title: Poly (lactic-co-glycolic acid) particles prepared by microfluidics and conventional methods. Modulated particle size and rheology.
abstract: OBJECTIVE
  Microfluidic techniques are expected to provide narrower particle size distribution than conventional methods for the preparation of poly (lactic-co-glycolic acid) (PLGA) microparticles. Besides, it is hypothesized that the particle size distribution of poly (lactic-co-glycolic acid) microparticles influences the settling behavior and rheological properties of its aqueous dispersions.
  
  
  METHODS
  For the preparation of PLGA particles, two different methods, microfluidic and conventional oil-in-water emulsification methods were employed. The particle size and particle size distribution of PLGA particles prepared by microfluidics were studied as a function of the flow rate of the organic phase while particles prepared by conventional methods were studied as a function of stirring rate. In order to study the stability and structural organization of colloidal dispersions, settling experiments and oscillatory rheological measurements were carried out on aqueous dispersions of PLGA particles with different particle size distributions.
  
  
  RESULTS
  Microfluidics technique allowed the control of size and size distribution of the droplets formed in the process of emulsification. This resulted in a narrower particle size distribution for samples prepared by MF with respect to samples prepared by conventional methods. Polydisperse samples showed a larger tendency to aggregate, thus confirming the advantages of microfluidics over conventional methods, especially if biomedical applications are envisaged.
authors.affiliation: Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, Madrid, 28006, Spain; Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, M5S 3H6, Canada.
authors.forename: Aurora
authors.initials: A
authors.lastname: Perez
authors.affiliation: Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, Madrid, 28006, Spain.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Hernández
authors.affiliation: Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, M5S 3H6, Canada; Present address: Department of Bioengineering, Universidad Carlos III de Madrid, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Velasco
authors.affiliation: Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, M5S 3H6, Canada.
authors.forename: Dan
authors.initials: D
authors.lastname: Voicu
authors.affiliation: Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, Madrid, 28006, Spain; Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, M5S 3H6, Canada. Electronic address: cmijangos@ictp.csic.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Mijangos
mesh_terms: D004655:Emulsions; D019344:Lactic Acid / Q000138:chemical synthesis / Q000737:chemistry*; D044085:Microfluidics; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011100:Polyglycolic Acid / Q000138:chemical synthesis / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012212:Rheology; D014867:Water / Q000737:chemistry
chemical_list: D004655:Emulsions; D014867:Water; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: Microfluidics; Oil-in-water emulsion; Poly (lactic-co-glycolic acid); Rheology; Settling experiments