Fig. 4.

Serosal scar formation in murine anastomosis model

a + b Murine surgery model of colorectal anastomosis, exemplary intraoperative photographs. a First, the serosal layer of the descending colon is stained with an Alexa Fluor 568 conjugated N-hydroxysuccinimide ester (NHS AF568). b The colon is then transected, and two holding sutures are placed at either side of the transected bowel ends. The anastomosis is then closed with single stitches. c–e  In vivo serosal staining with NHS AF568 prior to anastomosis surgery and co-staining with c podoplanin (PDPN), d fibronectin (FN1) and e type 3 collagen (COL3). PDPN-positive cells as well as the extracellular matrix (ECM) proteins FN1 and COL3 are deposited on top of the serosal layer as marked in red by the NHS AF568. Representative images of anastomosis at postoperative day (POD) 7. Scale bar = 200 µm, 100× magnification. n = 2–3 for POD 7, 14 and 21. f Schematic representation of serosal scar formation in murine anastomoses.