1: J Control Release. 2007 Dec 20;124(3):134-43. Epub 2007 Sep 7. Transport mechanisms of mmePEG750P(CL-co-TMC) polymeric micelles across the intestinal barrier. Mathot F, des Rieux A, Ariën A, Schneider YJ, Brewster M, Préat V. Université catholique de Louvain, Unité de Pharmacie Galénique, Avenue E. Mounier 73.20, UCL, 1200 Brussels, Belgium. Monomethylether poly(ethyleneglycol)(750)-poly(caprolactone-co-trimethylene carbonate) (mmePEG750)P(CL-co-TMC)) which spontaneously form micelles, can cross lipid bilayers via passive diffusion and demonstrate an oral bioavailability of 40% in rats. The aim of the current work was to study the transport mechanism(s) of drug-loaded mmePEG750P(CL-co-TMC) micelles across the intestinal barrier. The transport of radiolabelled polymer across Caco-2 cell monolayer was investigated by disrupting tight junctions and by inhibiting endocytosis. The polymer and drugs loaded in micelles independently crossed Caco-2 cell monolayers and did not use either the paracellular route or M-cells. The polymer did not affect P-gp pumps. This mechanistic study suggests that whereas drug-loaded micelles were absorbed by fluid-phase endocytosis, polymeric unimers diffused passively across the membrane concomitantly with micellar endocytosis. PMID: 17928087 [PubMed - in process] Related Links Passive diffusion of polymeric surfactants across lipid bilayers. [J Control Release. 2007] PMID:17524515 Intestinal uptake and biodistribution of novel polymeric micelles after oral administration. [J Control Release. 2006] PMID:16460829 Self-assembling PEG-p(CL-co-TMC) copolymers for oral delivery of poorly water-soluble drugs: a case study with risperidone. [J Control Release. 2005] PMID:15681087 Encapsulation of amphotericin B in poly(ethylene glycol)-block-poly(epsilon-caprolactone-co-trimethylenecarbonate) polymeric micelles. [Int J Pharm. 2006] PMID:16406402 Effects of pluronic P85 unimers and micelles on drug permeability in polarized BBMEC and Caco-2 cells. [Pharm Res. 1998] PMID:9794493