RESUMO
OBJECTIVE: To detect the release of endostatin in microcapsules of calcium alginate gel by emulsification-internal gelatification technology, to observe the distribution of Endostatin microcapsules in the eye by periocular injection and biocompatibility. METHODS: The calcium alginate gel microcapsules encapsulating endostatin were prepared by emulsification-internal gelatification technology, the release of endostatin in microcapsules in vitro was examined by uv-Spectrophotometry. 32 SD mice were divided into randomly four groups: group A, periocular injection of endostatin microcapsules 20 microl (2.4 g/L); group B, periocular injection of endostatin protein 20 microl (2.5 g/L); group C, periocular injection of null-Microcapsules 20 microl; group D, periocular injection of saline 20 microl. Western blot, immunohistochemical and enzyme-linked immunosorbent assay were used. Protein expression and pathology of the heart, liver, spleen, lung, kidney and periocular tissue were examined. Daily activities and eating condition were observed.t-test was used to analyze the data. RESULTS: SDS polyacrylamide gel electrophoresis showed strap of ES protein. Concentration of ES protein in superior schedule fluid gradually increased at 3, 7, 14, 21 days. A group: ES protein expression were observed in inner nuclear layer, outer nuclear layer and RPE lamina after periocular injection 7 or 14 days. B group: ES protein expression were observed in above tissues at 7 days, but not at 14 days. C and D group: ES protein expression were not observed in above tissues at 7 or 14 days. The results showed that Endostatin microcapsules was able to pass through the sclera and spread out in various retinal tissues. Concentration of endostatin in the homogenates of eyeball was (63.16 +/- 7.64) microg.L(-1).eye(-1) and (33.2 +/- 5.77) microg.L(-1).eye(-1) respectively after one and two weeks in A group, but (33.2 +/- 2.89) microg.L(-1).eye(-1) and (15.73 +/- 2.08) microg.L(-1).eye(-1). The concentration of endostatin was significant difference in two group, A group was obviously larger than B group (t = 6.364 and 4.920, P = 0.003 and 0.008 respectively). Periocular administration. Daily activities and eating condition were normal. The abnormality in important organs were not detected by pathologic examination. CONCLUSIONS: Endostatin microcapsules is able to release persistently, to pass through the sclera and spread out in various retinal tissues. There were good biocompatibility and not ill effect remarkably.