title: The fabrication of novel nanobubble ultrasound contrast agent for potential tumor imaging.
abstract: Novel biocompatible nanobubbles were fabricated by ultrasonication of a mixture of Span 60 and polyoxyethylene 40 stearate (PEG40S) followed by differential centrifugation to isolate the relevant subpopulation from the parent suspensions. Particle sizing analysis and optical microscopy inspection indicated that the freshly generated micro/nanobubble suspension was polydisperse and the size distribution was bimodal with large amounts of nanobubbles. To develop a nano-sized contrast agent that is small enough to leak through tumor pores, a fractionation to extract smaller bubbles by variation in the time of centrifugation at 20g (relative centrifuge field, RCF) was suggested. The results showed that the population of nanobubbles with a precisely controlled mean diameter could be sorted from the initial polydisperse suspensions to meet the specified requirements. The isolated bubbles were stable over two weeks under the protection of perfluoropropane gas. The acoustic behavior of the nano-sized contrast agent was evaluated using power Doppler imaging in a normal rabbit model. An excellent power Doppler enhancement was found in vivo renal imaging after intravenous injection of the obtained nanobubbles. Given the broad spectrum of potential clinical applications, the nano-sized contrast agent may provide a versatile adjunct for ultrasonic imaging enhancement and/or treatment of tumors.
authors.affiliation: Nanobiotechnology Division, State Key Laboratory of Urban Water Resources and Environment, School of Sciences, Harbin Institute of Technology, Harbin, People's Republic of China.
authors.forename: Zhanwen
authors.initials: Z
authors.lastname: Xing
authors.forename: Jinrui
authors.initials: J
authors.lastname: Wang
authors.forename: Hengte
authors.initials: H
authors.lastname: Ke
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.forename: Xiuli
authors.initials: X
authors.lastname: Yue
authors.forename: Zhifei
authors.initials: Z
authors.lastname: Dai
authors.forename: Jibin
authors.initials: J
authors.lastname: Liu
mesh_terms: D000818:Animals; D002498:Centrifugation; D003287:Contrast Media / Q000138:chemical synthesis*; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D007668:Kidney / Q000000981:diagnostic imaging; D008297:Male; D049329:Nanostructures / Q000737:chemistry*; D009369:Neoplasms / Q000000981:diagnostic imaging*; D010316:Particle Size; D011817:Rabbits; D013535:Suspensions; D013997:Time Factors; D014465:Ultrasonics; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D013535:Suspensions