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Background Hyaluronic acid is a mucopolysaccharide existing in extracellular matrix and having good biocompatibility.Using chemical crosslinking method can improve the physical properties of the material,so cross-linked hyaluronic has potential clinical application value.Objective The present study was to evaluate the histocompatibility and biological security of cross-linked hyaluronic acid as ophthalmic implant material.Methods Cross-linked hyaluronic acid implant material was prepared according to the criteria of Biological Evaluation of Medical Devices (GB/T16886.5-2003).Eighteen 8-week-old male New Zealand white rabbits were randomized into the experimental group and the control group.Cross-linked hyaluronic acid material with 5.0 mm diameter was implanted into corneal stroma interlaminationally in the experimental group,and only corneal stromal interlaminational pocket was made without any implanting material in the control group.Biological response of cornea was assessed in vivo from 1 week through 3 months after operation by slit lamp microscope.The corneas were obtained 2 weeks,1 month and 3 months respectively for histopathological examination.Mouse embryonic fibroblasts were cultured in cross-linked hyaluronic acid film plate,medical silicone material culture plate and regular culture plate respectively for 24 hours,and the cell growth state and morphology were observed under the inverted microscope and scan electron microscope.MTT assay was used to test the relative growth rate of the cultured cells 48 hours after cultured using extracted liquid of hyaluronic acid implant material.Results Cross-linked hyaluronic acid implant material showed a well healing to the corneas of rabbits during the observation duration,without obvious inflammatory response and neovascularization.The arrangement of stromal fibers was uniform in order,and no infiltration of inflammatory cells was seen under the light microscope.The cells grew well after cultured with cross-linked hyaluronic acid film and regular medium for 24 hours,but in the silicone culture group,fewer of adherent cells and more floating cells were found.The relative growth rate of the cells was 87.50％ 48 hours after cultured with extracted liquid of hyaluronic acid implant material.Conclusions The cross-linked hyaluronic acid material has good histocompatibility and biological security in rabbit cornea tissue.
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In order to investigate the effect of curcumin on proliferation and apoptosis of human pterygium fibroblasts (HPF) in culture and search for a new method to prevent the recurrence after pterygium surgery, HPF was incubated with 0-160 μmol/L curcumin for 24-96 h. The MTT method was used to assay the biologic activities of curcumin at different time points and different doses. The expression of proliferating cell nuclear antigen (PCNA) in each group was detected by immunohistochemistry. The cell cycle distribution was detected by flow cytometry (FCM). Administration of 20-80 μmol/L curcumin for 24-72 h could significantly inhibit HPF proliferation in a dose- and time-dependent manner (P＜0.05). After treatment with curcumin at different concentrations of 20, 40, 80 and 160 μmol/L for 24 h, FCM revealed there was a significant sub-G1 peak at each concentration. The number of HPF in G0/G1 phase was increased, while in S phase, it was decreased (P＜0.05). At the concentration of 20-80 μmol/L, curcumin, in a dose-dependent manner (P＜0.05), could inhibit the expression of PCNA in HPF. It was suggesterd that curcumin could significantly inhibit the proliferation of HPF, make HPF arrest in G0/G1 phase and induce the apoptosis of HPF in a dose- and time-dependent manner.
RÉSUMÉ
In order to investigate the effect of curcumin on proliferation and apoptosis of human pterygium fibroblasts (HPF) in culture and search for a new method to prevent the recurrence after pterygium surgery, HPF was incubated with 0-160 micromol/L curcumin for 24-96 h. The MTT method was used to assay the biologic activities of curcumin at different time points and different doses. The expression of proliferating cell nuclear antigen (PCNA) in each group was detected by immunohistochemistry. The cell cycle distribution was detected by flow cytometry (FCM). Administration of 20-80 micromol/L curcumin for 24-72 h could significantly inhibit HPF proliferation in a dose-and time-dependent manner (P<0.05). After treatment with curcumin at different concentrations of 20, 40, 80 and 160 micromol/L for 24 h, FCM revealed there was a significant sub-G1 peak at each concentration. The number of HPF in G0/G1 phase was increased, while in S phase, it was decreased (P<0.05). At the concentration of 20-80 micromol/L, curcumin, in a dose-dependent manner (P<0.05), could inhibit the expression of PCNA in HPF. It was suggested that curcumin could significantly inhibit the proliferation of HPF, make HPF arrest in G0/G1 phase and induce the apoptosis of HPF in a dose-and time-dependent manner.
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AIM: In order to search carrier material and better tissue culture method, the morphology and structure of the cultured cat corneal endothelium was observed. METHODS: The cat corneal endothelial cells were seeded on the Descemet's membrane of the dehydrated swine corneal stroma, and then cultured in the medium with epidermal growth factor and laminin for 7 days. The morphology and structure of reconstructed tissue was tested by the inverted microscope and the scanning electron microscope. RESULTS: As shown by the morphological observations, the cultured cat corneal endothelial cells formed an integrated membrane, and attached to the Descemet's membrane, which was similar to the nature tissue. The cells connected tightly to each other, and some of them arranged in hexagon approximately. CONCLUSION: The cat corneal endothelial cells could be rebuilt on the carrier of the dehydrated swine corneal stroma successfully, which is similar to the nature tissue.
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0.05). (2) In the total 12 rabbits, all the cornea grafts survived without rejection reaction, corneal haze or corneal neovascularization. The fresh grafts got transparent after 2 months, and the dehydrated grafts got transparent after 6 months. Histological study demonstrated both fresh and dehydrated stroma grafts had fused with rabbits'corneal stroma very well without lymphocytes infiltrating. (3) As shown in histological observations, the reconstructed cat corneal endothelial tissue was similar to the nature tissue. Cultured cat endothelial cells connected tightly to each other and attached to the Descemet's membrane closely. CONCLUSION: Swine corneal stroma has low immunogenicity and satisfying biocompatibility,it is an ideal biological carrier for cornea reconstruction in vitro.