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Introduction:Novel nanomaterials are the major driving force of nanomedicine.With the rapid development of nanotechnologies,increasing researches have been focused on combining two or more diagnosis and therapeutic functions into a nanoentity.Herein,for the first time,we reported the development of novel hybrid anisotropic nanoparticles(HANs)and evaluation of their use for cancer theranostics.Method:The HANs were synthesized using the seed-mediated process and were characterized by transmission electron microscopy(TEM),dynamic light scattering(DLS)and UV-Vis absorption spectra.The eighteen mice with HT29 colon tumor model were randomly divided into three groups(n=6 in each group).The chemotherapy and photothermal therapy(PT)effects of treated tumors after intratumoral administration of functional HANs were monitored with dual MR and PA imaging modalities in an accurate and quantitative way.Results:We successfully constructed novel multifunctional nanostructures by fusing several nanocomponents(iron-platinum alloy and gold nanocrystals)via solid-state interfaces in a control and predictable manner(Figure 1A).The resultant hybrid anisotropic nanostructures not only show excellent shape-control and monodispersity but also provide superior optical and magnetic properties.As expected,HANs keep their shape and morphology intact,and exhibit great stability in the physiological condition.More importantly,as pH-controlled iron reservoirs,HANs can release a significant amount of iron in response to the low extracellular pH in tumors.The released iron ions could cause the Fenton reaction,which eventually cause the apoptosis of tumor cells.Interestingly,the HANs also have a strong,broad absorption in the near-infrared(NIR)region.Under a near infrared(NIR)light irradiation the HANs can induce significant temperature elevation,which is able to locally eliminate cancer cells efficiently based on photothermal(PT)effect.Lastly,as T2 magnetic resonance imaging(MRI)contrast agents with a relatively high relaxivity and excellent photoacoustic imaging(PAI)contrast agents,the HANs were used as dual molecular imaging probes for image-guided therapy.Moreover,it is obviously helpful to monitor the therapeutic effect of treated tumors by detecting the distribution and diffusion of intratumorally injected HANs using both MR(Figure 1B)and PA(Figure 1C)imaging in real time.The group injected with the HANs showed dramatic reduction of tumor volume than the control group.After photothermally-treated with 808 nm laser(Figure 1D),the tumors almost disappeared in most of tumor-bearing mice pre-administrated with HANs(Figure 1E,F).Conclusion:As novel multifunctional nanoplatforms,the HANs combined muti-modality therapy(photothermal and chemical)and imaging(MRI and PAI)into a nanoplatform.The design of HANs allows for simultaneous delivery of imaging and therapeutic agents which provides great promises for cancer therapy under imaging guidance and truly integrated theranostic systems.