Tryptophan intrinsic fluorescence from wound healing correlates with re‐epithelialization in a rabbit model

Background Wound healing monitoring and timely decision‐making are critical for wound classification. Tryptophan (Tr) intrinsic fluorescence, detected at 295/340 nm, provides a noninvasive approach for wound assessment. Our previous work demonstrated that this autofluorescence is associated with keratinocytes in a highly proliferative state in vitro. Objective We investigated the correlation between Tr fluorescence and key wound healing parameters, including re‐epithelialization, fibrosis, neovascularization, and acute and chronic inflammation, using a rabbit model. Methods Seven rabbits underwent wound healing assessment over a 15‐day period. We employed histological analysis from central and marginal biopsies, and UV fluorescence imaging captured by a monochromatic near‐UV sensitive camera equipped with a passband optical filter (340 nm/12 nm). Excitation was achieved using a 295 nm LEDs ring lamp. Normalized fluorescence values were correlated with histological measurements using Pearson correlation. Results The UV fluorescence strongly exhibited a strong correlation with re‐epithelization (r = 0.8) at the wound edge, with peak intensity observed between the sixth and ninth days. Notably, wound‐healing dynamics differed between the wound center and edge, primarily attributed to variations in re‐epithelialization, neovascularization, and chronic inflammation. Conclusion Our findings highlight the presence of autofluorescence at 295/340 nm during wound healing, demonstrating a robust association with re‐epithelialization. This excitation/emission signal holds promise as a valuable noninvasive strategy for monitoring wound closure, re‐epithelialization, and other biological processes where Tr plays a pivotal role.