Liposome-based mucus-penetrating particles (MPP) for mucosal theranostics: Demonstration of diamagnetic chemical exchange saturation transfer (diaCEST) magnetic resonance imaging (MRI)

Liposomes engineered with muco-inert surfaces, or liposomal mucus-penetrating particles (MPP), can effectively bypass the adhesive mucus barrier and encapsulate contrast agents or therapeutics for efficient mucosal delivery. To study the interactions between liposomes and mucus, the surface density of muco-inert poly(ethylene glycol) coating was systematically varied, and the liposome mobility in human cervicovaginal mucus was characterized. Using diamagnetic Chemical Exchange Saturation Transfer (diaCEST) magnetic resonance imaging (MRI), liposomal MPP were shown to provide excellent coverage and retention in the mouse vagina. These results substantiate the potential of liposomal MPP for dual imaging and treatment at mucosal surfaces, like the vagina.294