New research on bismuth based nanomedicine from LING Daishun’s lab has been published in Nano Letters

2018-01-05 | 药学院英文网

Although metallic nanomaterials with high X-ray attenuation coefficients have been widely used as X-ray computed tomography (CT) contrast agents, their intrinsically poor biodegradability requires them to be cleared from the body to avoid any potential toxicity. However, extremely small-sized nanomaterials with outstanding renal clearance properties are not much effective for tumor targeting because of their too rapid clearancein vivo. On January 3, Professor LING Daishun’s lab published a research article entitled “Renal-Clearable Hollow Bismuth Subcarbonate Nanotubes for Tumor Targeted Computed Tomography Imaging and Chemoradiotherapy” in the top-tier research journalNano Letters(IF: 12.712). They reported on the hollow bismuth subcarbonate nanotubes (BNTs) assembled from renal-clearable ultrasmall bismuth subcarbonate nanoclusters for tumor-targeted imaging and chemoradiotherapy.

Controlled assembly of nanoparticles into various shapes and structures for tunable functionality can promote their targeted delivery and allow their controlled elimination from the body. Xi et al. achieved the designed assembly of small-sized (BiO)₂CO₃ nanoclusters (BNCs) into elongated and hollow (BiO)₂CO₃ nanotubes (BNTs). Compared to nanoclusters, the elongated BNTs showed longerin vivo circulation time, and could penetrate leaky tumor blood vessel walls more efficiently to achieve tumor accumulation. Apparently, the unique nanostructure of the BNTs promotedtheir tumor homing and enabled the drug loading,which were useful not only for tumor-targeted CT imaging, but also for synergistic radio- and chemotherapy.Simultaneous radio- and chemotherapy using doxorubicin-loaded BNTs could significantly increase cellular reactive oxygen species (ROS), aggravate DNA damage and suppress tumor volumes, highlighting their potential application in CT imaging-guided therapy.

Importantly, the elongated BNTs could be disassembled into isolated small nanoclusters in the acidic tumor microenvironment, which are smaller than the size threshold for efficient renal filtration (~8 nm),accelerating the payload release and kidney excretion. This disassembly process is expected to avoid potential long-term toxicity as theFDA declared. Such body clearable CT contrast agent with high imaging performance and multiple therapeutic functions shall have a substantial potential for biomedical applications.

This work was carried out by Ph.D. student HU Xi, Prof. SUN Jihong, Dr. LI Fangyuan et al. under the supervision of Professor LING. This research was mainly completed by College of Pharmaceutical Sciences, Zhejiang University.