INTRODUCTION: Chemical and enzymatic methods have been used to remove endogenous cellular components from xenografts.Unfortunately,these methods can introduce process residues that can cause bioincompatibility and increase the likelihood of graft rejection.A more benign method is needed to produce biocompatible xenograft corneas.Application of supercritical carbon dioxide(scCO2)fluid in tissue de-cellularization has been reported.Here we compare porcine corneas decellularized using the scCO2 process to corneas decellularized using Triton X-100.METHODS: Corneas were harvested from porcine eye balls and soaked sequentially in reverse osmosis water and sodium chloride(NaCl)solution.Finally,NaCl solution-treated corneas were subjected to scCO2 extraction in a high-pressure reaction apparatus(Applied Separations Inc.)to complete the de-cellularization procedure.For the Triton X-100 procedure,corneas were incubated in 0.2%Triton X-100 for 6 hours after NaCl treatment.Decellularization was assessed by histology.Decellularized corneas were tested for tissue porosity,absorbency,and tensile strength.Biocompatibility was assessed in cell cultures and in animal studies.Safety and performance were assessed in a rabbit cornea transplantation model.DISCUSSION & CONCLUSIONS: Both methods successfully removed endogenous corneal cells,as verified by histology.In terms of physical characteristics,scCO2–processed corneas had greater absorbency(25.22±4.11 vs.14.33±3.45 g/100m2; p<0.05)but lower tensile strength(stress max.load: 0.51 vs.0.95 MPa)in comparison to Triton X-100-treated tissues.In vitro cell growth assay showed better cell attachment and proliferation on scCO2-processed scaffolds.When tested for bioburden,no microbial contamination was found on scCO2-processed corneas while Triton X-100-processed corneas were contaminated.Terminal sterilization by gamma irradiation had no effect on cornea absorbency regardless of the process methods.With the exception of material tensile strength,scCO2-processed corneas were equal or superior to Triton X-100-treated corneas in all areas of measurement.ScCO2 is a promising tissue processing technology worth further exploration.