title: Poly(lactic-co-glycolic acid) as a particulate emulsifier.
abstract: The structure and stability of emulsions formed in the presence of nanoparticles of poly(lactic-co-glycolic acid) (PLGA) were characterised. From oil-water contact angles on PLGA films, it was deduced that particle surface hydrophobicity is linked to the oil phase polarity. Incorporation of polyvinyl alcohol molecules into the nanoparticle surfaces reduces the particle hydrophobicity sufficiently for oil-in-water emulsions to be preferentially stabilised. PLGA nanoparticles enhance the stability of emulsions formed from a wide range of oils of different polarities. The nanoparticle concentration was found to be a key parameter controlling the average size and coalescence stability of the emulsion drops. Visualisation of the interfacial structure by electron microscopy indicated that PLGA nanoparticles were located at the drop surfaces, evidence of the capacity of these particles to stabilise Pickering-type emulsions. These results provide insights into the mechanism of PLGA nanoparticle stabilisation of emulsions.
authors.affiliation: Ian Wark Research Institute, University of South Australia, Mawson Lakes, South Australia, Australia. catherine.whitby@unisa.edu.au
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Whitby
authors.forename: Li Hui
authors.initials: LH
authors.lastname: Lim
authors.forename: Nasrin Ghouchi
authors.initials: NG
authors.lastname: Eskandar
authors.forename: Spomenka
authors.initials: S
authors.lastname: Simovic
authors.forename: Clive A
authors.initials: CA
authors.lastname: Prestidge
mesh_terms: D004337:Drug Carriers / Q000138:chemical synthesis*; D045703:Emulsifying Agents / Q000737:chemistry*; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D019344:Lactic Acid / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D009821:Oils / Q000737:chemistry; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011142:Polyvinyl Alcohol / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D045703:Emulsifying Agents; D004655:Emulsions; D009821:Oils; D014867:Water; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011142:Polyvinyl Alcohol