Please use this identifier to cite or link to this item: http://hdl.handle.net/1783.1/59723

Ultrasound-Mediated Transscleral Delivery of Macromolecules to the Posterior Segment of Rabbit Eye In VivoUltrasound-Mediated Transscleral Delivery

Authors Suen, Wai Leung Langston HKUST affiliated (currently or previously)
Wong, Hoi Sang
Yu, Yu HKUST affiliated (currently or previously)
Lau, Chi Ming Laurence HKUST affiliated (currently or previously)
Lo, Amy Cheuk-Yin
Chau, Ying View this author's profile
Issue Date 2013
Source Investigative ophthalmology & visual science , v. 54, (6), 2013, Jun, p. 4358-4365
Summary PURPOSE. This study aims to determine the in vivo effectiveness of low-frequency ultrasound in mediating the transport of macromolecules to the posterior segment of the eye via transscleral route. It investigates if damage is caused by ultrasound at the tested operation parameters on the posterior ocular tissues and visual function. METHODS. Ultrasound (I-SATA = 0.12 W/cm(2), center frequency 40 kHz, 90-second continuous wave) was applied on the sclera of New Zealand white rabbits for one to three cycles. Solution of fluorescent dextran (70 kDa) was placed above sclera during and after ultrasound application to assess transscleral transport of macromolecules. Amount of dextran delivered to vitreous was determined by detection of fluorescence. Visual function of ultrasound-treated rabbits was examined by full-field electroretinography (ffERG). The effect of ultrasound on ocular tissue structures was examined by binocular indirect ophthalmoscope (BIO) and histology. RESULTS. Repeated ultrasound resulted in increasing concentration of dextran, which was otherwise undetectable in the vitreous. Transscleral barrier against dextran transport was restored to original value at 2 weeks postultrasound treatment. Studies from ffERG suggested that electric responses from neural transmission of retinal cells are normal at 1 day, 7 days, and 14 days after ultrasound applications. BIO and histology revealed no structural abnormality in posterior ocular tissues after ultrasound treatment. CONCLUSIONS. Low-frequency ultrasound significantly enhanced the penetration of macromolecules via transscleral route. No undesirable side effects have been found for up to 2 weeks after ultrasound application. The study supports that sonication is a potentially safe and effective method to modulate transscleral barriers for delivering macromolecular therapeutics to posterior segment of the eye.
Subjects
ISSN 0146-0404
Language English
Format Article
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