Probing the immune and healing response of murine intestinal mucosa by time-lapse 2-photon microscopy of laser-induced lesions with real-time dosimetry.

Research paper by Regina R Orzekowsky-Schroeder, Antje A Klinger, Sebastian S Freidank, Norbert N Linz, Sebastian S Eckert, Gereon G Hüttmann, Andreas A Gebert, Alfred A Vogel

Indexed on: 02 Nov '14Published on: 02 Nov '14Published in: Biomedical optics express


Gut mucosa is an important interface between body and environment. Immune response and healing processes of murine small intestinal mucosa were investigated by intravital time-lapse two-photon excited autofluorescence microscopy of the response to localized laser-induced damage. Epithelial lesions were created by 355-nm, 500-ps pulses from a microchip laser that produced minute cavitation bubbles. Size and dynamics of these bubbles were monitored using a novel interferometric backscattering technique with 80 nm resolution. Small bubbles (< 2.5 µm maximum radius) merely resulted in autofluorescence loss of the target cell. Larger bubbles (7-25 µm) affected several cells and provoked immigration of immune cells (polymorphonuclear leucocytes). Damaged cells were expelled into the lumen, and the epithelium healed within 2 hours by stretching and migration of adjacent epithelial cells.