Huang, DiChen, Ying-ShanThakur, SachinRupenthal, Ilva2017-08-132017-10European Journal of Pharmaceutics and Biopharmaceutics 119:125-136 Oct 20170939-6411https://hdl.handle.net/2292/35062Intravitreal injection is the most common administration route for the treatment of retinal diseases. However, the vitreous and some of the retinal layers themselves act as significant barriers to efficient delivery of drugs administered intravitreally. This study aimed to improve the diffusive mobility of nanoparticles (NPs) in the vitreous and enhance their permeation across the retina after intravitreal injection by application of ultrasound (US). Ex vivo posterior bovine eye cups were used and the vitreous was either left intact or removed gently from the neural retina. Hyaluronic acid coated human serum albumin NPs were administered into the eye cups and continuous US with a frequency of 1 MHz, an intensity of 0.5 W/cm(2), and a duration of 30 s was applied once or repeatedly via the transscleral route. After pre-determined time points, fluorescence intensities in the vitreous and the retina were analyzed. Short pulses of US significantly improved the diffusive mobility of NPs through the vitreous as well as their penetration across the neural retina into the retinal pigment epithelium and choroid without causing any detectable damage to the ocular tissues. Therefore, transscleral US could be a powerful and safe tool to enhance retinal delivery of intravitreally injected NPs.Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher.https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htmhttps://creativecommons.org/licenses/by-nc-nd/4.0/Journal Article10.1016/j.ejpb.2017.06.009Copyright: Elsevier28602870http://purl.org/eprint/accessRights/OpenAccess