The deswelling of microgels is governed by solvent characteristics and particle concentration. Soft nanoparticles have been synthesized and dispersed in small molecular solvents or oligomeric polystyrenes. Coarse-grained molecular dynamics simulations were performed to quantify particle dimensions. The linear viscoelasticity of these solutions was experimentally characterized. In good solvents

increasing the particle concentration induces deswelling because of the enhanced crowding-induced osmotic compression. Increasing the molecular mass of the solvent could also enhance deswelling by suppressing solvent penetration into the nanoparticle network. Equilibrium relations derived from the osmotic-pressure balance are developed to describe these two mechanisms and are shown to capture the simulation results. A single unified framework can describe the deswelling over a broad range of solvent masses and particle concentrations. In addition

varying the solvent mass shifts the fragility transition observed experimentally in solutions of soft nanoparticles

thereby linking deswelling to changes in the glassy dynamics. This work establishes a unified framework for understanding microgel deswelling across concentration- and solvent-controlled regimes.