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Updated: Oct 12, 2025

The Synthesis of RGD-functionalized Hydrogels as a Tool for Therapeutic Applications
Published on: October 7, 2016
Histidine-based hydrogels via singlet-oxygen photooxidation
Michelle S Liberato1, Nayara G S Cavalcante1, P Abinaya Sindu1
1Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, 05508-000, São Paulo, Brazil. catalani@usp.br.
Abstract:
The formation of hydrogels by photosensitized oxidation and crosslinking of histidine-derived polymers is demonstrated for the first time. The photooxidation of pendant His mediated by singlet oxygen was used to promote covalent coupling by its dimerization. As a proof-of-concept, two systems were studied: (i) chondroitin sulfate (CS) functionalized with His, and (ii) an elastin-like peptide (ELP) containing His produced by recombinant techniques. Both materials were crosslinked by irradiation at 425 nm in the presence of Zn-porphyrin derivatives yielding His-based hydrogels. The molecular structure and physicochemical properties of ELP-His and other 5 ELPs with photooxidizable amino acids were studied in silica by computer simulation. A correlation between the protein conformation and its elastic properties is discussed. CS-His hydrogels demonstrate larger storage moduli than ELPs with other amino acids. The obtained results show the potential use of photooxidation to create a new type of His-based hydrogels.
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