Fig. 5: Day post-wound generation and re-epithelialization prediction based on in vivo fluorescent images of nitric oxide (NO).

a Brightfield and fluorescent pictures dyed with DAF-FM captured by the imaging unit. Scale bars in the bottom right corner are 1 mm. (i) Brightfield image of the wound bed. (ii) The brightfield image shown in grayscale with a zoomed-in region. (iii) Fluorescent image of a wound bed dyed with DAF-FM. (iv) The fluorescent image is shown in grayscale with a zoomed-in region. b The fluorescent images are used to predict the day of healing and the percentage of re-epithelialization (% re-epi.) using a regression model. The full wound—fluorescent intensity plot shows the wound data and predictions based on the mean fluorescent intensity of the wound bed, which has a predicted positive relationship. The highest NO cluster-fluorescent intensity plot shows results based on k-means clustering, using the cluster with the highest mean fluorescent intensity in the clustered wound bed, which also has a positive relationship. The highest NO cluster—area plot shows the results based on the percentage of the wound area of the same wound cluster, which has a negative relationship. Our findings imply that as wound healing progresses, the area of the wound that highly expresses NO decreases, even though the intensity of NO within these regions remains elevated. This suggests that the spatial distribution of NO expression, rather than its overall intensity, may play a critical role in wound healing. c These images show the k-means clusters for each experimental wound. The color bars indicate the NO fluorescent intensity as percentages and are shown individually to highlight variations within the wound bed.