Copper-Free Azide-Alkyne Cycloaddition for Peptide Modification of Alginate Hydrogels.

Alginate, a biocompatible polymer naturally derived from algae, is widely used as a synthetic analogue of the extracellular matrix in tissue engineering. Integrin-binding peptide motifs, including RGD, a derivative of fibronectin, are typically grafted to the alginate polymer through carbodiimide reactions between peptide amines and alginate uronic acids. However, lack of chemo-selectivity of carbodiimide reactions can lead to side reactions that lower peptide bioactivity.