title: A novel technology: microfluidic devices for microbubble ultrasound contrast agent generation.
abstract: Microbubbles are used as ultrasound contrast agents, which enhance ultrasound imaging techniques. In addition, microbubbles currently show promise in disease therapeutics. Microfluidic devices have increased the ability to produce microbubbles with precise size, and high monodispersity compared to microbubbles created using traditional methods. This paper will review several variations in microfluidic device structures used to produce microbubbles as ultrasound contrast agents. Microfluidic device structures include T-junction, and axisymmetric and asymmetric flow-focusing. These devices have made it possible to produce microbubbles that can enter the vascular space; these microbubbles must be less than 10 μm in diameter and have high monodispersity. For different demands of microbubbles production rate, asymmetric flow-focusing devices were divided into individual and integrated devices. In addition, asymmetric flow-focusing devices can produce double layer and multilayer microbubbles loaded with drug or biological components. Details on the mechanisms of both bubble formation and device structures are provided. Finally, microfluidically produced microbubble acoustic responses, microbubble stability, and microbubble use in ultrasound imaging are discussed.
authors.affiliation: School of Pharmaceutical Sciences, Central South University, 172 Tongzipo Road, Changsha, 410013, Hunan, China.
authors.forename: Hangyu
authors.initials: H
authors.lastname: Lin
authors.affiliation: School of Pharmaceutical Sciences, Central South University, 172 Tongzipo Road, Changsha, 410013, Hunan, China.
authors.forename: Junfang
authors.initials: J
authors.lastname: Chen
authors.affiliation: School of Pharmaceutical Sciences, Central South University, 172 Tongzipo Road, Changsha, 410013, Hunan, China. ccpin2000@hotmail.com.
authors.forename: Chuanpin
authors.initials: C
authors.lastname: Chen
mesh_terms: D000162:Acoustics; D003287:Contrast Media; D004867:Equipment Design; D006801:Humans; D056656:Lab-On-A-Chip Devices; D045423:Microbubbles; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: Flow-focusing; Microbubbles; Microfluidics; T-junction; Ultrasound contrast agent