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Chitosan derivatives, and more specifically, glycosylated derivatives, are nowadays attracting much attention within the scientific community due to the fact that this set of engineered polysaccharides finds application in different sectors, spanning from food to the biomedical field. Overcoming chitosan (physical) limitations or grafting biological relevant molecules, to mention a few, represent two cardinal strategies to modify parent biopolymer; thereby, synthetizing high added value polysaccharides. The present review is focused on the introduction of oligosaccharide side chains on the backbone of chitosan. The synthetic aspects and the effect on physical-chemical properties of such modifications are discussed. Finally, examples of potential applications in biomaterials design and drug delivery of these novel modified chitosans are disclosed.

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The present paper explores the effect of boric acid on Chitlac, a lactose-modified chitosan which had previously shown interesting biological and physical-chemical features. The herewith-reported experimental evidences demonstrated that boric acid binds to Chitlac, producing conformational and association effects on the chitosan derivative. The thermodynamics of boric acid binding to Chitlac was explored by means of B NMR, circular dichroism (CD), and UV-vis spectroscopy, while macromolecular effects were investigated by means of viscometry and dynamic light scattering (DLS). The experimental results revealed a chain-chain association when limited amounts of boric acid were added to Chitlac. However, upon exceeding a critical boric acid limit dependent on the polysaccharide concentration, the soluble aggregates disentangle. The rheological behavior of Chitlac upon treatment with boric acid was explored showing a dilatant behavior in conditions of steady flow. An uncommonly high dependence in the scaling law between the zero-shear viscosity and the concentration of Chitlac was found, i.e., η ∝ C, pointing to interesting potential implications of the present system in biomaterials development.

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properties of extracellular matrix exert on skeletal muscle cells, the aim of this work was to investigate the effects of HELP hydrogels on myoblasts viability and functions.Methods: We recently synthesized a novel polypeptide, HELPc, by fusing the elastin-like backbone to a 41aa stretch present in the α2 chain of type IV collagen, containing two RGD motifs. To obtain hydrogels, the enzymatic cross-linking of the HELPc was accomplished by transglutaminase. Here, we employed both non cross-linked HELPc glass coatings and cross-linked HELPc hydrogels at different monomer density as adhesion substrates for C2C12 cells, used as myoblasts model.Results: By comparing cell adhesion, proliferation and differentiation, we revealed several striking differences. Depending on support rigidity, adhesion to HELPc substrates dictates cell morphology, spreading, focal adhesions formation and cytoskeletal organization. Hydrogels greatly stimulated cell proliferation, particularly in low serum-medium, and partially inhibited myogenic differentiation.Conclusions: In the whole, the results underline the potentiality of these genetically engineered polypeptides as a tool for dissecting crucial steps in myogenesis.