Fig. 5

In vivo wound healing activity and histological evaluation of wound sections. (A) Representative photographs of the rat skin wound healing treated with HSA NPs, soluble bFGF, and HSA-bFGF NPs, compared to NT at day 0, 3, 6, 9, 12, and 14. Dosage of soluble bFGF was 12.5 µg, and equivalent extent of bFGF was loaded in HSA-bFGF NPs. The boundary between the hairy part and the non-hairy part of the skin was marked (dashed line, red). Scale bars, 5 mm. See enlarged images in Fig. S3. (B) Quantitatively analyzed wound size reduction profile. n = 3 to 5. (C) Representative H&E staining images of the wound skin upon different treatments. Panniculus gap was presented as dashed lines and arrows (black). HSA-bFGF NPs showed significant tissue recovery with a large number of blood vessels (yellow arrows) and hair follicles (gray arrows) compared to other groups. Scale bars, 1 mm. See enlarged images in Fig. S4. (D) Magnified H&E staining images of each skin designated as solid boxes in (C) showing differences in tissue microstructures after wound healing process upon each treatment. Regeneration in progress was exhibited in blue box, restored region was in green box, and unwounded area was in red box, respectively. Stratum corneum and thickness of epidermis layer was formed similar to healthy skin in treated with HSA-bFGF NPs. Capillaries and glands were also found to be more comparable to intact epidermal structure. Scale bars, 100 μm