New formulations of Polysaccharide-based Hydrogels for Drug Release and Tissue Engineering

Polysaccharide-based hydrogels are very promising materials for a wide range of medical applications, ranging from tissue engineering to controlled drug delivery for local therapy. The most interesting property of this class of materials is the ability to be injected without any alteration of their chemical, mechanical and biological properties, by taking advantage of their thixotropic behavior. It is possible to modulate the rheological and chemical-physical properties of polysaccharide hydrogels by varying the cross-linking agents and exploiting their thixotropic behavior. We present here an overview of our synthetic strategies and applications of innovative polysaccharide-based hydrogels: hyaluronan-based hydrogel and new derivatives of carboxymethylcellulose have been used as matrices in the field of tissue engineering; while guar gum-based hydrogel and hybrid magnetic hydrogels, have been used as promising systems for targeted controlled drug release. Moreover, a new class of materials, interpenetrating hydrogels (IPH), have been obtained by mixing various native thixotropic hydrogels

Biochemical and molecular profiling of unknown olive genotypes from central Italy: determination of major and minor components

The phenotypic and genetic variability of local olives in a perspective of diversity conservation should be maintained and preserved. Fourteen unknown olive genotypes were selected from abandoned and isolated plants in Umbria region and characterized by ten SSR markers. The molecular analysis led to identify ten previously unknown genotypes within the patrimony of the region, made up by about 10 main cultivars and more than 100 minor ones. Fruit samples were randomly collected from the selected plants during two growing seasons and oil was extracted from each sample. Analyses of fatty acid composition, phenolic profile (flavonoids, phenolic acids, phenolic alcohols and lignans), tocopherols, squalene and sterols were performed on these oils. Significant differences were observed in terms of main fatty acids (e.g. oleic acid from 71.83 to 76.73%), but not for the minor ones. The important differences were instead obtained on the amount of α-tocopherol, ranging from 149 to 583 mg kg−1, and on squalene, spanning from 1059 to 5447 mg kg−1. Evaluation of major and minor compounds with the principal component analysis of the main oil quality parameters revealed differentiation according to the genotypes. The analysis of neglected olive genotypes from a small area of cultivation has led to the identification of a promising source of variability for most sought-after traits, which could be exploited for new olive plantations and to magnify the spectrum of local olive oils

Effects of long-term nitrogen addition and atmospheric nitrogen deposition on carbon accumulation in Picea sitchensis plantations

This study aimed to assess the combined effects of long-term nitrogen (N) supply and nitrogen deposition (Ndep) on carbon (C) accumulation within Sitka spruce [Picea sitchensis (Bong.) Carr.] plantations in Scotland. Six study sites established from 1970 to 1982 were periodically N-fertilized, monitored over time and commonly surveyed in 2010. Soil, aboveground biomass, and ground vegetation C stock changes were analyzed; aboveground C stocks were correlated with total additional N experienced at each site, that is, the sum of experimental N supply (Nadd) and site-specific accumulated Ndep from 1900 to 2010. Results showed a positive N effect on aboveground tree C stock and no decline in tree growth was observed either during fertilization or after the latest N addition. The amount of C in litter was significantly higher in experimentally N-treated plots, whereas the amount of C in understory vegetation was higher in control plots. Pooling all the compartments (that is, understory vegetation, litter, soil, and tree biomass) the total ecosystem C content was estimated for each site, and at most sites a higher C stock was estimated for N-treated plots. Differences in aboveground C accumulation rates between treated and control plots were lower at sites with high levels of accumulated Ndep. Our results indicate that site-specific accumulated Ndep should be considered to understand tree growth responses to N fertilization