title: [Aolymer-encapsulated microbubble contrast agent: preparation and in vitro echogenic characteristics].
abstract: OBJECTIVE
  To prepare an ultrasound microbubble contrast agent using PLLA-PEG-PLLA copolymer as the shell material, and test their acoustic characteristics in vitro.
  
  
  METHODS
  PLLA-PEG-PLLA tri-block co-polymers were synthesized by ring-opening polymerization. Microbubbles were prepared by using double emulsion technique. Light microscope and scanning electron microscope were applied to observe the morphology of the microbubbles. Their size distribution was analyzed using MASTERSIZER 2000. The acoustic characteristics of microbubbles were tested by using color Doppler Ultrasonography.
  
  
  RESULTS
  Microbubbles were well dispersed in water. Contrast enhancement was stronger and longer lasting at low mechanical index.
  
  
  CONCLUSIONS
  The polymer-encapsulated microbubbles prepared by using double emulsion technique with PLLA-PEG-PLLA as the shell material can be used as an ultrasound contrast agent.
authors.affiliation: State Key Laboratory of Polymer Materials and Engineering of China, College of Polymer Science and Engineering, Chengdu 610064, China.
authors.forename: Qiao-Feng
authors.initials: QF
authors.lastname: Jin
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhong
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Luo
mesh_terms: D003287:Contrast Media / Q000737:chemistry*; D004339:Drug Compounding; D007773:Lactates / Q000737:chemistry; D045423:Microbubbles; D011091:Polyesters / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D018615:Ultrasonography, Doppler, Color / Q000379:methods*
chemical_list: D003287:Contrast Media; D007773:Lactates; D011091:Polyesters; C088513:poly(lactic acid-ethylene glycol); D011092:Polyethylene Glycols; C033616:poly(lactide)