We employed molecular dynamic simulations (MD) and the Bennett's acceptance ratio method to compute the free energy of transfer, ΔGtrans, of phenol, methane, and 5-fluorouracil (5-FU), between bulk water and water-pNIPAM mixtures of different polymer volume fractions, ϕp. For this purpose, we first calculate the solvation free energies in both media to obtain ΔGtrans. Phenol and 5-FU (a medication used to treat cancer) attach to the pNIPAM surface so that they show negative values of ΔGtrans irrespective of temperature (above or below the lower critical solution temperature of pNIPAM, Tc). Conversely, methane switches the ΔGtrans sign when considering temperatures below (positive) and above (negative) Tc. In all cases, and contrasting with some theoretical predictions, ΔGtrans maintains a linear behavior with the pNIPAM concentration up to large polymer densities. We have also employed MD to compute the diffusion coefficient, D, of phenol in water-pNIPAM mixtures as a function of ϕp in the diluted limit. Both ΔGtrans and D as a function of ϕp are required inputs to obtain the release halftime of hollow pNIPAM microgels through Dynamic Density Functional Theory (DDFT). Our scaling strategy captures the experimental value of 2200 s for 50 μm radius microgels with no cavity, for ϕp ≃ 0.83 at 315 K.