Synthesis and photocuring of cinnamoyl trehalose esters

Synthesis and Application of Trehalose Materials

Trehalose is a naturally occurring, nonreducing disaccharide that is widely used in the biopharmaceutical, food, and cosmetic industries due to its stabilizing and cryoprotective properties. Over the years, scientists have developed methodologies to synthesize linear polymers with trehalose units either in the polymer backbone or as pendant groups. These macromolecules provide unique properties and characteristics, which often outperform trehalose itself. Additionally, numerous reports have focused on the synthesis and formulation of materials based on trehalose, such as nanoparticles, hydrogels, and thermoset networks. Among many applications, these polymers and materials have been used as protein stabilizers, as gene delivery systems, and to prevent amyloid aggregate formation. In this Perspective, recent developments in the synthesis and application of trehalose-based linear polymers, hydrogels, and nanomaterials are discussed, with a focus on utilization in the biomedical field.

UV-Curable Bio-Based Polymers Derived from Industrial Pulp and Paper Processes

Bio-based monomers represent the future market for polymer chemistry, since the political economics of different states promote green ventures toward more sustainable materials and processes. Industrial pulp and paper processing represent a large market that could advance the use of by-products to avoid waste production and reduce pollution. Lignin represents the most available side product that can be used to produce a bio-based monomer. This review is concentrated on the possibility of using bio-based monomer derivates from pulp and the paper industry for UV-curing processing. UV-curing represents the new frontier for thermoset production, allowing a fast reaction cure, less energy demand, and the elimination of solvent. The growing demand for new monomers increases research in the environmental field to substitute for petroleum-based products. This review provides an overview of the main monomers and relative families of compounds derived from industrial processes that are suitable for UV-curing. Particular focus is given to the developments reached in the last few years concerning lignin, rosin and terpenes and the related possible applications of these in UV-curing chemistry.

Synthesis, thermal properties and cell-compatibility of photocrosslinked cinnamoyl-modified hydroxypropyl cellulose

Biocompatibility of cinnamoyl-modified carbohydrate materials is not well-known, while they are attracting attention as a photoreactive material. In order to investigate biocompatible properties of cinnamoyl-modified carbohydrate, hydroxypropyl cellulose (HPC) was reacted with cinnamoyl chloride to yield cinnamoyl-modified HPC (HPC-C) for a cell proliferation test. HPC-Cs with three different degrees of substitution (DS) were prepared by changing a feed ratio of cinnamoyl chloride to HPC. The DS of the products ranged from 1.3 to 3.0 per one hydroxylpropyl anhydroglucose unit. Thermal analysis using DSC and TGA showed that the HPC-C with higher DS has a glass transition temperature and higher thermal stability. Ultraviolet (UV) light was irradiated on the HPC-C thin films, and changes in the UV-vis spectrum of the films were examined. In the course of UV irradiation, the absorbance at 280 nm was reduced. Fibroblast cells were cultured on the photocrosslinked HPC-C films, and cell growth was examined. The cell proliferation test revealed that the photocrosslinked HPC-C films have good compatibility with fibroblast cells.

Photocrosslinkable Trehalose Derivatives Carrying Mesogenic Groups: Synthesis, Characterization, and in Vitro Evaluation for Fibroblast Attachment

A photocrosslinkable trehalose derivative carrying mesogenic groups was synthesized by esterification reactions. The derivative (TC-HBPHA) was synthesized by the reaction of partially cinnamoyl-modified trehalose (TC4) with 4-(4-hexyloxybenzoyloxy)phenoxy-6-oxohexanoic acid (HBPHA) as a mesogenic unit. TC-HBPHA showed a nematic liquid crystalline mesophase at a temperature range from 150 °C to 175 °C in the heating process under observation with a polarized optical microscope. The dimerization of the cinnamoyl groups of TC-HBPHA by ultraviolet (UV) light irradiation was monitored by ultraviolet-visible (UV-Vis) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. The photocrosslinked film was obtained after the UV irradiation of TC-HBPHA, and it kept the liquid crystalline mesophase at almost the same temperature range. Fibroblast cells cultured on the photocrosslinked TC-HBPHA proliferated as well as on the polystyrene culture plate, indicating that the film has no toxicity. Interestingly, some cells on photocrosslinked TC-HBPHA had a spindle shape and aligned characteristically.

Fibroblast cell proliferation on photo-cured trehalose cinnamoyl ester thin films

Trehalose cinnamoyl esters (TCs) were synthesized by esterification of trehlaose with cinnamoyl chloride. Two TCs with different degrees of substitution were synthesized, and trehalose cinnamoyl ester thin film-coated glass plates were prepared by a dip-coating method. Photocuring of the TCs was confirmed by ultraviolet–visible spectral changes. The surface of photo-cured TCs were found smooth as observed in a scanning electron microscope. The cell proliferation on the photo-cured TCs was investigated using 3T3 Swiss Albino mouse embryo fibroblasts. The results of the cell proliferation assay revealed that the photo-cured TCs with higher degrees of substitution promoted the cell proliferation compared with a polystyrene culture plate and the photo-cured TCs with lower degrees of substitution. The contact angle of the photo-cured TCs with higher degrees of substitution was 101.0° ± 1.6°, which is much higher than that of the polystyrene culture plate, and it is out of the range known to be suitable for cell adhesion. Nevertheless, the cell unexpectedly grew best on the photo-cured TCs with higher degrees of substitution. Fibronectin binding assay was carried out using fluorescent probe-modified fibronectin, and more fibronectin was found adsorbed onto photo-cured TCs than a polystyrene culture plate.

Trehalose and trehalose-based polymers for environmentally benign, biocompatible and bioactive materials

Trehalose is a non-reducing disaccharide that is found in many organisms but not in mammals. This sugar plays important roles in cryptobiosis of selaginella mosses, tardigrades (water bears), and other animals which revive with water from a state of suspended animation induced by desiccation. The interesting properties of trehalose are due to its unique symmetrical low-energy structure, wherein two glucose units are bonded face-to-face by 1→1-glucoside links. The Hayashibara Co. Ltd., is credited for developing an inexpensive, environmentally benign and industrial-scale process for the enzymatic conversion of α-1,4-linked polyhexoses to α,α-d-trehalose, which made it easy to explore novel food, industrial, and medicinal uses for trehalose and its derivatives. Trehalose-chemistry is a relatively new and emerging field, and polymers of trehalose derivatives appear environmentally benign, biocompatible, and biodegradable. The discriminating properties of trehalose are attributed to its structure, symmetry, solubility, kinetic and thermodynamic stability and versatility. While syntheses of trehalose-based polymer networks can be straightforward, syntheses and characterization of well defined linear polymers with tailored properties using trehalose-based monomers is challenging, and typically involves protection and deprotection of hydroxyl groups to attain desired structural, morphological, biological, and physical and chemical properties in the resulting products. In this review, we will overview known literature on trehalose’s fascinating involvement in cryptobiology; highlight its applications in many fields; and then discuss methods we used to prepare new trehalose-based monomers and polymers and explain their properties.