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High-frequency (20 to 40 MHz) acoustic response of liquid-filled nanocapsules.
- Source :
-
IEEE transactions on ultrasonics, ferroelectrics, and frequency control [IEEE Trans Ultrason Ferroelectr Freq Control] 2014 Jan; Vol. 61 (1), pp. 5-15. - Publication Year :
- 2014
-
Abstract
- Liquid-core nanoparticles are promising candidates for targeted ultrasound-controlled therapy, but their acoustic detection remains challenging. High-frequency (20 to 40 MHz) tone burst sequences were implemented with a programmable ultrasound biomicroscope to characterize acoustic response from perfluorooctyl bromide-core nanoparticles with thick poly(lactide-coglycolide) (PLGA) shells. Radio-frequency signals were acquired from flowing solutions of nanoparticles with two different shell-thickness-to-particle-radius ratios, solid PLGA nanoparticles, and latex nanobeads (linear controls). Normalized fundamental (20 MHz) and second-harmonic power spectral density (PSD) increased with particle concentration and was highest for the thinnest shelled particles. The second- harmonic PSD was detectable from the nanoparticles for peak rarefactional pressures (PRP) from 0.97 to 2.01 MPa at 23 cycles and for tone bursts from 11 to 23 cycles at 2.01 MPa. Their second-harmonic¿to¿fundamental ratio increased as a function of PRP and number of cycles. Within the same PRP and cycle ranges, the second-harmonic¿to¿fundamental ratios from matched concentration solutions of latex nanobeads and solid PLGA nanoparticles was more weakly detectable but also increased with PRP and number of cycles. Nanoparticles were detectable under flow conditions in vitro using the contrast agent mode of a high-frequency commercial scanner. These results characterize linear acoustic response from the nanoparticles (20 to 40 MHz) and demonstrate potential for their highfrequency detection.
- Subjects :
- Contrast Media analysis
Contrast Media chemistry
Contrast Media radiation effects
Diffusion radiation effects
Drug Compounding methods
Fluorocarbons analysis
Lactic Acid chemistry
Lactic Acid radiation effects
Particle Size
Polyglycolic Acid chemistry
Polyglycolic Acid radiation effects
Polylactic Acid-Polyglycolic Acid Copolymer
Radiation Dosage
Solutions
Fluorocarbons chemistry
Fluorocarbons radiation effects
High-Energy Shock Waves
Nanocapsules chemistry
Nanocapsules radiation effects
Sonication methods
Ultrasonography methods
Subjects
Details
- Language :
- English
- ISSN :
- 1525-8955
- Volume :
- 61
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- IEEE transactions on ultrasonics, ferroelectrics, and frequency control
- Publication Type :
- Academic Journal
- Accession number :
- 24402891
- Full Text :
- https://doi.org/10.1109/TUFFC.2014.6689771