Generic synthesis and versatile applications of molecularly organic-inorganic hybrid mesoporous organosilica nanoparticles with asymmetric Janus topologies and structures

Precise control over the morphology,nanostructure,composition,and particle size of molecularly organic-inorganic hybrid mesoporous organosilica nanoparticles （MONs） still remains a major challenge,which severely restricts their broad applications.In this work an efficient bridged organic group-determined growth strategy has been proposed for the facile synthesis of highly dispersed and uniform MONs with multifarious Janus morphologies,nanostructures,organic-inorganic hybrid compositions,and particle sizes,which can be easily controlled simply by varying the bridged organic groups and the concentration of bis-silylated organosilica precursors used in the synthesis.In addition,the formation mechanism of Janus MONs determined by the bridged organic group has been discussed.Based on the specific structures,compositions,and asymmetric morphologies,all the synthesized Janus MONs with hollow structures （JHMONs） demonstrate excellent performances in nanomedicine as desirable drug carriers with high drug-loading efficiencies/capacities,pH-responsive drug releasing,and enhanced therapeutic efficiencies,as attractive contrastenhanced contrast agents for ultrasound imaging,and as excellent bilirubin adsorbents with noticeably high adsorption capacities and high blood compatibilities.The developed versatile synthetic strategy and the obtained JHMONs are extremely important in the development and applications of MONs,particularly in the areas of nanoscience and nanotechnology.