Safety and efficacy of intracapsular tranilast microspheres in experimental posterior capsule opacification.
ABSTRACT To evaluate the safety and efficacy of a sustained-release agent designed to reduce posterior capsule opacification (PCO).
Department of Ophthalmology, EENT Hospital, Fudan University, Shanghai, Peoples Republic of China.
Free tranilast (TFree) was incorporated into polylactic acid microspheres and then tested using a rabbit model of PCO. Twenty-nine rabbits were randomized into 5 groups treated with balanced saline solution (BSS control); TFree; or 0.5, 1.0, or 2.0 mg tranilast microspheres (TMicro). Standard phacoemulsification cataract surgery, including manual aspiration of all visible soft lens matter, was performed in all groups. The selected test agent was then injected into the lens capsule. Postoperative clinical examinations were performed at 1, 3, 7, 14, 30, 60, and 90 days. Posterior capsule opacification was quantified using high-resolution computer image analysis at 1, 2, and 3 months. Histological examination was performed at 3 months.
Eyes treated with TMicro had significantly less PCO than the eyes in the BSS and TFree groups. While the BSS control eyes had increased PCO over 3 months, eyes in the TMicro group had reduced PCO over time in a dose-dependent fashion. Histological examination showed reduced lens epithelial cell proliferation in the TMicro groups, with no manifest damage to the cornea, iris, or retina compared with the BSS controls. There was a transient increase in postoperative inflammation in all tranilast-treated groups compared with the BSS controls.
Sustained-release intracapsular tranilast reduced PCO in an experimental model of PCO, suggesting further investigation of its therapeutic potential is justified.
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ABSTRACT: To evaluate efficacy of a neodymium:YAG (Nd:YAG) laser photolysis system in removing lens epithelial cells (LECs) and characterize the effect of the laser on laminin and fibronectin involved in LEC adhesion and migration. Cadaver eyes were evaluated using the Miyake technique. The lenses were removed with phacoemulsification. The modified Nd:YAG laser was used to clean the LECs from the capsule. Only the fornix was cleaned in some eyes and the anterior subcapsular area in other eyes. Some areas were not treated and acted as controls. Standard irrigation/aspiration (I/A) removal of LECs was performed in additional eyes. The eyes were analyzed using light microscopy and immunohistochemical staining. Histopathologic evaluation showed that the laser removed the LECs from the anterior lens capsule and from the fornix. Immunohistochemical staining showed fibronectin and laminin staining in the untreated areas that was absent in the treated areas. Standard I/A removal of the LECs showed absence of cells but persistent laminin and fibronectin. Electron microscopy showed epithelial cells in untreated areas with an absence of the LECs and debris in treated areas. The laser photolysis system removed LECs from the anterior lens capsule and capsule fornix. Along with the cells, laminin, fibronectin, and cell debris remained in the untreated areas but were removed by the treatment. This treatment may be useful in preventing posterior capsule opacification.Journal of Cataract and Refractive Surgery 06/2010; 36(6):1003-10. · 2.75 Impact Factor
Article: Phenolic compounds in oats[Show abstract] [Hide abstract]
ABSTRACT: This research project examined how to treat raw oat material for oat-based food products in order to sustain or increase the levels of phenolic compounds. The focus was mainly on the avenanthramides, which are potentially health beneficial bioactive components found exclusively in oats. A proposed enzymatic decrease in avenanthramide levels when non heat-treated milled oats are steeped in water was investigated. The decrease was strongly suggested to be caused by a polyphenol oxidase. Although the avenanthramides are only found in oats, the polyphenol oxidase enzyme that acted on avenanthramides was also found to be present in wheat, barley and rye. The effects of a highly controlled steeping and germination process on levels of phenolic compounds and related enzyme activities in oats were studied. The process resulted in increased levels of avenanthramides and some unknown compounds to various extents depending on cultivar. This increase was suggested to be partly due to enzymatically catalysed de novo biosynthesis. Whether germination was the reason behind elevated levels of avenanthramides in one harvest year compared with another, in the same oat genotypes, were investigated. The differences in avenanthramide levels between the two years could not be explained by preharvest sprouting of the oat grains in the field. The content and location of tricin was studied in various oat samples. Tricin was found to be localised to oat hulls and was detected and quantified in a minority of all oat samples analysed. The overall conclusion was that germination of oats can be a good method to sustain or increase avenanthramides and other potentially health beneficial phenolic compounds. It is important to inactivate the polyphenol oxidase present in oats and other cereal grain ingredients included in oat-based food products, since it may otherwise decrease the levels of avenanthramides in these products. Oat hulls may be a good source of tricin if high-tricin cultivars are chosen.
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ABSTRACT: To analyze the release kinetics and the clinical and histological effects of UV-cross-linked hyaluronic acid as a release-system for the transforming growth factor β-2 antagonist tranilast with anti-phlogistic properties on intraocular pressure after trabeculectomy in an aggressive scarring animal model. Hyaluronate acid was UV-cross linked and loaded with tranilast. The release of tranilast into a buffered salt solution was assessed spectrophotometrically. Glaucoma filtration surgery, similar to that performed in clinical practice, was performed on chinchilla rabbits. The rabbits were divided in 3 groups. (Group A: trabeculectomy alone, group B: trabeculectomy with a cross-linked hyaluronic acid gel preparation and group C: trabeculectomy with cross-linked hyaluronic gel preparation mixed with tranilast). Antifibrotic efficacy was established by clinical response and histologic examination. The cross-linked gels released tranilast for up to 26 h. The release plotted as a function of the square root of time was consistent with a largely diffusion-controlled release system. Both the gel preparation alone and the gel preparation mixed with tranilast were well tolerated in vivo. No adverse effects such as inflammation, corneal toxicity or blurring of the optical media were observed. The intraocular pressure reached preoperative levels within 9 days after surgery in control animals and group B, but remained significantly reduced (p = 0.00016) in the group with tranilast until day 22. The data of this pilot study suggest that the intraoperative application of UV-crossed linked hyaluronic acid used as a slow release system for tranilast may improve the surgical outcome of glaucoma filtration surgery.Current eye research 06/2012; 37(6):463-70. · 1.51 Impact Factor