Novel therapies for proliferative retinopathies.

Proliferative retinopathies, such as neovascular age-related macular degeneration and proliferative diabetic retinopathy, are a special health issue due to their contribution to irreversible blindness. Although the promoting conditions and physiopathology of proliferative retinopathies are different, these feature a highly detrimental angiogenesis driven by the overproduction of vascular endothelial growth factor (VEGF). This article describes the mechanism of action of ocular antiangiogenic therapies currently found in clinical development. Systems classify accordingly as (a) novel anti-VEGF systems, (b) molecules targeting non-VEGF pathways, and (c) gene therapies. Whereas most therapies are designed to neutralize VEGF, there is a significant set of products with diverse complexity and mechanism of action. Anti-VEGF therapies are still the most studied approach to tackle angiogenesis. Therapies targeting non-VEGF pathways, however, are highlighted because they could be an option for patients nonresponsive to anti-VEGF therapies. Finally, gene therapy is a promissory technology platform but still is subject to demonstrate safety and efficacy.

Molecular and physical characterization of octenyl succinic anhydride-modified starches with potential applications in pharmaceutics.

Five commercially available starches modified with octenyl succinic anhydride (OSA) are characterized at a molecular, physicochemical and bulk level providing useful data for designing pharmaceutical products. The degree of substitution (DS) of the starches range from 0.017 to 0.032 and their molecular weights (Mw) and radius of gyration (Rz) are lower than those of native starch, suggesting additional modification processes besides the chemical treatment with OSA. The ability of the starches to reduce the water surface tension keeps a direct relationship with the DS and an inverse association with the Mw. Thermal properties, crystallinity assays and morphology evidence that most modified starches characterize by amorphous aggregated structures, possibly generated by gelatinization processes, which favor the flow properties of the powders. Water sorption and surface energy behaviors seem to be related to the number of octenyl succinate (OS) moieties. After dispersion in water, shear-thinning and Newtonian behaviors also depend on the type of OS-starch.

Quantifying the surface properties of enzymatically-made porous starches by using a surface energy analyzer.

The behavior of starch during processing and its performance in products is influenced by the surface energetics/structure of the constituent particles. This work investigates the effect of enzymatically-produced porous maize starch particles on their energetic surface properties using inverse gas chromatography-based surface energy analysis (SEA). Three modified maize starch samples treated with amylase (AM), glucoamylase (AMG) and cyclodextrin-glycosyltransferase (CGT), were used for the study. The dispersive surface energy varied from 36.71 (native) to 43.34 mJ/m2 (AMG < CGT < AM). Enzyme catalysis resulted in porous starches with a more acidic (AMG) and a more basic (AM) surfaces. CGT exhibited similar acid-base balance as native starch but with higher concentration of active sites on the surface. This is the first study on the surface energy of enzymatically-treated porous starch materials using SEA, revealing significant information regarding the surface interactions that can affect performance of food and pharmaceutical products.