Facile synthetic routes for photocatalytic Pb₃(BTC)₂·H₂O coordination polymers

Abstract Herein, we report on the successful synthesis of photocatalytic Pb₃(BTC)₂·H₂O polymers via different methods including the surfactant-assisted hydrothermal method, ultrasonic method and reflux method. As the crystal growth is subjected to preparation atmosphere, changes in reaction conditions do not alter the crystal structures of products, but vary their morphology. High ultraviolet-light-driven photocatalytic abilities are attributed to the stable Pb₃(BTC)₂·H₂O, and the effective productions of h⁺ and ˙OH on the catalysts

y-secretase inhibition of murine choroidal neovascularization is associated with reduction of superoxide and proinflammatory cytokines

PURPOSE. This study aimed to determine whether upregulation of γ-secretase could inhibit laser-induced choroidal neovascularization (CNV) and if this was associated with a reduction in both oxidative stress and proinflammatory cytokines. METHODS. γ-Secretase, or its catalytic subunit presenilin 1 (PS1), were upregulated by exposure to either pigment epithelial derived factor (PEDF) or an AAV2 vector containing a PS1 gene driven by a vascular endothelial-cadherin promoter. Retinal endothelial cells were infected with AAV2 or exposed to PEDF in the presence or absence of VEGF and in vitro angiogenesis determined. Mouse eyes either received intravitreal injection of PEDF, DAPT (a γ-secretase inhibitor) or PEDF + DAPT at the time of laser injury, or AAV2 infection 3 weeks before receiving laser burns. Lesion volume was determined 14 days post laser injury. Superoxide generation, antioxidant activity and the production of proinflammatory mediators were assessed. Knockdown of γ-secretase was achieved using siRNA. RESULTS. γ-Secretase upregulation and PS1 overexpression suppressed VEGF-induced in vitro angiogenesis and in vivo laser-induced CNV. This was associated with a reduction in the expression of VEGF and angiogenin 1 together with reduced superoxide anion generation and an increase in MnSOD compared with untreated CNV eyes. PS1 overexpression reduced proinflammatory factors and microglial activation in eyes with CNV compared with control. siRNA inhibition of γ-secretase resulted in increased angiogenesis. CONCLUSIONS. γ-Secretase, and in particular PS1 alone, are potent regulators of angiogenesis and this is due in part to stabilizing endogenous superoxide generation and reducing proinflammatory cytokine expression during CNV