Determining Vitreous Viscosity Using Fluorescence Recovery After Photobleaching

Overview

Journal PLoS One

Specialties General Medicine
Science

Date 2022 Feb 10

PMID 35143514

Authors

Nishanthan Srikantha

Yurema Teijeiro-Gonzalez

Andrew Simpson

Naba Elsaid

Satyanarayana Somavarapu

Klaus Suhling

Timothy L Jackson

Affiliations

Soon will be listed here.

Abstract

Purpose: Vitreous humor is a complex biofluid whose composition determines its structure and function. Vitreous viscosity will affect the delivery, distribution, and half-life of intraocular drugs, and key physiological molecules. The central pig vitreous is thought to closely match human vitreous viscosity. Diffusion is inversely related to viscosity, and diffusion is of fundamental importance for all biochemical reactions. Fluorescence Recovery After Photobleaching (FRAP) may provide a novel means of measuring intravitreal diffusion that could be applied to drugs and physiological macromolecules. It would also provide information about vitreous viscosity, which is relevant to drug elimination, and delivery.

Methods: Vitreous viscosity and intravitreal macromolecular diffusion of fluorescently labelled macromolecules were investigated in porcine eyes using fluorescence recovery after photobleaching (FRAP). Fluorescein isothiocyanate conjugated (FITC) dextrans and ficolls of varying molecular weights (MWs), and FITC-bovine serum albumin (BSA) were employed using FRAP bleach areas of different diameters.

Results: The mean (±standard deviation) viscosity of porcine vitreous using dextran, ficoll and BSA were 3.54 ± 1.40, 2.86 ± 1.13 and 4.54 ± 0.13 cP respectively, with an average of 3.65 ± 0.60 cP.

Conclusions: FRAP is a feasible and practical optical method to quantify the diffusion of macromolecules through vitreous.

Citing Articles

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