In the fast-developing field of tissue engineering there is a constant demand for new materials as scaffolds for cell seeding, which can better mimic a natural extracellular matrix as well as control cell behavior. Among other materials, polysaccharides are widely used for this purpose. One of the main candidates for scaffold fabrication is alginate. However, it lacks sites for cell adhesion. That is why one of the steps toward the development of suitable scaffolds for cells is the introduction of the biofunctionality to the alginate structure. In this work we focused on bone-sialoprotein derived peptide (TYRAY) conjugation to the molecule of alginate. Here the comparison study on four different approaches of peptide conjugation was performed including traditional and novel modification methods, based on 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxy succinimide (EDC/NHS), 4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinium chloride (DMTMM), thiol-Michael addition and Cu-catalyzed azide–alkyne cycloaddition reactions. It was shown that the combination of the alginate amidation with the use of and subsequent Cu-catalyzed azide–alkyne cycloaddition led to efficient peptide conjugation, which was proven with both NMR and XPS methods. Moreover, the cell culture experiment proved the positive effect of peptide presence on the adhesion of human embryonic stem cells.

The design of favorable mechanical properties and suitable surface modifications of hydrogels in order to stimulate specific cell response is a great challenge. N-(2-Hydroxypropyl) methacryl-amide (HPMA) was utilized to form macroporous cryogel scaffolds for stem cell applications. Furthermore, one group of scaffolds was enhanced by copolymerization of HPMA with methacryloyl-GGGRGDS-OH peptide in an effort to integrate biomimetic adhesion sites. The cryogels were characterized by stiffness and equilibrium swelling measurements as well as by scanning electron microscopy. Cell culture experiments were performed with human adipose-derived stem cells and substrates were found completely non-toxic. Moreover, RGDS-enriched cryogels supported cell attachment, spreading and proliferation, so they can be considered suitable for designed aims.