2.6.1 In vivo wound assay
Skin is the main barrier that protects the body against external damage
bacterial infection. Upon scald injury, bacteria can easily penetrate
during the lengthy wound recovery process. In vitro studies have
shown that the THB@ANVs hydrogel has great promise for bacteria resist
and scald wound repair. Therefore, the deep second-degree scald wound
model (16mm in diameter) of rat was successfully established using a
scald equipment, with parameters
set at 500 g, 95 ℃, 15s (Figure S15). As shown in Figure 5A, hydrogels
were applied on the wound after debridement treatment, and S.
aureus were dropped onto the wound surface to verify the
anti-infectious ability of THB@ANVs hydrogel. Different to human, the
primary wound closure of rat relies more on contracture of the loose
skin, rather than re-epithelialization and deposition of connective
tissue. Thus, silicone fixing rings are used to increase the tension of
skins in the wound healing assessment of rats. The photographic images
of the wound appearances on days 1, 3, 7, and 14 time points taken after
treatment with PBS, blank hydrogels, ANVs hydrogels or THB@ANVs
hydrogels on the deep second-degree scald model of rats are shown in
Figure 5B. To quantitatively determine the wound regeneration, the
percentages of wound sizes were measured and analyzed (figure 5C).