ABSTRACT
OBJECTIVE@#To prepare vitamin E polyethylene glycol 1000 succinate (TPGS)-modified insulin-loaded liposomes (T-LPs/INS) and evaluate its safety, corneal permeability, ocular surface retention and pharmacokinetics in rabbit eyes.@*METHODS@#The safety of the preparation was investigated in human corneal endothelial cells (HCECs) using CCK8 assay and live/dead cell staining. In the ocular surface retention study, 6 rabbits were randomized into 2 equal groups for application of fluorescein sodium dilution or T-LPs/INS labeled with fluorescein in both eyes, which were photographed under cobalt blue light at different time points. In the cornea penetration test, another 6 rabbits divided into 2 groups for application of Nile red diluent or T-LPs/INS labeled with Nile red in both eyes, after which the corneas were harvested for microscopic observation. In the pharmacokinetic study, 2 groups of rabbits (n=24) were treated with eye drops of T-LPs/INS or insulin, and the aqueous humor and cornea were collected at different time points for measurement of insulin concentrations using enzyme linked immunosorbent assay. DAS2 software was used to analyze the pharmacokinetic parameters.@*RESULTS@#The prepared T-LPs/INS showed good safety in cultured HCECs. Corneal permeability assay and fluorescence tracer ocular surface retention assay demonstrated a significantly higher corneal permeability of T-LPs/INS with a prolonged drug residence in the cornea. In the pharmacokinetic study, insulin concentrations in the cornea at 6, 15, 45, 60, and 120 min (P < 0.01) and in the aqueous humor at 15, 45, 60, and 120 min after dosing were significantly higher in T-LPs/INS group. The changes in insulin concentrations in the cornea and aqueous humor were consistent with a two-compartment model in T-LPs/INS group and with the one-compartment model in the insulin group.@*CONCLUSION@#The prepared T-LPs/INS shows an improved corneal permeability, ocular surface retention capacity and eye tissue concentration of insulin in rabbits.
Subject(s)
Humans , Animals , Rabbits , Insulin , Liposomes , Endothelial Cells , Lipopolysaccharides , Vitamin E , Cornea , FluoresceinABSTRACT
Background Laser in situ keratomileusis (LASIK) is widely applicated to correct the refractive error in ophthalmology nowadays.However,the morphology and structure changes of anterior eye segment caused by the ablation of corneal stroma and suction of negative pressure during surgery should be concerned.Objective This study was to assess the changes of the anterior eye segment parameters and the factors influencing these parameters after LASIK.Methods The clinical data of 59 eyes of 31 patients who received LASIK in Chongqing Medal Eye Institute during May 2012 to July 2013 were retrospectively analyzed.The mean age of the patients was (24.52±8.41) years and the spherical equivalent was (-5.96±3.75) D.The central anterior chamber angle (ACA),anterior chamber volume (ACV),anterior chamber depth (ACD) were measured with Sirius Scheimpflug tomography,and lens thickness (LT) was measured by A-scan before operation and 1,3,6 months after operation.The anterior chamber was divided into anterior and posterior parts by the plane of cornea 4 mm radius area.The ACD of cornea 4 mm radius area sagittal height section (Sag4mm ACD) (the height from posterior corneal vertex to corneal radius of 4 mm plane) and residual ACD (RACD) (the height from corneal radius of 4 mm plane to the anterior lens surface) were computed.The association between ACD and RACD or LT were assessed by Pearson correlation analysis.Results The ACA,ACV,ACD,RACD and LT were significantly different among various time points before and after LASIK (F =8.319,P＜0.05;F =11.596,P＜0.05;F =24.045,P＜0.01;F =16.087,P＜0.05;F =15.333,P＜0.01),and the ACA,ACV,ACD and RACD were significantly decreased 1-6 months after LASIK than those before LASIK (all at P＜0.05).There were no significant differences in the Sag4 mm ACD between pre-and postLASIK (all at P＞0.05).The LT was significantly increased after surgery in comparison with that before surgery (P＜0.01).The positive correlations were found between RACD and ACD before LASIK and in 1,3,6 months after LASIK (r =0.976,0.824,0.724,0.938,all at P＜0.05) and negative correlation between LT and ACD in 3 and 6 months after LASIK (r=-0.344,P＜0.01;r =-0.363,P＜0.01).Conclusions The ACD decrease following LASIK mainly in the sector from the plane of cornea 4 mm radius area to lens surface.The change of ACD might be associated with forward shifting of anterior lens surface caused by enhanced accommodation.
ABSTRACT
Objective To observe the effect of lentivirus vector-medicated enhanced green fluorescence protein (EGFP) transfection on in vitro corneal epithelial cells.Methods Primary corneal epithelial cells of rabbits were cultured and transfected with lentivirus vector into different multiplicity of infection (MOI) in order to find the best transfection dose.After 24,48,72,and 96 h of transfection,expression of EGFP was observed under microscope and detected by RT-PCR.The transfection rate of corneal epithelial cells was calculated in different MOI.Results EGFP was expressed in corneal epithelial cells 48 h after transfection,which increased with the increasing transfection time.The transfection rate of corneal epithelial cells was 4.5%?0.6%,30.4%?0.9%,51.9%?1.4%,and 75.4%?0.7%,respectively,when MOI was 1,10,50,and 100(P