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 30mg center dot 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 20mg center dot mL - 1 gels, but with increased hydrogel stiffness ( 30mg center dot mL - 1), their cellular adhesion decreased significantly.