Abstract
Purpose :
Our purpose was to investigate the effect of physicochemical properties on exosomes interactions with glaucoma eye drops in the context of the pathway by which exosomes enter the target cells.
Methods :
Exosomes were isolated by precipitation method and concentrations were determined by Tunable Resistive Pulse Sensing technology. To evaluate the ionic strength (IS) effects on exosomes size and ZP, different PBS buffer strengths, eye drops solutions used for POAG treatment; Alphagan-P®, V-OPTIC®, AZOPT®, Lumigan®, and Travatan®, their active ingredients; Timolol maleate, Brinzolamide or their preservative benzalkonium chloride were analyzed. The size, ZP, and IS of exosomes were measured using NTA and Zeta sizer devices, respectively. The contribution of exosomes interactions to the internalization ratio, regulated by TM cells, was examined at different time points.
Results :
Exosomes size and ZP were affected by the IS of the buffer rather than exosomes type. Commercial glaucoma eye drops including β-blocker, α-2-agonist, and prostaglandin analogs, reduced NPCE exosomes ZP. Whereas, exposure of exosomes to carbonic anhydrase inhibitor caused an increase in the ZP. A correlation was found between increased ZP values and increased NPCE exosomes uptake by TM cells. We were able to show that Benzalkonium chloride stands behind this ZP effect and not Timolol or Brinzolamide.
Conclusions :
Our findings suggest that exosomes size, surface membrane charge, and IS of the surrounding, have an impact on exosomes:exosomes interactions which affect the uptake of NPCE exosomes by TM cells.
This is a 2021 ARVO Annual Meeting abstract.