Modelling methacrylated chitosan hydrogel properties through an experimental design approach: from composition to material properties.

Hydrogels of biopolymers are gradually substituting synthetic hydrogels in tissue engineering applications due to their properties. However, biopolymeric hydrogels are difficult to standardize because of the intrinsic variability of the material and the reversibility of physical crosslinking processes. In this work, we synthesized a photocrosslinkable derivative of chitosan (Cs), namely methacrylated chitosan (CsMA), in which the added methacrylic groups allow the formation of hydrogels through radical polymerization triggered by UV exposure.

Modulation of Methacrylated Hyaluronic Acid Hydrogels Enables Their Use as 3D Cultured Model.

Bioengineered hydrogels represent physiologically relevant platforms for cell behaviour studies in the tissue engineering and regenerative medicine fields, as well as in in vitro disease models. Hyaluronic acid (HA) is an ideal platform since it is a natural biocompatible polymer that is widely used to study cellular crosstalk, cell adhesion and cell proliferation, and is one of the major components of the extracellular matrix (ECM). We synthesised chemically modified HA with photo-crosslinkable methacrylated groups (HA-MA) in aqueous solutions and in strictly monitored pH and temperature conditions to obtain hydrogels with controlled bulk properties.

Functional Organic Materials for Photovoltaics: The Synthesis as a Tool for Managing Properties for Solid State Applications.

The continuous increase in the global energy demand deeply impacts the environment. Consequently, the research is moving towards more sustainable forms of energy production, storage and saving. Suitable technologies and materials are fundamental to win the challenge towards a greener and more eco-friendly society.

Control of Electron Transfer Processes in Multidimensional Arylamine-Based Mixed-Valence Compounds by Molecular Backbone Design.

Four trigonal topology compounds with three diarylamines redox centers and dibenzofulvene as core bridge have been synthesized. Their radical cations exhibit appealing intramolecular electron transfer pathways between three redox centers, depending on their position on the core bridge. By changing such positions (on either 2,7- or 3,6-), and the length of the bridge, the control of the intramolecular electron transfer pathways was achieved through the electron self-exchange route.

High-Performance Electrofluorochromic Switching Devices Using a Novel Arylamine-Fluorene Redox-Active Fluorophore.

Fluorescent light modulation by small electric potentials has gained huge interest in the past few years. This phenomenon, called electrofluorochromism, is of the utmost importance for applications in optoelectronic devices. Huge efforts are being addressed to developing electrofluorochromic systems with improved performances.

[1]Benzothieno[3,2-b]benzothiophene-Based Organic Dyes for Dye-Sensitized Solar Cells.

Three new metal-free organic dyes with the [1]benzothieno[3,2-b]benzothiophene (BTBT) π-bridge, having the structure donor-π-acceptor (D-π-A) and labeled as 19, 20 and 21, have been designed and synthesized for application in dye-sensitized solar cells (DSSC). Once the design of the π-acceptor block was fixed, containing the BTBT as the π-bridge and the cyanoacrylic group as the electron acceptor and anchoring unit, we selected three donor units with different electron-donor capacity, in order to assemble new chromophores with high molar extinction coefficients (ε), whose absorption features well reflect the good performance of the final DSSC devices. Starting with the 19 dye, which shows a molar extinction coefficient ε of over 14,000 M(-1) cm(-1) and takes into account the absorption maximun at the longer wavelength, the substitution of the BFT donor unit with the BFA yields a great enhancement of absorptivity (molar extinction coefficient ε > 42,000 M(-1) cm(-1)), until reaching the higher value (ε > 69,000 M(-1) cm(-1)) with the BFPhz donor unit.

Photodynamic activity of thiophene-derived lysosome-specific dyes.

The photodynamic activity occurring through the lysosome photo-damage is effective in terms of triggered synergic effects which can avoid chemo-resistance pathways. The potential photodynamic activity of two fluorescent lysosome-specific probes was studied providing their interaction with human serum albumin, demonstrating their in vitro generation of singlet oxygen and investigating the resulted photo-toxic effect in human cancer cells.

Thiophene-based fluorescent probes with low cytotoxicity and high photostability for lysosomes in living cells.

Background: Selective imaging of lysosomes by fluorescence microscopy using specific fluorescent probes allows the study of biological processes and it is potentially useful also for diagnosis. Lysosomes are involved in numerous physiological processes, such as bone and tissue remodeling, plasma membrane repair, and cholesterol homeostasis, along with cell death and cell signaling. Despite the great number of dyes available today on the market, the search for new fluorescent dyes easily up-taken by cells, biocompatible and bearing bright and long-lasting fluorescence is still a priority.

A reassessment of the association between azulene and [60]fullerene. Possible pitfalls in the determination of binding constants through fluorescence spectroscopy.

We show here that the recently reported surprisingly large association constant (K = 7.6 x 10(4) M(-1)) between azulene and [60]fullerene is due to experimental artifacts, pointing out potential errors in the characterization of association equilibria by fluorescence spectroscopy, and suggesting the best experimental practices.

Weighting non-covalent forces in the molecular recognition of C(60). Relevance of concave-convex complementarity.

The relative contributions of several weak intermolecular forces to the overall stability of the complexes formed between structurally related receptors and [60]fullerene are compared, revealing a discernible contribution from concave-convex complementarity.