Efficient functionalization of alginate biomaterials

Abstract

Peptide coupled alginates obtained by chemical functionalization of alginates are commonly used as scaffold materials for cells in regenerative medicine and tissue engineering. We here present an alternative to the commonly used carbodiimide chemistry, using partial periodate oxidation followed by reductive amination. High and precise degrees of substitution were obtained with high reproducibility, and without formation of by-products. A protocol was established using l-Tyrosine methyl ester as a model compound and the non-toxic pic-BH3 as the reducing agent. DOSY was used to indirectly verify covalent binding and the structure of the product was further elucidated using NMR spectroscopy. The coupling efficiency was to some extent dependent on alginate composition, being most efficient on mannuronan. Three different bioactive peptide sequences (GRGDYP, GRGDSP and KHIFSDDSSE) were coupled to 8% periodate oxidized alginate resulting in degrees of substitution between 3.9 and 6.9%. Cell adhesion studies of mouse myoblasts (C2C12) and human dental stem cells (RP89) to gels containing various amounts of GRGDSP coupled alginate demonstrated the bioactivity of the material where RP89 cells needed higher peptide concentrations to adhere.

Fabrication and physicochemical characterization of porous composite microgranules with selenium oxyanions and risedronate sodium for potential applications in bone tumors

“…It is typically extracted from brown algae (Phaeophyceae). 18,19 This polysaccharide is biodegradable and biocompatible and due to cross-linking properties, able to form gels, beads, fibers and foams. ALGs have been combined with various bioceramics to form promising scaffolds for tissue regeneration and drugdelivery systems.…”

Influence of K+ and Na+ ions on the degradation of wet‐spun alginate fibers for tissue engineering

“…With the progress of technology, recent evolution in the tissue engineering field has now led to the definition of a biomaterial as a material intended to interface with biological systems to evaluate, treat, augment or replace any tissue, organ or function of the body, and boundaries for the use of biomaterials are still expanding . Nowadays, the design of novel biomaterials is focused on mimicking the extracellular matrices of body tissues, as these can regulate host responses in a well‐defined manner, and naturally derived materials have recently been obtained much attention owing to their inherent biocompatibility …”

“…[5][6][7] Nowadays, the design of novel biomaterials is focused on mimicking the extracellular matrices of body tissues, as these can regulate host responses in a well-defined manner, and naturally derived materials have recently been obtained much attention owing to their inherent biocompatibility. [8][9][10] Alginate is a common and typical biomaterial that has been extensively studied on account of its high biocompatibility, 11 low toxicity, relatively low cost, and the safe mild gelation condition with divalent cations such as Ca 21 and Ba 21 , 12 which are preferred as candidates for biomedical applications, 13,14 for instance, drug delivery, tissue scaffold, wound dressing, 15 and so on. Alginate is a polysaccharide naturally found in all species of brown algae and some bacteria, which is a common term used for a family of polyanionic linear polymers composed of 1,4linked b-D-mannuronic and a-L-guluronic acid residues in varying proportions, sequence, and molecular weight.…”

Biomimetic sulphated alginate hydrogels suppress IL-1β-induced inflammatory responses in human chondrocytes

“…As native alginate is relatively inert, functionalisation by covalent modification has been extensively explored (Dalheim et al, 2015;Pawar and Edgar, 2012;Rowley et al, 1999). One such strategy is by chemical sulphation, increasing the negative charge and thus promoting electrostatic interactions characteristic of sulphated GAGs.…”