title: Interaction of poly(lactic-co-glycolic acid) nanoparticles at fluid interfaces.
abstract: OBJECTIVE
  Adsorption and localization of nanoparticles at fluid interfaces are key factors in processes like transport through membranes or emulsion stabilization. Adsorption of poly(lactic-co-glycolic acid) (PLGA) and Pluronic coated PLGA nanoparticles (NPs) were studied at three different fluid interfaces. The effect of particle surface modification and type of interface was investigated with the aim of fine tuning interfacial interaction of the nanoparticles.
  
  
  METHODS
  Surface tension measurements were carried out to determine the surface activity and adsorption kinetics of the particles. Particles layers at the air/water interface were further studied using the Langmuir balance technique by recording the surface pressure-area isotherms. Interfacial rheological measurements were performed to characterize the structural properties of the nanoparticle interfacial films.
  
  
  RESULTS
  Interfacial adsorption and its kinetics were explained by the diffusion controlled adsorption theory and considering the energy barrier of particle transport to the interface. Surface modification by Pluronic increased the interfacial activity of nanoparticles at all interfaces. Surface activity of PLGA-Pluronic particles could be described by the contributions of both the PLGA NPs and the effective portion of their Pluronic shell. Both particle films present mainly elastic dilatational properties suggesting that particles are in kinetically separated state.
authors.affiliation: Laboratory of Interfaces and Nanostructures, Institute of Chemistry, Eötvös Loránd University, Budapest 112, PO Box 32, H-1518 Budapest, Hungary. Electronic address: ggyulai@chem.elte.hu.
authors.forename: Gergő
authors.initials: G
authors.lastname: Gyulai
authors.affiliation: Laboratory of Interfaces and Nanostructures, Institute of Chemistry, Eötvös Loránd University, Budapest 112, PO Box 32, H-1518 Budapest, Hungary.
authors.forename: Éva
authors.initials: É
authors.lastname: Kiss
keywords: Adsorption kinetics; Interfacial dilatational rheology; Interfacial structure; PLGA nanoparticles; Pluronic stabilized nanoparticles