title: Acoustic characterization of a new trisacryl contrast agent. Part I: In vitro study.
abstract: The objective of the study was to acoustically characterize trisacryl polymeric microparticles (TMP), which are derived from biocompatible embolic agents. With significant acoustic properties, these polymeric particles could be potentially used as targeted ultrasound contrast agents, directed towards a specific site, with ligands conjugation on the polymeric network surface. In the in vitro study, a pulser/receiver (PRF of 1 kHz), associated to different transducers (5, 10 and 15 MHz), was used to measure the acoustic properties of the TMP inserted in a Couette flow device. Acoustic characterization according to TMP concentration (0.12-15.63 mg/ml), frequency (4.5-17 MHz, defined by each transducer bandwidth), ultrasound pressure (137-378 kPa) and exposure time (0-30 min) was conducted. Particle attenuation was also evaluated according to TMP concentration and emission frequency. Backscattering increased non linearly with concentration and maximum enhancement was of 16.4 dB+/-0.89 dB above 7.8 mg/ml. This parameter was found non-linear with increasing applied pressure and no harmonic oscillation could be noticed. Attenuation reached approximately 1.4 dB/cm at 15 MHz and for the 15.6 mg/ml suspension. The TMP have revealed in vitro ultrasound properties comparable to those observed with known contrast agents, studied in similar in vitro systems. However, such set-ups combined with a rather aqueous suspending medium, have some limitations and further investigations need now to be conducted to approach in vivo conditions in terms of flow and blood environment.
authors.affiliation: University Paris-Sud, Imaging Department and UPRES EA4040, 39 Rue Camille Desmoulins, Orsay, F-91405, Institut Gustave Roussy, 94805 Villejuif Cedex, France.
authors.forename: Sonia
authors.initials: S
authors.lastname: Lavisse
authors.forename: Valerie
authors.initials: V
authors.lastname: Rouffiac
authors.forename: Pierre
authors.initials: P
authors.lastname: Peronneau
authors.forename: Angelo
authors.initials: A
authors.lastname: Paci
authors.forename: Celine
authors.initials: C
authors.lastname: Chaix
authors.forename: Philippe
authors.initials: P
authors.lastname: Reb
authors.forename: Alain
authors.initials: A
authors.lastname: Roche
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lassau
mesh_terms: D000162:Acoustics; D000180:Acrylic Resins / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D066298:In Vitro Techniques; D010316:Particle Size
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D003287:Contrast Media; C496735:trisacryl gelatin microspheres; D005780:Gelatin