Tissue auto-fluorescence lifetime imaging in porcine burn wound models (Conference Presentation)

The tissue of the extracellular matrix (ECM) are made up of distinct structural proteins, including different types of collagens. Intrinsic autofluorescence lifetimes of ECM proteins offer a non-contact, label-free characterization of tissues. This is especially useful in monitoring wound healing, where differentiating between different tissue matrix signatures can assist in evaluating the tissue structure underneath. Our previous work has demonstrated distinction between collagen types from bovine and human tissues. In this abstract, we are applying our frequency domain imaging technique to look at burn wounds in porcine skin. In this abstract, we measured normal skin tissues and compared their frequency domain lifetime scans to superficial burn tissues (80°C for 20 s) that have been healing for 21 days. Hairs were plucked from all samples prior to the scans. Each sample was scanned with 5 millimeter by 5 millimeter area at 70 µm step resolution. The scans were modulated at 20 MHz and the acquired tissue intensities were then calculated using Fast Fourier Transform and fitted to a two-exponential decay model per our previous work. The autofluorescence lifetime of the normal skin sample showed a uniform lifetime of 6.9±0.5 ns (n=8). The burn wound tissue showed an increase in lifetime to 7.4±0.6 ns (n=12). The data suggests that as wound tissue heals, in this case porcine burn model, the autofluorescence lifetime is altered, signifying potential correlation to the collagen remodeling underneath. This can be used to determine the effect of treatments on wound healing in a noninvasive nondestructive manner.