Fig. 4: Design of the in vivo experimental protocol.

A 12.5 Gy dose was delivered three times in 1 week through a 2 × 3 cm window centered on the colorectal region using a medical accelerator (a). Surgery was performed 3 weeks later with a low colo-colic anastomosis during which the treatment was applied: control (surgery procedure with administration of PBS), PF-127 alone, EVs alone, or PF-127 containing EVs (b). Eight weeks after the end of the irradiation, colo-colic anastomoses were evaluated by colonoscopy. Immediately after colonoscopy, the rats were sacrificed, and an autopsy was performed. The colonic anastomosis was then extracted for histological analysis (c).