Due to the compatibility between these hydrogels and biological tissues, they have the potential to become a useful therapeutic delivery vehicle in the treatment of peripheral artery disease, ischemic heart disease and the survival of cell and tissue transplants.


The research was undertaken by scientists at Georgia Tech and Emory University, and published in the Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0905447107). It presented a biofunctional hydrogel that delivers growth factors in a controlled way. Because of the modular nature of the system, the researchers could easily incorporate other bioactive factors such as adhesive ligands, degradable cross-links, and bioactive growth factors.


The study demonstrated both a robust and a flexible strategy to deliver pro-vascularization characteristics that control the delivery of factors in a cell-demanded fashion. It also demonstrated that this approach is preferable to simple delivery of the growth factor in a functional animal model.


To place the hydrogel deeper inside the body than the pre-formed matrix construct would allow, and to be able to fill in an injured area of any shape, the researchers developed a liquid material that forms a gel inside the body when exposed to ultraviolet light.


As most injuries are not well-defined, it is impossible to take a pre-formed construct and fill the irregular-sized site. Instead the team looked at accessing the area in a minimally invasive way and injecting this solution through the skin, all without surgery.


The material has suitability for delivering bioactive factors in numerous applications. As lead author Andrés García points out, “The backbone PEG hydrogel has an excellent record of biosafety and clinical experience, and the modularity of the delivery systems offers significant flexibility and advantages.”


The team are now examining other growth factors and bioactive factors, as well as considering other functional models where insufficient vascularization is limiting, including delivery and integration of pancreatic islets.


The team are also conducting new research into the clinical viability of these hydrogels as therapeutic vascularization therapies to treat peripheral artery disease and ischemic heart disease, and cell transplantation to treat diabetes. There is also the possibility of further studies incorporating more or different growth factors to achieve even more robust healing effects.