The polymer/SiO2 hybrid material (P/SiO2-MPS) with core-shell structure were synthesized using the dense nanosilica spheres (DNSS) as core and pH responsive poly(acrylic acid) (PAA) as a shell. Meanwhile, using ibuprofen (IBU) as a model drug, the structure and properties of obtained P/SiO2-MPS were characterized by SEM, TEM, FT-IR, TGA, EDS, NMR, XRD, DLS and SAXS. The results elucidated that PM was successfully incorporated onto the surface of DNSS, and thereafter the thickness of PM shell could be controlled by adjusting the additive amount of AA. Particularly, SAXS patterns evidently exhibited that P/SiO2-MPS before IBU-loading and after releasing possessed the surface fractal feature, which increased from 2.19 for SiO2-MPS, to 2.41 for P/SiO2-MPS, to 2.54 for IBU-loaded P/SiO2-MPS, and to 2.65 for IBU-released P/SiO2-MPS. Moreover, the IBU-releasing percentage of three samples (P/SiO2-MPS-1, P/SiO2MPS-3 and P/SiO2-MPS-5) increased gradually at both pH 3.0 and 7.4 with the enlarged thickness of PM shells, while for P/SiO2-MPS-7 with the thickest PM layer, its release rate was not more than that of P/ SiO2-MPS-5. Therefore, IBU molecules were hindered from passing through PAA layer. Furthermore, the IBU loading of P/SiO2-MPS was fitted into the pseudo-second-order model, while its drug-release kinetic profile was favorable to Korsmeyer-Peppas model. These observations evidently demonstrated that the surface effects of P/SiO2-MPS on its surface fractal feature and the diffusion of IBU delivery were very important, and therefore its mechanism was essentially proposed. (C) 2017 Elsevier B.V. All rights reserved.