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Shape-controlled synthesis of liquid metal nanodroplets for photothermal therapy


The capping agents for liquid metal (LM) nanodroplets in aqueous solutions are restricted to thiol-containing and positively-charged molecules or macromolecules. However, both thiolate-metal complex and electrostatic interaction are liable to detachment upon strong mechanical forces such as sonication, leading to limited stability and applications. To address this, we utilized ultrasmall water soluble melanin nanoparticles (MNPs) as the capping agent, which exhibited strong metal binding capability with the oxide layer of gallium based LMs and resulted in enhanced stability. Interestingly, shape-controlled synthesis of LM nanodroplets can be achieved by the incorporation of MNPs. Various EGaIn nanostructures including nanorice, nanosphere and nanorod were obtained by simply tuning the feed ratio, sonication time, and suspension temperature. Among these shapes, EGaIn nanorice has the best photothermal conversion efficiency, which could be leveraged for photothermal therapy.

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This work was supported by the grants from the Alfred P. Sloan Foundation (Sloan Research Fellowship), the National Natural Science Foundation of China (Nos. 21504034, 31671035, and 51473071), the National Key Research and Development Program of China (No. 2017ZX09304021), the Jiangsu Provincial Medical Innovation Team (No. CXTDA2017024), and Natural Science Foundation of Jiangsu Province (Nos. BK20161137, BK20170204, and BE2016632). This work was performed in part at the Analytical Instrumentation Facility (AIF) at North Carolina State University, which is supported by the State of North Carolina and the National Science Foundation (award number ECCS-1542015). The AIF is a member of the North Carolina Research Triangle Nanotechnology Network (RTNN), a site in the National Nanotechnology Coordinated Infrastructure (NNCI).

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Correspondence to Min Yang or Zhen Gu.

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Yan, J., Zhang, X., Liu, Y. et al. Shape-controlled synthesis of liquid metal nanodroplets for photothermal therapy. Nano Res. 12, 1313–1320 (2019).

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  • liquid metal
  • melanin nanoparticles
  • nanomedicine
  • shape-controlled synthesis
  • photothermal therapy