Motility Is Blocked by Drug-Free Thermosensitive Hydrogel.

motility in biological fluids plays a prominent, but understudied, role in parasite infectivity. In this study, the ability of a thermosensitive hydrogel (pluronic F127) to physically immobilize was investigated. Blocking parasite motility could prevent its attachment to the mucosa, thus reducing the acquisition of the infection. The trajectory of individual parasites was monitored by multiple particle tracking. Mean square displacement, diffusivity, and velocity were calculated from , coordinates during time. Major results are that exhibited different types of trajectories in a diluted solution composed of lactate buffer similar to "run-and-tumble" motion reported for flagellated bacteria. The fastest specimen moves with a velocity of 19 μm/s. Observation of movements showed that the cell body remains rigid during swimming and that the propulsive forces necessary to generate the movement are the result of flagellar beating. Parasite motility was partially slowed down using hydroxyethylcellulose hydrogel, used as a reference for the development of vaginal microbicides, while 100% of were immobile in F127 hydrogel. Once completed by biological investigations on mice, this report suggests using drug-free formulation composed of F127 as a new strategy to prevent attachment to the mucosa. The concept will be extended to other flagellated organisms where the motility is driven by cilia and flagella.