4.5 In vivo wound healing assessment in a deep Ⅱ° scald wound molding
On 0 d, The SD rats weighing 180−200 g were anesthetized with inhaled gas anesthesia (O2 2 L/min,2% isoflurane) before surgery, and the hair on their back was shaved. To induce a deep Ⅱ° scald wound, a preheated copper-block (500g) of a temperature control scald instrument at the temperature of 95 °C for 15 s at the dorsal area of each rat. Twelve rats were randomly divided into four groups with different treatments: (1) Control group in which saline alone was applied to the wounds, (2) blank hydrogel group, (3) ANVs hydrogel group, (4) THB@ANVs hydrogel group. 2mm hydrogel in with the same area as the wound were applied to cover the wounds of group (2)(3)(4).
On 1d, 60 μL of 106 S. aureus were dropped onto the wound surface after debridement, then saline or hydrogel were applied to the scald wound and covered by Tegaderm™ film dressing (3M Deutschland GmbH, Neuss, Germany). After incubating the hydrogel on the wound for 6 hours, photodynamic therapy was performed using 100 mW/cm2 white light source for 10 min. The sustained release time of gel is 3 days, and the frequency of dressing change is consistent with it. Photodynamic therapy was performed every day from 1~7d, and every other day from 8~14d, and sampled on days 3, 7, 14 and 21 have been collected. The images of wound healing regions were recorded on days 0, 1, 3, 7, and 14. The wound areas and vascular regeneration were measured and analyzed by Image J software.