This work reports the development of an injectable hydrogel based on RGD-alginate that can crosslink in situ and is capable of delivering endothelial cells. It was carried out in collaboration with the team of Professor Raquel Soares, from the Centre of Pharmacology and Chemical Biopathology, Faculty of Medicine, University of Porto.

Sílvia J. Bidarra, Cristina C. Barrias, Keila B. Fonseca, Mário A. Barbosa, Raquel Soares and Pedro L. Granja. Biomaterials, 2011.

Cell-based therapies offer an attractive approach for revascularization and regeneration of tissues. However, and despite the pressing clinical needs for effective revascularization strategies, the successful immobilization of viable vascular cells within 3D matrices has been difficult to achieve. In this paper the in vitro potential of a natural, injectable RGD-alginate hydrogel as an in situ forming matrix to deliver endothelial cells was evaluated. Several techniques were employed to investigate how these microenvironments could influence the behavior of vascular cells, namely their ability to promote the outward migration of viable, proliferative cells, retaining the ability to form a 3D arrangement. Cells within RGD-grafted alginate hydrogel were able to proliferate and maintained 80% of viability for at least 48h post-immobilization. Additionally, entrapped cells created a 3D organization into cellular networks and, when put in contact with matrigel, cells migrated out of the RGD-matrix. Overall, the obtained results support the idea that the RGD peptides conjugated to alginate provide a 3D environment for endothelial cells adhesion, survival, migration and organization.