Polyacrylamide-based hydrogels are popular materials that have been extensively studied for their applications in the field of biomaterials due to their permeability and biological compatibility. A major limitation of this polymeric material, however, in biological applications stems from their limited mechanical stiffness. In order to increase the mechanical stiffness of these hydrogels, colloidal particles are added to act as interactive filler and reinforce the soft hydrogel matrix. Various surface chemistries are being explored to alter the nature of particle-matrix adhesion. The current study examines the effects of the surface chemistry and volume fraction of particles on the mechanical properties of polyacrylamide-polyacrylate-based hydrogels using oscillatory rheology.