Abstract
Purpose :
Nanocarriers have been used in drug delivery to increase the bioavailability of drug and to provide sustained delivery. Liposomes are particularly attractive for ocular drug delivery due to their excellent biocompatibility and non-toxicity. The aim of this work is to investigate the effect of liposome size on transcleral transport.
Methods :
Multilamellar Vesicles (MLVs) were prepared using the thin film hydration technique. Size reduction of the MLVs was performed by subsequent extrusions to form Large Unilamellar Vesicles (LUVs) of desired sizes. Liposomes of different sizes were produced by varying the size of the filter used in extrusion. Porcine sclera was mounted in an Ussing chamber. The liposomes (~1µm and 90nm in size) were fluorescently tagged and used in the donor chamber of an ex vivo Ussing chamber setup, maintained at 37°C. Post transport study, the liposome localization in the tissue was visualized using an epifluorescence microscope.
Results :
A size dependent transport behavior of the liposomes was observed over the study duration of 96 hours ex vivo. MLVs of approximately 1µm in size were found to remain on the episcleral surface and minimal liposome transport was observed through the sclera (average transport of 6.78% of total scleral thickness; SD =2.24%; n=3). LUVs of approximately 90nm were found to transport through a larger part of the sclera (Transport of 45.66% of the total scleral thickness; SD =0.95%; n=3).
Conclusions :
This study shows that transcleral transport of liposomes is dependent on its size.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.