A Synthetic Toolbox for the In Situ Formation of Functionalized Homo‐ and Heteropolysaccharide‐Based Hydrogel Libraries

Abstract

A synthetic toolbox for the introduction of aldehydo and hydrazido groups into the polysaccharides hyaluronic acid, alginate, dextran, pullulan, glycogen, and carboxymethyl cellulose and their use for hydrogel formation is reported. Upon mixing differently functionalized polysaccharides derived from the same natural precursor, hydrazone cross-linking takes place, which results in formation of a hydrogel composed of one type of polysaccharide backbone. Likewise, hydrogels based on two different polysaccharide strands can be formed after mixing the corresponding aldehydo- and hydrazido-modified polysaccharides. A second line of these studies paves the way to introduce a biomedically relevant ligand, namely, the adhesion factor cyclic RGD pentapeptide, by using an orthogonal click reaction. This set of modified polysaccharides served to create a library of hydrogels that differ in the combination of polysaccharide strands and the degree of cross-linking. The different hydrogels were evaluated with respect to their rheological properties, their ability to absorb water, and their cytotoxicity towards human fibroblast cell cultures. None of the hydrogels studied were cytotoxic, and, hence, they are in principal biocompatible for applications in tissue engineering.

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO2 Utilization

“…[108] 3h is ag lucopyranosided erivative prepared startingf rom glucose and potentially renewable compounds, such as methanol [3d] and benzaldehyde [109] (Scheme 10). [110] In 2005, Haba et al reportedt he anionic homopolymerization of 3h initiatedb yD BU or by potassium tert-butoxide, thus claiming the first 5CCs anionic polymerization withoutd ecarboxylation. [111] More recently,W ooley and coworkers expanded the scope of the organocatalyzedr ingopeningh omopolymerizationo f3h,c onfirming the controlled nature of the process.…”

Chemical Functionalization of Polysaccharides—Towards Biocompatible Hydrogels for Biomedical Applications

“… Hetero‐cross‐linked hydrogel 34 obtained upon condensation of oxidized and modified dextran and RGD‐functionalized pullulan hydrazide; the photograph shows the hydrogel which was employed in myocardial tissue engineering …”

“…In this study a set of soft ( G ′=20–180 Pa) hydrogels with a high water adsorption capability was generated via the divergent approach of hydrogel formation. In this study, in situ gelation was carried out in the presence of myocardial stem cells to target the production of new cardiac tissue after myocardial infarction …”

“…One strategy to get insight into the regioselectivity of a derivatization method is by conducting the derivatization chemistry with suitably blocked monosaccharides. These serve as synthetic models for analyzing the ratio of different products formed and provide a guideline for the chemistry of derivatization on the monomeric units in the polysaccharide …”

Multimodal Porphyrin-Based Conjugates: Synthesis and characterization for applications as amyloid ligands, photodynamic therapy agents and chiroptical materials

“…87,88 Nevertheless, one can also combine small organic molecules or nanoparticles with polymeric biomolecules, such as peptides or polysaccharides, to give rise to materials of well-defined structure and specific optical, electronic or biological properties that make the material attractive for a multitude of applications. [89][90][91] Biomolecules, such as proteins, polysaccharides, nucleic acids and lipids, often occur in nature as highly ordered supramolecular architectures. 92,93 The propensity to spontaneously, or upon an initiation, self-associate into organized assemblies of various structures even in vitro makes these biomolecules attractive candidates for making new materials.…”