Incorporation of Fmoc-Y nanofibers into Ca-alginate hydrogels for improving their mechanical properties and the controlled release of small molecules

The simple peptide Fmoc-tyrosine (Fmoc-Y) with a self-assembled nanofiber structure was incorporated into Ca-alginate hydrogels to create an interpenetrating network (IPN) hybrid hydrogel. SEM and CD analysis was employed to confirm the integrity of the Fmoc-Y nanofiber structure. In the IPN hybrid hydrogel, the self-assembled Fmoc-Y nanofiber hydrogel can reinforce the Ca-alginate network. The IPN hydrogel exhibits enhanced storage moduli and fracture energy, about several times compared to those of Ca-alginate, Fmoc-Y and semi-IPN hydrogels. Furthermore, the IPN hydrogel reveals minimal release (less than 1%) for hydrophilic small molecules at acidic pH and sustained release at physiological pH, which can be achieved by simply tuning the Fmoc-Y concentration. Owing to the cost-efficiency of the raw materials and ease of fabrication, the synthesized hybrid hydrogels provide new options for diverse applications.