Abstract
Purpose: :
Reverse thermal gels are chemicals that readily dissolve in water and undergo phase transition to a hydrogel with changes in ambient temperature. Thermal gels can 1) be designed to undergo gelation at body temperature and 2) be modified to incorporate bio-molecules to guide cell interaction. Thus they have numerous biomedical implications including tissue engineering and drug delivery. In this study, we tested the toxic effects of a novel thermal gel Polyurethane/ Poly-ethylene-glycol (ESHU) on cultured bovine corneal endothelium cells by evaluating cell viability.
Methods: :
Cultured monolayers of primary bovine corneal endothelium were exposed for 24 hours to one of the following 4 liquids: 1) Control (serum-free DMEM), 2) ESHU (15% dilution of DMEM), 3) perfluoron (PFO or perfluoro-n-octane) and 4) a 5000cs silicone oil. After at 1 hr, 12 hr, and 24 hrs viability of cultured corneal endothelium cells was evaluated by immunofluorescent microscopy after staining with Calcein AM, propidium iodide (PI), and Hoechst. Cytotoxicity was calculated as PI nuclei/total nuclei in three separate cultures. Cell morphology was also assessed by microscopy.
Results: :
Cytotoxicity analysis demonstrated that there was no significant damage to cultured corneal endothelium cells by ESHU gel or PFO treatment compared to the control (P>0.05, two- way ANOVA) at each timepoint. Silicone oil treated cultures, however, demonstrated marked cell death at all timepoints when compared to controls (P<0.001, two- way ANOVA) and ESHU gel treatment cultures (P<0.001, two- way ANOVA), with nearly 75% cell death at 24 hours. Qualitatively, corneal endothelium cells treated with ESHU thermal gel for 48 hr showed no evidence of altered cellular morphology on microscopic examination.
Conclusions: :
In this cell culture model, ESHU thermal gel appear safe with respect to limited contact with bovine corneal endothelium, and support a practical role for further investigations of thermal gels in drug delivery.
Keywords: cell survival • retina • cornea: endothelium