Soft PEG-Hydrogels with Independently Tunable Stiffness and RGDS-Content for Cell Adhesion Studies

Poly(ethylene)glycol (PEG)‐based hydrogels are often used as matrix material for cell culturing. An efficient method to prepare soft PEG gels is by cross‐linking via copper‐free strain‐promoted azide‐alkyne cycloaddition (SPAAC). Here, the effect of polymer density and RGDS‐content on hydrogel formation and cell adhesion was studied, by varying the total polymer content (10, 20 and 30 mg · mL−1) and the amount of RGDS moieties (0–100%) independently of each other. Rheology studies confirmed the soft nature of the hydrogels (G′ = 25–2 298 Pa). HOS cells are able to adhere well to all RGDS‐containing gels. Interestingly, both HeLa cells and NIH 3T3 fibroblasts showed substantial adherence to 10 and 20 mg · mL−1 gels, but with increased hydrogel stiffness (30 mg · mL−1), their cellular adhesion decreased significantly. Soft poly(ethylene) glycol (PEG) hydrogels cross‐linked via strain‐promoted azide‐alkyne cycloaddition (SPAAC) are prepared with independently tunable stiffness and RGDS‐content. Rheology studies confirms the soft nature of the hydrogels. HOS cells adhere to all RGDS‐containing gels independent of gel stiffness. HeLa cells and NIH 3T3 fibroblasts show significantly decreased cell adhesion on the stiffest hydrogel.