The wound temperatures at the beginning of treatment were consistently lower than the core temperatures. The wound temperature in the animals treated with PDT rose by 13.4 ± 0.5°C and the maximum temperature achieved in this group was 44.5°C (Figure 3). However, a smaller increase in temperature was noted in wounds irradiated with laser light in the absence of MB (7.1 ± 2.6°C) with 40.1°C being the highest temperature reached in this group. Figure 3 Effect of laser light alone and laser light with Erlotinib solubility dmso methylene blue on wound temperature. Temperature

was measured using a thermistor tunnelled into the centre of the wounds. There was an immediate increase in the temperature of the wounds following the start of irradiation with laser light of 665 nm wavelength and power rating of 200 mW/cm2. There was a bigger increase in temperature in the PDT treated wounds (black squares) than in the light only (grey triangles)

treated group. The temperature dropped upon cessation of irradiation. Histological findings following PDT The cytotoxic effect of PDT on host tissue was examined in 18 biopsies from wounds treated with laser light and MB in combination. All exhibited a clear demarcation between wound and the skin and extended INCB018424 into adipose or loose areolar tissue on their deep aspect. Some included fragments of the underlying skeletal muscle. In the area of the wound, the epidermis had been removed to leave either a thin layer of the underlying connective tissue overlying the panniculus adiposus, or a wound base of adipose tissue. In contrast, the adjacent tissue had retained its epidermis complete with appendages. None of the wounds examined showed evidence of extensive tissue necrosis. Normal

wound architecture was seen in wounds that were sampled immediately after PDT (Figure 4A). By 24 hours there was a heavy lymphocytic infiltrate, which in some sections extended buy Atezolizumab quite deeply to involve the underlying muscle. This was very prominent at the wound edges but less marked towards the centre (Figure 4B). When present in the latter areas, inflammatory cells could be seen infiltrating between dermal adipocytes. Wounds examined at 24 hours in the presence of bacteria exhibited a similar pattern of inflammatory cell infiltration regardless of whether they were treated with laser light and MB, either alone or in combination (Figure 4C). Moderate to heavy bacterial deposits were observed in some wounds and were generally localised to areas with a heavy fibrin slough. Observations were made on three biopsies for each experimental condition. Figure 4 Haematoxylin & Eosin stained sections of treated and control wounds. (A) Normal tissue architecture is seen in wounds taken immediately after treatment with photodynamic therapy. (B) At 24 hours, a dense cellular infiltrate appears at the wound edges inoculated with MRSA and treated with methylene blue only (L-S+).