The porogen poly [(2-hydrocinnamoyloxyethyl methacrylate)-random-2-2-(9'-adeninylacetoxyethyl methacrylate), P(hCEMA-r-A), and the diblock copolymer poly(tert-butyl acrylate)-block-poly [(2-cinnamoyloxyethyl methacrylate)]-random-2-(1'-thyminylacetoxyethyl methaerylate)], PtBA-b-P(CEMA-r-T), formed micelles with PtBA coronas and P(CEMA-r-T)/P(hCEMA-r-A) cores in chloroform/cyclohexane. The cores of the micelles were cross-linked by UV light. Addition of deuterated N,N-dimethylformamide (DMF-d(7)) into a nanosphere solution in deuterated chloroform triggered porogen release. The kinetics was followed by NMR spectroscopy, and a classical model was used to treat the data to yield the diffusion coefficient D. The molar mass dependence of D suggested that the porogen diffused out of the cores as coils. In neat CDCl3, the porous nanospheres obtained after porogen extraction reuptook the porogen with high efficiency, but the kinetics was more complex than that of porogen release.