Permeation kinetics of dimethyl sulfoxide in porcine corneoscleral discs

Sergio Enrique Tapia Lishner; Leah A Marquez-Curtis; Janet A W Elliott

doi:10.1016/j.cryobiol.2023.104566

Permeation kinetics of dimethyl sulfoxide in porcine corneoscleral discs

Cryobiology. 2023 Dec:113:104566. doi: 10.1016/j.cryobiol.2023.104566. Epub 2023 Aug 11.

Authors

Sergio Enrique Tapia Lishner¹, Leah A Marquez-Curtis², Janet A W Elliott³

Affiliations

¹ Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada.
² Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
³ Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada. Electronic address: janet.elliott@ualberta.ca.

PMID: 37572874
DOI: 10.1016/j.cryobiol.2023.104566

Abstract

The cornea is the transparent tissue in front of the eye that bends light to help the eye focus. More than five million people's vision can be restored by a corneal transplant (keratoplasty), but there is a scarcity of suitable donor tissue. Cryopreservation could potentially increase the on-demand availability of corneas by reducing expiration and contamination during hypothermic storage, and allow equitable distribution. Understanding the transport of water and cryoprotectants across the tissue is important in developing effective cryopreservation protocols. Here, we first measured the shrinking and swelling kinetics at 22 °C and 0 °C of porcine corneoscleral discs when exposed to phosphate-buffered saline and to a cryoprotectant vehicle solution containing 2.5% chondroitin sulfate and 1% dextran. Other valuable measurements were made including the density and osmolality of the vehicle solution at 0 °C, and the water fraction of porcine cornea and sclera. Using the knowledge gained from this first part to minimize background swelling, we then examined permeation kinetics of dimethyl sulfoxide (Me₂SO) in porcine corneoscleral discs at 0 °C, the temperature at which cryoprotectant loading typically occurs. The concentration data obtained as a function of time were fitted to a Fick's law model of one-dimensional diffusion to measure an effective diffusion coefficient of Me₂SO, which was found to be 5.306×10^-11 m²/s. We further quantified permeation kinetics of Me₂SO in sclera alone at 0 °C to support our hypothesis that our measurements for corneoscleral discs will not be affected by the presence of the sclera. The obtained effective diffusion coefficient can be used in modelling aimed at developing cryopreservation protocols that minimize the exposure time of the corneas during the cryoprotectant loading step.

Keywords: Chondroitin sulfate; Cornea; Dextran; Diffusion coefficient; Dimethyl sulfoxide; Pig; Sclera; Shrinking and swelling kinetics.

MeSH terms

Animals
Cornea
Cryopreservation* / methods
Cryoprotective Agents / pharmacology
Dimethyl Sulfoxide*
Humans
Swine
Water

Substances

Dimethyl Sulfoxide
Cryoprotective Agents
Water