Nanoparticles attenuate P-glycoprotein/MDR1 function in A549 human alveolar epithelial cells

The effect of nanoparticles on the release of the P-gp substrate, rhodamine 123 from A549 human alveolar epithelial cell layers was studied. Cell layers were loaded with rhodamine 123 for 30 min (t0), and fluorescence was measured after further 30 min of release (t30). Our findings suggest that nanomaterials can attenuate membrane transporter function depending on size and surface properties and hence might influence the disposition of xenobiotics as well as endogenous substrates.