Bioadhesive mannosylated nanoparticles for oral drug delivery

The aim of this work was to design mannosylated Gantrez AN nanoparticles (M-NP) and to describe their gut bioadhesive properties in order to develop a promising carrier for future applications in oral drug delivery. For that purpose, the process of the nanoparticles coating with mannosamine was optimized by the incubation of Gantrez AN nanoparticles with different volumes of mannosamine aqueous solutions at different times. Then, the nanoparticles were characterized by measuring the size, zeta potential, mannosamine content, and concanavalin A (Con A) binding. Furthermore, in vivo quantitative bioadhesion study and kinetic analysis of the bioadhesion curves were performed after oral administration to rats of fluorescently labelled nanoparticles. The selected mannosylated nanoparticles (M-NP1 and M-NP10) were of homogenous sizes (about 300 and 200 nm), negatively charged and successfully coated with 36 and 18 microg mannosamine/mg NP, respectively. In vitro agglutination assay using Con A confirmed the successful coating of nanoparticles with mannosamine. The gut distribution profile of M-NP1 indicated a stronger bioadhesive capacity than M-NP10 and non-mannosylated ones, 1 h post-administration. Interestingly, M-NP1 showed an important ileum tropism where around 20% of the given dose remained adhered. Besides, the kinetic parameters of the bioadhesion profile of M-NP1 indicated their higher bioadhesive capacity with Q(max) and AUC(adh) about 2-times higher than control ones. Moreover, fluorescence microscopy corroborated the stronger interactions of M-NP1 with the normal mucosa and demonstrated a strong uptake of these carriers by Peyer's patches. In conclusion, we propose that mannosylated nanoparticles could be a promising non-live vector for oral delivery strategies.