The　targeted　and　sustained　drug　release　from　stimuli-responsive　nanodelivery　systems　is　limited　by　the　irreversible　and　uncontrolled　disruption　of　the　currently　used　nanostructures.　Bionic　nanocapsules　are　designed　by　cross-linking　polythymine　and　photoisomerized　polyazobenzene　(PETAzo)　with　adenine-modified　ZnS　(ZnS-A)　nanoparticles　(NPs)　via　nucleobase　pairing.　The　ZnS-A　NPs　convert　X-rays　into　UV　radiation　that　isomerizes　the　azobenzene　groups,　which　allows　controlled　diffusion　of　the　active　payloads　across　the　bilayer　membranes.　In　addition,　the　nucleobase　pairing　interactions　between　PETAzo　and　ZnS-A　prevent　drug　leakage　during　their　in　vivo　circulation,　which　not　only　enhances　tumor　accumulation　but　also　maintains　stability.　These　nanocapsules　with　tunable　permeability　show　prolonged　retention,　remotely　controlled　drug　release,　enhanced　targeted　accumulation,　and　effective　antitumor　effects,　indicating　their　potential　as　an　anticancer　drug　delivery　system.　©　2019　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim