ABSTRACT
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.
ABSTRACT
<p><b>OBJECTIVE</b>To develop an RP-HPLC method for assay of pilocarpine in rabbit ocular aqueous humor.</p><p><b>METHODS</b>The RP-HPLC method was performed on a column of ODS-C(18) with the mobile phase consisting of 0.5% of triethylamine (TEA) of phosphate solutions (10 mmol/L, pH 2.5) and acetonitrile (98/2,v/v). The detection wavelength was 215 nm and flow rate was 1.0 ml/min. Ninety albino rabbits were divided into 3 groups (30 in each):group 1 received 50 microl of eye drops containing 1% generic pilocarpine, group 21% mixture pilocarpine solution consisting of aqueous sample and liposome and group 31% liposome pilocarpine, respectively. The aqueous humor was withdrawn at 5, 10, 30, 40, 60, 90, 120, 180, 240 and 360 min. Pilocarpine was extracted from aqueous humor with dichloromethane.</p><p><b>RESULT</b>The linear calibration curve was obtained in the concentration range of 0.1 - 20 microg/ml. The average recovery was (68.1+/-2.7)% (n=9). Inter-day and intra-day RSD were 4.33% and 2.87%, respectively. In three formations 1% liposome pilocarpine was the best for the areas under curve and measurable amounts.</p><p><b>CONCLUSION</b>The RP-HPLC method is simple and reliable for pilocarpine measurement in ocular aqueous. Liposome formulation can significantly increase the bioavailability of pilocarpine in ocular aqueous.</p>
Subject(s)
Animals , Rabbits , Aqueous Humor , Chemistry , Chemistry, Pharmaceutical , Chromatography, High Pressure Liquid , PilocarpineABSTRACT
<p><b>OBJECTIVE</b>To compare the action of miosis of 1% pilocarpine liposome with 1% pilocarpine solution in rabbits.</p><p><b>METHODS</b>18 white rabbits were randomly divided into 3 groups. Test group received 1% pilocarpine liposome, positive control group received 1% pilocarpine solution, negative control group received liposome. Each eye drop instilled into left eye of rabbits and sterile saline solution instilled into right eye as control. The pupil diameter was measured at time intervals of beginning, 0.25, 0.5, 1, 2, 3, 4, 5, 7 hours.</p><p><b>RESULTS</b>The mean pupil diameter change of 3 groups in both eyes was not significant (P > 0.05) at beginning. The strongest action of miosis took place 0.25 h in positive control group and 0.5 h in test group after instillation. The dilation of pupil in both groups took place 1 h and 3 h, and the restoration of pupil in both groups took place at 5 h and 7 h. The mean pupil diameter of negative control group was not significant in seven hours.</p><p><b>CONCLUSIONS</b>The results suggest that 1% pilocarpine liposome improves the bioavailability and prolong the duration of its action.</p>
Subject(s)
Animals , Female , Male , Rabbits , Delayed-Action Preparations , Liposomes , Pharmacology , Miotics , Pharmacology , Pilocarpine , Pharmacology , Pupil , Random AllocationABSTRACT
OBJECTIVE: To examine the effects and safety of doubled-frequency Nd:YAG laser peripheral iridoplasty(LPI) for angle-closure glaucoma (ACG) with relieving the pupillary block. METHODS: Thirty-seven eyes of 29 patients of ACG with mean intraocular pressure (IOP) of (33.5+/-9.3)mmHg, were treated by LPI. In the follow-up of 5 approximate, equals 35 months, the IOP, angle and complications from LPI were examined. RESULTS: The mean IOP of the patients was reduced to (17.2+/-5.3)mmHg (P<0.0001). Thirty-three eyes of 25 patients, who had negative of dark room provocative test, maintained the angle opened without adjunctive antiglaucoma treatment. Four eyes of 4 patients continued to developed angle closure and had a high IOP. CONCLUSION: Peripheral iridoplasty doubled frequency Nd:YAG laser is a safe and effective method for treatment of ACG.