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.