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Objective To investigate the corneal permeability of cyclosprin A (CsA) loaded on polymeric vector after topical application.Methods The grafted copolymer chitosan-graft-cyclodextrin (CS-g-CD) was synthesized,and the physicochemical structures of the polymer were investigated using nuclear magnetic resonance spectroscopy (NMR) and fourier transform infrared spectroscopy (FT-IR).A novel CsA eye drop was prepared using the grafted copolymer as carrier material.The physicochemical properties of eye drop,including drug-loading content,osmotic pressure and viscosity were investigated by high performance liquid chromatography-mass spectrometry (HPLC-MS),osmotic pressure gauge and viscometer,respectively.New Zealand albino rabbits were randomly divided into intact cornea CsA group,epithelium debrided CsA group and epithelium debrided control group.The corneal epithelia of the left eyes was debrided in the cornea epithelium debrided group.Cornea irritation test was performed on New Zealand albino rabbits.The aqueous humor was taken and the corneas were collected at 0.5 hour and 1 hour after instilled.The concentration of CsA was measured by HPLC-MS.Cy5 labeled vector loaded with Coumarin 6 served as model copolymers system,the penetration capabilities of the double fluorescent labeling copolymers system were monitored in vivo using two-photon scanning fluorescence microscopy on murine corneas after topical application.The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results The polymer of CS-g-CD was successfully synthesized and confirmed using NMR and FT-IR.The drug loading of CsA in eye drop solution was 0.06 ％;the osmotic pressure was 305 mOsmol/kg and the viscosity was 36.5 cP.The CsA drug delivery system had a reversible temperature-sensitive drug release behavior and had no obvious irritation on the eyes of New Zealand rabbits.One hour after treatment,the concentration of CsA in the cornea and aqueous humor of epithelium debrided CsA group was (5.88 ± 1.46) μg/g and (149.19 ± 3.93) ng/ml,respectively,which was significantly higher than (3.98 ±0.95) μg/g and (30.25± 11.43) ng/ml in epithelium debrided control group (both at P＜0.05);the concentration of CsA in the aqueous humor of intact cornea CsA group was (7.23 ± 1.31)ng/ml,which was significantly lower than that in epithelium debrided CsA group (P＜0.05).Polymer vectors were mainly retained in the corneal epithelium,and coumarin 6 gradually diffused into the deep corneal stroma with time.Conclusions The grafted copolymer can load CsA,and the eye drop can effectively overcome the corneal barrier and increase the corneal permeability of CsA.
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Objective To investigate the corneal permeability of cyclosprin A (CsA) loaded on polymeric vector after topical application. Methods The grafted copolymer chitosan.graft.cyclodextrin ( CS.g.CD ) was synthesized, and the physicochemical structures of the polymer were investigated using nuclear magnetic resonance spectroscopy ( NMR) and fourier transform infrared spectroscopy ( FT.IR) . A novel CsA eye drop was prepared using the grafted copolymer as carrier material. The physicochemical properties of eye drop,including drug.loading content, osmotic pressure and viscosity were investigated by high performance liquid chromatography.mass spectrometry ( HPLC.MS) ,osmotic pressure gauge and viscometer,respectively. New Zealand albino rabbits were randomly divided into intact cornea CsA group, epithelium debrided CsA group and epithelium debrided control group. The corneal epithelia of the left eyes was debrided in the cornea epithelium debrided group. Cornea irritation test was performed on New Zealand albino rabbits. The aqueous humor was taken and the corneas were collected at 0. 5 hour and 1 hour after instilled. The concentration of CsA was measured by HPLC.MS. Cy5 labeled vector loaded with Coumarin 6 served as model copolymers system, the penetration capabilities of the double fluorescent labeling copolymers system were monitored in vivo using two.photon scanning fluorescence microscopy on murine corneas after topical application. The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results The polymer of CS.g.CD was successfully synthesized and confirmed using NMR and FT.IR. The drug loading of CsA in eye drop solution was 0. 06 ％;the osmotic pressure was 305 mOsmol/kg and the viscosity was 36. 5 cP. The CsA drug delivery system had a reversible temperature.sensitive drug release behavior and had no obvious irritation on the eyes of New Zealand rabbits. One hour after treatment,the concentration of CsA in the cornea and aqueous humor of epithelium debrided CsA group was (5. 88±1. 46)μg/g and (149. 19±3. 93)ng/ml,respectively,which was significantly higher than (3. 98±0. 95)μg/g and (30. 25±11. 43)ng/ml in epithelium debrided control group (both at P<0. 05);the concentration of CsA in the aqueous humor of intact cornea CsA group was ( 7. 23 ± 1. 31 ) ng/ml, which was significantly lower than that in epithelium debrided CsA group ( P<0. 05 ) . Polymer vectors were mainly retained in the corneal epithelium, and coumarin 6 gradually diffused into the deep corneal stroma with time. Conclusions The grafted copolymer can load CsA,and the eye drop can effectively overcome the corneal barrier and increase the corneal permeability of CsA.
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AIM: To comparatively analyze the application of laser confocal microscopy and corneal smear in the diagnosis of fungal keratitis.METHODS: Totally 77 patients (77 eyes) diagnosed as fungal keratitis were selected.Laser confocal microscopy and corneal smear examination were performed to observe the characteristics of the images, and the detection rate of fungus were compared between the two methods.RESULTS: Of the 77 patients, 66 eyes (86%) were positive and 11 eyes were negative detected by laser confocal microscopy;51 eyes (66%) were positive and 26 eyes were negative detected by corneal smear examination, the difference was statistically significant compared between two group (P<0.05).CONCLUSION: Laser corneal confocal microscopy is relatively safe and sensitive.If combined the application of laser corneal confocal microscopy and corneal smear examination in clinical, the diagnosis rate of fungal keratitis may be improved.
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Objective To investigate the effect of different mechanical environment ( in vivo and in vitro) on expression of basic fibroblast growth factor (bFGF) and explore the role of mechanical stimulation in corneal tissue repair after laser assisted in situ keratomileusis (LASIK) surgery. Methods Animal models by LASIK surgery were established to keep the corneas under different mechanical environment. The experimental animals were killed at the first week or the first month after LASIK surgery to obtain the corneas. In addition, the primary corneal fibroblasts were subjected to cyclic mechanical stretch (0.1 Hz; 5%, 10%, 15% stretch; 6 h or 24 h) using Flexcell 4 000 tension system. Expression of bFGF was determined by ELISA method. Results At the first week after LASIK surgery, expression of bFGF was increased significantly in 30% group (residual stroma bed accounting for 30% of the whole cornea), as compared with the control group (P<0.05), and then it was decreased to the normal level in all groups at the first month after LASIK surgery. Analysis on the same surgery method at different time showed that there were significant differences only in 30% group at the first week and month (P<0.05). Cyclic stretch experiment in vitro indicated that bFGF expression in 15% stretch group was significantly increased after 6 h than that in the control group (P<0.05), with a significant decrease after 24 h (P<0.05). Conclusions Mechanical stimulation can regulate bFGF expression of corneal tissues and corneal frbroblasts, and bFGF plays a positive role in the early corneal tissue repair after LASIK surgery.