating with variable pore sizes function better in hindering the bacterial adhesion compared to a non-porous titania coating used as control. Figure1. TEM images obtained from mesoporous titania synthesized by different templates a)CTAB b)P123 c)P123+swelling agent (1:1) Results from QCM-D measurements clearly reveals that a higher amount of antibiotic can be loaded on the surfaces with bigger pore sizes which in turn can lead to a higher release of antibiotic from these surfaces. These observations can be linked well to the bacterial adhesion results which showed clear differences on the adhesion of bacteria strains in the presence of different antibiotics. A decreased attachment was observed when the pore sizes of antibacterial loaded surfaces were increased. These observations confirm that the mesopoorus titania substrates can act as efficient drug release implant coating to combat bacterial adhesion and potential implant related infections. The amount of antibiotic loaded on the coating can be regulated by varying the pore size of the mesoporous titania films. Conclusion: This study provides significant promise for the use of mesoporous titania thin films for reducing implant infection by locally transferring the antibiotics to the susceptible infection sites and by applying nanotechnology to create antimicrobial surfaces without using antibiotics.
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