In the project a series of hydrogels were produced via organic sol-gel chemistry, and their structure and composition shown to control the release of nutrients in response to changes in pH. Polymer networks were formed via the creation of polyurea and polyurethane linkages, with pH-responsive hydrogels based on hydrophilic polymers exhibiting pH response swelling thanks to their ability to go from uncharged to cationic with decreasing pH.

By testing and analyzing a range of different formulations, with specific focus on (pH-dependent) water uptake, extractable fraction, release and cell culture studies, several promising materials were formulated with the ability to release glucose in response to changes in pH. Those changes were mediated through the absorption of acidic species, the combined effect being the enhanced viability of mammalian cells in culture and in the absence of human intervention. These gels show excellent initial performance and clear promise with respect to further optimizations such as controlled nutrient loading and fine tuning of the release characteristics of these materials by altering the mesh size and targeted reductions in extractable fraction.