Rapid and cytocompatible cell-laden silk hydrogel formation: Via riboflavin-mediated crosslinking

Susanna Piluso, Daniela Flores Gomez, Inge Dokter, Liliana Moreira Texeira, Yang Li, Jeroen Leijten, René van Weeren, Tina Vermonden, Marcel Karperien, Jos Malda

Published: 7 November 2020


Bioactive hydrogels based on naturally-derived polymers are of great interest for regenerative medicine applications. Among naturally-derived polymers, silk fibroin has been extensively explored as a biomaterial for tissue engineering due to its unique mechanical properties. Here, we demonstrate the rapid gelation of cell-laden silk fibroin hydrogels by visible light-induced crosslinking using riboflavin as a photo-initiator, in presence of an electron acceptor. The gelation kinetics were monitored by in situ photo-rheometry. Gelation was achieved in minutes and could be tuned owing to its direct proportionality to the electron acceptor concentration. The concentration of the electron acceptor did not affect the elastic modulus of the hydrogels, which could be altered by varying the polymer content. Further, the biocompatible riboflavin photo-initiator combined with sodium persulfate allowed for the encapsulation of cells within silk fibroin hydrogels. To confirm the cytocompatibility of the silk fibroin formulations, three cell types (articular cartilage-derived progenitor cells, mesenchymal stem cells and dental-pulp-derived stem cells) were encapsulated within the hydrogels, which associated with a viability >80% for all cell types. These results demonstrated that fast gelation of silk fibroin can be achieved by combining it with riboflavin and electron acceptors, which results in a hydrogel that can be used in tissue engineering and cell delivery applications.

Graphical abstract: Rapid and cytocompatible cell-laden silk hydrogel formation via riboflavin-mediated crosslinking

Full Access Link: Journal of Materials Chemistry B