1: J Control Release. 2006 Nov;116(1):1-27. Epub 2006 Aug 23. Nanoparticles as potential oral delivery systems of proteins and vaccines: a mechanistic approach. des Rieux A, Fievez V, Garinot M, Schneider YJ, Preat V. Universite Catholique de Louvain, Unite de Pharmacie Galenique, Avenue E. Mounier, 73-20, 1200 Brussels, Belgium. Peptides and proteins remain poorly bioavailable upon oral administration. One of the most promising strategies to improve their oral delivery relies on their association with colloidal carriers, e.g. polymeric nanoparticles, stable in gastrointestinal tract, protective for encapsulated substances and able to modulate physicochemical characteristics, drug release and biological behavior. The mechanisms of transport of these nanoparticles across intestinal mucosa are reviewed. In particular, the influence of size and surface properties on their non-specific uptake or their targeted uptake by enterocytes and/or M cells is discussed. Enhancement of their uptake by appropriate cells, i.e. M cells by (i) modeling surface properties to optimize access to and transport by M cells (ii) identifying surface markers specific to human M cell allowing targeting to M cells and nanoparticles transcytosis is illustrated. Encouraging results upon in vivo testing are reported but low bioavailability and lack of control on absorbed dose slow down products development. Vaccines are certainly the most promising applications for orally delivered nanoparticles. PMID: 17050027 [PubMed - indexed for MEDLINE] Related Links Polymeric nanoparticles for oral delivery of drugs and vaccines: a critical evaluation of in vivo studies. [Crit Rev Ther Drug Carrier Syst. 2005] PMID:16313233 Transmucosal macromolecular drug delivery. [J Control Release. 2005] PMID:15588901 Targeting approaches to oral drug delivery. [Expert Opin Biol Ther. 2002] PMID:11772341 Pharmaceutical approaches to colon targeted drug delivery systems. [J Pharm Pharm Sci. 2003] PMID:12753729 Targeted delivery of drugs to the gastrointestinal tract. [Crit Rev Ther Drug Carrier Syst. 2001] PMID:11605896