Preparing Modified Hyaluronic Acid with Tunable Content of Vinyl Groups for Use in Fabrication of Scaffolds by Photoinduced Crosslinking

Materials based on hyaluronic acid (HA) are extensively used in tissue engineering as scaffolds. Photoinduced crosslinking is one way to prepare them, and, for this, HA must be modified with vinyl groups, which are capable of participating in free-radical reactions upon exposure to light. The quantity of grafted vinyl groups, represented as the degree of substitution (DS), is an important parameter of modified HA (mHA) that is related to the mechanical, chemical, and biological properties of scaffolds. Here, we demonstrate the feasibility of tuning DS by varying the reaction parameters (composition and concentration of reaction components and reaction conditions) and investigate the effect of DS on the viscosity of mHA solutions. As example, we consider the photoinduced reaction of mHA in the presence of flavin mononucleotide as the initiator, which can be used in fabrication of noncytotoxic scaffolds by 3D printing. The growth behavior of fibroblasts on the scaffold surface is studied.

Photoinduced synthesis of alkylalkynyl sulfones through a reaction of potassium alkyltrifluoroborates, sulfur dioxide, and alkynyl bromides

A photoinduced reaction of potassium alkyltrifluoroborates, sodium metabisulfite, and alkynyl bromides under visible light irradiation at room temperature is developed.

Ag photoionization-induced single-pass assembly of Ag2S nanodots in flowing thiol droplets

A photoinduced reaction to produce Ag2S nanodots from Ag nanoagglomerates was achieved in a single-pass gas stream.

A photoinduced reaction of perfluoroalkyl halides with 1,3-diarylprop-2-yn-1-ones catalyzed by DABSO

The sulfur dioxide surrogate of DABCO·(SO2)2 is used as an efficient catalyst for the cleavage of the perfluoroalkyl-halogen bond under visible-light irradiation. A plausible mechanism supported by theoretical calculations is proposed.

Photoinitiated Synthesis of Sulfides in Water

Herein, we report a synthetic route to obtain aryl sulfides using inexpensive and non-toxic reactants and water as solvent, that avoids the use of catalysts or heating. The photoinduced reaction between soluble substrates and a series of thiols in alkaline aqueous medium produces the corresponding sulfides in moderate to good yields.

Synthesis of phthalonitrile derivatives by photoinduced reactions. New unsymmetrical substituted zinc phthalocyanines

The synthesis of new phthalonitrile derivatives by photoinduced reaction is described. Novel unsymmetrically substituted Zn(II) phthalocyanine bearing an aryl alcohol group (ArZnPc) was synthesized by the ring expansion reaction of boron(III) subphthalocyanine chloride with an appropriated phthalonitrile. The spectroscopic and photodynamic properties of these ArZnPc were studied.