Salmonella-like bioadhesive nanoparticles

The aim of this work was to evaluate the bioadhesive potential of a polymeric vector obtained by the association between Gantrez((R)) AN nanoparticles and flagella-enriched Salmonella enteritidis extract. Fluorescently labelled nanoparticles (SE-NP) were prepared, after incubation between the polymer and the extract, by a solvent displacement method and cross-linkage with 1,3-diaminopropane. SE-NP displayed a size close to 280 nm and the amount of associated bacterial extract was 18 mu g/mg nanoparticle. Flagellin represents more than 80% of the total proteins associated with SE-NP, which was identified by SDS-PAGE and confirmed by Western blotting. Conceming the bioadhesive properties, SE-NP shows an important tropism for the ileum. In fact, about 50% of the given dose of SE-NP was found in this gut region for at least 3 h. Interestingly, the bioadhesive ability of SE-NP correlated well with the described colonisation profile for Salmonella enteritidis. This fact was corroborated by competitive tissue distribution studies. Thus, when SE-NP and Salmonella cells were administered together by the oral route, both the bacteria and the nanoparticles displayed a similar distribution within the intestinal mucosa. However, the ability of SENP to be taken up by Peyer's patches appeared to be negatively affected by the presence of the bacteria. Similarly, when SE-NP was administered 30 min before cells, SE-NP were found broadly distributed in Peyer's patches, whereas the bacteria were neither able to adhere to nor penetrate this lymphoid tissue. In summary, SE-NP demonstrated their Salmonella-like gut colonization, which can be a useful vector for oral targeting strategies. (c) 2005 Elsevier B.V All rights reserved.