title: Preparation and evaluation of poly(L-lactide-co-glycolide) (PLGA) microbubbles as a contrast agent for myocardial contrast echocardiography.
abstract: A kind of absorbable PLGA microbubble-based contrast agent (PLGA microspheres with porous or hollow inner structure) was fabricated by an improved double emulsion-solvent evaporation method. The contrast efficiency was evaluated and proved both in vitro and in vivo. By adjusting the polymer concentration and volume of the inner aqueous phase during the fabrication of microbubbles, the inner structure of the microbubbles could be controlled. Both air-filled and perfluoropropane-filled microbubbles can opacify the left ventricle. However, when compared with air-filled microbubbles, perfluoropropane-filled microbubbles can produce significantly longer enhancement in left ventricle in the dog model due to the lower diffusivity and lower solubility of perfluoropropane in blood. A suspension of perfluoropropane-filled PLGA microbubbles (1.8 microm average microbubbles size, 2 x 10(8) microbubbles/mL concentration) has successfully and safely achieved myocardial opacification in closed-chest dogs. A perfusion defect was observed in both of the two dogs with acute myocardial infarction with Power Contrast Imaging (PCI) triggered technology. In the examination of contrast in both ventricular and myocardial opacification, the high mechanical index (MI) was found to have superior contrast sensitivity over the low MI for PLGA-based contrast agents.
authors.affiliation: State Key Laboratory of Polymer Physics & Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100080, People's Republic of China.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Cui
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Bei
authors.forename: Shenguo
authors.initials: S
authors.lastname: Wang
authors.forename: Guang
authors.initials: G
authors.lastname: Zhi
authors.forename: Yuying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xiaoshu
authors.initials: X
authors.lastname: Zhou
authors.forename: Hanwei
authors.initials: H
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000162:Acoustics; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D001673:Biodegradation, Environmental; D003287:Contrast Media / Q000494:pharmacology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004452:Echocardiography / Q000379:methods*; D005466:Fluorocarbons / Q000737:chemistry; D006352:Heart Ventricles / Q000473:pathology*; D019344:Lactic Acid / Q000737:chemistry* / Q000494:pharmacology; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D009206:Myocardium / Q000473:pathology*; D011100:Polyglycolic Acid / Q000737:chemistry* / Q000494:pharmacology; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology; D012997:Solvents; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D001672:Biocompatible Materials; D003287:Contrast Media; D005466:Fluorocarbons; D011108:Polymers; D012997:Solvents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C042852:perflutren