[Experimental research of endostatin microcapsules by periocular injection]

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.

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.

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.

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.