[Transport of PLGA nanoparticles across Caco-2/HT29-MTX co-cultured cells].

The present study is to establish Caco-2/HT29-MTX co-cultured cells and investigate the transport capability of PLGA nanoparticles with different surface chemical properties across Caco-2/HT29-MTX co-cultured cells. PLGA-NPs, mPEG-PLGA-NPs and chitosan coated PLGA-NPs were prepared by nanoprecipitation method using poly(lactic-co-glycolic acid) as carrier material with surface modified by methoxy poly(ethylene glycol) and chitosan. The particle size and zeta potential of nanoparticles were measured by dynamic light scattering.

Preparation, characterization and uptake of PEG-coated, muco-inert nanoparticles in HGC-27 cells, a mucin-producing, gastric-cancer cell line.

To prepare polyethylene glycol (PEG)-coated, muco-inert nanoparticles, we investigated the interaction between nanoparticles and mucin, and analyzed the cellular uptake of nanoparticles in HGC-27 cells, which are a mucin-producing, gastric cancer cell line. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were manufactured through a nanoprecipitation/emulsion evaporation technique, and coumarin-6 was encapsulated as a fluorescent marker. We characterized and evaluated the nanoparticles.

[Transport of mPEG-PLGA nanoparticles across the rat nasal mucosa].

To investigate the effects of particle size, mPEG molecular weight, coating density and zeta potential of monomethoxyl poly(ethylene glycol)-poly(lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles on their transportation across the rat nasal mucosa, mPEG-PLGA-NPs with different mPEG molecular weights (M(r) 1 000, 2 000) and coating density (0, 5%, 10%, 15%) and chitosan coated PLGA-NP, which loaded coumarin-6 as fluorescent marker, were prepared with the nanoprecipitation method and emulsion-solvent evaporation method, and determine their particle size, zeta potential, the efficiency of fluorescent labeling, in vitro leakage rate and the stability with the lysozyme were determined. The effects of physical and chemical properties on the transmucosal transport of the fluorescent nanoparticles were investigated by confocal laser scanning microscopy (CLSM). The result showed that the size of nanoparticles prepared with nanoprecipitation method varied between 120 and 200 nm; the size of nanoparticles prepared with emulsion-solvent evaporation method varied between 420 and 450 nm.

Bioavailability of oral methylnaltrexone increases with a phosphatidylcholine-based formulation.

Objective: Methylnaltrexone (MNTX), a peripherally restricted opioid antagonist with mu-opioid receptor selectivity, can reduce opioid activity in the gastrointestinal tract while sparing the pain relief afforded by opioids. Since the bioavailability of oral MNTX is low, it is necessary to explore the oral formulations of MNTX that increase its bioavailability.

Materials And Methods: An MNTX-phosphatidylcholine complex (MNTX-PC) formulation was prepared.