Intestinal locomotion by means of mucoadhesive films

Colonoscopy is a standard medical procedure in which a long flexible endoscope is inserted into the rectum for inspection of the colon. Pushing the endoscope along the colon from behind can cause painful cramps to the patient, and entails the risk of perforation of the colonic wall. For this reason, a new intestine inspection device is being developed at TU Delft. The main challenge for the development of such a device is the locomotion mechanism along the colonic surface, which is highly deformable and covered with a layer of lubricative mucus. Successful intestinal locomotion can be achieved by manipulating the friction with the colonic surface. The paper describes a new biologically inspired method to manipulate friction along the colonic surface by means of mucoadhesive films. Mucoadhesives are polymers developed for controlled drug delivery, which can adhere to the mucus layer of the colonic surface. In vitro experiments showed that significantly high friction can be achieved by interposing mucoadhesive films between the intestine inspection device and the colonic wall. Moreover, the friction of the films appears to depend on their contact area with the colonic surface. It seems, therefore, feasible to switch between high and low friction values by altering the size of the contact area between the intestine inspection device and the colonic surface