Pluronic^® F-68 Enhances the Nanoparticle-Cell Interaction

Nowadays, the various surfactants find wide application in pharmaceutical industry. The nanoparticle preparation process by emulsion techniques essentially requires a surfactant, most commonly Pluronic^® F-68 [1]. This non-ionic tenside influences cell physiology and was tested in clinical trial for the treatment of sickle cell disease [2] and myocardial infarction [3]. Out of these reasons, even residual tenside in nanoparticle preparations might influence the cells as well as their interaction with the colloidal carriers. At this, Caco-2 single cells were incubated with fluorescent polystyrene nanoparticles, in presence of increasing amounts of Pluronic^® F-68 and cell-associated nanoparticles were detected by flow cytometry. Independent from incubation temperature, the cell-associated fraction of nanoparticles concurrently increased with the tenside concentration. Ongoing from micropipette aspiration experiments this effect could be attributed to an increase of membrane stiffness of Caco-2 cells in presence of Pluronic^® F-68. Furthermore, the toxicity assay revealed that viability of the cells remained unaffected at any concentration of Pluronic^® F-68.