Abstract
Purpose: :
The aim of our research was to compare protective activity of 3% trehalose eye drops with 6 different commercially available kinds of eye drops on human corneal epithelium cultured in vitro.
Methods: :
Human epithelial cells in confluent monolayer were covered with 7 kinds of preparations: 1) 3% trehalose, 2) 0,3% hydroksymethylcelulose, unpreserved, 3) hydroxypropyl guar, Polyquad, 4) 0,1% hyaluronic acid, Oxyd, 5) 0,2% hyaluronic acid, BAK, 6) 0,3% hydroksymethylcelulose, dexpanthenol, EDTA, 7) polyvinyl acetate, BAK and PBS as a control. After the time of acute exposition (5, 10 and 20 minutes), preparations were discarded and coverslips were put on air under the fume hood for 0, 5, 15 and 30 minutes. After that, they underwent different tests: live/dead assay kit (Sigma), test on p63 expression and the presence of caspase 3.The membrane functions by neutral red staining were examined. Cells in every chamber were also evaluated in scanning electron microscope (EVO LS15, Zeiss).
Results: :
The desiccation induced apoptosis rate of corneal epithelial cells was significantly lower in sample with trehalose eye drops. Trehalose eye drops allowed cells to survive even after 30 minutes of drying. In these cases ultrastructural examination also confirmed the beneficial influence: cells were of proper shape, with visible nucleoli. Immunofluorescence staining for p63 showed strong signal from nucleuses in these samples. Neutral red dye was successfully absorbed by living cells, confirming the proper function of membranes and endosomal vehicles. We have found also significantly higher apoptosis rate of cultured epithelial cells treated with preparations containing preservatives, especially BAK.
Conclusions: :
Trehalose - based eye drops were the most efficient in corneal protection, keeping cells in proper morphology and function, as well as preventing cellular death from desiccation.
Keywords: cornea: epithelium • drug toxicity/drug effects • apoptosis/cell death