A　novel　pH-sensitive　controlled　release　system　is　proposed　by　using　mussel-inspired　polydopamine　(PDA)　coated　mesoporous　silica　nanoparticles　(MSNs)　as　nanocarriers.MSNs　with　a　large　pore　diameter　are　synthesized　by　using　1,3,5-trimethylbenzene　as　a　pore-expanding　agent　and　are　modified　with　a　PDA　coating　by　virtue　of　oxidative　self-polymerization　of　dopamine　in　neutral　pH.　PDA　coated　MSNs　are　characterized　by　FTIR,　TEM,　N2　adsorption　and　XPS　techniques.　The　PDA　coating　can　work　as　pH-sensitive　gatekeepers　to　control　the　release　of　drug　molecules　from　MSNs　in　response　to　the　pH-stimulus.　Doxorubicin　(DOX,　an　anticancer　drug)　can　be　released　in　the　acid　media　and　blocked　in　the　neutral　media.　(C)　2014　Elsevier　B.V.　All　rights　reserved.