The purpose of this study was to examine the effect of toluidine blue (TB)-mediated photodynamic therapy (PDT) on oral wound infections in rats. The study called for a combination treatment of a 1mg/ml solution of TB with a red light at three intensity settings of 12 J/cm(2), 24 J/cm(2) and 48 J/cm(2). In the group that was given the highest light dose of 48 J/cm(2), an average kill rate of approximately 97% was achieved. A lesser killing effect was achieved in the group that was subjected to the lowest light dose of 12 J/cm(2), where an average of approximately 25% of the bacteria survived. After PDT, the lesions were allowed to develop, and the peak size of the lesions was larger in the control group than in the test groups, especially for the 48 J/cm(2) group. We also observed that in the 24 J/cm(2) and 48 J/cm(2) groups the lesions were of significantly smaller size. Our study demonstrated that combined TB-PDT therapy can successfully treat oral wound infections in rats. These promising results recommend the use of this treatment as a possible alternative to topical anti-microbials in future clinical applications.

Towards the goal of developing scalable, economical and effective antimicrobial textiles to reduce infection transmission, here we prepared color-variable photodynamic materials comprised of photosensitizer (PS)-loaded wool/acrylic (W/A) blends. Wool fibers in the W/A blended fabrics were loaded with the photosensitizer rose bengal (RB), and the acrylic fibers were dyed with a variety of traditional cationic dyes (cationic yellow, cationic blue and cationic red) to broaden their color range. Investigations on the colorimetric and photodynamic properties of a series of these materials were implemented through CIELab evaluation, as well as photooxidation and antibacterial studies. Generally, the photodynamic efficacy of these dual-dyed fabrics was impacted by both the choice, and how much of the traditional cationic dye was employed in the dyeing of the W/A fabrics. When compared with the PS-only singly-dyed material, RB-W/A, that showed a 99.97% (3.5 log units; p = 0.02) reduction of Staphylococcus aureus under visible light illumination (λ ≥ 420 nm, 60 min), the addition of cationic dyes led to a slight decrease in the photoinactivation ability of the dual-dyed fabrics, but was still able to achieve a 99.3% inactivation of S. aureus. Overall, our findings demonstrate the feasibility and potential applications of low cost and color variable RB-loaded W/A blended fabrics as effective self-disinfecting textiles against pathogen transmission.