Fig. 8. Macroscopic evaluation and histological analysis of wound models in vivo. (A) Scheme for in vivo test including the establishment of K.pneumoniae infection model and subsequent treatment regime. (B) Changes in mice body weight during the treatment. (C) Representative photographs of wounds at day 0, 4, 8, and 12 and (D) wound closure rates. (E) Representative photographs of bacteria colonies derived from the infected sites of mice with different treatment as indicated. (F) Corresponding quantitative data of bacterial colonies in (E). (G) Wound area traces of each group during 12 days.
The wound closure efficacy after different treatments was also assessed by performing histological analysis of wound tissues. As shown in Fig. 9A, mass inflammatory cells were observed in PBS, HMPB, Ofloxacin, and OHH NPs groups, suggesting the wound recovery was incomplete. However, the wounds of OHH NPs+NIR showed almost as complete as normal tissue without obvious inflammation. Furthermore, the collagen deposition of wound area was investigated by Masson’s trichrome staining. Fig. 9B showed the regenerated collagen fiber stained with blue color in OHH NPs+NIR-treated group was continuous and more obvious than that in other treated groups, which reflected better recovery of combination therapy. All of the results confirmed the best healing efficiency of OHH NPs+NIR strategy.