Use of poloxamers for deswelling of organ-cultured corneas.
OBJECTIVE
Dextran T500, routinely used as a deswelling supplement in organ culture (OC), has been suspected of being toxic to corneal endothelial cells (ECs). This study was conducted to evaluate the innovative use of poloxamers compared with dextran for deswelling OC corneas.


METHODS
Five poloxamers (P124, P188, P237, P338, and P407) were dissolved respectively in a standard OC medium to reach 350 mOsmol/kg. In vitro cytotoxicity of these media was tested by MTT assay on human corneal epithelial and endothelial cell lines and on primary human corneal fibroblasts. Paired human corneas stored in OC for at least 21 days were assigned for 48 hours to a poloxamer medium or to a standard deswelling medium containing 5% dextran T500. Corneal EC density, morphometry, visualization, mortality, stromal thickness, transparency, and folding were evaluated before and after deswelling. Corneas were finally cut into three parts for histologic and ultrastructural observation.


RESULTS
Besides similar corneal transparency improvement and thickness deswelling, poloxamers (except P124) reduced EC loss and facilitated endothelial visualization, but improved stromal folding less than dextran. The similar ultrastructures observed in the two groups were epithelial shedding, normal collagen fiber diameter and organization, uptake of deswelling agents by ECs, vacuolization but normal organelles in ECs and keratocytes, and endothelial surface modifications.


CONCLUSIONS
P188, P237, P338, and P407 performed similarly in preserving ECs, improving EC visualization, deswelling corneal stroma and inducing moderate injuries to corneal ultrastructure. They appear superior to dextran for corneal deswelling in OC.
Zhao
Min
M
Corneal Graft Biology, Imaging and Engineering Laboratory, Faculty of Medicine, University Jean Monnet, Saint-Etienne, France.
Thuret
Gilles
G
Piselli
Simone
S
Pipparelli
Aurelien
A
Acquart
Sophie
S
Peoc'h
Michel
M
Dumollard
Jean-Marc
JM
Gain
Philippe
P
D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea; D015715:Corneal Edema / Q000517:prevention & control*; D003911:Dextrans / Q000494:pharmacology / Q000633:toxicity; D004728:Endothelium, Corneal / Q000187:drug effects; D019573:Epithelium, Corneal / Q000187:drug effects; D005260:Female; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009924:Organ Culture Techniques; D009926:Organ Preservation / Q000379:methods; D009994:Osmolar Concentration; D020442:Poloxamer / Q000494:pharmacology* / Q000633:toxicity; D013501:Surface-Active Agents / Q000494:pharmacology* / Q000633:toxicity
D003911:Dextrans; D013501:Surface-Active Agents; D020442:Poloxamer