Tunable, Photoreactive Hydrogel System To Probe Synergies between Mechanical and Biomolecular Cues on Adipose-Derived...

The incorporation of the photoreactive molecule benzophenone into polyacrylamide hydrogels, allowing for orthogonal control over spatial incorporation of biomolecules and selective modulation of matrix stiffness, is described. Adipose-derived mesenchymal stem cells were cultured on matrices whose elastic moduli are tuned to ∼5, ∼14, and ∼37 kPa combined with an immobilized growth factor, bone morphogenic protein 2 (BMP-2), and their lineage differentiation was determined. BMP-2 was observed to have the most pronounced effect at the intermediate stiffness, while the lowest and highest stiffness hydrogels are directed by elasticity alone. Together, this approach describes a facile platform for fundamental studies of cell fate decisions in the context of both mechanical and biochemical cues and may lead to improved insight and effectiveness of stem cell therapies.