3.3.1. Peptide Conjugation with the Use of EDC/NHS

Sodium alginate (0.05 M) was dissolved in MES buffer (pH 6.5) overnight. Solutions of the peptide (TYRAY, 0.006 M), EDC (0.06 M), and NHS (0.12 M) in MES buffer were prepared right before the reaction. The final concentration of sodium alginate and peptide in the reaction mixture was 2 w/v%. First, the solutions of EDC and NHS were added to the alginate solution and left for the activation reaction for 3 h being stirred under ambient conditions. After that, the solution of the peptide was added, and the substitution reaction was maintained for 24 h being stirred under ambient conditions. After the reaction, the mixture was dialyzed (MWCO = 6–8 kDa) against deionized water with an addition of NaCl (2 changes), subsequently with the addition of EtOH (2 changes), and finally with pure water (4 changes). The obtained solution was lyophilized and used for subsequent analysis. Obtained modified alginate (n = 3) was noted as Alg-TYRAY(EDC).