2.4.2. Antibacterial Assay

Prior to inoculation, PCL/TiO2 samples with different TiO2 concentration were UV-irradiated for 5 h to stimulate the photocatalytic reaction in the TiO2 material. Other samples (pure PCL and cpTi substrate) were UV-irradiated and sterilized for the same time interval. These specimens were used for carrying out the antibacterial assay against bacterium Staphylococcus aureus (NCIM 5021). In brief, the samples were placed in 12 welled plates containing 2 mL nutrient broth. A bacterial inoculum of 1 × 107 CFU/mL was added to each well. The plates were then allowed to incubate for 24 h at 37 ◦C.

After 24 h the samples were carefully removed and rinsed. The samples were sonicated for one minute with an interval of one minute. Five cycles were repeated to ensure complete extraction of bacteria. These samples were centrifuged, and the bacterial pellet obtained, was resuspended in PBS. The bacterial solution was then spread onto pre-cooled agar plates and incubated for 24 h at 37 ◦C. The resulting colonies were then counted, and the log values were calculated for them. The reduction in bacterial growth was estimated as a reduction in log CFU/mL values
