title: Preparation and in vitro evaluation of poly(D,L-lactide-co-glycolide) air-filled nanocapsules as a contrast agent for ultrasound imaging.
abstract: The aim of this study was to prepare air-filled nanocapsules intended ultrasound contrast agents (UCAs) with a biodegradable polymeric shell composed of poly(d,l-lactide-co-glycolide) (PLGA). Because of their size, current commercial UCAs are not capable of penetrating the irregular vasculature that feeds growing tumors. The new generation of UCAs should be designed on the nanoscale to enhance tumor detection, in addition, the polymeric shell in contrast with monomolecular stabilized UCAs improves the mechanical properties against ultrasound pressure and lack of stability. The preparation method of air-filled nanocapsules was based on a modification of the double-emulsion solvent evaporation technique. Air-filled nanocapsules with a mean diameter of 370±96nm were obtained. Electronic microscopies revealed spherical-shaped particles with smooth surfaces and a capsular morphology, with a shell thickness of ∼50nm. Air-filled nanocapsules showed echogenic power in vitro, providing an enhancement of up to 15dB at a concentration of 0.045mg/mL at a frequency of 10MHz. Loss of signal for air-filled nanocapsules was 2dB after 30min, suggesting high stability. The prepared contrast agent in this work has the potential to be used in ultrasound imaging.
authors.affiliation: Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Mexico. nestormm05@hotmail.com
authors.forename: Mendoza-Muñoz
authors.initials: MM
authors.lastname: Néstor
authors.forename: Noriega-Peláez Eddy
authors.initials: NP
authors.lastname: Kei
authors.forename: Nava-Arzaluz María
authors.initials: NA
authors.lastname: Guadalupe
authors.forename: Mendoza-Elvira Susana
authors.initials: ME
authors.lastname: Elisa
authors.forename: Ganem-Quintanar
authors.initials: GQ
authors.lastname: Adriana
authors.forename: Quintanar-Guerrero
authors.initials: QG
authors.lastname: David
mesh_terms: D000388:Air; D001639:Bicarbonates / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D003287:Contrast Media / Q000138:chemical synthesis*; D004655:Emulsions / Q000737:chemistry; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000737:chemistry*; D008854:Microscopy, Electron; D053769:Nanocapsules / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012997:Solvents / Q000737:chemistry; D014463:Ultrasonography
chemical_list: D001639:Bicarbonates; D001672:Biocompatible Materials; D003287:Contrast Media; D004655:Emulsions; D053769:Nanocapsules; D012997:Solvents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C027043:ammonium bicarbonate