Construction of a plasmid for human brain-derived neurotrophic factor and its effect on retinal pigment epithelial cell viability

Several studies have investigated the protective functions of brain-derived neurotrophic factor（BDNF） in retinitis pigmentosa. However, a BDNF-based therapy for retinitis pigmentosa is not yet available. To develop an efficient treatment for fundus disease, an eukaryotic expression plasmid was generated and used to transfect human 293 T cells to assess the expression and bioactivity of BDNF on acute retinal pigment epithelial-19（ARPE-19） cells, a human retinal epithelial cell line. After 96 hours of co-culture in a Transwell chamber, ARPE-19 cells exposed to BDNF secreted by 293 T cells were more viable than ARPE-19 cells not exposed to secreted BDNF. Western blot assay showed that Bax levels were downregulated and that Bcl-2 levels were upregulated in human ARPE-19 cells exposed to BDNF. Furthermore, 293 T cells transfected with the BDNF gene steadily secreted the protein. The powerful anti-apoptotic function of this BDNF may be useful for the treatment of retinitis pigmentosa and other retinal degenerative diseases.

Preparation and properties of rare earth luminous fiber containing red organic fluorescent pigment

Rare earth luminous fiber was prepared by method of melt spinning. X-ray diffraction （XRD）, scanning electron micros-copy （SEM）, and fluorescence spectrophotometer as well as afterglow brightness tester were used to characterize the resulting sam-ples. Results from XRD and SEM demonstrated that the phase of SrA12O4：Eu2＋,Dy3＋in the fiber was not destroyed in the manufac-turing process and the as-formed luminous fiber consisted of irregular particles. Under ultraviolet excitation, the luminous fiber exhib-ited a yellow-green and orange-red emission band with a maximum at 520 nm and around 600 nm originating from SrAl2O4：Eu2＋, Dy3＋and red organic fluorescent pigments. The energy transfer process was further studied. Furthermore, the emission colors of lu-minous fibers could be tuned from yellow-green to orange-red easily by doping red organic fluorescent pigment, making the materials have potential application in many areas.

Effect of red emitting fluorescent pigment on fluorescent color of SrAl2O4：Eu2＋,Dy3＋ phosphors

Green-blue fluorescence emitting SrAl_2O_4：Eu^（2＋）,Dy^（3＋） phosphors（SAOED） were coated by SiO_2 and a coumarin type red-emitting fluorescent pigment（FP）.The effects of the FP on the morphology,crystal structure,photoluminescence properties and fluorescent color of the SAOED phosphors were systematically investigated by scanning electron microscopy（SEM）,FT-IR,X-ray diffraction（XRD）,photoluminescence spectra and CIE-1931 chromaticity coordinates characterization.Even though the surface of the SAOED phosphors became rough after being coated with SiO_2 and FP,crystal lattice of SrAl_2O_4 did not have any obvious lattice distortions.The photoluminescence spectra indicated that the SAOED phosphors could be used as the excitation light source to excite the FP to emit red fluorescence.The emission spectrum of the FP-coated SAOED consisted of a broad band with two emission peaks at 520 and 610 nm,and its fluorescence emission color was a mixed color of the SAOED phosphors and FP.The fluorescence color of the SAOED/SiO_2/FP composites tended to transfer to red area with the increase of the FP content varying from 0.1%to 0.9%.