Table 10.

summary of the effect of ultrasound on the delivery of various tracer molecules with differing physicochemical properties.

Ref	Changing factor	Route of delivery	- ultrasound	+ ultrasound
			Effect
70	Charge & Lipophilicity	Transcorneal	After 60 minutes coincubation, the negatively charged (-2), mildly lipophobic sodium fluorescein and the negatively charged (-2), and comparatively lipophilic dexamethasone sodium phosphate achieved moderate (5 x 10-7 cm/s) and poor (0.11 x 10-7 cm/s) transcorneal permeability, respectively, whilst positively charged (+5), severely lipophobic tobramycin achieved a higher 25 x 10-7 cm/s permeability.	After 5 minutes of 400 kHz ultrasound, and 60 minutes coincubation, tobramycin permeability increased by 5 x 10-7 cm/s, dexamethasone permeability increased by 127% to 0.25 x 10-7 cm/s, and fluorescein permeability increased by 149% to 12 x 10-7 cm/s.
69	Lipophilicity	Transscleral	Corneal permeability of all beta blockers tested was limited to 0.4-1.2 x 10-5 cm/s after 60 minutes coincubation.	Ultrasound increased the permeability of all tested beta blockers after 60 minutes of ultrasound, however, highly lipophilic beta blockers showed improved permeability compared to less lipophilic beta blockers.
72	weight	Transscleral	After 15 minutes coincubation, the penetration depth of 20kDa FITC-dextrans was greater than larger 70 kDa and 150 kDa dextrans at 100, 60 and 50 µm, respectively.	Transscleral penetration of FITC-dextrans appeared inversely proportional to size, with 20 kDa, 70 kDa and 150 kDa dextrans achieving penetration distances of 360, * 300 and 178 µm, respectively.
64	diameter	V/VR	PEGylated polystyrene nanospheres with a hydrodynamic diameter of 52, 131 and 218 nm achieved poor vitreoretinal uptake into RPE cells after 2-4 hours coincubation.	52 nm nanospheres achieved an RPE cell uptake 17-fold higher compared to control after 30 s ultrasound. 131 nm nanospheres required 120 s of ultrasound to achieve a 9.4-fold increase in cell uptake, whilst larger 218 nm nanospheres failed to improve their delivery even after 120 s sonication and 2-4 hours of coincubation.

*The 20kDa dextrans were delivered through the entire scleral thickness.